Using remote sensing techniques to evaluate lining efficacy of watercourses

However, studies assessing the efficacy of such lining are few and have depended mainly on a few sample watercourses supported by limited water measurement and agricultural data, and their results are not conclusive. Satellite Remote Sensing (SRS) is seen as a cost-effective evaluation tool in view of its large area of coverage, which is synoptic and repetitive. The analysis of multi-year satellite data has made it possible to evaluate the lining efficacy of about 30 watercourses located in the fresh, marginal, and saline groundwater zones of the Bhakra canal command in Haryana, India. The lined watercourses, together with concomitant groundwater development and use, have sustained tail- to-head uniformity of water distribution even after 20 years of lining. The SRS technique can be used as a stand-alone tool in an environment where only small amounts of groundwater supplies are used to support surface water supplies. In areas with substantial groundwater supplies, isolation of lining efficacy will require additional data on groundwater support. The SRS technique is particularly useful as a screening tool to identify problem watercourses where field verification data can be collected for cost-effective and quick evaluation of watercourse lining. The cost of using this technique works out to only US$0.17 per hectare of the area served by the watercourses. This cost is based on the 1996 cost of satellite images, covering a geographic area of about 225 square km. (Author abstract, modified)