Project Number: 6206-13610-006-26
Project Type: Specific Cooperative Agreement

Start Date: Jun 20, 2007
End Date: Jun 19, 2009

Objective:
The main purpose of this project is to develop improved soil, water, and nutrient management practices for irrigated crops to promote efficient resource use and water quality protection in the U.S. and Pakistan. This will be achieved through proper resource assessment, development of improved irrigation practices, appropriate drainage design, and better land practices. The project will also look to reduce pollutant discharge from irrigated agriculture and preserve soil and water quality while conserving shallow groundwater in Pakistan. The impact of new irrigation management strategies will be assessed at the field and watershed scale.

Approach:
SWAT will be used to identify areas in Pakistan with similar soil and water compositions to direct specific management practices. This component of the project requires training Pakistani scientists to use the SWAT/GIS Interface model. Arrangements will be made to train scientists, selected by ARS and Pakistani counterparts, to become proficient in using the Digital Elevation Model (DEM), delineation of watersheds, and the formation of databases containing land use, soil type, and weather information needed for SWAT predictions. Global DEM information is currently available for GIS map development of watersheds in Pakistan. Reliable weather parameters such as daily precipitation, mininum and maximum air temperature, humidity, solar radiation, and evapotranspiration are critical input requirements for SWAT. The general approach for applying the SWAT model is: 1) to develop a DEM of the watershed; 2) Use of DEM, for delineation of watershed boundaries, designate the main watershed outlets and subdivision into subwatersheds; 3) Delineation of Hydrological Response Units (HRUs) on the bases numbers of soil types and land uses, in each sub watershed; and 4) SWAT calibration and validation in selected watershed for hydrology and management practices and water quality. Application of SWAT model using these newly developed databases will allow for direct comparison in measurable environmental endpoints of water quality and quantity with and without new agricultural management practices as well as erosion control and aquifer recharge measures within the selected watershed. The model will be applied in irrigated areas of the Indus Basin for study of all these components required for enhancement of water productivity to meet the growing food requirement of country. This data generated by the model in Pakistan will be used by ARS scientists to further expand and validate SWAT using the new parameters.