GEO-SYSTEM BASED AQUIFER DEVELOPMENT THROUGH ARTIFICIAL RECHARGE IN PUDUKKOTTAI DISTRICT, TAMIL NADU, INDIA
International Journal of Water Research
Water has become a scarce resource all the World. Water resources of Earth can be classified as surface water and groundwater in which groundwater is the main source for the drinking, domestic and agriculture. The Pudukkottai district is one of the chronic drought prone areas in Tamil Nadu. But, at the same time, the district is pitted with over 5,400 tanks/water bodies widely distributed throughout in general and clustered more in Vellar delta in particular, as the interlobel depressions have
... l depressions have provided basic depressions for the surface water to accumulate. However, these surface water bodies are heavily silted. In Pudukkottai district, there are three divergent aquifer systems, hard rock aquifer system in the western, sedimentary aquifer system constituted by the Tertiary Sandstone (Cuddalore Sandstone) in the central and quaternary aquifer system constituted by fluvial, fluvio-marine and marine systems in the eastern parts of the district. Though, a hierarchy of data is available with many agencies viz: monthly water level data for the past nearly three decades, borehole lithology, geophysical resistivity data, etc., not much of holistic and comprehensive studies have been done especially using the virtues available with Remote Sensing technology involving various Image Processing techniques and GIS using 3D visualization to understand the subsurface geology, aquifer parameters, etc. which could provide vital information for water management. So in the present study, these advanced tools were utilized deservingly to understand water resources for further effective planning. After generating the above buffered GIS layers, overlay functions were executed and the areas of coincidence of more than 3 to 5 variables were buffered out as suitable area for artificial recharge and most of the area fell under this category. The subsurface/groundwater is a very important resource having direct bearing over various developmental planning. The occurrence and the mobility of groundwater vary from aquifer system to aquifer system. In hard crystalline rocks, it is controlled predominantly by the fracture systems and their dynamics. In contrast, in layered sedimentary formations, the groundwater and its behaviour is controlled by primary porosity, type of layering, the rhythmicity of the layers, their compaction etc. and accordingly groundwater occurs in artesian/sub artesian/ confined/semi confined conditions etc. In Quaternary formations, again groundwater availability and the aquifer performance depends on primary porosity and the type/nature of layering. But, in the case of Quaternaries, the morphology and dimension of the layering will be very small when compared to the sedimentary formations, like Tertiary Sandstones and accordingly the groundwater behaviour will vary. Further, as it is a hidden resource, detailed understanding is essential before framing any developmental strategies for groundwater development. So, detailed Geomatics based studies were carried out in understanding the suitable technique in the particular artificial recharge zones.