Planning for mitigating flash flood Events: a case of Almora district in Uttarakhand

Abstract

India has faced serious natural disasters with major floods prevailing over time. Between the period of 2000-2015, India witnessed at least 56 natural catastrophe incidents per year, the main of which were floods of at least 25 occurrences per year (EM-DAT 2017). The Himalayan range offers enabling factors for flash floods due to their rough ground formation. Flash flood is annual occurrence in Uttarakhand during the Monsoon season. Over recent years, the amount of rainfall in this region has also risen, thereby posing even greater threats and challenges. Almora experienced one of the most damaging flash-floods during the 2010 Monsoon season. It was the worst flash flood of Almora of the last twenty years which resulted in huge fatalities. This flash flood devastated several villages and towns etc., and a lot of homes were wiped out by the Kosi River water and mud. New technologies further contribute to the environmental imbalance, with river water flows restricted and streamside construction operation leading to a higher number of landslides and further flooding, particularly in hilly terrain. Human environmental activities such as rapid urbanization, deforestation and attempts to regulate water supply for agriculture and generation of electricity will be one of the key parameters leading to sudden climate change. Implementing flood protection steps often involves very long planning horizons of 30 years or more, because each phase is time-consuming to implement or entail significant investment, or both. Adaptation steps will most generally be selected based on forecasts of flood risk over the planning period. Studies at different locations have shown that the likelihood of flooding is significantly impaired by climate change and urban growth and is expected to rise over the next century (Ehret et al . , 2008; Hinkel et al . , 2014; Muis et al . , 2015; Muller, 2007; Semadeni-Davies et al., 2008; Zhou et al . , 2012; Zhu et al . , 2007). Spatial and temporal projections in urban development are focused on uncertain demographic trends and predictions in economic forecasting (Cohen, 2004; Granger and Jeon, 2007), and future societal aspirations are practically unknown. In such a scenario, flood preparation strategies or, more broadly, policies focus on predictions of the potential circumstances that tend to be extremely uncertain (Walker et al., 2001), the needed expenditure may well be postponed for fear of making unacceptablechoices. Aerts et al.( 2014). Thus it emerges that these conventional steps need to be avoided, and improvements to their effect on the atmosphere need to be recommended. This thesis study aims to mitigate the post disaster events led by unknown cloud bursting events, and also looks for preparation strategies so as to mitigate oncoming events to an optimum level. Flash flood issue can be addressed by diverting more attention on high-threat areas that can be identified spatially through GIS mapping and technical processes based on parameters that directly influence it, and successive responsive guidelines and standards can be set to reduce the impact during a disaster and minimize those events. Despite the identification, certain guidelines must be applied strictly to all high alert zones, as they hold maximum chances of future occurrence of a disaster event. Upon conclusion of the preparation of guidelines, one of the established hotspot areas will be assessed and the guidelines will be implemented and moulded taking into consideration the village's on-ground situation, i.e. micro-level evaluation to ensure the relevance of the criteria set. There is also a need to make such rules for all other danger areas except for hotspots because the catastrophe will inevitably happen anywhere, so safety guidelines must always be provided as a general applicability