Flood effects on soil quality in the southern and central foothills of Pathanamthitta district of Kerala

Abstract

A study was undertaken to assess the quality of post-flood soils in AEU 12 of Pathanamthitta district and develop GIS maps depicting the spatial distribution of soil quality. A minimum data set of indicators for assessing soil quality was set up from seventeen selected physical, chemical and biological parameters analysed using principal component analysis. Six principal components with eigen value greater than 1 were selected and nine parameters with higher factor loadings were retained for the minimum data set viz., soil pH, available Mg, sand per cent, available K, available P, available B, acid phosphatase activity and silt per cent. A weighted soil quality index was formulated after assigning appropriate weights and scores to the selected indicators. Mean soil quality was found to be higher in areas with sediment deposition after the floods in the Pampa basin. Soil quality was observed to be medium for majority of the samples (54.7%) analysed.