Sustainable Ground Water Management based on Morphometric Analysis using Integrated Remote Sensing techniques and GIS approach of Kodayar basin, Southern India

Abstract

Morphometric analysis furnishes a prolific hydro-geomorphological outlook in systematic understanding of a drainage basin. The occurrence of groundwater is highly controlled by various morphometric parameters, which can be utilized to sustainably manage the groundwater resources of a basin by identifying the potential recharge areas. In the present study, remote sensing data and GIS tools are employed to delineate the Kodayar basin on which morphometric analysis was carried out and accordingly, a groundwater management plan has been proposed. The Kodayar basin has an area of 1696.12 km² and is designated a fourth order basin. As per ground water resource estimation, 2020, annual extractable groundwater resource is 25439.53 ham with net ground water availability for future use is 20955.83 ham. Geologically, the area comprises of quaternary coastal sands in the coastal belt and archean hard rock in the northern & western parts. Excessive groundwater withdrawal from the wells tapping the coastal aquifers creates an imbalance in the aquifer system and may lead to salt water intrusion in the fresh water pocket in peak summer. The mean bifurcation ratio of the basin is 4.80 and total length of streams of all orders is 515.34 km. The circulatory ratio and elongation ratio of the basin is 0.79 and 0.77 respectively. The drainage pattern is dendritic which is controlled by emplacement of batholithic plutons and subsequent tectonic activity in the geological past. The drainage density of the area is less, i.e. 0.30 which shows that the area has low runoff and high infiltration. The basin has moderate relief indicating moderate runoff & erosion processes. High value of elongation ratio indicates moderate relief & moderate slope. Factors like infiltration rate, slope and relief play a major role in groundwater recharge and these factors are taken into consideration for proposing the artificial recharge structures. This study is helpful in watershed management and wise utilization of water resources.