Guest blog by: Madhusoodhanan C.G. and Sreeja K.G
The state of Kerala experienced extreme precipitation events during the 2018 South West monsoon period with multiple episodes culminating in devastating floods across the state during 14th-18th August 2018. This year, with an early onset of monsoons that dovetailed with strong summer showers, the state received about 41% excess rainfall (2394 mm against the normal of 1700 mm) during the period June 1st to August 22nd . Almost all of its reservoirs were near full storage by mid-July.
The heavy downpour and the uncontrolled opening of the spillway gates of almost all reservoirs that inundated huge stretches of river banks and floodplains, along with massive landslides across the Western Ghats affected more than 1.5 million people, with close to 500 human casualties, immense losses to property, livelihoods and resource security apart from the extensive damage to forests, wildlife and biodiversity. Maximum destruction was observed along the rivers of Periyar, Chalakudy and Pamba, all having multiple dams on their tributaries. The debate is still on as to the various reasons, both manmade and natural, behind the floods and the resultant wide-ranging casualties [2,3,4,5,6]. Meanwhile things have taken a rather unexpected turn in the flood ravaged state.
Continue reading “Can floods lead to drought? After the flood, severe drought looming over Kerala”
Central Water Commission is the only agency doing flood forecasting in India. As per CWC’s Flood Forecasting website[i] the Data Flow Map has information about 226 Flood Forecast Sites in the country comprising of 166 Level Forecast Sites and 60 Inflow Forecast Sites. It also monitors 700 Flood sites, information made available through List Based Exploration and Hydrograph View, but no flood forecasting is done for these sites.
In order to better understand the CWC’s flood monitoring and forecasting work, in this article, we have given an overview of CWC’s flood forecasting and monitoring sites in South India. It includes state wise list of CWC’s Level Forecast, Inflow Forecast and level monitoring sites in South India. Similar report has been published for North India[ii] and North East India[iii] and East India[iv].
Tamil Nadu There are 3 Level Forecasting, 48 Level Monitoring and 14 Inflow Forecasting sites in Tamil Nadu State. Out of total 65 sites, 19 Level Monitoring and 2 Inflow Forecasting sites are inactive. MWL information is given only for 1 Inflow Forecasting site out of 14. IRRUKKANKUDI, Sathanur and Gomukhi sites are repeated with incomplete information. Out of 48, HFL figure and date is not provided for 25 Level Monitoring sites.
Continue reading “SOUTH INDIA Overview of CWC Flood Forecasting Sites”
About Kerala Rivers
Of Kerala‘s 44 rivers, 41 flow westwards and the rest towards east. The basin area of major rivers is located within the Western Ghats, a global biodiversity hotspot, while some other northern rivers originate in laterite hills. The short length of the rivers coupled with very high population density (over 30 million people living in a land area of 38,000 sq km) creates high dependency on water and the rivers‘ susceptibility towards environmental onslaughts.
In the six major rivers featured in the Status Report, we discuss biodiversity in riparian upper catchments and low lying wetlands. Overall, the southern Western Ghats region with catchments including many of the major riers of Kerala, Karnataka and Tamil Nadu has the highest freshwater species richness (260–312 species) and endemism (103–129 species), with particularly unique diversity of fish in Chalakudy and Periyar rivers. In rivers like Bharatapuzha, of the 6000 odd sq km catchment, a mere 100 sq km has intact forests in the catchment of Kunthipuzha, the lifeline of the river‘s summer flows. The Vembanad-Kol wetland, the largest estuarine system in India, is fed by 10 rivers. It supports diverse livelihoods – below sea level paddy farming, fishing, coir retting, to name a few. The wetlands offer flood protection for thickly-populated coastal areas and contributes to groundwater recharge.
Continue reading “Kerala Rivers Profile”