Project Number: 6218-11130-005-00
Project Type: Appropriated

Start Date: Mar 11, 2012
End Date: Mar 10, 2017

Objective:
The long-term objective of this project is to develop soil and water conservation decision support information for policy makers, land managers, and producers to help identify the scope of additional conservation measures to mitigate the detrimental impacts of anticipated climate change. The Fort Cobb Reservoir watershed in west central Oklahoma is representative of the physiography of the region and was selected as the project watershed. Obj 1: Quantify the effects of past climate variations on runoff, soil erosion, sediment transport and fate, and nutrient movement for the Fort Cobb Reservoir (FCR) watershed, using available data records, reconstructed chronology of reservoir sedimentation, and computer modeling of watershed processes. 1A: Identify past climate variations; determine corresponding impacts on watershed runoff, sediment yield, and reservoir sedimentation; derive climate-flow-sediment relationships. 1B: Reconstruct chronology of watershed sediment yield from reservoir sedimentation profiles; identify sediment sources; estimate sediment yield of major erosive storm-runoff events for calibration/validation of simulation models. 1C: Identify reference land use, conservation, and climate conditions to serve as baseline for assessment of climate change scenario impacts; calibrate/validate hydrologic and erosion simulation models using data developed under subobj 1A/1B. Obj 2: Determine the potential impacts of three selected climate change scenarios on the hydrologic system and on the soil and water resources of the FCR watershed. 2A: Determine trends in annual precipitation and air temperature for 3 greenhouse gas (GHG) emission scenarios; identify changes in seasonal/monthly precipitation and temperature distribution within a year, estimate monthly precipitation and temperature statistics expected to prevail around the half century mark. 2B: Develop/evaluate spatio-temporal downscaling methods that integrate changed climate statistics into a synthetic weather generator; generate ensembles of daily weather outcomes for each GHG emission scenario that reflect the statistical characteristics of projected climate change for use in climate impact assessment in Obj 3. Obj 3: Identify soil and water conservation strategies and options that are adapted to and mitigate the detrimental impacts of climate change, and test their effectiveness at enhancing the resilience of agricultural landscapes under anticipated climatic changes. 3A: Estimate extent of soil erosion/sedimentation under 3 selected GHG emission scenarios assuming constant baseline land use and conservation conditions; identify soil conservation options/practices/coverage that mitigate soil erosion and sedimentation directly attributable to climate change; determine risk of exceeding soil erosion and sedimentation rates under climate change. 3B: Develop communication tools that synthesize information across combinations of conservation practices, conservation coverage, climate change scenario, and conservation effectiveness and help land managers select conservation options that best meet soil/water conservation goals.

Approach:
The effects of past climate variations on runoff, soil erosion, sediment transport and fate, and nutrient movement for the Fort Cobb Reservoir (FCR) watershed are quantified based on available climate, hydrology, and environmental data records, reconstructed chronology of reservoir sedimentation, and computer modeling of watershed processes. Published climate data from Global Climate Models (GCM) are used to determine trends in annual precipitation and air temperature for three greenhouse gas (GHG) emission scenarios, identify changes in seasonal and monthly precipitation and temperature distribution within a year, and estimate monthly precipitation and temperature statistics that are expected to prevail around the half century mark. Synthetic weather generation models are used to generate daily weather outcomes that reflect the statistical characteristics of the projected climate change. Soil and water conservation strategies and options that are adapted to and mitigate the detrimental impacts of climate change are identified based on simulated soil erosion and sedimentation. Selected soil conservation options, practices, and coverage are tested with regard to their effectiveness at enhancing the resilience of agricultural landscapes under anticipated climatic changes. Risk of exceeding predefined soil erosion and sedimentation rates under climate change are determined. Information across combinations of conservation practices, conservation coverage, climate change scenario, and conservation effectiveness is synthesized and communicated in a format relevant to land managers, conservationists, and producers, as well as other practitioners.