Spatial-temporal optimization of conservation practices affected by future climate scenarios in agricultural watersheds

Transcription

1 Spatial-temporal optimization of conservation practices affected by future climate scenarios in agricultural watersheds A study in Eagle Creek Watershed, Indiana Kelli Walters Debora Piemonti and Meghna Babbar-Sebens Civil and Construction Engineering Oregon State University 13 May 2013

2 Overview Introduction Motivation Objectives Hydrologic modeling using SWAT Effects of stakeholder attitudes and land tenure Future work: incorporating climate change 2

3 Eagle Creek Watershed, IN Existing infrastructure, data collection, support and partnerships ~ 16 km NW of Indianapolis Drainage area = 420 km 2 Agricultural land use Eagle Creek Reservoir Recreation Drinking water Flood control 3

4 Introduction Altered hydrologic cycle due to: Deforestation Artificial agricultural drainage systems Urbanization Residential development Climate change 2008 Flood from Hawcreek and Hospital Areas. Taken from: &action=print&thread=326 Resulting in: Changed flood and drought patterns Water quality issues Greenish-brown algal scum collecting along White River Taken from: CIWRP/Algae_Information/ _WhiteRiver_Diatoms.htm 4

5 Motivation Structural solutions Caused downstream flooding Separated rivers from floodplains Decreased upland storage Increased sediment/contaminant transport 5

6 Motivation Increase upland storage capacity by storing and treating water locally Improve infiltration rates in the ground Reestablish naturalized flows Improve watershed health (habitat quality, stream flow patterns, and health and diversity of plant and animal communities) 6

7 Proposed Solution Distribution of conservation practices Wetlands Riparian buffers Strip-cropping Conservation crop rotation Filter strips Grassed waterways Cover crops Conservation Tillage USDA-NRCS 7

8 Objectives Modeled watershed management plans Evaluate impacts of conservation practices Create an optimized management plan Social attitudes and economic factors influence acceptance and implementation of practices Create an adaptive tool to manage extreme runoff that incorporates stakeholders in the decision-making/design processes 8

9 Hydrologic Modeling - SWAT Soil and Water Assessment Tool (SWAT) Developed by USDA Agricultural Research Services ( Models impacts of BMPs on water, sediment, and nutrients and pesticide yields Designed for large, complex, ungaged watersheds Semi-distributed, lumped model Basic inputs and outputs for SWAT. Taken from: 9

10 Hydrologic Modeling - SWAT Preliminary identification of upland storage sites (wetlands and ponds) using GIS Simulate effects of conservation practices in these areas on stream flow and water quality SWAT model calibrated for ECW potential upland storage sites. Calibration for flows at Clermont Station Nash-Sutcliffe Efficiencies: (Zionsville) (Claremont) 10

11 Stakeholder Influence Objectives and Constraints: Flows, erosion, nutrients, costs Optimal solution Model Simulation and Optimization Stakeholders Modified optimal solution 11

12 Stakeholder Influence Objective functions: Peak flow reduction Sediment reduction Nitrates reduction Looked at land tenure distribution Land owner Share renter Cash renter Social attitudes Economic profit Prevention of flooding Soil conservation/productivity preservation Fertilizer loss 12

13 Stakeholder Influence Experiment 1: Comparison of costs and benefits of individual conservation practices Sensitivity analysis of conservation practices over the entire watershed. 13

14 Stakeholder Influence Experiment 2: Optimization of multiple conservation practices with varying distribution of land tenure Cost-Benefits vs. Peak Flow reductions for different land tenures using all practices. 14

15 Stakeholder Influence Experiment 3: Optimization of multiple conservation practices with uniform land tenure and multiple social attitudes. Attitude Objective function Weights Economic profit Prevention of flooding Cost/Benefits Peak flow Reduction Sediments Reduction Nitrates reduction Cost/Benefits Peak flow Reduction Sediments Reduction Nitrates reduction High Low Low Medium Medium High Low Low Attitude Objective function Weights Soil conservation/producti vity preservation Cost/Benefits Peak flow Reduction Sediments Reduction Nitrates reduction Medium Low High Low Fertilizer loss Cost/Benefits Medium Peak flow Reduction Sediments Reduction Nitrates reduction Low Low High 15

16 Conclusions Stakeholder preferences will affect the results of an optimal distribution of conservation practices. When practices are removed from the system due to certain attitude (i.e, economics profits) the modified alternatives experienced: A decrease in nitrates reduction by 2-50% A decrease in peak flow by %, and A decrease in sediments by 20-77%. The selection of a BMP will depend on the specific weights that are assigned to the objective functions based on different attitudes. Differences in land tenure also affect the optimal solution but on a lower scale. 16

17 Future Work Modeled watershed management plans, including stakeholder attitudes ( ) Climate change will alter the long-term effectiveness of conservation practices and management plans Create an adaptive decision-making tool to manage extreme runoff affected by future climate scenarios 17

18 Future Work North American Regional Climate Change Assessment Program (NARCCAP) Run a set of regional climate models (RCMs) driven by a set of atmosphere-ocean general circulation models (AOGCMs) IPCC A-2 emissions scenario : Compare current simulated data with observed data in the Eagle Creek Watershed : Use the future simulated data from the RCM- AOGCM that best matched the current data as input into the SWAT model for future projections 18

19 Future Work Use NARCCAP data as climate input into hydrologic model Use SWAT to simulate long-term hydrologic impacts of practices for current and future climate scenarios How does climate change impact the hydrology of the watershed? Which BMPs are most effective with climate change? What are the long-term effects of the BMPs compared to short-term effects previously studied? Create an optimized runoff management plan and provide a tool for managing extreme runoff affected by climate change. 19

20 Questions? ACKNOWLEDGEMENTS Debora Piemonti Dr. Meghna Babbar-Sebens REFERENCES Milly, P.C.D., J. Betancourt, M. Falkenmark, R.M. Hirsch, Z.W. Kundzewicz, D.P. Lettenmaier, and R.J. Stouffer Stationarity is dead: Whither water management? Science, 319(5863), "NARCCAP: The North American Regional Climate Change Assessment Program." NARCCAP: The North American Regional Climate Change Assessment Program. University Corporation for Atmospheric Research (UCAR), Web. 20