WATER LOGGING & SOIL SALINITY IN COASTAL AREAS: ASSESSMENT AND MANAGEMENT

Abstract

The present study deals with the problem of water-logging and soil salinity in the coastal regions of Odisha. A combined approach has been adopted for this study consisting of GIS, RS and extensive field sampling. Quantification of water-logged areas has been achieved along with spatial distribution of ionic species responsible for salinization of soil and water. Identification of salt affected areas has not been possible by Remote sensing due to the spectral signatures of bare soil being masked by salt-tolerant vegetation. To overcome this limitation an extensive field sampling for both soil and water was done and detailed physicochemical analysis was done from salinity perspective. Also the results of physico-chemical analysis were transferred on GIS Platform for representation and analysis. Also, lithological details and geo-physical well logs were used to bring out the causes of the problem. Indices were also worked out to assess the suitability of water from agricultural view point. Frequent occurrence of near surface clays was commonly observed leading to increasing restriction on the sub-surface drainage and most of the villages were found to contain saline water in greater part of Ersama block. An interesting finding for the deep aquifers was that regions showing high ionic concentrations were located away from the shore line especially in the northern region. Geo-physical electrical logs and their interpretation for the Ersama block tend to support the occurrence of rather fresh water in the sandy horizon towards the south-eastern part of the Ersma block, which may be further explored in detail. From agricultural view point a temporal decline in area under paddy production was visible