摘要：The suitability of groundwater for irrigation uses was assessed in Cumbum valley covering a total area ofabout 1485.62 km 2 . The study area is located in Uttamapalyam taluk and a small part of Periyakulam Talukof Madurai district, Tamil Nadu. Fifty five groundwater samples were collected from open wells in the variouslocations in the study area. The samples were analyzed for major cations and anions and other parametersviz., EC, Kelley’s ratio, SAR values, Mg-hazards, HCO 3 and RSC have been worked out to know the suitabilityof the groundwater for irrigational purpose. Piper trilinear diagram interpretations were made to know thechemical type of the groundwaters. It reveals that the subsurface water is alkaline earth (Ca+Mg) thenalkalies (Na+K) type. The groundwater samples fall under class-I of Doneen’s classification and use in goodto permissible zone according to Wilcox classification. According to the SAR values plotted in the USSLStaff diagram, most of the groundwater samples belong to C 3 -S 1 (41.82%) class indicating that the groundwatercould be used for all types of crops on soils of medium to high permeability.
