Development of a GIS based application for selection of villages for sodic land reclamation
EC and RSC data:
The contour maps of Electrical Conductivity and Residual Sodium Carbonate (in groundwater) were reclassified each into two categories. In EC map the area having EC value less than or equal to 2dS/m in class1 and the rest in class2 (>2.0 dS/m). Similarly the RSC map was assigned class1 for the area falling in RSC value less than or equal to 1.5 meq/l and the rest in class2. These two EC & RSC layers were integrated with village boundary layer separately. The two layers thus obtained were assigned rank and weight values for each village depending on their maximum area falling in rank1 or rank2. Finally, each village has been assigned a weightage value (product of rank and multiplication factor).  All the polygons with EC less than or equal to 2dS/m and polygons with EC greater than 2 dS/m were merged to obtain EC layer with two ranges. This layer was integrated with village boundary layer through union. From the union coverage assigned, all the villages that intersect with EC polygon less than or equal to 2 dS/m were assigned rank1 and rest were assigned rank4. The selection thus made is shown in table2.  |