Trends in hydro-meteorological variables in the Brahmaputra basin in India and their impact on flood events

摘要

The Brahmaputra River basin in India has an area of 1.94 × 10~5 km!2. Floods are almost an annual feature in the basin, with variable magnitudes and frequencies. The annual rainfall variability index (RVI), monthly evaporation variability index and monthly maximum temperature variability index range from -1.77 to +1.85, -0.892 to +2.11 and -0.185 to +0.115, respectively. A negative relationship was found between the difference of monthly mean maximum and minimum temperature and rainfall, with gradient of up to -54.52 mm per °C. To study hydro-meteorological variables, a long-term- multidisciplinary study has been in progress since 1983. Evaporation was relatively less during high rainfall months, resulting in higher runoff generation inducing floods.