Space application for disaster mitigation

The Assam government working on a comprehensive plan to increase the holding capacity of its floodplain water bodies to divert excess water for flood mitigation is good news. The North Eastern Space Application Centre (NESAC) has already identified 206 waterbodies in 17 districts for the purpose. The ambitious project is aimed at reducing the level of floodwater of different tributaries of the Brahmaputra that flow through villages and towns on their catchments. The feasibility study will also explore if some of the tributaries can be connected to some wetlands to reduce flood levels in the rivers. This is going to be another groundbreaking space application for flood mitigation in the state. The NESAC study suggested that selected wetlands should be larger than 10 hectares in area and are within a range of 3.5 km from the buffer zone of the rivers causing recurring floods. The state government proposes to excavate these waterbodies by 2 metres and construct 2 metre-high embankments to increase water holding capacities. It is estimated that increasing the water holding capacity will reduce flood intensity by 20% to 80%. The projected benefits will depend on the efficient execution of excavation work, embankment construction, and a steady flow of funds. The central government has asked the state government to submit a comprehensive feasibility report by December on proposed floodwater diversion through these wetlands. Initial estimates of connecting the flood-causing rivers with these wetlands and rejuvenating these water bodies to increase their water-carrying capacity and likely connecting some rivers to some of the identified wetlands are put at Rs 500 crore. The state building its capacity is crucial to successfully implement the plan, and the feasibility report needs to reflect on this requirement. The application of remote sensing and space technology has advanced scientific research on floods in the state, which has helped in designing structural as well as non-structural flood mitigation measures. The NESAC has developed a Flood Early Warning System (FLEWS) for the Brahmaputra basin in the state based on numerical rainfall prediction and a physics-based distributed hydrological model. The Assam State Disaster Management Authority has been implementing this FLWES since 2009 for issuing flood alerts, watches, and advisories in revenue circles of flood-prone districts, post-flood monitoring of breaches in embankments, and fresh inundation. The Assam River Atlas, developed by NESAC, is another example of space application in flood mitigation and disaster preparedness. Ravaging annual floods that occur in multiple waves cause substantial damage to agriculture, and reducing flood intensity can go a long way in bringing down the restoration, relief, and rehabilitation cost. Rejuvenation of the water bodies will also contribute to fish production, enhance other ecosystem services, support paddy farming, and boost tourism to provide sustainable livelihoods. Scenic natural landscapes of resident and migratory birds are prime attractions for tourists and birders. The proposed rejuvenation of floodplain water bodies for flood mitigation will bring additional benefits of optimally tapping the tourism and livelihood potential. Community participation plays a crucial role in the rejuvenation of water bodies degraded due to chemical and physical pollution as well as siltation caused by flood water. Prioritizing awareness building in the community on the harmful effects of polluting water during the implementation of the plan will be critical to making wetland conservation a sustained collaborative initiative of government departments and people. NESAC has generated a huge database on rivers, infrastructure, and natural resources on their floodplain. The state government making pragmatic utilization of this data requires meticulous planning and execution. The central government and the state government are aware of the gaps in the execution of various flood mitigation problems owing to delays in fund flow, which results in the release of quantum allocation of disaster management floods at the fag end of financial years. States improving their capacity for judicious utilization of funds and timely submission of utilization certificates can facilitate early disbursement of funds during the lean season. So far, repair of embankment breaches and restoration of damaged infrastructure have been dominating the flood preparedness, but collaboration with NESAC has allowed the Assam State Disaster Management Authority to focus on FLWES, mapping of floodplain areas, and detailed and more accurate study of the rivers for better disaster planning. The proposed plan will unlock more opportunities for space application-based research to suggest improved intervention for flood mitigation in the state. This will become a reality only when the central government comes forward to provide adequate funds to NESAC for undertaking more scientific research and studies in the Northeast region. The entire northeast region is being susceptible to natural disasters like floods, erosion, landslides, and earthquakes; state governments also spare resources to fund such research and studies commissioned to NESAC. The rise in extreme weather events in the region due to climate change impact has compounded disaster risks. Space application-based solutions have become an urgent need to increase the disaster resilience of the region.