Hydronomic Zones for Developing Basin Water Conservation Strategies

Abstract

"In this report, the concept and procedures of hydronomic (hydro water + nomus management) zones are introduced. A set of six hydronomic zones are developed and defined based on key differences between reaches or areas of river basins. These are the: Water Source Zone, Natural Recapture Zone, Regulated Recapture Zone, Stagnation Zone, Final Use Zone, and Environmentally Sensitive Zone. The zones are defined based on similar hydrological, geological and topographical conditions and the fate of water outflow from the zone. In addition, two conditions are defined which influence how water is managed: whether or not there is appreciable salinity or pollution loading; and whether or not groundwater that can be used for utilization or storage is present. Generic strategies for irrigation for four water management areas, the Natural Recapture, Regulated Recapture, Final Use, and Stagnation Zones, are presented. The Water Source Zone and Environmentally Sensitive Zone are discussed in terms of their overall significance in basin water use and management.

"Hydronomic zones allow us to define, characterize, and develop management strategies for areas with similar characteristics. The concept of zoning is demonstrated in four agricultural areas representing a wide variety of situations: the Kirindi Oya basin in Sri Lanka, Egypts Nile basin, the Bhakra command area in Haryana, India and the Gediz basin in Turkey. We were readily able to apply the zones within each basin and suggest water management strategies for each zone. Hydronomic zones hold potential as a tool to help us better understand complex water interactions within river basins, to isolate similar areas within basins and to help us develop sets of water management strategies better tailored to different conditions within basins."