Published Paper Details:

This paper conducts a comprehensive analysis of rainfall patterns and their hydrological implications in Kolkata, West Bengal, India, spanning the monsoon period from 2011 to 2020. The study employs data from the Centre of Hydro technology and Remote Sensing (CHRS) and the India Water Resources Information System (India-WRIS). Advanced geospatial tools, including ArcGIS, ArcMap, and HEC-HMS, are utilized, coupled with BHUVAN's land-use and land-cover data, and the curve number from TR-55 by the USDA Soil Conservation Service (SCS), now Natural Resources Conservation Service (NRCS), serving as a basis for estimating runoff potential based on land use and soil type. The study focuses on the analysis of rainfall variability, identification of precipitation trends, and assessment of hydrological responses to rainfall events. Additionally, HEC-HMS is employed for hydrological modeling, simulating runoff and streamflow dynamics under varying rainfall scenarios. The findings reveal that the peak discharge in most subbasins and reaches around Kolkata occurred in 2014, with some experiencing peak discharge in 2015. During this period, peak discharge reached approximately 1000 - 1300 m3/s in Reaches 21, 18, 31, 30, 28, 27 and 26 (generated in HEC-HMS) with a recorded rainfall of 374.12 mm in July 2014 in the city and also the city's basin registered a peak discharge rate of 50.3 m3/s in the same time. Analyzing recent trends, it is observed that the city typically receives rainfall ranging between 300 mm to 400 mm, suggesting a consistent peak discharge of maximum of 50m3/s during each monsoon season.