Correlation Analysis of Land Use Land Cover and Nutrient Concentration in Upper Lake Bhopal Using Remote Sensing and Gis Techniques

Abstract

To control the quality of surface water, nonpoint source pollution requires special attention. Understanding the critical buffer zone is crucial for managing watersheds. ASTER DEM, a Landsat image, and the annual average of phosphate and nitrate concentration were used in this study. ERDAS Imagine software was used to classify the image into four land cover classes. Arc GIS software was used to create buffer zones at radial distances of 100, 200, 500, 1000, and 2000 meters from the stream's discharge point into the lake. The class area (CA), class level percentage of like adjacency, Landscape level Percentage of like adjacencies, Shannon’s Diversity Index (SHDI), Shannon’s Evenness Index (SHEI) was measured using FRAGSTAT software. The Nutrient concentration at each discharge point was predicted using the best fitted technique after comparing six spatial interpolation methods. Phosphate and nitrate concentration and land use indices were correlated using statistical analysis software SPSS. The 500-meter buffer zone's agricultural and barren land areas were found to have the strongest correlation with phosphate concentration. For both nitrate and phosphate, the correlation between like adjacency percentage and nutrient concentrations was weak and statistically non-significant for all buffer distances (p > 0.05), suggesting that this metric alone has little explanatory power. A strong scale dependent correlation found between nitrate concentration and landscape fragmentation on the other hand phosphate concentration did not show any significant correlations at any buffer distance. Correlation between Shannon's Diversity Index (SHDI) and nutrient concentration was scale dependant. Impact of built up land on both nutrients was found minimum.