Search

Due to recent rainfall extremes and tropical cyclones that form over the Bay of Bengal during the pre- and post-monsoon seasons, the Nagavali and Vamsadhara basins in India experience frequent floods, causing significant loss of human life and damage to agricultural lands and infrastructure. This study provides an integrated hydrologic and hydraulic modeling system that is based on the Soil and Water Assessment Tool model and the 2-Dimensional Hydrological Engineering Centre-River Analysis System, which simulates floods using Global Forecasting System rainfall forecasts with a 48-h lead time. The integrated model was used to simulate the streamflow, flood area extent, and depth for the historical flood events (i.e., 1991–2018) with peak discharges of 1200 m3/s in the Nagavali basin and 1360 m3/s in the Vamsadhara basin. The integrated model predicted flood inundation depths that were in good agreement with observed inundation depths provided by the Central Water Commission. The inundation maps generated by the integrated modeling system with a 48-h lead time for tropical cyclone Titli demonstrated an accuracy of more than 75%. The insights gained from this study will help the public and government agencies make better decisions and deal with floods. [ABSTRACT FROM AUTHOR]

The practice of shifting cultivation has been increased due to an increase in population and is affecting the global issues, such as land use/land cover, biodiversity loss and environmental degradation, etc. In this study, the area of shifting cultivation lands in 1996, 2001, 2006, 2011, and 2016 were analyzed in West Karbi Anglong district of Assam by using time series imagery of Landsat Thematic Mapper, Enhanced Thematic Mapper Plus, and Operational Land Imagery with 30 m. The results showed that, from 1996 to 2016 the area under shifting cultivation has been increased from 149 to 215 km2, and was mainly distributed at elevations of 250-500 and 500-750 m and on slopes of < 10°, 10°-20° and 20°-30°. The area under permanent cultivation was increased from 10 to 72 km2. [ABSTRACT FROM AUTHOR]