A GIS for irrigation management

Abstract

This work describes the development, operational functionalities and spatial modeling applications of a Geographic Information Systems (GIS)-based irrigation management system, to be used by irrigation consortia and local governmental institutions. The system provides tools for the exploration of spatially-referenced databases relevant for irrigation and the evaluation of irrigation scenarios under different soil, climatic and management conditions. The irrigation water management system makes use of ArcView GIS and the Avenue programming language for customization of GIS applications and design of new tools for modeling irrigation water requirements and identifying of areas with water deficit. Irrigation requirements can be estimated taking into account different scenarios of cropping pattern, climatic conditions (from dry to wet year), applied irrigation method, volume of water available for irrigation and hydraulic characteristics of the water distribution system. The irrigation water management system runs on different scales of both irrigation (from irrigation field to irrigation consortia) and administrative (from municipality to region) units. The integration of spatial climatic and soil data is based on the “false-raster” format, a vector layer composed of regular square grid cells. The size of simulation units is a function of the surface area under consideration which means that the exploration of GIS database and development of irrigation scenarios provide more detailed data at field and municipality scale and less number of information at consortia and regional scales. An example of operational functionality of the GIS-based irrigation water management system is given for the Apulia region, in Southern Italy.