A GIS-BASED REGIONAL PLANNING TOOL FOR IRRIGATION DEMAND ASSESSMENT AND SAVINGS USING SWAT

Regional planning for irrigated agriculture requires a thorough understanding of the hydrological processes and spatial and temporal variations associated with hydrological factors such as rainfall, soils, and crops grown in different units of the region. The objective of this study was to improve the capabilities of a basin-scale hydrologic simulation model for regional planning of irrigated agriculture. In this study, a Geographical Information System (GIS) based hydrological model, Soil and Water Assessment Tool (SWAT), was configured as a regional planning tool with a canal irrigation capability for estimating irrigation demand. The tool was capable of simulating hydrological processes associated with soil-plant-water interactions and capable of capturing the spatial and temporal variability of the major factors, which are important in regional planning. The tool was applied to the irrigation districts in the Lower Rio Grande Valley in Texas. It was validated for crop evapotranspiration and canal conveyance efficiency and applied to analyzing the demand and potential water savings of alternative water conservation measures. Estimated potential water savings were 234.2, 65.9, and 194.0 Mm3 for conservation measures related to on-farm management improvements, replacing sugarcane with corn, and improving canal conveyance efficiency, respectively. Results indicated that on-farm management measures might be as beneficial as improving canal conveyance systems. The planning tool (with hydrological modeling and GIS capabilities) and estimations made would be useful for regional planners and irrigation district managers. The tool could be used for other irrigation systems as well.

[1]  Prabhata K. Swamee,et al.  Design of Minimum Seepage Loss Canal Sections , 2001 .

[2]  J. Doorenbos,et al.  Guidelines for predicting crop water requirements , 1977 .

[3]  Raghavan Srinivasan,et al.  Hydrologic Modelling of the United States with the Soil and Water Assessment Tool , 1998 .

[4]  George H. Hargreaves,et al.  Agricultural Benefits for Senegal River Basin , 1985 .

[5]  C. Santhi,et al.  A new planning model for canal scheduling of rotational irrigation , 2000 .

[6]  John R. Williams,et al.  EPIC-erosion/productivity impact calculator: 1. Model documentation. , 1990 .

[7]  G. P. Merkley,et al.  Decision Support Model for Irrigation Water Management , 1997 .

[8]  Raghavan Srinivasan,et al.  CONTINENTAL SCALE SIMULATION OF THE HYDROLOGIC BALANCE 1 , 1999 .

[9]  John R. Williams,et al.  LARGE AREA HYDROLOGIC MODELING AND ASSESSMENT PART I: MODEL DEVELOPMENT 1 , 1998 .

[10]  J. Monteith.  Evaporation and environment. , 1965, Symposia of the Society for Experimental Biology.

[11]  R. Allen,et al.  Evapotranspiration and Irrigation Water Requirements , 1990 .

[12]  Raghavan Srinivasan,et al.  Integration of Watershed Tools and Swat Model Into Basins , 2002 .

[13]  C. Priestley,et al.  On the Assessment of Surface Heat Flux and Evaporation Using Large-Scale Parameters , 1972 .

[14]  G. Fipps.  Potential Water Savings in Irrigated Agriculture for the Rio Grande Planning Region (Region M) , 2005 .

[15]  K. R. Rushton,et al.  Water losses from irrigation canals , 1987 .

[16]  C. Stöckle,et al.  Simulation of Supplemental Irrigation from On‐Farm Ponds , 1991 .

[17]  Wim G.M. Bastiaanssen,et al.  Irrigation Performance using Hydrological and Remote Sensing Modeling , 2002 .