ecohydrology of surface and groundwater dependent systems ...hydrologie.org/redbooks/a328/p328...

Ecohydrology of Surface and Groundwater Dependent Systems: Concepts, Methods and Recent Developments Edited by Martin Thoms, Kate Heal, Eva Bøgh, Antonio Chambel & Vladimir SmakhtinIAHS Publ. 328 (2009) ISBN 978-1-901502-99-2, 240 + viii pp. Price £51.00

This volume is an outcome of the symposium of the same name organized by the IAHS international commissions on Continental Erosion (ICCE), on Groundwater (ICGW), and on Surface Water (ICSW) and the International Association of Hydrogeologists (IAH) in Hyderabad, India, September 2009.

The articles in this volume provide an exciting contribution to the field of Ecohydrology. As a collection they represent an expansion of this emerging field of science, from its initial focus on the relationships between water and vegetation in different landscape settings, to one that considers the: Ecohydrology of riverine landscapes, Ecohydrology and groundwater systems and Ecohydrology and catchment land-use issues.

Contents

Preface by Martin Thoms, Kate Heal, Eva Bøgh, Antonio Chambel & Vladimir Smakhtin

v

1 Ecohydrology of Riverine Landscapes

The wetting and drying regime of a terminal flood plain–wetland system: implic-ations for waterbird habitat Scott C. Rayburg & Martin Thoms

3

The effect of flow on the macrozoobenthos structure in a re-opened oxbow lake: a case study of the Słupia River, northern Poland Krystian Tadeusz Obolewski, Katarzyna Glińska–Lewczuk & Szymon Kobus

13

A transdisciplinary approach for modelling macroinvertebrate habitats in lowland streams Jens Kiesel, Daniel Hering, Britta Schmalz & Nicola Fohrer

24

Modelling the spatial variations of stream temperature and its impacts on habitat suitability in small lowland streams Eva Boegh, Martin Olsen, John Conallin & Esbern Holmes

34

The character and behaviour of flood plain vegetation landscapes Rajendra L. Shilpakar & Martin Thoms

42

An assessment of temporal habitat availability in a gravel-bed river using a Lidar-derived CFD model Neil S. Entwistle, David J. Milan & George L. Heritage

53

Mapping stream surface flow types by balloon: an inexpensive high resolution remote sensing solution to rapid assessment of stream habitat heterogeneity? Michael A. Reid & Martin C. Thoms

62

An investigation of the role of geomorphology in influencing biotope distribution George L. Heritage, David J. Milan & Neil S. Entwistle

68

Fuzzy logic-based expert system for native fish habitat assessment in a scarcity information context R. I. Meza & H. X. Vargas

77

The development of interdisciplinary flow-ecology models for the wetlands of the northern Murray-Darling Basin Neil Saintilan, Joanne Ling & Li Wen

86

Hydrological indices for quantifying ecologically relevant flow conditions in intermittent alluvial plain rivers J. Schmidt, S. T. Larned, D. Arscott & J. C. Diettrich

94

The potential effect of re-snagging on hydraulic habitat Mark Southwell, Martin Thoms & Craig Boys

103

An index of river health for river plain network regions Ying Zhang, Ling Liu, Jianzhong Wang, Juan Chen & Chengpeng Lu

112

Computation methods of minimum and optimal instream ecological flow for the upper Huaihe River, China Qiongfang Li, Tao Cai, Hongjie Wang, Yunhong Xue, Linlong Bai, Peng Li & Bin You

122

The ecohydrology of stream networks Celeste Harris, Martin Thoms & Murray Scown

127

2 Ecohydrology and Groundwater Systems

The effect of groundwater supply on the hydrochemical diversity of flood plain lakes in the temperate climatic zone Katarzyna Glińska-Lewczuk, Szymon Kobus, Krystian Obolewski & Jarosław Chormański

139

Groundwater–surface water interactions at a fen margin: hydrological controls on the micro-habitat of an indicator snail species Vertigo geyeri Anna Kuczyńska, Paul Johnston & Bruce Misstear

151

Enhanced groundwater modelling methods for analyses in ecohydrology Deborah L. Hathaway, Nabil Shafike & Karen MacClune

161

Estimation of hydrological dynamics and ecohydrological effects in the Karst region of southwest China Xi Chen, Zhicai Zhang, Pen Shi & Xuanwu Xue

170

The contribution of groundwater to soil moisture in Populus euphratica root zone layer Yonghua Zhu, Liliang Ren, Qicheng Zhang, Haishen Lü, Zhongbo Yu, Yanqing Wu & Huali Feng

181

3 Ecohydrology and Catchment and Land-use Issues

Onset of the rainy season and crop yield in sub-Saharan Africa – tools and per-spectives for Cameroon Patrick Laux, Greta Jäckel, Munang Tingem & Harald Kunstmann

191

Comparative study of the treatment of eutrophic water of different submerged plants with different planting densities X. F. Chen, L. L. Ren & B. H. Guan

201

The effect of gravel-sand mulch on soil moisture in the semi-arid loess region Haishen Lü, Yonghua Zhu, Zhongbo Yu & Long Xiang

208

Simulating the evolution of potential natural vegetation due to long-term climate change and its effect on the water balance of the Hanjiang River basin, China Fei Yuan, Liliang Ren, Qinghua Luan & Zhongbo Yu

216

Water balance and mean water residence time of the Vembanad Wetland of Ker-ala State, India R. Gopakumar & K. Takara

223

Key word index 233

Ecohydrology of Surface and Groundwater Dependent Systems: Concepts, Methods and Recent Developments(Proc. of JS.1 at the Joint IAHS & IAH Convention, Hyderabad, India, September 2009). IAHS Publ. 328, 2009, 3-12

The wetting and drying regime of a terminal flood plain–wetland system: implications for waterbird habitat

SCOTT C. RAYBURG & MARTIN THOMSRiverine Landscapes Research Laboratory, University of Canberra, Australian Capital Territory 2601, [email protected]

Abstract Suitable habitat is essential for successful colonial waterbird breeding in ephemeral wetlands located throughout inland Australia. Two important habitat requirements for waterbirds are an inundated area of sufficient depth and of suitable duration for breeding, and a sufficient inundated area of shallow water from which they can feed. We investigated the influence of a variable wetting and drying regime on these habitat requirements, and related them to known waterbird breeding events in the Narran Lakes, Australia. The complexity of the Narran lakes ecosystem, with its different wetland components, makes it an ideal site for the provision of these habitat conditions. As a collective, they provide the essential breeding and feeding habitats for sufficient durations to enable breeding to occur. This spatial complementarity of habitat is fundamental to the importance of the Narran flood plain–wetland complex as a waterbird refuge. Habitat complexity within this system is capitalised on by waterbirds and must be recognised in water management plans.Key words Narran lakes ecosystem; aquatic habitat; waterbird breeding; habitat complexity; spatial complementarity; dryland wetlands

Ecohydrology of Surface and Groundwater Dependent Systems: Concepts, Methods and Recent Developments(Proc. of JS.1 at the Joint IAHS & IAH Convention, Hyderabad, India, September 2009). IAHS Publ. 328, 2009, 13-23.

The effect of flow on the macrozoobenthos structure in a re-opened oxbow lake: a case study of the Słupia River, northern Poland

KRYSTIAN TADEUSZ OBOLEWSKI, KATARZYNA GLIŃSKA–LEWCZUK & SZYMON KOBUSDepartment of Land Reclamation and Environmental Management, University of Warmia and Mazury, Plac Łódzki 2, 10-756 Olsztyn, [email protected]

Abstract This study focuses on the assessment of relationships between flow and macrozoobenthos structure that was performed in a re-opened oxbow lake, Osokowy Staw, located near the Słupia River, northern Poland. Macrozoobenthos samples were taken between 1999 and 2005 at six sampling sites near the shore and four in the middle of the water body. In July 2000 the Osokowy Staw was re-opened and connected with the river through PVC pipes which enabled free water inflow and outflow. After re-opening, macrozoobenthos density increased from 99 to 659 individuals m-2 and the wet biomass from 0.03 to 73.1 g wet weight m-2, although these increases were not statistically insignificant. In the closed Osokowy Staw the dominant species was Asellus aquaticus. After re-opening it was replaced by bivalves and Chironomidae larvae (during the first year) and then, in 2005, A. aquaticus became the most abundant again. The number of taxa increased from four in the closed water body to 17 during the first year after re-opening and 14 in the next year. The Shannon biodiversity index also increased from H′ = 0.35 (in 1999) to H′ = 1.5 (in 2005). Revitalization processes of the re-opened oxbow lake were connected with the qualitative and quantitative recolonization by riverine macrozoobenthos.Key words oxbow lake; macrozoobenthos; reconnection; Słupia River, Poland

Ecohydrology of Surface and Groundwater Dependent Systems: Concepts, Methods and Recent Developments(Proc. of JS.1 at the Joint IAHS & IAH Convention, Hyderabad, India, September 2009). IAHS Publ. 328, 2009, 24-33

A transdisciplinary approach for modelling macroinvertebrate habitats in lowland streams

JENS KIESEL1, DANIEL HERING2, BRITTA SCHMALZ1 & NICOLA FOHRER1

1Department of Hydrology and Water Resources Management, Ecology Centre, Christian-Albrechts-University Kiel, Olshausenstr. 75, 24118 Kiel, [email protected]

2Department of Applied Zoology/Hydrobiology, Institute of Biology, University Duisburg-Essen, Universitätsstr. 5, 45141 Essen, Germany

Abstract Manifold anthropogenic influences are the main cause of river habitat degradation and extensive regeneration needs to be conducted to achieve the aims of the Water Framework Directive in Europe. As the outcome of river and stream rehabilitation measures is sometimes difficult to foresee, a GIS-based approach consisting of an eco-hydrologic, a hydraulic and a GIS mapping submodel is suggested for creating an integrated catchment and an in-stream modelling system to dynamically depict the influence of abiotic changes on the habitat quality. The Driver–Pressure–State–Impact–(Response) concept is utilised to depict the complex cause–effect chain of hydromorphological changes on macroinvertebrate habitats in lowland streams. A first application of the three submodels has been conducted in the North German Kielstau catchment and first results of modelling and mapping the impact on selected habitat parameters are displayed. Further work needs to be done in linking the submodels and in assessing the impact of the altered state on the macroinvertebrate fauna by parameter functions derived from a knowledge-based database and sampling schemes.Key words DPSI; hydrological model; hydraulic model; GIS; parameter functions; hydromorphology; macroinvertebrate; lowland


Modelling the spatial variations of stream temperature and its impacts on habitat suitability in small lowland streams

EVA BOEGH, MARTIN OLSEN, JOHN CONALLIN & ESBERN HOLMESDept. of Environmental, Social and Spatial Change, Roskilde University, PO Box 260, 4000 Roskilde, [email protected]

Abstract Water temperature strongly impacts stream ecosystem and function. On Sjælland, the main island of Denmark, low summer stream discharge rates are very sensitive to groundwater abstraction, which is therefore also partly responsible for the poor ecological conditions of most streams. However, the combined impacts of water depth, velocity and water temperature on habitat suitability during low-flow conditions are not known. The aim of this study is to measure and model spatio-temporal stream temperature variations as a function of stream surface shade from near stream land cover and to quantify such impacts on stream habitat suitability during low flows. Brown trout is chosen as a bio-indicator of stream ecological conditions because of its well-known preferences for physical habitat conditions such as temperature. A spatially distributed physically-based stream temperature model (Heat Source model) is set up for a 2.4 km reach of Helligrenden stream for a 10-day period in August 2008 at which time low flows are prevailing. Hourly water temperature measurements are obtained from five stream segments representative of meadows and forest stream reaches, and a temperature suitability index representing the fulfilment of temperature requirement of brown trout is calculated for the sites. Water temperatures are found to increase downstream by up to 2°C per km in open meadow reaches, thereby leading to temperature levels which are unsuitable for brown trout. In contrast, cooling rates of as much as –2.4°C per km are simulated for the forest reach. This suggests that planting of trees in riparian zones of downstream stream reaches can significantly improve stream habitat conditions during low flow conditions at Sjælland. Key words stream temperature; low flow; physical stream habitat suitability; Denmark

Ecohydrology of Surface and Groundwater Dependent Systems: Concepts, Methods and Recent Developments(Proc. of JS.1 at the Joint IAHS & IAH Convention, Hyderabad, India, September 2009). IAHS Publ. 328, 2009,42-52.

mailto:[email protected]

The character and behaviour of flood plain vegetation landscapes

RAJENDRA L. SHILPAKAR & MARTIN THOMSRiverine Landscapes Research Laboratory, University of Canberra, Australian Capital Territory 2601, [email protected]

Abstract Flood plains are an important component of the riverine landscape providing a range of ecosystem goods and services. In dryland environments, flood plains are a refuge for a wide variety of plant and animal species. Flood plain features often appear to display relatively coarse gradients of structure with distance from the main river channel in response to decreasing flow efficiencies and increasing elevation. However, when viewed at smaller scales, flood plains are heterogeneous landforms representing a mosaic of patches embedded within the large flood plain ecotone. This may occur because smaller scale variations in topography may disrupt longitudinal and lateral patterns. Flood plains are dynamic ecosystems and an obvious example of this is changing vegetation patterns overtime, which create a dynamic heterogeneous vegetation environment in flood plains. Complex patterns of change in flood plain landforms and associated vegetation influence the productivity and biodiversity of these systems. Consequently, understanding the character of flood plain vegetation landscapes and the changing nature of vegetation patches over time may be an important tool for managing these ecosystems. This study investigates how the flood plain vegetation-patch character of the lower Murrumbidgee River, Australia, changes over time. A series of vegetation community maps of the flood plain, spanning a period of 40 years, were used to determine the landscape patch character of this fragmented landscape. Patch characteristics such as size, patch number, length and shape complexity were calculated for each vegetation state and subjected to a range of uni- and multivariate statistical analyses to elucidate patterns in the flood plain landscape over time. The influence of changing hydrology on this important flood plain ecosystem is discussed.Key words flood plain vegetation landscapes; fragmentation; ecotones; patch mosaics


An assessment of temporal habitat availability in a gravel-bed river using a Lidar-derived CFD model

NEIL S. ENTWISTLE1, DAVID J. MILAN2 & GEORGE L. HERITAGE1

1University of Salford, Built and Human Environment Research Institute, School of Environment and Life Sciences, Peel Building, Manchester M5 4WT, UK [email protected]

2University of Gloucestershire, Department of Natural & Social Sciences, FCH, Swindon Road, Cheltenham GL50 4AZ, UK

Abstract Riffle-pool sequences in gravel-bed rivers provide the template for a number of fish and inverte-brate habitats. Water flowing over these morphologies creates spatial hydraulic variations over a rivers flow regime that are logistically impossible to measure in the field. This paper utilises the FLUENT Computa -tional Fluid Dynamics (CFD) model to construct a 0.2 m DEM for a 180 m reach of Kingsdale Beck, UK. CFD modelling allows spatial estimation of flow hydraulics for flows up to bankfull. With increasing discharge, complex patterns of hydraulic variation are revealed that exist within larger macroscale flow structures. During elevated flows these could act as biotic refugia. The spatial distribution and areal extent of habitat refugia for two commonly occurring macroinvertebrate species: Gammarus pulex (Amphipoda, Crustacea) and Ephemerella ignita (Ephemeroptera, Insecta), are explored for three discharges from baseflow up to bankfull. Temporal modelling permitted mapping of these refugia across the flow regime. Key words Terrestrial Laser Scanning; CFD; gravel-bed shear stress; habitat availability


Mapping stream surface flow types by balloon: an inexpensive high resolution remote sensing solution to rapid assessment of stream habitat heterogeneity?

MICHAEL A. REID & MARTIN C. THOMSRiverine Landscapes Research Laboratory, University of Canberra, Australian Capital Territory 2601, [email protected]

Abstract Spatial variation in hydraulic conditions in streams often results in distinct water surface patterns, or surface flow types. Recent studies have demonstrated that these surface flow types represent a distinct suite of hydraulic conditions with biological relevance, highlighting the potential value of surface flow type mapping as a rapid method for assessing hydraulic habitat heterogeneity in streams. Traditional approaches to surface flow mapping have used stream bank visual assessment of the presence and extent of flow type within assessment reaches. Such methods are subject to assessor bias and, particularly in larger streams, difficulties in assessing areal extent from strongly oblique views. This study uses a high resolution remote sensing approach to map surface flow types. The approach uses a balloon-mounted digital video recorder to record images of study reaches in plan view at a height of approximately 12 m. Ortho-rectified images are then used to identify surface flow types and digitise their extent. Areal extents of surface flow types derived through this process in a trial study were compared to those derived from streamside visual assessment to provide a preliminary test of the efficacy of the approach. Key words hydraulic habitat; surface flow types; remotely sensed data; river habitat heterogeneity


An investigation of the role of geomorphology in influencing biotope distribution

GEORGE L. HERITAGE1,3, DAVID J. MILAN2 & NEIL S. ENTWISTLE3

1JBA Consulting, The Brew House, Wilderspool Park, Greenall’s Avenue, Warrington WA4 6HL, [email protected]

2University of Gloucestershire, Department of Natural and Social Sciences, FCH, Swindon Road, Cheltenham GL50 4AZ, UK

3University of Salford, Built and Human Environment Research Institute, School of Environment and Life Sciences, Peel Building, Manchester M5 4WT, UK

Abstract Riffle–pool–point bar sequences provide the template for a number of aquatic habitats. Water flowing over these morphologies generates spatial hydraulic variation over a river’s flow regime resulting in a changing mosaic of hydraulic habitats or biotopes. Little attention has been given to the explicit spatial and temporal distribution of biotopes in relation to channel morphology. This study uses terrestrial LiDAR data to map biotope distribution at two discharges. A link was found between the riffle units and key characteristic biotopes. Biotope type change was also broadly consistent over this scale but areal coverage varied between units. It is argued that management options for such river systems targeted at maintaining the gross morphology will succeed in creating a variety of hydraulic biotopes that are consistent in their types across riffles; however, distribution and dominance are likely to be controlled by more local factors such as bed material and channel slope. Key words hydraulic habitat; biotope; riffle–pool; terrestrial laser scanning; flow regime


Fuzzy logic-based expert system for native fish habitat assessment in a scarcity information context

R. I. MEZA & H. X. VARGASCivil Engineering Department, Water Resources and Environmental Division, University of Chile,


Av. Blanco Encalada #2002, 3º piso, Santiago, [email protected]

Abstract Expert systems are typically developed to solve unclear application fields or problems. Such is the case for Chilean river ecosystems, and their fish fauna. In Chile, fish fauna studies are led almost exclusively by biologists, but no or little information is available about reproductive season, fertility, reproductive strategies, age, locomotive capacity, migration, trophic dynamic or niche, to name a few. Quantitative studies are required to analyse the impact of exotic over native species and the antropic effect over a population’s decrease. This information is essential to take appropriate conservation measures for each species and aquatic system. On the other hand, the lack of an adequate hydrometric network forces the use of complementary tools that introduce uncertainties, which are expensive and of difficult quantification. Due to the absence of gauged data for the study area, an expert system application methodology was coupled to the hydrological and hydraulic models, GR4J and HEC-RAS, respectively. Fish species information was taken from biological studies performed for the basin of the Bio Bio River where 17 fish species (13 native and 4 exotic, were found); furthermore, 7 species are classified as vulnerable and 7 are endangered. Conclusions are focused on the methodology as well as on information quality and source. The research indicated that habitat modelling efforts would be strongly limited by Chile’s unclear environmental policy, including lack of data in all areas for an environmental study. Chile’s capacity to adopt holistic tools for water resources management is commented. The study concludes with recommendations for improving the integration of environmental policy issues into Chile’s water resource management.Key words CASIMIR; Chile; Huequecura; fish habitat assessment; fuzzy logic; hydraulic modelling; hydrological modelling; water resources management; water law; free-market approach


The development of interdisciplinary flow-ecology models for the wetlands of the northern Murray-Darling Basin

NEIL SAINTILAN, JOANNE LING & LI WEN Rivers and Wetlands Unit, NSW Department of Environment and Climate Change, PO Box A290, Sydney South, New South Wales 1232, [email protected]

Abstract The purpose of eco-hydrological research within the Rivers Environmental Research Program is to inform decisions made about the application of environmental water over operation and planning timeframes within the northern segment of the Murray-Darling Basin, Australia. The Subprogram has acquired high resolution elevation data and inundation time-series to model the wetland hydraulic properties, and this modelling is forming the basis of wetland hydrological models being developed to link catchment inflows to wetland inundation over timescales ranging from the individual flow event to the 100-year planning horizon. Decision Support Systems are being developed which incorporate the hydrological and ecological response models to allow water resources planners and wetland managers to model the ecological outcomes of water resource planning and climate change scenarios. Key words decision support; ecosystem response; modelling; wetlands; Australia


Hydrological indices for quantifying ecologically relevant flow conditions in intermittent alluvial plain rivers

J. SCHMIDT1, S. T. LARNED1, D. ARSCOTT2 & J. C. DIETTRICH1

1National Institute of Water and Atmospheric Research (NIWA), PO Box 8602, Christchurch, New [email protected]

2Stroud Water Research Center, 970 Spencer Road, Avondale, Pennsylvania 19311, USA

Abstract Many alluvial plain river systems are under pressure from human impacts, including land-use changes, channel modifications, and hydrological alterations. Flow variation in alluvial plain rivers is


influenced by groundwater–surface water exchange, changes of channel form, climatic variation, and water abstraction. Consequently, these rivers often have complex spatial and temporal flow patterns. The natural hydro-geomorphic complexity along intermittent alluvial plain rivers poses a challenge for: (i) developing relationships between recharge and river flows, (ii) predicting effects of water resource developments, and (iii) understanding hydrological effects on ecological systems. Hydrological models that can reconstruct historic flows and/or predict future flows are required for assessing potential hydrological impacts of changing water use, land use, or climate change. If strong flow–ecology relationships exist, these models can also be used to infer potential ecological effects related to the impact in question. In this paper we present a model that accounts for spatial and temporal flow variation in intermittent alluvial plain rivers, and we describe a suite of hydrological indices that can be used to examine flow–ecology relationships. The model we developed, the Empirical Longitudinal Flow MODel (ELFMOD), reconstructs longitudinal and temporal flow patterns along river sections using measured flows at sites along the section and other predictor variables (e.g. groundwater levels, rainfall). Spatio-temporal flow matrices simulated by ELFMOD are used to generate a large range of hydrological indices that describe flow states and flow changes in space and time. Interpretation of these indices increases our understanding of complex flow regimes and hydrological controls of ecological processes and can aid river management.Key words alluvial plain river; intermittent; ephemeral; ecohydrology; surface water / groundwater interactions; New Zealand


The potential effect of re-snagging on hydraulic habitat

MARK SOUTHWELL1, MARTIN THOMS1 & CRAIG BOYS2

1Riverine Landscapes Research Laboratory, Resource and Environmental Sciences, University of Canberra, Australian Capital Territory 2601, [email protected]

2New South Wales Department of Primary Industries, Port Stephens Fisheries Centre, Private Bag 1, Nelson Bay, New South Wales 2315, Australia

Abstract Within riverine ecosystems, physical diversity facilitates biodiversity. In particular, large wood within river channels influences the distribution of hydraulic patches and their character, within the river landscape. We surveyed 30 reaches along the Barwon–Darling River in southeastern Australia to describe their hydraulic character, before and after the reintroduction of large wood (re-snagging). We found considerable hydraulic diversity within the reaches, but there was little difference between reach types (control, reference or re-snagged) and survey times. No significant differences were observed between the re-snagged reaches at the two survey times when all reaches were considered together, although differences were identified in some individual hydraulic patch variables. These results may be due to the low-flow conditions during and between survey runs. Successive surveys at a range of flow levels, both before and after the occurrence of larger flow events (which may encourage scour around re-introduced large wood), will be required to clarify this.Key words large wood; acoustic doppler profiler; Barwon-Darling River; hydraulic diversity


An index of river health for river plain network regions

YING ZHANG, LING LIU, JIANZHONG WANG, JUAN CHEN & CHENGPENG LUState Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098, [email protected]

Abstract We propose a new concept – “water health” – based on ecological health to describe the degrada-tion of aquatic ecosystems in relation to human-induced watershed alterations, and present a partial applica-tion of these ideas in a river plain network region. An indicator framework for the analysis and assessment of “water health” is presented which takes environmental, ecological, landscape and social service



functions into consideration. The meaning and method of determination of each indicator is described. The entropy method was adopted to calculate the weight of index, applying the weighted sum model. These approaches were implemented to assess the four main functions of “water health” for Xinghua city, China. It was found that the water quality is inferred as being only lightly polluted – “the general stage”; ecological and landscape functions were also in this category. In addition, large-scale exploitation of the social service function has also influenced the regional environment to some extent.Key words water health; river health; ecological integrity; indicators; river plain network regions


Computation methods of minimum and optimal instream ecological flow for the upper Huaihe River, China

QIONGFANG LI1, TAO CAI1, HONGJIE WANG1,2, YUNHONG XUE2, LINLONG BAI2, PENG LI2 & BIN YOU2

1State Key Laboratory of Hydrology, Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098, [email protected]

2Bureau of Xinyang Hydrology and Water Resources Survey, China

Abstract Hydrological processes are a key driver of the presence and absence and structure of aquatic communities. In this paper relationships between river ecosystem processes and the hydrological regime of the upper Huaihe River, China, are investigated, and computation methods for determining minimum and optimal ecological flows are proposed. A series of minimum and optimal instream ecological flows are proposed for three hydrological stations and these are compared to that obtained by the Tennant Method. The results provide a reference for preserving river hydrological processes and maintenance of river ecosystem stability and health. Key words minimum instream ecological flow; optimal instream ecological flow; the upper Huaihe River, China


The ecohydrology of stream networks

CELESTE HARRIS, MARTIN THOMS & MURRAY SCOWN Riverine Landscapes Research Laboratory, University of Canberra, Australian Capital Territory 2601, Australiaceleste.harris @canberra.edu.au

Abstract Stream ordering approaches to the study of entire stream networks are relatively simple and provide only crude estimations of the physical makeup of river ecosystems. These fail to acknowledge the importance of the hierarchical organisation of rivers and consequently use very crude variables when characterising stream networks. We provide an alternative typology for characterising the physical structure of rivers, which focuses on a specific level within the geomorphic river hierarchy, and employs a set of regional, catchment and valley criteria for developing a quantitative river characterisation scheme. Fifteen geomorphic variables were extracted from digital data using automated geographic information system modules and evaluated using a series of multivariate analyses. This allowed distinct river types within a stream network to emerge. Our approach was demonstrated in the Ovens River, Australia. The physical structure of the Ovens River stream network was further analysed using a series of community metrics: richness, composition and diversity of river types.Key words riverine networks; geographic information system (GIS); physical diversity; complex systems; river characterisation


The effect of groundwater supply on the hydrochemical



http://dict.cnki.net/dict_result.aspx?searchword=%E5%BC%80%E5%8F%91%E5%88%A9%E7%94%A8&tjType=sentence&style=&t=exploitation+and+utilization

diversity of flood plain lakes in the temperate climatic zone

KATARZYNA GLIŃSKA-LEWCZUK1, SZYMON KOBUS1, KRYSTIAN OBOLEWSKI1 & JAROSŁAW CHORMAŃSKI2

1Department of Land Reclamation and Environmental Management, University of Warmia and Mazury in Olsztyn, Plac Łódzki 2, [email protected]

2Division of Hydrology and Water Resources, Warsaw University of Life Sciences, Poland

Abstract In this paper we investigate the spatial heterogeneity of chemical parameters within flood plain lakes with different ground and river water recharge intensities. We assumed that the direct influence of groundwater recharge is ultimately related to the vertical stratification of temperature and aeration of the whole water column. Accordingly, we seasonally monitored physical and chemical properties of 22 oxbow lakes in the postglacial river valleys of the Słupia, Drwęca and Łyna rivers of Poland. The results were compared with groundwater from transects of piezometers located near the oxbow lakes. The flood plain water bodies showed variability (both in vertical and spatial dimension) in temperature, aeration and specific conductivity, affected mainly by lateral connectivity to the river. The temperatures and oxygen contents declined with the increasing depth of water and distance to the river channel. The detected differences in vertical gradients of physico-chemical parameters within one reservoir, or a group of those, confirmed the evidence of groundwater recharge. Key words oxbow lake; groundwater; hydrological connectivity; thermal gradient; aeration


Groundwater–surface water interactions at a fen margin: hydrological controls on the micro-habitat of an indicator snail species Vertigo geyeri

ANNA KUCZYŃSKA, PAUL JOHNSTON & BRUCE MISSTEARTrinity College Dublin, Department of Civil, Structural and Environmental Engineering, Museum Building, Dublin 2, [email protected]

Abstract Pollardstown fen is an important groundwater-dependent ecosystem in eastern Ireland. One of the ecological features of the fen is the rare snail species Vertigo geyeri, which is protected under the European Union Habitats Directive. A major study in the period 2002–2005 focused on establishing the micro-meteorological and micro-hydrological requirements for this indicator snail species at Pollardstown fen. It was shown that high relative humidity (above 80%) and close proximity to a phreatic water surface (approximately 0.1 m below ground surface) are important for maintaining snail populations. A study of the groundwater inflows to the fen, involving measurements of vertical and lateral hydraulic gradients, coupled with an evaluation of soil thermodynamics and meteorological observations, suggested that the hydrological regime of the fen is sensitive to both the groundwater inflow rate and the transpiration process of the wetland vegetation. Local topography and geomorphology are important considerations when deciding on the extent of potential snail conservation areas, as the long-term viability of conservation sites is likely to be greater in areas with gentle slopes that allow seepages to emerge at lower levels, if such seepages are reduced or lost at higher elevations.Key words fen; wetland; eco-hydrology; hydro-ecology; Vertigo geyeri; bioindicators


Enhanced groundwater modelling methods for analyses in ecohydrology


DEBORAH L. HATHAWAY1, NABIL SHAFIKE2 & KAREN MACCLUNE1

1S.S. Papadopulos & Associates, Inc., 3100 Arapahoe, Suite 203, Boulder, Colorado, [email protected]

2New Mexico Interstate Stream Commission, 131 Tijeras, Albuquerque, New Mexico, USA

Abstract Water operations policy to support improved habitat for riparian and aquatic species is being implemented in many regions of the United States. Habitat-motivated outcomes include surface and groundwater hydrology metrics. The desired hydrological outcomes include specific seasonal hydrographs to support spawning and other fish needs; and, overbank flooding or maintenance of shallow groundwater conditions to support native riparian vegetation, providing nesting habitat or serving other ecological functions. Success in achieving surface water and groundwater metrics is dependent on multiple concurrent interactions, not only between surface water and groundwater within the hydrogeological setting of the near-river zone, i.e. river gains and losses, but also on evapotranspiration, which varies by plant group, season, and depth to groundwater; and, on regional groundwater boundary conditions, which may be influenced by climate, urban, or irrigation demand. Finally, the river bed itself may undergo change under different flow regimes, and present further uncertainty in extrapolating from historic hydrological relationships to future conditions. To improve understanding of hydrological relationships in the near-river zone and assess impacts of water operation alternatives on ecology-based hydrological metrics, a modelling approach has been developed that incorporates transient processes that potentially impact groundwater conditions and groundwater–surface water interactions. This approach has been applied to the evaluation of river restoration and water operation alternatives on the Rio Grande in New Mexico and the San Joaquin River in California, USA. Very high-resolution three-dimensional groundwater models are employed, with the width and depth of wetted river channel and flooded overbank areas set as flow-dependent boundary conditions, obtained from a companion surface water routing model. To incorporate variable water demand by vegetation, riparian plant functional groups are identified that can be separately assigned potential evapotranspiration rates, seasonally-varying rates of water use, and rooting depths. External transient processes, such as regional water demand, that impact the near-river groundwater zone are specified according to a hypothesized future condition. Model simulations illustrate the sensitivity of desired hydrological metrics to other elements of the ecosystem, and demonstrate the need to evaluate possible future scenarios not against static assumptions drawn from past observed conditions, but in light of physically-based transient system dynamics.Key words riparian; groundwater; ecohydrology; modelling; conjunctive use; New Mexico; California; San Joaquin; Rio Grande


Estimation of hydrological dynamics and ecohydrological effects in the Karst region of southwest China

XI CHEN, ZHICAI ZHANG, PEN SHI & XUANWU XUE State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098, [email protected]

Abstract Temporal and spatial distributions of hydrological processes are key drivers on Karst ecological systems through changing soil moisture dynamics, nutrient cycling and vegetation cover. This study investigates Karst basin hydrological processes through modelling of the interactions between hydrology, rock and soil, and vegetation. A distributed hydrological model was developed by integrating hydrological dynamics of porous and fissure flows. A small Karst basin, with detailed observation data of hydro-geological conditions and eco-hydrological processes, was selected for model calibration and validation. The results show that the new model is able to capture the sharp rise and decrease of the underground streamflow hydrograph. The simulated soil moisture content and evapotranspiration reveal impacts of epikarst and vegetation cover on hydrology. Key words Karst; ecohydrology; vegetation; distributed ecohydrological model


The contribution of groundwater to soil moisture in Populus euphratica root zone layer


YONGHUA ZHU1, LILIANG REN1, QICHENG ZHANG1, HAISHEN LÜ1,2, ZHONGBO YU1, YANQING WU3 & HUALI FENG4

1State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098, [email protected]

2College of Science, Hohai University, Nanjing, 210098, China3School of Environmental Science and Engineering, Shanghai Jiaotong University, Shanghai 200240, China4Nanjing Hydraulic Research Institute, Naijing 210029, China

Abstract Populus euphratica is the predominant tree species forming natural woodlands in the Ejina basin of northwest China. Changes in P. euphratica woodlands represent significant changes in the basin’s ecology. The growth and development of these woodlands relies on groundwater recharged by flows in the middle reaches of the Heihe River. In recent years reduced flow in the Ejina basin, because of increase of water consumption, has endangered woodland ecology, environmental quality and social development. In order to maintain ecological stability and ecological restoration in the Ejina basin, a certain volume of water should be transported downstream, at the same time P. euphratica should be artificially cultivated. Therefore determining the contribution of the current groundwater to the soil moisture in the root zone of P. euphratica is required for making ecological restoration plans in the Ejina basin. A HYDRUS-1D model is used to determine the required groundwater and soil moisture conditions during the growing period from 1 May to 31 October for P. euphratica woodlands. The results of this study suggest the contribution of groundwater to root-zone soil moisture is 442 mm.Key words arid region; contribution of groundwater to soil moisture; HYDRUS-1D


Onset of the rainy season and crop yield in sub-Saharan Africa – tools and perspectives for Cameroon

PATRICK LAUX1, GRETA JÄCKEL1, MUNANG TINGEM2 & HARALD KUNSTMANN1

1 Institute for Meteorology and Climate Research, Forschungszentrum Karlsruhe GmbH, Garmisch-Partenkirchen, [email protected]

2Climate Change Adaptation Unit, Division of Environmental Policy Implementation (DEPI), United Nations Environment Programme (UNEP), Nairobi, Kenya

Abstract In dry sub-humid and semi-arid regions, where rainfall is limited to only a few months per year, rainfall is the most important factor affecting crop growth and yield. Every year, farmers are faced with the crucial question of when to start planting. Do the first rainfalls after the dry season resemble the onset of the rainy season (ORS) or not? A fuzzy logic-based algorithm for estimating the ORS and the optimal planting date was developed. It is based on rainfall data and accounts for agriculturally meaningful aspects. The ORS algorithm, which calculates the planting date for each year, was coupled to the physically-based crop model CropSyst. A Monte Carlo approach was applied to generate annual planting dates from 1979 to 2003. Therefore, the definition constraints, which are allowed to vary within reasonable parameter ranges, are generated randomly. The averaged crop yield served as a performance measure for each realization. The parameter range of the best realizations is retained. Various iterations are necessary to obtain a robust set of “optimal” definition parameters. The coupled ORS definition-crop modelling system was applied for two different crop species and five different observation stations across Cameroon for the period 1979–2003. It is shown that the derived “optimal” planting dates would allow for significantly increased crop yields compared to the existing planting rules in Cameroon.Key words crop modelling; CropSyst; Monte Carlo approach; onset of the rainy season; planting date



Comparative study of the treatment of eutrophic water of different submerged plants with different planting densities

X. F. CHEN1, L. L. REN1 & B. H. GUAN2

1State Key Laboratory of Hydrology, Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098, China [email protected]

2 State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China

Abstract A comparison of the purification ability of eutrophic water by two submerged macrophytes with different planting densities, is outlined in this manuscript. Removal of total nitrogen (TN) and total phosphorus (TP) from eutrophic water by Hydrilla verticillata and Potamogeton crispus planted at different densities were shown to differ. Both H. verticillata and P. crispus had high removal rates of TN, TP and chlorophyll a from eutrophic water, and their removal ability increased with increasing plant density. At the same density, P. crispus had higher removal ability for TN than H. verticillata; conversely, H. verticillata had higher removal ability for TP than P. crispus. The results suggested that density should be taken into account in restoration programmes of submerged macrophyte and the optimal submerged macrophyte should be chosen by the highest removal rate for different eutrophic composition (TN, TP).Key words submerged macrophytes; eutrophic water; treatment; planting density


The effect of gravel-sand mulch on soil moisture in the semi-arid loess region

HAISHEN LÜ1,2, YONGHUA ZHU2, ZHONGBO YU2,3 & LONG XIANG2

1 College of Science, Hohai University, Nanjing 210098, [email protected]

2 State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098, China

3 Department of Geoscience, University of Nevada, Las Vegas, Nevada 89154, USA

Abstract In the semi-arid loess region of northwest China, the use of gravel and sand as mulch has been an indigenous farming technique for crop production for over 300 years. This study was carried out to quantify the effect of gravel-sand mulch on soil water in the semi-arid loess region of northwest China using HYDRUS-1D code. The field experiment (4 April 2001–12 July 2001) consisted of two treatments: no mulching as a control and gravel-sand mulching. The results show that the gravel-sand mulch field can provide a more favorable soil moisture environment for plant growth. In the initial stage of watermelon growth, there was higher soil water content in the gravel-sand mulch field, which was very beneficial to the germination of watermelon. Gravel-sand mulch can improve soil moisture conditions. It is effective in reducing evaporation and improving transpiration. Gravel-sand mulch can improve the infiltration of rainwater to depth. After a little rainfall, the soil moisture gathered at 12–30 cm depth soil layer for the gravel-sand mulch field and at 0–20 cm depth soil layer for the no-mulch field. The results indicated that the higher soil moisture content in the layer (12–30 cm) may enhance watermelon growth. Key words gravel-sand mulching; HYDRUS-1D; northwest China; semi-arid; soil moisture movement


Simulating the evolution of potential natural vegetation due to long-term climate change and its effect on the water balance of the Hanjiang River basin, China

FEI YUAN1, LILIANG REN1, QINGHUA LUAN2 & ZHONGBO YU1

1State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, College of Hydrology and Water Resources, Hohai University, no. 1 Xikang Road, Nanjing 210098, [email protected]

2Hebei University of Engineering, Guangming South Street 199, Handan 056038, China

Abstract The dynamics of potential natural vegetation in the 21st century and its possible impact on the water budget of the Hanjiang River basin were assessed in this study. Based on the predictions of the IPCC-SRES climate scenarios from the PRECIS regional climate model, changes in plant functional types (PFTs) and leaf area index (LAI) were simulated via the Lund-Potsdam-Jena dynamic global vegetation model. Subsequently, the predicted PFTs and LAI were used in the Xinanjiang vegetation–hydrology model for the rainfall–runoff simulations. The results show that in the 21st century the forest PFTs will be gradually degraded and replaced by the grass PFT, and overall the basin-averaged LAI will decrease. Accordingly vegetation transpiration and evaporative loss of the intercepted canopy water will tend to drop, while soil evaporation may rise sharply. As a result, total evapotranspiration will increase moderately, with a slight increase in annual runoff depth. These both result from higher annual precipitation. Key words vegetation; climate change; LPJ-DGVM; Xinanjiang hydrologic model


Water balance and mean water residence time of the Vembanad Wetland of Kerala State, India

R. GOPAKUMAR1 & K. TAKARA2

1Centre for Water Resources Development and Management, Kozhikode-673571, Kerala, [email protected]

2Disaster Prevention Research Institute, Kyoto University, Uji, Kyoto 611-0011, Japan

Abstract The Vembanad Wetland complex of Kerala State in India comprises the Vembanad backwater lake and the deltaic regions of five rivers, which drain into the lake. The wetland has many functions, including flood and pollution control, biodiversity, agriculture, inland navigation and tourism. Artificial impacts including land reclamation and reductions in tidal flushing have led to significant environmental degradation of this wetland complex. This study examines the hydrology of the Vembanad Wetland in terms of river flow variability, seasonal water level variations, residence time and overall water balance. Estimates of water residence time in the Vembanad backwater lake are nearly identical for the scenario of freshwater flows during monsoons and for the non-monsoon scenario, if the lake is left open for tidal flushing. Therefore, one of the strategies for ecological restoration of the Vembanad Wetland is to allow periodic tidal flushing by rescheduling the operation of the Thanneermukkom (TM) barrage during the non-monsoon period. The study also shows that a major share of the freshwater drained into the wetland from the rivers is discharged to the Arabian Sea. Increasing the storage within the river basins is essential for the optimal utilization of river flows and the wetlands’ sustainability. Key words Vembanad Wetland, India; hydrology; hydroperiod; residence time; water balance



ecohydrology of surface and groundwater dependent systems ...hydrologie.org/redbooks/a328/p328...

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