Water Quality Assessment by Using Landsat Images in Urban Wetland: A Case Study of Deepor Beel, Assam

The health of Deepor Beel in Assam has declined since the unprecedented rapid growth of the Guwahati Urban area in the past few decades. This urban water body has immense importance as it acts as a growth corridor of the different governmental projects and supports thousands of livelihoods around. To keep enduring the economic benefit and maintain the ecosystem of the lake, the lake’s health has to be kept nontoxic. Hence frequent monitoring and evaluation of the water qualityWater quality of the lake are essential. The present work attempts to analyze the water qualityWater quality of the wetland with remote sensingRemote sensing techniques by monitoring the effect of urbanizationUrbanization on Deepor Beel. To determine the current state of the water quality in Deepor Beel, statistical studies were carried out on biological (Chl-a) and physical (turbidity, TDS, conductivity, pH) indicators. Linear and non-linear regression models between water qualityWater quality parameters and reflectance of Landsat imagery were fitted based on bandBand combinations. For 2004 and 2020 two different periods the result shows, in 2020 the turbidityTurbidity and TDSTDS in Deepor Beel have increased significantly (>50%) due to the direct influx of urban sewages to the lake’s water. Adequate measures to reduce the non-point source of pollutant inflow by targeting the source areas (Waste dumping areas) near the city need to be priorities for stakeholders. Moreover, reducing the recession urbanizationUrbanization around the Deepor Beel and wetland effective management could be a key strategy for improving water qualityWater quality in the lake.