Volume No. 11 Issue No.: 3 Page No.: 608-616 January-March 2017
REMOTE SENSING AND GIS-BASED INTEGRATION OF GROUND WATER LEVEL DYNAMICS AND SOIL SALINITY COMPARISON OF WONJI SUGAR CANE IRRIGATION FARM, ETHIOPIA
Asfaw E., Suryabhagavan K. V.*1 and Mekuria A.2
1. School of Earth Sciences, Addis Ababa University, Addis Ababa (ETHIOPIA)
2. Center for Environmental Science, Addis Ababa University, Addis Ababa (ETHIOPIA)
Received on : December 12, 2016
Rising saline shallow groundwater and associated soil salinization problems are widespread especially in arid and semiarid areas. There are numerous studies on groundwater-associated salinity, but more information is required on the effects of groundwater dynamics on soil salinization. Frequent irrigation with small quantities of water is effective to reduce soil surface salt accumulation induced by saline shallow groundwater. Landsat image of 1985, 1995 and 2012 were analyzed for temporal and spatial detection of salt affected areas in Wonji sugarcane plantation and the risk of soil salinity was evaluated. Spatial overlay analysis between salt affected areas and canal and water table were made to assess spatial distribution as well as relationships with these features. The result shows that about 65.9% of the areas were non-saline in 1985, which gradually decreased to 44.9% in 2012. Out of this 4312 ha under non-salinity in 1985, only 2940 ha remained as non-saline, whereas the rest 1372 ha was transformed to slightly saline, moderately saline and waterlogged with a large area converted to slightly saline. Large area change was observed in the slightly and moderately saline soil categories. Moderately saline soil was about 11.4% in 1985, which was increased to 14.4% and 15.6% in 1995 and 2012, respectively. Areas highly vulnerable to salinization were related to the ground water level that normally occurred on the lacustrine sediment in this sugarcane plantation.
Keywords : Ground water level, Landsat, Salinity index, Salt affected area