KERALA FLOOD

        

                 Mining and dams exacerbated devastating Kerala floods  

             Torrential rains pounded southwest India in August, triggering devastating floods in the state of Kerala that have so far killed at least 483 people and forced hundreds of thousands from their homes. The monsoon rains have been heavier than usual, but scientists say that outdated dam-management systems and increasing mining and development in the Western Ghats mountain range — a biodiversity hotspot that ecologists are trying to conserve — exacerbated the disaster.

        Kerala received 758.6 millimeters of rain between 1 and 19 August — 2.6 times the average for that time of year. The unusually heavy downpours caused rivers to overflow. Many of the fatalities were a result of landslides in rural areas, triggered by the massive downpours. Authorities say the floods are the state’s most damaging in 100 years.

           A contributing factor is that after the heavy rain, authorities began to release water from several of the state’s 44 dams, where reservoirs were close to overflowing. The neighbouring state of Tamil Nadu also purged water from its over-filled Mullaperiyar dam, which wreaked yet more havoc downstream in Kerala.

       Scientists say state governments often allow reservoirs to fill completely early in the monsoon season, and do not release water slowly at regular intervals to prevent overfilling later in the season. “India’s reservoir management is unscientific,” says meteorologist Madhavan Nair Rajeevan, secretary of India’s ministry of Earth sciences, which oversees the country’s meteorological institutes. Computer models and meteorological forecasts are used in Europe and the United States to predict the rate at which water flows into reservoirs and how much water needs to be stored — but few authorities in India use such systems, says Rajeevan. He suggests that prediction systems should be introduced across India.