drylands deserts and desertification 16-18 november 2020 ......bedouin contemporary resilience: the...
TRANSCRIPT
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Drylands Deserts and Desertification
16-18 November 2020
Book of Abstracts
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Contents KEYNOTE ................................................................................................................................................... 8
Migration and Climate Change: Defining issues for Global Health ................................................ 8
Prof. Bernadette N. Kumar ............................................................................................................... 8
LECTURERS – arranged alphabetically by Lecturer’s First Name: ................................................... 9
Clay dispersion: An important factor in channel runoff generation in a semi-arid area, with low
rain intensities ......................................................................................................................................... 9
Prof. Aaron Yair .................................................................................................................................. 9
Perspectives on desertification as a determinant of public health in Nigeria .............................. 10
Prof. Adetoun Mustapha ................................................................................................................. 10
Grapevine berry development: Understanding environmental and cultural impacts on berry
weight loss and shriveling. .................................................................................................................. 11
Prof. Alain Deloire ............................................................................................................................ 11
The utility of UAV high resolution imagery and point cloud data for canopy characteristics, LAI
retrieval and Evapotranspiration and Transpiration in commercial vineyards in California ...... 12
Dr. Alfonso Torres-Rua .................................................................................................................... 12
Biosphere-atmosphere chemical interactions during drought and heat waves in dryland
ecosystems ........................................................................................................................................... 13
Prof. Alex Guenther ......................................................................................................................... 13
Managing irrigation water as a function of its quality ...................................................................... 14
Dr, Alon Ben-Gal .............................................................................................................................. 14
Can Desalination Be A Sustainable Technology for Dryland Countries Who Seek To Mitigate
Climate Change? .................................................................................................................................. 15
Prof. Alon Tal .................................................................................................................................... 15
Integrated Foliar Nutrients Application Improve Cereals Growth and Productivity under
Moisture Stress Condition in Semiarid Climates ............................................................................. 16
Dr. Amanullah ................................................................................................................................... 16
Driving down the costs of solar-powered electrodialysis desalination, drip irrigation, and the
combination of the two ......................................................................................................................... 17
Prof. Amos Winter ............................................................................................................................ 17
Mapping and Monitoring Saline and sodic Soil Reclamation in Semi-arid and Arid
Environments of India Using Geo-information Tools ...................................................................... 18
Dr. A.N. Singh ................................................................................................................................... 18
Decentralized solar powered membrane filtration: Opportunities in desert environments ....... 20
Dr. Andrea Schaefer ........................................................................................................................ 20
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Identifying weak links in the hydraulic chain of grapevines: insights into the impacts of water
stress on water uptake and transport physiology ............................................................................ 22
Dr. Andrew McElrone ....................................................................................................................... 22
Human Agency and Resilience to Holocene Desertification in the Eastern Mongolian Gobi .. 23
Prof. Arlene Rosen ........................................................................................................................... 23
Bedouin Contemporary Resilience: The Struggle for Dominating Local Governance .............. 24
Prof. Avinoam Meir ........................................................................................................................... 24
Cultural Landscapes and Paleoenvironmental Change at the end of the Pleistocene: The
Earliest Peopling of the Atacama Desert and its Descendent Until Present ............................... 26
Dr. Calogero M. Santoro ................................................................................................................. 26
Are multiple disasters caused by climate change in Australia: really unprecedented and
unpredictable? ...................................................................................................................................... 27
Prof. Colin MacDougall .................................................................................................................... 27
Selective Transport of Phosphorous Through Anion Exchange Membranes ............................. 28
Prof. David Jassby ........................................................................................................................... 28
Acquiring Needed Water Without Depriving Neighbors or Wildlife ............................................... 29
Dr. Elaine Solowey ........................................................................................................................... 29
Effects of variable irrigation practices during extreme heat events on grapevine physiology
and berry chemistry ............................................................................................................................. 30
Dr. Elisabeth Forrestel ..................................................................................................................... 30
A different landscape: toward a novel approach to sedentarization processes in arid and
Semi-arid environments ...................................................................................................................... 31
Dr. Emir Galilee ................................................................................................................................ 31
Characterization of bed load discharge in unsteady flow events in an ephemeral channel in
semi-arid region .................................................................................................................................... 32
Mr. Eran Halfi .................................................................................................................................... 32
Satellite retrieval of vineyard leaf area index and impact of vine canopy structure and interrow
cover crop on retrieval algorithm........................................................................................................ 33
Dr. Feng Gao .................................................................................................................................... 33
Characterization of Microbiological Water Quality and Prevalence of Waterborne Diseases in
Marigat Urban Centre Baringo County, Kenya ................................................................................ 34
Prof. George Ogendi ........................................................................................................................ 34
Desert Societies and Imperial Powers: Conflicts, Resilience, and Coexistence in the Near
East during the First Millennium CE .................................................................................................. 35
Prof. Gideon Avni ............................................................................................................................. 35
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Resilience vs. Collapse in the Eastern Asian Dryland-Steppe Belt: Historic and Archaeological
Perspectives on Responses to Climatic Anomalies ........................................................................ 36
Prof. Gideon Shelach-Lavi, ............................................................................................................. 36
The delicate balance of defining grapevine drought tolerance ..................................................... 37
Prof. Gregory Gambetta .................................................................................................................. 37
Climatic uncertainty and the architecture of survivability ............................................................... 38
Prof. Isaac A. Meir (Sakis), ............................................................................................................. 38
Behavioural and physiological responses of insects to climate change and consequences at
the community level: the example of a host-parasitoid system in cereal fields .......................... 39
Prof. Joan Van Baaren .................................................................................................................... 39
Plot-and-berm agroecosystems in aeolian sand hinterlands around the Mediterranean basin:
A case of regional agri-cultural connectivity? .................................................................................. 40
Dr. Joel Roskin ................................................................................................................................. 40
Design and applications of vapor-gap membranes for water and resource recovery ............... 42
Asst. Prof. Jongho Lee .................................................................................................................... 42
Temperature shift between vineyards modulates berry phenology, primary and secondary
metabolism in a varietal collection of wine grapevine..................................................................... 43
Mr. Kelem Gashu ............................................................................................................................. 43
Use of an Evapotranspiration Toolkit for Near-Real-Time Irrigation Management: Advantages
and Limitations ...................................................................................................................................... 44
Dr. Kyle Knipper ............................................................................................................................... 44
Survival strategists among the Bedouins living in the driest regions of the Sinai Peninsula .... 45
Mr. Leizer Bergman ......................................................................................................................... 45
Modelling drought-induced dieback of Aleppo pine at the arid timberline ................................... 46
Ms. Lisa Wingate and Mr. Jérôme Ogée ..................................................................................... 46
Amplified aeolian-fluvial sedimentation and landscape evolution along the southern margins
of the northwestern Negev Dunefield (Israel) since the late Pleistocene .................................... 47
Mr. Lotem Robins ............................................................................................................................. 47
Recent Advances in Ion Selectivity with Capacitive Deionization ................................................ 49
Prof. Louis C.P.M. de Smet ............................................................................................................ 49
Evaluation of a Remote Sensing-based toolkit to monitor vine water use and status for
irrigation scheduling in California vineyards. .................................................................................... 50
Dr. Maria Mar Alsina ........................................................................................................................ 50
Mapping evapotranspiration over viticultural landscapes using multi-sensor remote sensing. 51
Dr. Martha Anderson ....................................................................................................................... 51
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Understanding forests in a warming world through model-data integration ................................ 52
Prof. Naomi Christina Tague .......................................................................................................... 52
A new method to estimate sensible heat fluxes from wavelet analysis of semi-high frequency
radiometric canopy temperature ........................................................................................................ 53
Dr. Nicolas Bambach ....................................................................................................................... 53
Are desert societies permanently at risk of collapse? Ways to include arid environments in the
present social-ecological system model ........................................................................................... 54
Dr. Noa Avriel-Avni ........................................................................................................................... 54
Time-series clustering of remote-sensing retrievals for defining management zones in a
vineyard ................................................................................................................................................. 56
Dr. Noa Ohana-Levi ......................................................................................................................... 56
Runoff generation, rill erosion and time-scales for hyper-arid abandoned alluvial surfaces, the
Negev desert, Israel ............................................................................................................................. 57
Prof. Noam Greenbaum .................................................................................................................. 57
Dating gully incision into an abandoned alluvial surface along the eastern termination of the
Altyn Tagh Fault ................................................................................................................................... 58
Dr. Nimrod Wieler ............................................................................................................................. 58
Ecological interactions under climate change: How shifts in vegetation cover may affect
desert lizards?....................................................................................................................................... 59
Dr. Ofir Levy ...................................................................................................................................... 59
The effect of runoff collecting basins’ geometry on soil water evaporative losses .................... 60
Prof. Pedro Berliner ......................................................................................................................... 60
Development of a batch reverse osmosis (RO) system for high-recovery .................................. 61
Prof. Phillip Davies ........................................................................................................................... 61
Sediment yields in hyper-arid areas of the Middle East exemplified by Nahal Nehushtan,
Israel ....................................................................................................................................................... 62
Dr. Rachel Armoza-Zvuloni ............................................................................................................. 62
Thar Desert in a Flux ........................................................................................................................... 63
Dr. R.P. Dhir ...................................................................................................................................... 63
Reconstruction of the Holocene flood record for the Southern Judea Desert using Palaeoflood
hydrology ............................................................................................................................................... 64
Mr. Rami Zituni ................................................................................................................................. 64
Phosphate Fertilization Management in Israel: Where Irrigation and Water-Treatment
Technologies Meet ............................................................................................................................... 66
Dr. Ran Erel....................................................................................................................................... 66
Novel electrospun membranes for membrane distillation .............................................................. 68
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Prof. Ranil Wickramasinghe ........................................................................................................... 68
An integrated process of anaerobic membrane bioreactor, microalgae cultivation, and
hydrothermal carbonization for treatment of food industry wastewater and resource recovery
................................................................................................................................................................ 69
Dr. Roy Bernstein ............................................................................................................................. 69
Energy recovery from waste activated sludge in a circular economy approach ........................ 70
Dr. Roy Posmanik ............................................................................................................................ 70
A novel community-scale, solar-powered approach to treating unsafe surface water for
drinking .................................................................................................................................................. 71
Prof. Samuel Dorevitch ................................................................................................................... 71
Material strategies to overcome fouling, wetting, and scaling in membrane distillation ............ 72
Asst. Prof. Shihong Lin .................................................................................................................... 72
Impact of Regulated Deficit Irrigation Strategies on Grape Quality in the Semi Arid Region of
the Okanagan Valley (BC, Canada) .................................................................................................. 73
Dr. Simone Castellarin ..................................................................................................................... 73
Extracting flash flood distribution and frequencies in arid regions using post flood spectral
indices .................................................................................................................................................... 74
Dr. Sivan Isaacson ........................................................................................................................... 74
Long term degradation and rapid restoration of the Negev’s Agroecosystems –lessons
learned towards sustainable dryland management ........................................................................ 75
Dr. Stefan Leu ................................................................................................................................... 75
Drought resilience improvement in temperate-climate vineyard ecosystems ............................. 76
Prof. Stefano Poni ............................................................................................................................ 76
Isotopes changing through time: Stories from tree rings ............................................................... 77
Prof. Steven Leavitt .......................................................................................................................... 77
The Permutations of Collapse: Climate, Mobility, and Negev Societies ...................................... 78
Prof. Steven Rosen .......................................................................................................................... 78
The “landscape of heat”: behavioural thermoregulation and its impact in a warming world .... 79
Dr. Susan Cunningham ................................................................................................................... 79
Plant nutrition as a function of irrigation water quality .................................................................... 80
Prof. Uri Yermiyahu .......................................................................................................................... 80
Resilience of Ancient Desert Societies, a View from the Southern Negev, Israel ..................... 81
Dr. Uzi Avner ..................................................................................................................................... 81
Highlighting Partners in Health’s Experience of Addressing Climate Disasters ......................... 82
Mr. Victor Kanyema ......................................................................................................................... 82
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The GRAPEX project: Understanding vineyard evapotranspiration in order to develop remote
sensing tools to detect stress and reduce water use ...................................................................... 83
Dr. Williams Kustas .......................................................................................................................... 83
Engineering Polymer Membranes with Controlled Surface Patterns for Enhanced Water
Treatment .............................................................................................................................................. 84
Prof. Yifu Ding ................................................................................................................................... 84
Late shoot pruning improves wine quality of field grown Vitis vinifera cv. Malbec. .................... 85
Dr. Yishai Netzer .............................................................................................................................. 85
Geodiversity as a key for human survival in the harshest deserts on earth................................ 86
Dr. Yoav Avni .................................................................................................................................... 86
Geological evolution inducing natural desertification in the arid zone of the Middle East – past,
present and future ................................................................................................................................ 87
Dr. Yoav Avni .................................................................................................................................... 87
Distributed RO/NF Water Desalination and Purification Systems: Energy and Pressure
Optimal Operation, Operational Flexibility and Fouling Mitigation ................................................ 88
Prof. Yoram Cohen .......................................................................................................................... 88
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KEYNOTE
Migration and Climate Change: Defining issues for Global Health Prof. Bernadette N. Kumar
President EUPHA Section for Migrant and Ethnic Minority Health
Co- Chair Lancet Migration
Chair Global Society on Migration, Ethnicity, Race and Health
Norwegian Institute of Public Health
The UCL Lancet Commission on Migration Health (2018) calls migration the defining issue
of our times, essential to growing economies and an integral part of the socio-cultural
fabric of our societies. It is imperative to understand why this is the case, how migration
health has evolved and where we are headed. Despite the positive impacts of migration
globally, with international labor workers contributing to economies worldwide, migrants
often face challenges that threaten basic human rights, including the right to health clearly
evident from the COVID 19 pandemic. Global commitments to the Sustainable
Development Goals, Universal Health Coverage, equity in health, and international
agreements aim to improve the responses to migration, however global health policies are
still not migrant inclusive. With rising populism and xenophobic rhetoric in many countries,
societies ought to be engaged effectively to counter misinformed narratives, harmful
migration policies should be discouraged and provision of universal access to health care
ensured. Another defining issue of our times is climate change. Climate change means
that people have to move often involuntarily. People used to a certain way of living, certain
livelihoods, lifestyles, health risks and advantages will experience change. There are
definitely very strong intersections between climate change and migration. Therefore, we
must view these with the intersectionality lens and using a cross-cutting approach, which
means we need to break down the silos. Migration and agricultural economy are
interlinked: rural societies change due to rural- urban migration and that definitely affects
agricultural economies. At the same time, agricultural economies are not what they used to
be 25 years ago-30 years ago. The only way prevent migration in these settings is
therefore ensuring sustainable living conditions conducive to livelihoods. Many of the gaps
in research, policy and practice remain unmet and as the fields of migration health and
climate change evolve, these ought to be bridged through changes in policy and practice.
Global academic institutions, civil society, UN agencies, and governments must
collaborate to address the principles of intersectionality in research, and to hold
stakeholders accountable. Radical action is crucial; to transform evidence at local,
regional, and global levels, to contribute to improving health and preventing morbidity and
mortality for migrants and nationals, and to strive towards leaving no one behind.
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LECTURERS – arranged alphabetically by Lecturer’s First
Name:
Clay dispersion: An important factor in channel runoff generation in a
semi-arid area, with low rain intensities Prof. Aaron Yair
The Department of Geography, Hebrew University of Jerusalem, Israel
Water Session: Flash Floods in the Arid Environment
Overland flow is usually regarded as an important contributor to storm channel flow. This
observation is certainly applicable to dryland areas, where base flow is often irrelevant,
particularly in small watersheds. This study examines channel runoff generation in the
extensive loess-covered areas that characterize the mildly arid area of western Israel,
where the average annual rainfall is 280 mm. Hydrological data point to a peculiar
hydrological behavior of the ephemeral streams that experience a high frequency of
sporadic channel flow events. Even in extreme rain events, peak discharges are
exceptionally low, indicative of a limited contributing area. Hydrographs are characterized
by very steep rising and falling limbs, usually representative of saturated areas, located in
the vicinity of the runoff recording station. Based on this observation, we advanced the
hypothesis that storm runoff originated in the limited area of the active channel, with
negligible runoff from the adjoining hillslopes. We argue that a quasi-permanent surface
seal, at the top of the alluvial deposit, drastically limits the hydraulic conductivity of the
alluvial fill, allowing runoff generation at very low rain intensities. The occurrence of the
surface seal is ascribed to the combination of two main factors. A high clay content
(~40%), where the dominant clays are smectite and illite, characterized by a laminar
structure and a high-water absorption capacity. The swelling of the clay particles
considerably reduces the porosity of the alluvial material, allowing runoff generation at very
low rain intensities while limiting the depth of water penetration in the channel itself. Data
presented fit the concept of “Partial Area Contribution” identified in humid areas. However,
the application of this concept to dryland areas is based on completely different reasons.
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Perspectives on desertification as a determinant of public health in
Nigeria Prof. Adetoun Mustapha
Nigerian Institute for Medical Research and Imperial College,London, England
Human Session: Desertification and Public Health
Nigeria is one of the countries in West Africa that is suffering from the cumulative negative
effects of population growth, anthropogenic activities, urbanisation, unsustainable water
and land management and climate variability, resulting in rapid desertification. According
to the Food and Agriculture Organization (FAO), about 15% of Nigeria land is prone to
desertification. The effect is pronounced in the northernmost part of Nigeria, which is the
major producer of agricultural products and the food basket of the country. Climate
dependent activities and agriculture provides income and employment for most of the
population. Desertification is therefore threatening rural livelihoods and causing food
insecurity, malnutrition in children, unemployment, forced migration and amplifying poverty
and conflicts over access to land and resources
Land ownership and control is a delicate issue in Nigeria. There is no legal recognition of
citizenship based on residency – migrants’ group are seen as settlers because they do not
control land and are often alienated from their host community’s natural resources. After
recurrent droughts in the Sahel region, pastoralists have gradually moved southwards
where they reportedly graze cattle in farms triggering deadly conflicts with farmers. The
herders and farmers clashes are threatening the unity of the country and promoting
activities of regional militia. Studies have linked severity of desertification to exposure to
heat waves and decrease host resistance to viruses such as influenza and parasites such
as malaria; vector borne disease such as cholera, increased prevalence of skin
malignancies, and loss of plants of medicinal importance in northern Nigeria
Nigeria is a party to the United Nations Convention to Combat Desertification (UNCCD)
and the Nigerian government is implementing several policies and programmes to combat
desertification including the Great Green Wall project among others. The speed of
implementation and adequacy of these as well as involvement of all relevant stakeholders
have been subject of debate. The magnitude of environmental health risks posed by
desertification in Nigeria has not been adequately quantified. For a country projected to
become the world’s third most populous country by the year 2050, the public health
implications of desertification need to be addressed. How this topic can become a priority
in public health research agenda and ways various collaboration can support the
attainment will be discussed.
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Grapevine berry development: Understanding environmental and
cultural impacts on berry weight loss and shriveling. Prof. Alain Deloire
Montpellier University, l'Institut Agro, France
Food Session Vineyards and Viticulture
Berry shrivelling is an important phenomenon that occurs through grape berry water loss
due to the alteration of the fruit water budget when transpiration and potential water back
flow to the plant exceeds the import of water into the berry through the phloem and xylem.
Berry shrivelling can have a significant economic impact, reducing yields by up to ≥25%
with consequences on berry composition and the resulting wine. Its occurrence and
consequences are expected to increase due to predicted climate warming, shifting grape
development, and ripening into warmer periods (i.e., heat waves).
Berry fresh mass loss is variable between seasons, sites, and vineyards and it seems to
be accelerated by higher temperatures, water constraints and/or stress and excessive
bunch sun exposure. Berry shrivelling can occur, before (as early as bloom, affecting the
ovaries) or after veraison in red and white varieties.
A recent study on individual Shiraz berries (Montpellier l’Institut Agro vineyard; vines
trained in vertical shoot positioning under fertirrigation) revealed interesting and original
results comparing normal to shrivelled berries in terms of fresh mass, °Brix, probable
alcohol and quantity of sugar per berry (mg/berry). The results clearly demonstrated that
the increase in probable alcohol/°Brix per berry (post plateau of berry sugar loading) is not
due to berry sugar accumulation during ripening but only to berry water loss. This
conforms with previous results on the same cultivar (McCarthy and Coombe 1999; Rogiers
et al., 2006; Rogiers and Holzapfel 2015).
Late ripening berry shrivel in Shiraz may begin at around 90 days after flowering, but it is
not evident every season. While loss in mesocarp cell vitality and cell membrane integrity
precedes the onset of shrivel, the internal biochemical and physiological events that lead
to these developmental processes remain largely unknown. However, it was demonstrated
that hypoxia (low oxygen) in the berry mesocarp may contribute to the onset of cell death
(Xiao et al., 2018a). Previous studies have shown that high temperature and dehydration
can exacerbate the extent of cell death and berry dehydration (Bonada et al., 2013; Xiao et
al., 2018b), and this can be ameliorated with shade covers (Caravia et al., 2016). It is
interesting to note that unlike seeded wine grapes, table grapes do not tend to undergo
this late ripening loss in cell vitality. Ultimately, berry shrivelling will affect grape and wine
composition and sensory profiles (Suklje et al., 2016).
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The utility of UAV high resolution imagery and point cloud data for
canopy characteristics, LAI retrieval and Evapotranspiration and
Transpiration in commercial vineyards in California Dr. Alfonso Torres-Rua
Utah State University, USA
Ecosystem Session: Remote Sensing in Viticulture
In recent years, unmanned aerial vehicles (UAVs) have facilitated the development of
novel approaches for crop monitoring applications, from vegetation indices to
evapotranspiration (ET) and soil moisture estimation. In addition to the orthomosaic
products from the UAV optical sensors, 3D (point cloud) information derived from
photogrammetric algorithms, are becoming part of crop monitoring applications such as
yield estimation. In this study, we document the advantages of UAV information in
clumped canopy environments as in orchards and vineyards for estimation of canopy
characteristics that support estimation of Evaporation and Transpiration. On this regard,
we will discuss the experience of application of UAV information in commercial vineyards
by the Utah State University AggieAir small Unmanned Aerial System (sUAS) Program as
part of the ARS-USDA GRAPEX Project (Grape Remote sensing Atmospheric Profile and
Evapotranspiration eXperiment) conducted since 2014 over multiple vineyards located in
California. In this study, example of UAV point cloud characteristics, developed algorithms
to process this information, canopy derived products, and their influence on ET and
Transpiration estimation are presented and discussed.
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Biosphere-atmosphere chemical interactions during drought and heat
waves in dryland ecosystems Prof. Alex Guenther
University of. California, Irvine, USA
Ecosystem Session: A Torch in the Dark…
Biogenic volatile organic compounds (BVOC) are produced by terrestrial ecosystems and
emitted into the atmosphere where they participate in chemical reactions that determine
the atmospheric distributions of air pollutants and short-lived climate forcers including
organic aerosol, ozone and methane. BVOC are the dominant global emission of reactive
organics into the atmosphere and are included in most air quality and climate models with
simple representations that broadly describe the observed behavior under optimal
ecological conditions. It is well known BVOC emissions are sensitive to abiotic (e.g.,
drought and heat waves) and biotic (e.g., herbivores and microbes) stresses but these
processes are difficult to quantify and are currently either omitted or highly simplified in
numerical models. We assess the role of BVOC in biosphere-atmosphere chemical
interactions during drought and heat waves in dryland ecosystems by synthesizing
observations from Yatir forest and other field sties with laboratory investigations of drought
and heat stress-induced BVOC emission and incorporating the results into the BVOC
emission component of a regional chemistry and transport model. Model simulations using
the MEGAN BVOC emission model embedded in the WRF-Chem chemistry and transport
model are used to investigate the impact of drought and heat stress induced BVOC
emission on atmospheric chemical composition and determine the potential for significant
interactions and feedbacks. MEGAN simulations with and without stress are used to
quantify the potential sensitivity of BVOC emission response. WRF-Chem regional model
simulations are used to demonstrate how the stress-induced changes can influence
atmospheric chemistry and ecosystem functioning to assess potential interactions and
feedbacks.
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Managing irrigation water as a function of its quality Dr, Alon Ben-Gal
Agricultural Research Organization – Volcani, Institute of Soil, Water and Environmental
Sciences, Gilat Research Center, Israel
Water Session: Water in Agriculture
Water scarcity and the need for increased agricultural production have led to greater
utilization of non-conventional, marginal- to low-quality, sources of water for irrigation.
These water sources mainly recycled municipal waste water and brackish groundwater,
are typically characterized by high concentrations of contaminants including salts.
Agronomic success when irrigating with water high in salts is contingent upon water
management in which salts are disallowed from accumulating in crop root zones. Salinity
management most often entails application of excess water for leaching and drainage
collection and disposal. Addition of salt to agricultural systems causes degradation of soils
and negative effects to crops. Leaching of salts leads to contamination of deep soils and
groundwater or to drainage waters requiring treatment and disposal solutions.
An additional aspect of water-source and quality specific management is found in plant
nutrition-fertilization practices. Interactions between salts and nutrient minerals in soils and
plants require rethinking of traditional fertilization methods and regimes.
The recent addition of desalinated water to address chronic water shortages in dry regions
including Israel, may coincidentally provide opportunity for a more sustainable solution for
agriculture. Desalination can supply very high-quality water to irrigate high-value, salt-
sensitive crops and leads to reduction of salinity of recycled wastewater. While allowing
less leaching and therefore more sustainable irrigation, the utilization of desalinated water
comes with its own set of challenges including cost, unpredictable actual contents of
minerals when mixed with other water sources in distribution systems, and requirements
for provision of minerals, removed in desalination processes but needed in agricultural
applications.
Recent research has provided understanding and tools for optimizing water and nutrient
use efficiency as a function of water quality. These include models for crops response
which recently have been coupled with economic data to offer tools for decision making for
planners and growers.
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Can Desalination Be A Sustainable Technology for Dryland Countries
Who Seek To Mitigate Climate Change? Prof. Alon Tal
Tel Aviv, University, Israel
Water Session: Water & Energy
Desalination has proven to be a transformative technology for dryland countries that suffer
from chronic water shortages. Given the extraordinary proliferation of seawater
desalination plants around the world, Israel offers an instructive case study. It is a country
that for a decade has relied on desalination for most of its municipal water supply. This
reliance on sea water for meeting the country’s hydrological needs is anticipated to
increase over the next decades as the local population is set to double. The presentation
details the extraordinary environmental benefits that desalination has brought the country.
But during an age when stabilizing atmospheric concentration of carbon has become
axiomatic among environmental policy makers, is desal a sustainable alternative in light of
the planet’s climate change crisis? Indeed, there are many environmental impacts
associated with desalination technologies, but the one area of particular concern involves
its considerable carbon footprint. This lecture will offer a brief description of Israel’s desal
experience with a focus on the future capacity that will be required and its associated
energy requirements and emissions. Because Israel’s desalination facilities are among the
most energy-efficient in the world, these projections can offer a “best-case-scenario” for
other countries who are considering the transition to reliance on seawater for municipal or
even agricultural water supply. The presentation will seek to provide answers to questions
such as: Will the anticipated doubling in desal capacity undermine national efforts to
mitigate greenhouse gas emissions? Can Israel’s desalination plants become more
energy efficient? What would be a responsible energy component for a dryland country’s
desalination strategy. And given the growing scarcity of water on the planet, what are the
implications of desalination for global mitigation efforts?
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Integrated Foliar Nutrients Application Improve Cereals Growth and
Productivity under Moisture Stress Condition in Semiarid Climates Dr. Amanullah
Department of Agronomy, Faculty of Crop Production Sciences, The University of
Agriculture, Peshawar-Pakistan
Food Session: Nutrition and Management of Drylands
The increase in world population, especially in developing countries where soil fertility and
health are decreasing continuously leading to soil degradation and desertification. Water
scarcity in developing countries mostly under semiarid climates is one of the major
problems that decrease crop growth and yield leading to food security problems.
Integrated foliar nutrients management system could improve crop growth, yield and yield
components of crops under arid and semiarid climates. There is lack of research to study
the impact of integrated foliar nutrients management in field crops. Therefore, field
experiments were conducted for many years (2008-2013) with an objective to investigate
the impact of integrated foliar nutrients management on cereals productivity (wheat and
maize) under the semiarid condition at the Agronomy Research Farm, The University of
Agriculture Peshawar. The objective of these experiments was to investigate the impact of
sole and integrated foliar application on wheat and maize productivity under moisture
stress condition in semiarid climate. Foliar treated plots had higher yield and yield
components than control plots. From wheat experiments it was concluded that combined
(integrated) foliar application of Zn + B increases yield components and grain yield of
wheat under dryland as well as irrigated conditions. Combined foliar application of
micronutrients (Zn+B) was better than combined application of macro nutrients (P+K) in
terms yield and yield components. Combined application of B + macro nutrients (P+K)
increased yield and yield components than combined application of Zn + macro (P+K)
nutrients. Combined application of K + micronutrients (Zn+B) was better than combined
application of P + micronutrients (Zn+B). Foliar application of micronutrients at booting
stage of wheat was more beneficial in terms of yield and yield components. From maize
experiments, it was concluded that foliar P and Zn treated plots (rest) had better
performance in terms of improved growth, higher yield and yield components than control
(no foliar spray). Application of foliar P at the rate of 3% and Zn at the rate of 0.3%
improved growth, increased yield and yield components of maize under moisture stress
condition. Foliar potassium and zinc improved growth and increased yield and yield
components in maize over control. Application of foliar potassium @ 2% and foliar zinc @
0.2% are more beneficial in terms of higher yield and yield components. Early application
of foliar P, K and Zn at boot stage had positive impact on growth, yield and yield
components of maize as compared to late spray of both nutrients (P and Zn) at silking.
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Driving down the costs of solar-powered electrodialysis desalination,
drip irrigation, and the combination of the two Prof. Amos Winter
Global Engineering and Research (GEAR) Laboratory, Department of Mechanical
Engineering, Massachusetts Institute of Technology ,USA
Water Session: Water in Agriculture
This talk will present innovations from the MIT Global Engineering and Research (GEAR)
Lab to aggressively reduce the costs of solar-powered desalination and drip irrigation, with
the aim of making the technologies affordable for resource- constrained, off-grid markets
throughout the world. Community-scale electrodialysis (ED) desalination systems for
brackish groundwater require half the specific energy, and produce one-third the water
wastage, as reverse osmosis (RO) systems. GEAR Lab has created PV-ED control and
system optimization strategies, whereby the pumping flow rate and electrochemical power
are actively controlled to match available solar irradiance. We have demonstrated that
these PV-ED systems can directly utilize 76% of captured solar energy, need minimal to
no battery capacity, can produce water 54% faster than an equivalently-sized PV-ED
system that runs on constant power, and can meet near price-parity with on-grid RO
(inclusive of the cost of the PV power system) in terms of levelized cost of water. In a
parallel research effort, GEAR Lab has created ultra-low pressure, pressure- compensated
drip irrigation (DI) emitters to reduce required pumping power and facilitate solar-powered
irrigation. These devices were realized by creating predictive, parametric design theory to
describe the fluid-structure mechanics within the emitter that control water flow, to
minimize activation pressure. During two years of field pilots in Jordan and Morocco,
GEAR Lab’s emitters have demonstrated >50% pumping power reduction while
maintaining required water distribution uniformity compared to standard products. They
can reduce the cost of a solar-powered DI system by 40% compared to current industry
design practice. Our team is currently embarking on co-optimized desalination-drip
systems, which show promise for economic viability because of the combined energy and
water savings achieved through the PV-ED and PV-DI subsystems.
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Mapping and Monitoring Saline and sodic Soil Reclamation in Semi-arid
and Arid Environments of India Using Geo-information Tools Dr. A.N. Singh
Ex. Director, Remote Sensing Applications Center, Uttar Pradesh, India
Food Session: Nutrition and Management of Drylands
About 57 per cent of land area in India is reported to be degraded, of which the lands
under cultivation are the most degraded, followed by the grazing lands and the forests.
Soil salinity and sodicity has degraded 6.73 M ha in the semi-arid and arid climatic regions
of the country, significantly affecting its productivity and in several cases turning it
completely barren. It is estimated that due to the intensive use of natural resources in view
of the population pressure, and climate change effects, these lands may further increase
to 16.2 M ha by the year 2050 (ICAR-CSSRI Vision 2050). To counter their further
increase, large scale sodic land reclamation has been taken up in the states of Punjab,
Haryana, Uttar Pradesh, Rajasthan, and Bihar. In Uttar Pradesh, which has the largest
sodic land area, about 0.40 M ha area has been reclaimed under the Uttar Pradesh Sodic
Land Reclamation Project. The project, supported through a World Bank loan, was carried
out during 1993- 2018 in three phases. An important aspect of the project has been the
extensive use of geo-informatics in project planning, implementation, and monitoring which
included initially the use of aerial photographs and subsequently the multi-date, multi-
sensor, multi-spectral data from Landsat and IRS satellites. A multi-stage remote sensing
approach was adopted to cater to the requirement of reclamation programme. While the
large reclamation sites in different districts were selected based on the Landsat TM
derived map, the field plots for reclamation were selected based on 1:15,000 scale aerial
photographs in the first phase, IRS LISS III (23 m) and high-resolution Pan (6 m) merged
data in the second phase, and IRS LISS-IV data (multi-spectral, 6m) in the third phase.
Land levelling, field bunding, provision of adequate drainage, use of Gypsum as a
reclaiming agent, and keeping the land under rice-wheat crop rotation with a green
manuring crop in the summer season, were the important components of the reclamation
technology.
In order to assess the success of reclamation, land use change was monitored after a
period of five years using high resolution IRS data. The land use change monitoring at field
plot level showed that between 73 to 91% of the severely sodic barren plots had been
converted to rice- wheat cropping, indicating that reclamation had a significant positive
impact on increasing cropping intensity and long-term sustainability. The increase in
average cropping intensity from the pre-reclamation period of 124% to nearly 200% during
post-reclamation has led to higher total farm production, helping the small farm holders not
only achieve self-sufficiency in the availability of food grains for their family consumption,
but also additional income. Environmental impact assessment has been carried out by
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studying pre- and post- project soil quality, ground water level and its quality, surface water
quality, as well as floral and faunal biodiversity. These studies, involving the use of
Geographical Information System (GIS), have shown positive improvements in soil quality,
floral and faunal biodiversity, whereas no adverse impact was found on the quality of
ground and surface water. The project has thus been able to not only achieve food self-
sufficiency for the farm families, but has also helped in national food security and
environmental sustainability.
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Decentralized solar powered membrane filtration: Opportunities in
desert environments Dr. Andrea Schaefer
Karlsruhe Inst. of Technology, Germany
Water Session: Water and Energy:
Water availability in desert environments remain a grave concern – and has always been a
matter of survival. With climate change this need will be further exacerbated as
temperatures rise becomes more severe and water resources more scarce. Renewable
energy powered membrane filtration – or desalination – cannot increase the quantity of
water. The advanced treatment can however make water that is unfit for consumption
potable as is illustrated in Figure 1 at the example of a site in Tanzania, East Africa.
Decentralized – or autonomous – treatment systems are typically small, do not rely on
infrastructure and need to be robust to withstand operation in the harsh environment that
characterizes deserts. Providing the energy for operation, specifically the operation of the
high pressure pump required for nanofiltration or reverse osmosis, renewable energy is an
obvious choice. In deserts where solar irradiance is typically abundant, photovoltaics or
solar energy are suitable so long as sand storms and dust as well as excessive heat can
be managed.
The research on directly coupled renewable energy powered membrane filtration system
of the Schäfer-Richards teams began in Australia two decades ago. Brackish
groundwaters were treated in the Australian outback that contained a wealth of
contaminants ranging from salts through to natural uranium. The direct coupling means
that the renewable energy resource is neither converted nor stored, resulting in a
fluctuation of energy with solar irradiance, while water is stored for periods of shutdown
(bad weather, nights).
Treating brackish water is a significantly more economic option to seawater desalination,
because the salinity and hence the pressure requirements are lower. Contaminants that
occur in brackish groundwater, in addition to salinity, may include nitrates, arsenic,
fluoride, uranium and many more. Organic matter contents is bound to increase with
climate change, while micropollutants, such as pesticides, are increasing in occurrence
globally. Nanofiltration and reverse osmosis can remove many of these contaminants,
while the generation of a concentrate remains a challenge in remote areas. Evaporation
ponds may be a viable option in desert environments. The formation of inorganic scaling
through salt precipitation is a further operational challenge.
This lecture intents to provide an overview of renewable energy powered
nanofiltration/reverse osmosis and inspire a discussion about the suitability of such
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technologies in the desert context. Issues may span from typical water contaminants to the
operational issues such as extreme temperatures.
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Identifying weak links in the hydraulic chain of grapevines: insights into
the impacts of water stress on water uptake and transport physiology Dr. Andrew McElrone
USDA-ARS, UC Davis, Department of Viticulture and Enology, USA
Food Session: Viticulture and Vineyards
Water scarcity threatens the economic viability of viticulture in dry growing regions of the
western US, and changing climatic conditions could exacerbate this situation. Growers
commonly employ conservation techniques like deficit irrigation, where less water is
applied than is needed to match vineyard evapotranspiration (ET) demands. This practice
depletes soil water over time and induces water stress in vines. Water stress in grapevines
results in decreased growth and fruit yield, but is often used to control vigor and improve
fruit quality. Many physiological processes in grapevines are disrupted by water stress, but
the severity and timing of disruption vary between roots, stems and leaves. Some literature
suggests that grapevines are hyper-susceptible to drought-induced hydraulic dysfunction.
Here I will summarize a compilation of our hydraulic physiology, X-ray microCT, neutron
radiography, sap flow, and modelling efforts on various Vitis genotypes that demonstrate
most hydraulic dysfunction in grapevines occurs outside the xylem (i.e. in fine root cortical
and epidermal cells, where water is initially absorbed, and in leaf mesophyll cells, where
water evaporates before exiting the stomata). A thorough understanding of the
mechanisms impacted by water deficits is needed to effectively implement precision
irrigation strategies tailored to a given genotype and to maximize vineyard water use
efficiency. Such information would enable growers to better approach stress thresholds of
vines thereby limiting detrimental effects such as reduced fruit ripening or future bud
fruitfulness, and could also accelerate germplasm screening to identify improved plant
material that better tolerates water stress.
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Human Agency and Resilience to Holocene Desertification in the
Eastern Mongolian Gobi Prof. Arlene Rosen
University of Texas at Austin, USA
Human Session: Resilience of Desert Societies
The archaeology of the eastern Mongolian Gobi Desert provides us with excellent examples of the
adaptability of human societies to rapidly changing environments. Researchers once believed
prehistoric populations in dryland regions were at the mercy of increasing desertification
throughout the Holocene. They assumed these societies were compelled to turn to pastoralism in
response to desertification, and subsequently, herding economies themselves intensified
landscape degradation. However, new research in the Mongolian Gobi Desert indicates a different
trajectory of human interaction with this desert steppe environment. Here the progression from
forager to herder reveals adaptability, resilience and a sustainable existence over the course of
millennia.
Our research in the eastern Gobi Desert of southern Mongolia demonstrates that since the retreat
of the Pleistocene 11,700 years ago, the landscape and vegetation of the region has profoundly
changed. In the Middle Holocene, lakes and wetlands punctuated the landscape. These ultimately
disappeared due to temperature shifts and southward movement of the East Asian Monsoon.
Wetland patches are critically important to mobile foragers in semi-arid environments. They provide
year-round natural “stores” of plant and animal resources and often, seasonal migrations are
tethered around these lush mosaic environments. New geoarchaeological and phytolith research at
Zaraa Uul, Sukhbaatar Province, Mongolia shows that former Pleistocene lakebeds supported
small freshwater ponds and wetlands during the Middle Holocene. These marshes formed a rich
environment for hunter/gatherers who found reliable sources of grass seeds, rhizomes of sedges,
and a variety of animals concentrated near these water sources. The reliably resource-rich points
on the semi-arid landscape minimized subsistence risk, and facilitated movement of hunter-
gatherers throughout this region of the otherwise inhospitable Gobi Desert, up until the period of
time when pastoralists began to dominate this landscape, ca. 3500 years ago.
The entrance of pastoralists to the region coincided with the disappearance of the former wetlands,
and the beginning of true desertification. Geoarchaeological and phytolith research at the Ikh Nart
Nature Reserve, Dornogobi Province, suggests that the herders and their sheep/goats and cattle
introduced the lusher Stipa grass varieties and shrubs from more northerly steppe zones, thus
contributing to the “improvement” of the vegetation communities despite the retreat of the East
Asian Monsoons and increasing range of the dryland zones. This allowed a sustainable existence
in this region, and increasing social complexity. These findings are in profound contrast to
assumptions that pastoralists contribute to the degradation of dryland environments.
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Bedouin Contemporary Resilience: The Struggle for Dominating Local
Governance Prof. Avinoam Meir
Department of Geography and Environmental Development, Ben Gurion University of the
Negev, Israel
Human Session: Resilience of Desert Societies
Understanding resilience of contemporary Israeli Indigenous Bedouin in the Negev desert
rests on several assumptions. First, they may not be generalized as struggling necessarily
for classical desert survival, as only a negligible number of small communities in remote
areas in the eastern Negev and Negev Highlands may be represented as such. Second,
resilience may not necessarily be approached in terms of natural bio-physical resources
solely and in facing climate change, but may assume a multifaceted dimensionality
including social-cultural-political resources. Third, in a more-than-bio-physical-resources
perspective, resilience should be looked at as closely associated with the notion of place
and its broad spatio-temporal relationality, whereby bio-physical resources are one among
many components. And fourth, place-based resilience of the Bedouin as a desert
community has been acquired historically through desert pastoral-semi nomadic
subsistence to become an inherited cultural quality imported now into their contemporary
semi-urbanized labor market life.
With these assumptions as scaffoldings, the resilience of contemporary post-nomadic and
post-pastoral Bedouin will be examined in the arena that turns out to be crucial for them—
municipal politics. In particular this resilience is manifested in their struggle for domination
of local governance in their localities. Based on a recent study, this question is explored as
a process spanning the pre-1948 to present day period through the dynamics of
domination of local governance. The State of Israel has been compelling the Bedouin to
resettle into seven towns, but as of today only about half of the 270,000 Bedouin have
resettled, the rest are still living in unrecognized squatter villages. As a consequence of the
power of Bedouin place-based and land steadfastness, eleven (as of now) such villages
are now in a process of recognition and becoming municipalized.
Most of these localities are located within what the Bedouin regard as their traditional
pastoral-nomadic territories. Hence, there has been a sustained tension between the
Bedouin and the state over the issue of who indeed dominates local governance in
Bedouin localities. For reasons of national ideology, national security, national partisan
politics and regional development targeted primarily to the Jewish population, the state has
been consistently maneuvering to retain municipal control through non-democratic
measures, administrative-bureaucratic apparatus and legislative tools so as to eliminate
local and regional effects of Bedouin municipal-territorial dominance. In contrast the
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Bedouin have been reacting with civil action and legal measures to transfer domination of
local governance into their hands at all spatial scales of municipal bodies—local councils
and regional councils.
Thus, from a phase of virtually full domination of their tribal semi-nomadic local
governance in the pre-state period, through a phase of lost-domination in early statehood
years and early stages of semi-urbanization, through to contemporary recognition of some
villages, the Bedouin have been gradually extricating domination of local governance from
state grip and becoming dominant in municipal affairs of their localities. This process has
been powered by a long-term tension between governance up-scaling predilection by the
Israeli settler-state and down-scaling predilection by the Indigenous Bedouin. The
Indigenous Bedouin have been realizing their value of historical place-based resilience
and relationality of their localities with their culture and bio-physical environment, rejecting
in fact the modern governance imposed upon them.
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Cultural Landscapes and Paleoenvironmental Change at the end of the
Pleistocene: The Earliest Peopling of the Atacama Desert and its
Descendent Until Present Dr. Calogero M. Santoro
Instituto de Alta Investigación, Universidad de Tarapacá, Arica, Chile
Human Session; Resilience of Desert Societies
After the last glacial maximum (ca. 17,000 to 10,000-9,000 years cal B.P.) America had
exceptional conditions for hunter-gatherer groups. The Pampa del Tamarugal (PdT), in the
core of the Atacama Desert in northernmost Chile was full of vegetation and animals that
flourished as consequence of an abnormal increase in rainfall in the high Andes that
flowed toward the Pacific. The permanent riparian flows and subterranean water enabled
dense network of gallery forests, oases and springs that housed fauna currently extinct
(such as megaterium, American horse, palaeollama) and modern extirpated taxa (vicuñas,
guanaco, birds and rodents). The first immigrants who arrived around 13,000 expanded
over this Pampa. Sooner they learned how to manage local regional and supra-regional
resources applying different technologies to all kind of materials, to produce different
artifacts. Besides typical snapped stones, the extraordinary conservation of organic
material have allowed us to find remains of cordage and weaving made out of plant and
animal fibers, human hair, mineral pigments, sea shells used as ornaments, bone artifacts,
and carved wood. The first human inhabitants of the Pampa (pampinos) generated a
whole socio-cultural world and circuits of mobility and social interaction that reached the
Pacific coast, high Andean territories (80 to 100 km away respectively) and beyond into
the eastern Andean valleys and the tropical forest (800 km).
Around 10,000 to 9,000 cal year B.P. this ecosystem collapsed and people moved away
from the PdT toward the coast and the Andes, where inter-independent way of life were
developed. Around 3,500 cal years B.P. another pluvial anomaly made people to come
back to the PdT as former wetland and ravines flourished, with less water flow though. As
hunting gathering strategies were not sufficient to support an increasing number of people
that demanded a wide range of goods (pottery, textiles, metal objects, baskets, etc.), a
strong transformative program that encompassed cultivated crops and trees were
introduced and artificially irrigated in the Atacama Desert. This economy was
complemented by fish and shellfish brought from the Pacific coast. This sedentary way of
life that remained until ca. 1000 years cal BP, and its concomitants green revolution,
produced major ecological transformations of certain fertile loci within the Desert. All of the
crops we buy and consume today from local farming were introduced in that epoch (for
instance maize, beans, chili peppers, quinoa, potatoes, sweet potatoes), including an
iconic fruit tree, the algarrobo (cfr. carob tree) as well as the chañar.
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Are multiple disasters caused by climate change in Australia: really
unprecedented and unpredictable? Prof. Colin MacDougall
Flinders University, Adelaide Australia
Human Session: Desertification and Public Health
Australia changed early in 2020 due to a succession of disasters, in the form of droughts
and fires, soon to be followed by the COVID-19 pandemic. Since then, fierce contenders
for the word of the year include unprecedented, new normal, pivoting and green shoots. As
if these disasters emerged from nowhere and the scientific and policy communities had to
quickly invent new strategies. On the contrary, the scale of climate change warnings has
been matched only by Australian political and commercial intransigence and denial: fuelled
by well-funded anti science movements. Our landscape, industry and way of life are
profoundly changing to overcome policy neglect about climate change denial. Disaster
researchers and organisations are responding by reframing the old view of a sudden and
short event as persistent, consistent. A strong evidence base is informing our
understanding of recovery pathways. Political science is helping us to understand how
climate change denial is organised and funded. Meanwhile, young Australians are
organising and imagining a more sustainable planet.
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Selective Transport of Phosphorous Through Anion Exchange
Membranes Prof. David Jassby
Dept. of Civil and Environmental Engineering, University of California, Los Angeles, USA
Water Session: Advanced functional materials in water treatment applications
The selective extraction of phosphorous from wastewater remains a challenge.
Phosphorous, in the form of phosphate, is a valuable commodity chemical that is widely
used in many industrial applications, but is particularly valuable as a fertilizer. Wastewater
(municipal and certain industrial streams) is rich in phosphate, but this phosphate is largely
lost in the treated effluent (i.e., discharged into the environment) or trapped in biosolids.
While struvite precipitation is a viable option, it often requires the addition of magnesium
and a pH adjustment. Therefore, the ability to extract phosphate from wastewater in its
pure form without additional chemical modifications is an attractive target. In this
presentation, we present our preliminary findings regarding the development of a
phosphate-specific membrane. The membrane is based on the formation of a composite
organic-inorganic framework, where the inorganic component form specific and reversible
complexes with phosphate, while the organic fraction functions as an anion exchange
membrane that prevents the passage of competing anions. Using this material, we
demonstrate excellent selectivity towards phosphate, and propose a novel platform
towards the selective extraction of other valuable compounds.
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Acquiring Needed Water Without Depriving Neighbors or Wildlife Dr. Elaine Solowey
The Arava Institute for Environmental Studies, Kibbutz Ketura, Israel
Human Session: Gender, Leadership and Environment
Deserts are increasingly coming under cultivation due to population pressure, the spread
of cities into agricultural land and the shortage of new agricultural lands to utilize. Many
current agricultural endeavors in arid and hyper-arid zones are patently unsustainable in
their use of land, water and materials. It is some areas necessary to use arid and hyper
arid zones for food production. But because of the difficult and fragile soils the agricultural
endeavors themselves should be designed for long term preservation conservation and
reclamation. If possible, water thrifty native plants should be used. They should be planted
in sustainable formats with wise use of local water resources and an eye to preventing
wind and water erosion. A farm in an arid zone with a small extra water budget should be
encouraged to invest in some native low water use plants. There are some underutilized
sources of water in hyperarid zones that can be tapped The use of a swale is a strategy
allowing for the harvest of a short term crop For water collection an area can be dug as a
liman, covered with stones or plastic Another under-utilized source of water can
sometimes be found in the earth as there is often water between 1 and 3 meters under the
ground. Extraction methods can be as simple as a hand pump for direct distribution or as
complex as a feed into a drip system. It is important to know that these systems require
some investment in labor, in materials and in design.
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Effects of variable irrigation practices during extreme heat events on
grapevine physiology and berry chemistry Dr. Elisabeth Forrestel
University of California at Davis, USA
Food Session: Viticulture and Vineyards
Future climate will expose vineyards to extreme heat events of greater frequency, intensity
and duration. These extreme events will be coupled with higher evaporative demand under
warming climates and increased drought potential across many wine growing regions of
the world, including California. In grapevine and other speciality crops, these higher
temperatures, which occur during critical developmental stages, result in reduced
photosynthetic capacity, delayed ripening, as well as reduced yield and quality. As growers
primarily respond to extreme heat via irrigation, understanding cultivar-specific water
demands will better inform grower decisions and increase water use efficiency. However,
little information exists on current irrigation and cultivar-specific responses to extreme
heat. To evaluate the use of irrigation applied prior to and during heat waves (HWs), and
its effect on grapevine physiology and berry composition, we exposed Vitis vinifera cv.
Cabernet Sauvignon vines to three differential irrigation treatments across two seasons in
an established vineyard in the Lodi AVA of the Central Valley of California. The baseline
treatment was under water deficit (60% ET), while the 2x baseline ET and 3x baseline ET
treatments had double and triple the irrigation of the baseline, respectively. Throughout
HWs in the 2019 season there was a significant reduction in gas exchange, an increase in
leaf temperature, and lower evaporative cooling in the baseline treatment, while no
differences were observed between 2x and 3x treatments. However, after HWs the
baseline treatment showed signs of recovery from physiological stress. Skin tannin and
anthocyanin content, the onset of anthocyanin synthesis, pH, and acidity were affected
negatively by underwatering (60% ET) or overwatering (3x). Additionally, the baseline
treatment had the highest total soluble solids (TSS), and the lowest yield. Furthermore,
significant changes in anthocyanin hydroxylation and profile were found due to differential
irrigation, where the 2x treatment had a higher proportion of dihydroxylated anthocyanins
and malvidins. HW1, which took place pre-veraison, had a significant effect on the
changes seen among treatments on berry composition and yield, while HW2 accentuated
the differences found in berry composition. This study highlights the detrimental effects of
insufficient or excess water applications during heat waves on grapevine physiology and
berry composition. Our preliminary work moves towards generating better irrigation
management guidelines during heatwaves, which will be critical under increasing heat and
drought in many agricultural regions around the world.
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A different landscape: toward a novel approach to sedentarization
processes in arid and Semi-arid environments Dr. Emir Galilee
Ben Gurion Institute for the study of Israel and Zionism, Ben Gurion University of the
Negev, Israel
Human Session: Resilience of Desert Societies
Rent landscape: toward a novel approach to sedentarization processes in arid and Semi-
arid environments
Between the end of the 19th century and the mid-20th century the region of the Negev has
gone thru long and consistent change. The change was a combination of the utilizations of
natural resources and economical patterns, social structure, believes and culture. The
cultural landscape of the region characterized in patterns of nomads in process of
sedentarization.
Most of the scholars of nomadic societies in the world, especially in the Negev dealt with
sedentarization processes as a forced/orchestrated, "Top-own" process made by the
central regime. Scholars who come from different perspectives focused on the
orchestrated aspects the process (Yiftahel 2008 Yahel 2019 Shmuely and Khamaisi 2011).
These researches mainly ignored the internal changes within the nomadic society itself. In
1980 Salzman and Sadala has identified different processes of sedentarisation among
nomads. Part of this processes are internal changes within the societies themselves and
not just forced or responses to the act of the central government.
In this presentation, based on fieldwork among the Negev Bedouins in the past two
decades, I want to present a novel approach to the sedentarization process of the Negev
Bedouins. I would like to present the "bottom up" processes rely on the internal changes of
the Bedouin society itself.
My presentation will analyses the gradient of aridity of the Negev in a cultural perspective,
material culture, utilization of natural resources, the characterization and evolution of
buildings, and the tension and corporation between pasturing and agriculture in the arid
and semi-arid areas of the Negev (Galilee 2019).
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Characterization of bed load discharge in unsteady flow events in an
ephemeral channel in semi-arid region Mr. Eran Halfi
Dead Sea and Arava Science Center; Ben Gurion University of the Negev, Israel
Water Session: Flash Floods in the Arid Environment
There are many methods and equations for estimating bedload flux in steady flow
conditions. Yet, very little is known about the effect of very unsteady flows, such as flash
floods, on bedload flux. The unpredictable nature of the floods together with many logistic
difficulties and safety issues in monitoring explain this gap in knowledge. Global climate
change may increase flood event occurrence, making their understanding even more
crucial. This research focuses on two durations of flash floods where the flow is most
rapidly changing: a) flash flood bore arriving on dry river bed and b) flash flood bore
arriving on a column of moving water. During those times hydraulics parameters and
bedload transport are monitored and there relation is examined and characterized.
The methodology of our study is based on the demonstrated ability of the Eshtemoa
gauging station to automatically monitor the variation of bedload flux depending on flow
and bed characteristics, along with innovative equipment including hydrophones and
geophones for capturing acoustic signals of bedload sediments (1 Hz), video cameras for
continuous monitoring of water surface velocity (by the LSPIV method to determine its
structure and velocity) and 3-D velocimetry for characterizing turbulence (40 Hz).
Additional to these, a well-planned deployment was carried out, including alerting sensors
and cellular transmission, enabling to be onsite when bores arrive.
During the winters of 2015-2019, eleven flow events were monitored out of which three
flow events were sufficiently large to transport significant amounts of bedload. An
innovative mass aggregation based calibration between the acoustic indirect sensor and
the direct slot sampler allow determination of bedload flux at a frequency of 1 Hz. The
results indicate an increase of the turbulent nature (increase of the turbulent kinetic energy
and the instantaneous vertical velocities), shear stress and bedload flux during the rising
limb in the first two minutes of bore arrival.
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Satellite retrieval of vineyard leaf area index and impact of vine canopy
structure and interrow cover crop on retrieval algorithm Dr. Feng Gao
United States Department of Agriculture (USDA), Agricultural Research Service, Hydrology
and Remote Sensing Lab, USA
Ecosystem Session: Remote Sensing in Viticulture
Leaf area index (LAI) is an essential biophysical parameter in most land-surface models,
governing the partitioning of energy, carbon, and water fluxes between the soil and canopy
components of the land-surface system. Ground measurement of LAI is labor-intensive
and time-consuming. LAI retrieval using routine remote-sensing data provides an indirect
estimation of LAI with spatial and temporal variability. The remote-sensing LAI retrieval
can be conducted using the empirical relationship of LAI and vegetation indices or through
the inversion of a physical radiative transfer model. In the previous study, we have
developed an approach that uses the Moderate Resolution Imaging Spectroradiometer
(MODIS) LAI data product as a reference to retrieve Landsat LAI. This method has been
successfully incorporated into the disaggregated ALEXI (DisALEXI) evapotranspiration
model to map energy fluxes at 30 m resolution over vineyards as part of the Grape
Remote sensing Atmospheric Profile and Evapotranspiration eXperiment (GRAPEX)
project. The approach produces Landsat LAI data product that is consistent with MODIS.
Recently, the approach has been applied to the Harmonized Landsat and Sentinel-2 (HLS)
data to generate a more frequent (3-4-day) 30-m resolution LAI. Comparing to LAI field
measurements over the GRAPEX experimental sites from 2017 to 2019, HLS LAI captures
the spatial and temporal variability. However, the agreement varies on measurement dates
and sites. This could be due to different vine plant structure, interrow cover crop, or
clumping factor. In this presentation, we will assess HLS LAI across different sites and
years. The causes of differences will be analyzed. Sampling size and spatial heterogeneity
will be assessed using Unmanned Aerial Vehicle (UAV) and the Vegetation and
Environment monitoring New MicroSatellite (VENµS) imagery. An improved method that
combines MODIS LAI samples and field measurements will be presented. The challenges
of satellite retrieval of vineyard leaf area index will be discussed.
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Characterization of Microbiological Water Quality and Prevalence of
Waterborne Diseases in Marigat Urban Centre Baringo County, Kenya Prof. George Ogendi
Department of Environmental Science, Egerton University, Kenya
Human Session: Desertification and Public Health
Access to safe water is a precondition for health and is a basic human right. It is however
worth noting that approximately 20% of the global population lack access to potable water
whereas over 30% lack access to basic sanitation. The situation is much worse in the arid
and semi-arid lands (ASALs) in the developing countries. It is because of the foregoing
water and sanitation situation that 3.4 million deaths are reported annually. An assessment
of the microbiological water quality and prevalence of waterborne diseases was conducted
in Marigat, a sprawling urban area in the ASALs of northern Kenya. We employed a mixed
methods research design in this study: Field sampling followed by laboratory
measurements, and a Cross-sectional household survey. A structured questionnaire was
administered to household heads. Ten water samples were collected from the drinking
water sources and at the household level (Point of Use) during the dry and wet seasons
and analyzed for E. coli and TC bacteria using the MPN method. Health records of
persons that sought healthcare services at various Marigat health centres were reviewed
to determine prevalence of waterborne diseases. The E. coli levels in household water
samples ranged from 200cfu/100ml to 2500cfu/100ml, whereas the range was
25cfu/100ml to 4575cfu/100ml for Total Coliforms. The study findings indicated that there
was a significant association between level of education and covering of water storage
container (P< 0.05). There was a significant interaction between the point of water sources
and season in terms of E. coli and TC (P < 0.01) TC (P< 0.05) respectively. Nearly half of
the respondents indicated that diarrhea and typhoid were the most prevalent waterborne
diseases in children under the age of 5 years during dry season. Typhoid and cholera
were more prevalent duri