hydrology of a cloudforest in la tigra honduras
TRANSCRIPT
Luis Caballero, PhD
Associate Professor Watershed Sciences and Hydrology
Zamorano University, Honduras (1993-2013)
Humuya Bosque latifoliado
Río Nacaome Río CholutecaSan Lucas
Tela
La Ceiba
Hydrology of Honduras, two different scenarios
Background• Honduras and La Tigra National Park
• The importance in terms of water
• The problems
• The study – Motivations
– Objectives
– Methodology (site and instrumentation)
– Results and discussion
– Conclusions
The study motivation
• To protect NR effectively, society needs to value them
• In developing countries there is lack of data, information and basic knowledge.
• We, usually, do not protect what we don’t know.
• Bridging hydrologic science with economic analysis to foster good land and environmental policies.
• Water is a critical resource for both, drinking and food security
National parks are important areas for present and future generation
We all heard a lot a about biodiversity
scenic values, carbon sequestration, logging, etc.
But, we heart much less, in the recent pass, about the most important resource:
Water
If we protect for water, most of the other resources would be protected too.
“La Tigra National have been studied extensively, but not its water production potential” Why?
The problems within and outside the park When water production clashes with other space uses
Agriculture
Fuel wood
Urbanization
Hunting/Mining
Conflicting interests
Material and Methods
La Tigra Experimental Watershed, Honduras
Cornell/Zamorano University
Funding: CANON-NP/OAS/ Cornell/CSS
Documents and Settings\lac76\Desktop\Luis Backup\Desktop\GIS Data La Tigra\Deforested Area 2.kmz
Weir WS4
Weir WS2Weir WS1
Weir WS3Final outlet
Streamflow data and water samples collection
Simple past digital filter similar to one proposed by Lyne and
Hollick (1979) and Nathan and McMahon (1990).
where:
QT(t) = Total observed streamflow at time step t
QB(t) = filtered baseflow at time step t
QP(t-1) = calculated runoff at time step t-1
If QT(t) = QT(t-1) then runoff = 0 and total streamflow = baseflow
If QT(t) > QT(t-1) then runoff > 0 and equation 2 and 3 applies for every
time step.
Hydrograph separation:
1.
2.
3.
The modeling approach
Conceptual approach Parameters
Figure 4: Schematic representation for saturation excess
overland flow, infiltration, interflow and baseflow for a
characteristic hill slopes (Steenhuis et al., 2009)
Runoff Producing Areas
Modeling approach
Selecting model parameters, a view from the field
Exposed bedrock areas
Saturated areas
Results: Climate-hydrology
Precipitation: How much and how variable?
0
50
100
150
200
250
300
350
Pre
cip
itat
ion (
mm
/mo
nth
)
Month
2008
2009
Zamorano mean
La Tigra mean
Precipitation: How much and how variable?
0
100
200
300
400
500
600
6/10/2009 6/25/2009 7/10/2009 7/25/2009 8/9/2009 8/24/2009
Cum
mula
tive
P (
mm
)
Date
Cumulative rainfall amount influenced by
convective storms events
(June 10-August 27-2009)
1800 m.a.s.l. = 402 mm
1450 m.a.s.l. = 299 mm
1350 m.a.s.l. = 515 mm
Precipitation: How much and how variable?
0
50
100
150
200
250
300
350
400
9/10/2008 9/20/2008 9/30/2008 10/10/2008
Pre
cip
itat
ion (
mm
)
Date
Cumulative rainfall for three rain gauges influenced by frontal system
(9/10/08 through 10/16/08)
1350 m.a.s.l. = 321 mm
1450 m.a.s.l = 344 mm
1800 m.a.s.l = 343 mm
Precipitación characteristics
Figure 2.5. Rainfall-runoff relationship for 29 precipitation events
measured at WS1 during one year (October 2008 to October 2009.
Rainfall-runoff relationships
Figure 2.6. Baseflow recession during the dry season
(March-May, 2009) ). Solid line regression.
Baseflow recession
Water balance
Modeling Objective
• To test if the model is able to simulate the observed runoff hydrograph from a cloud forest and other forested areas in Honduras, and then use the model to infer differences in hydrologic behavior between cloud forests and non-cloud forest watersheds.
Figure 4.2a. Comparison between observed and modelled daily flows for WS1
For a set of parameters (Tables 4.2 and 4.3)
RESULTS
Figure 4.3a. Comparison between daily observed and modelled stremflow for WS1 with various
set of parameters (listed in table 4.2 and 4.3.
Figure 4.2d. Comparison between observed and modeled daily flow for
WS4 catchment. For various set of parameters listed in table 4.2 and 4.3.
Figura 4.3d. Comparison between daily observed and modelled stremflow
for WS4 with various set of parameters (listed in table 4.2 and 4.3)
Conclusions:
• Three times as much water was produced by the large cloud forest watershed compared to the smaller forested watersheds
• Rainfall intensity was generally low and less than the infiltration capacity of the soil.
• Surface runoff is likely produced from the saturated and rock outcrop areas(less than 10%)
• At least 90% of falling rainfall infiltrates the soil profile and/or is intercepted by the plant canopy
Conclusions:
• Cutting down more cloud forest will likely dry up springs and decline the amount of water during the dry season when it most needed for drinking water
• With our current data, it is not possible to determine how much discharge comes from saturated areas and how much from interflow. This two water sources are interconnected, highlighting the difficulty to accurately and un-ambiguously account for each separately.
Why this findings are so important?
Hydrology of cloudforest was unknown.
Cloudforest are major sources of water supply to rural communities in C.A.
Good climate, rich O.M. and humid environments good for Agriculture/pasture.
Traditionally, convincing policy and decision makers to protect NR is a not easy.
But, sound science and practical knowledge can make a difference, so does education of the public.
We hope our little contribution in knowledge can incentive future work.
It is not about the cloudforest itself, these areas, are the headwater for major rivers, thus critical for hydro-energy, food production and
water supply for densely populated urban centers
II Part:
Agricultural adaptation to
climate change
Map of target areas
Project Aproaches• Territorial approach.
– Focus en watershed processes and systems: selecting farms that could be affected or benefit by lack or excess of water in the catchment.
– Concentrate investments to establish a “farmer school for climate adaptation” or “demonstration farms”.
– Support the implementation of climate adaptation practices on neighboring farms (education and training, testing drought resistant varieties, new crops, etc.)
• Social and institutional approach
Ozatlan group: Lead farmer, Sr. Odilio Amaya
Strategy: Increase water balance in the farm.• Implement soil and water conservation practices to
increase infiltration and reduce soil erosion.• Plant different options of life barriers to reduce
sedimentation on the ditches.• Build on farm water conservation structures to capture
runoff• Harvest runoff water from a nearby dry creek, and divert
it to the demonstration plot. • Diversify crops to minimize impact of draught on farm
income.• Promote improved drought resistant varieties
a. Utilize different types life barriers, to protect water conservation ditches.
b. Divert runoff water from nearby dry creek and conserve it in a earth pond.
Harvesting runoff from microcatments and house roofs tops Transport to infiltration ditches
While conducting excess water to other
ditches downhill in a zigzag shapeTo increase on farm water balance
and soil water supply for crops
Building capacity for a more climate resilience agriculture in the dry corridor of
central America, Ozatlán, Usulután, El Salvador
ENGILITY/IRG
Allowing for more
residence time in
the farms
Farmers school methodology: Practical and conceptual approach
Increased crop resilience to
droughts and improved food
security in rural familiesLuis A. Caballero, PhD.
Associate professor Watershed Sciences and Hydrology, Zamorano University
In Ozatlan farmer´s school Ing. Albino Peñate shows soil and water practices and crop diversification, among them: Loroco flower (to make pupusas), maracuya (to make drinks), drought resistant corn, and fruit trees.
Totogalpa group: Marcial Diaz farmStrategy: Increase water access and promote more efficient use.• Collect runoff passing through his farm, to increase
residence time to recharge water table.
• Improved access water through building a hand-dug well
• Improved irrigation through a drip irrigation plot, used as demonstration plot.
• Improved soil and water management practices to conserve soil and water, leading to more resilient cropping systems.
• Training and income generation, as a group, to invest on their owns farms.
Actions to establish a farmer school
a. A cropping plot under high water efficiency (drip irrigation)
b. A hand dug well to increase water supply during dry period (cost sharing).
c. A water detention pond to increase water table recharge above the hand-dug well
d. A water harvesting pond to increase water supply during short term droughts
Actions to establish a farmer school
Water harvesting pond
Drip irrigation training plot
0
10
20
30
40
50
60
70
6/1
9/0
5
6/2
0/0
5
6/2
1/0
5
6/2
2/0
5
6/2
3/0
5
6/2
4/0
5
6/2
5/0
5
6/2
6/0
5
6/2
7/0
5
6/2
8/0
5
6/2
9/0
5
6/3
0/0
5
Tiempo (Días)
Ca
uda
l (l
/s)
0
10
20
30
40
50
60
70
Pre
cip
itació
n (
mm
)
Precipitación Caudal
Capiro-Zapotillo paired experimental watersheds, Zamorano Honduras
(early steps in watershed hydrology research)
Acknowledgments:1. Zamorano University watershed team 1996-2012
2. Cornell University, Ithaca New York, USA.
3. American Association for the Advancement of Science (AAAS-US National Park
Service/The Canon Company
4. The Organization of American Sates (OAS)
3. Field research support from CATIE, AMITIGRA and the Municipality of Valle de Angeles
5. USAID for its continued support over the last 25 years of profesional development
Luis A. Caballero Bonilla, PhD
Soil and Water Enginiering
Independent consultant water resources/watersheds and climate adaptation
2025 Overlook Drive, Fort Collins Co. 80526
E-mail: [email protected]
Phone: (970) 631-8187
http://soilandwater.bee.cornell.edu/publications/caballero-thesis2012.pdf
http://onlinelibrary.wiley.com/doi/10.1111/j.1752-1688.2012.00668.x/abstract
http://www.degruyter.com/view/j/johh.2013.61.issue-1/jhh-2013-0003/jhh-2013-0003.xml
Thanks
Gracias