By: Aaftab Ahmad
Irrigation suffices crop water requirements for optimum crop production in arid regions. It consumes about 72% of available fresh water in the world while contributing 40% of the world food supply. As the global population increasing rapidly and the available fresh water per capita is decreasing, so scarce natural resources (such as land and water) must be used wisely. Development of an optimum water supply and on farm distribution system for irrigated lands will increase water use efficiency and will reduce water supply cost. Different techniques of GIS have been used in irrigated agriculture to increase water use efficiency and yield in farm lands. In this study, the combination of digital elevation modelling (DEM) and least cost path analysis (LCPA) was used to develop an optimum irrigation scheme. Digital elevation model was used to generate the complete topography of the irrigated farms to determine water flow path from Haddah sewerage water treatment plant (Makah Province Saudi Arabia) to farm fields(date palm) near Bahrah town (in downstream of Wadi Fatima, Makkah province). Least-cost path analysis was used to find cheapest water supply path between source and the irrigated lands to decrease construction cost and water losses. The combination of least-cost path analysis and digital elevation model in water allocation for irrigated lands was efficient and cost effective as compared to the existing unlined water allocation channel. Construction and material cost was more as compared to unlined channel but it saved more than 50% water for development of an optimum irrigation scheme.
Aaftab Ahmad, Burhan A. M Niyazi, Chaabani Anis
Department of Hydrology and Water Resources Management, King Abdul Aziz University, Jeddah, Saudi Arabia
Key words: Irrigation, GIS, DEM, LCPA, Water resources.