Assessment of Water Allocations using Remote Sensing and GIS Modeling for Indus Basin, Pakistan

Funded by the United States Agency for International Development (USAID) and implemented by the International Food Policy Research Institute (IFPRI), the PSSP provides analysis in four areas: agricultural production and productivity; water management and irrigation; macroeconomics, markets and trade; and poverty reduction and safety nets. The PSSP is undertaken with guidance from the Government of Pakistan through the federal Planning Commission and a National Advisory Committee, and in collaboration with Innovative Development Strategies (Pvt) Ltd. (IDS), Islamabad, and other development partners. The Competitive Grants Program (CGP) is a component of the PSSP that provides support to Pakistani researchers on topics addressing the PSSP and related objectives. This working paper is an output from a CGP grant awarded in February 2013. The study focuses on the assessment of water allocations using remote sensing and GIS modeling for the Indus Basin, Pakistan. The analysis shows that the area affected by soil salinity (strongly saline) in the basin has increased by 2.5% during the last five years. Crop water use and crop yield are also variable for different canal commands with different water allowances (WAs). The average crop water use is 342 mm and 516 mm for Rabi and Kharif season, respectively. The variation in wheat yield ranged between 5,280 to 423 kg ha-1, while rice yield varied from 3,312 to 1,925 kg ha-1. Water productivity of wheat is also variable with a maximum of 1.34 kg m-3 and minimum estimated at less than 0.2 kg m-3. The mean, median, and standard deviation are estimated at 0.66, 0.59, and 0.31 kg m-3, respectively. The water productivity of rice shows maximum of 1.12 kg m-3 and minimum estimated at less than 0.4 kg m-3. The mean, median, and standard deviation are estimated at 0.59, 0.57, and 0.17 kg m-3, respectively. The cost incurred to irrigate one acre of land with groundwater is around Rs. 4,000 and Rs. 9,000 for wheat and rice, respectively, while canal water costs are only Rs. 50 and Rs. 85. The study suggests several rationalization policies based on cost and water productivity to reduce the cost gap between the two irrigation sources. The analysis highlights the importance of efficient water use and the need for policies to promote the use of canal water over groundwater. The study also emphasizes the need for further research on the impact of soil salinity on crop yields and water productivity. The study area is the Indus Basin Irrigation System, which is one of the largest irrigation systems in the world. The basin covers an area of approximately 1 million hectares and is home to a diverse range of crops, including wheat, rice, and cotton. The study focuses on two representative canal commands, the Lower Chenab Canal and the Muzaffargarh Canal, which are located in the Punjab province of Pakistan. The study uses remote sensing and GIS modeling to estimate crop water use and corresponding water productivity for each canal command area. The analysis is based on three years of data, from 2009 to 2011, and uses a range of satellite imagery and ground-based data sources. The study also uses a spatial database to evaluate and create maps of water productivity in the different canal commands. The study highlights the importance of efficient water use in the Indus Basin Irrigation System and the need for policies to promote the use of canal water over groundwater. The analysis also emphasizes the need for further research on the impact of soil salinity on crop yields and water productivity.