ABSTRACT
Monitoring drought and estimating soil degradation in association is becoming a mandate for planning purposes in arid and semi-arid areas. The present study highlights the spatio-temporal distribution of drought and soil erosion problems in Puruliya district, a semi-arid district of the western part of West Bengal, India. The drought frequency of the area was assessed from the time-series Moderate Resolution Imaging Spectroradiometer (MODIS) data for the period from 2000 to 2013. The frequency of drought- affected months was computed, and the mean frequency was estimated to be 7 months. Similarly, the potential soil erosion was assessed using the Revised Universal Soil Loss Equation (RUSLE). The district was categorized into five erosion potential zones. It was observed that the very high and severe erosion risk zones cover more than 25% of the total area. The average erosion of the district was estimated to be 76 tonnes/ha/year. The problem of erosion is worse in agricultural areas and open fields. The slope-length and steepness (LS) factor was found to be the major erosion controlling factor. An effort was also made to identify the possible interrelation between the soil erosion and drought frequency for better monitoring and policy decision making. It was found that areas with very high to severe soil erosion problems experienced more than 12 months of drought frequency in that period. In the context of the contemporary trend of applying open source software and free data, the present study was conducted using Q-GIS and data freely available from United States Geological Survey (USGS), National Remote Sensing Centre (NRSC), etc.
