HILL TORRENTS WATER MANAGEMENT USING GEOINFORMATICS

Abstract

Efficient management of floodwater and its application for agricultural purposes can be tackled by hydraulic structures. These structures, in context to spate irrigation are categorized as check dams (reservoirs), diversion, distribution and field structures. The key focus is to demarcate the potential catchments in spate irrigation system and to identify the site for a dam in the catchment area of the Vehowa hill torrent using tools of geoinformatics. The feasibility analysis of the dam has been resolute using the topographic features ( digital elevation model and topographic sheets). The digitized irrigation network to locate potential sites for field structures is proved as a better tool. The output of results has been integrated in the geo-database, for the rationale of future development projects, aiming to bring improvement in the agricultural system, as a second objective of this research study. The study area consists of two components i.e. regional level study area and micro level study area. In the regional level study area, the potential catchments are demarcated whereas in detailed study area a dam site is identified. The micro level study area is selected in the district of Dera Ghazi Khan naming "Vehowa hill torrent". The catchment of this area extends at adjacent three districts. The command area, irrigated by spate irrigation and Vehowa River, is demarcated on high resolution satellite imagery (Spot imagery, 2.5 m resolution). Spate irrigation systems differ considerably from surface and groundwater irrigation systems. In the controlled irrigation systems, flows are normally according to the design parameters, whereas in spate irrigation systems flows fluctuate widely in space and time. To enhance the efficiency of this system, spate hydraulic structures play an important role. However, the sustainability of these structures depends on the suitable structure's site and its design. This study provides procedural approach to explore the potential sites for spate hydraulic structure.