Mapping of Soil Erosion Zones of Meghadrigedda Catchment, Visakhapatnam, India for Conservation <br/>—A Geospatial Approach

Meghadrigedda, a non-perennial drainage system is one of the major water resources of Vishakhapatnam city located in the northern coastal region of Andhra Pradesh, India. It traverses through the hilly terrain of Eastern GhatMobile Belt (EGMB) characterized by khondalitic rock formations. Excessive siltation scenario aggravated due to soil erosion in its catchment is threatening the very existence of Meghadrigedda reservoir. In order to assess the intensity of soil erosion as well as silt deposition in the reservoir, an integrated study has been undertaken which takes into consideration various topographic, morphological, soil, and land use/land cover characteristics of the basin. The study aims at identification and mapping of erosion prone zones with respect to silt deposition using remote sensing and GIS techniques.Alteration in human induced land use practices in its catchment due to rapid growth in population, urbanization and industrialization are found to be of prime reasons for various forms of erosion. The study has noticed that various forms of erosion like sheet, gully and stream erosion are responsible for the siltation at large scale which is causing reduction of its designed storage capacity by 40%. Various sub-watersheds of the basin have been prioritized on the basis of erosion intensity for suggesting various mitigation measures like check-dam construction, afforestation etc. to protect the reservoir from the silting problem.

Hydrogeomorphology, NDWI and, NDVI of the Meghadrigedda Sub-Watersheds for Optimal Utilization of Resources, Visakhapatnam District, Andhra Pradesh-India Using Landsat Data 2000 and sentinel Data 2020

With global warming and over-exploitation of water resources due to population explosion and related issues, numerous studies are being carried around the world in an effort to reinstate a state of a balanced life between the existing water resources and their utilization by human beings. Keeping in view, a watershed of 366 sq.km on 1:50,000 scale 65O/1 SOI map surrounding the Meghadrigedda reservoir in Visakhapatnam district of Andhra Pradesh, India has been taken up for the study. The watershed has been delineated into nine sub-watersheds and hydrogeomorphology, drainage, drainage density, slope, NDVI and NDWI of the study area has been carried out using Landsat data 2010 and Sentinel data 2020 in ARCGIS 10.0 environment. All the villages in the catchment greatly depend on groundwater for irrigation, drinking as well as personal utilization. Change detection has been carried on to display the decline in surface water and ground water due to increased concentration of built-up land, siltation of ponds as well as decrease in the number of ponds. The watershed is experiencing large scale anthropogenic activities. The government must curb built-up activities and desilt the ponds to sustain the monsoon water, facilitating more recharge. The results of the study can serve as a basis for planning as well as for the development of a sustainable basin area.