Hydrological model based framework for flood analysis and management

Abstract

quotEffective flood management practices lead to flood control and mitigation besides minimizing losses to life and damages to infrastructures and other physical losses. Systematic study of a river basin is required to understand the factors responsible for flooding to take adequate remedial measures for controlling and managing floods. Nowadays, flood events all over the world have increased due to climate change effects even in the areas which are normally not prone to flooding. This has further necessitated proper hydrological modeling of a river basin to assess various flood scenarios in the event of fluctuating rainfall patterns and also changes in the land use pattern with time. Therefore, in the present study part of the Upper Sabarmati River basin, commencing from Udaipur, Rajasthan to Derol Bridge, Gujarat having a total catchment area of 6114.5sq.km is considered for hydrology modeling. The study was carried out in four phases: 1) Land use land cover change analysis, 2) Rainfall Trend analysis, 3) Feedback analysis from expert opinion survey for understanding floods and their parameters; and 4) Selection and development of hydrological models, sensitivity analysis and flood control measures. newlineThe Land use land cover change analysis was carried out by using four decadal LULC thematic maps of study area: LULC 1985, LULC 1995, LULC 2005 and LULC 2017. The change detection analysis of these maps shows continuous increase in deciduous broadleaf forest and cropland by 4% and 9% respectively, whereas the mixed forest cover decreased continuously by 0.50% (approximately) from the year 1985 to 2017. newlineThe Rainfall trend analysis was performed using the Agro-climatic data of three rain gauge stations namely Jotasan, Kheroj (upstream) and Derol (downstream). From the rainfall trend analysis, it is observed that the average rainfall trend pattern is stabilized in the Derol rain gauge station whereas in other two Kheroj and Jotasan stations, the rainfall trend is continuously increasing with every passing year. It was als