Mapping of Center-Pivot Irrigation Systems in Sudan Using Remote Sensing and GIS Techniques: A Case Study of the Al Waha Project

الملخص

This paper presents the mapping of center-pivot irrigation systems in Sudan using remote sensing and GIS techniques to support national and regional agricultural auditing, water and energy use management, and policy development. Landsat-8 imagery with 15 m spatial resolution was employed to identify and map individual pivots. A total of 1,373 active pivots covering approximately 70,078.2 ha was recorded in 2020, located in the River Nile, Northern, Khartoum, Kordofan, and Gazira states (774, 296, 248, 49, and 6 pivots, respectively). A detailed case study of a commercial agricultural project in Khartoum State documented an increase in pivots from 29 to 105 between 2009 and 2020, respectively  covering about 5,972 ha. The calculated map accuracy was 96.4% and NDVI was demonstrated  to delineate planted area and evaluate within-pivot biomass. Map layers of irrigation networks, soil types, and crop distribution were prepared, showing that the project is irrigated by Blue Nile pump stations and canals; soils are classified mainly as loam and sandy-clay-loam, and Rhodes, alfalfa and corn are cultivated on 79, 20 and 6 pivots, respectively. The pivots consumed both water and energy; an estimated 3,625.83 m³/ha-year (water) and 176.7 L/ha-year (diesel) for alfalfa, while an estimated 3,429.84 m³/ha-year (water) and 167.1 L/ha-year (diesel) for Rhodes. The estimated irrigation efficiency based on CROPWAT/CLIMWAT revealed seasonal variations; alfalfa averaged ~70% (57–87%), while Rhodes averaged ~77%, peaking at ~99–100% in July–August and declining to ~49–55% in September–October. This study demonstrated the opportunity of using RS and GIS derived data to provide direct agro-informatics insights and support more efficient management of water, energy and other applications, thereby strengthening agricultural decision-making, improving productivity, and enhancing resource sustainability in Sudan.