scholarly journals Advances in flash flood modelling in urbanized and data scarce-areas

2022 ◽  
Author(s):  
Yakob Umer
Keyword(s):  
Flash Flood ◽  
Flood Modelling

scholarly journals Assessing the impact of resolution and soil datasets on flash-flood modelling

2019 ◽  
Vol 23 (3) ◽  
pp. 1801-1818 ◽  
Author(s):  
Alexane Lovat ◽  
Béatrice Vincendon ◽  
Véronique Ducrocq
Keyword(s):  
Land Cover ◽  
Soil Texture ◽  
Flash Flood ◽  
Grid Cell ◽  
Coupled System ◽  
High Water ◽  
Catchment Scale ◽  
Flood Modelling ◽  
Flood Simulations ◽  
The Impact

Abstract. The present study assesses the impacts of two grid resolutions and the descriptors of soil texture and land cover on flash-flood modelling at local and basin scales. The ISBA-TOP coupled system, which is dedicated to Mediterranean flash-flood simulations, is used with two grid-cell sizes (300 and 1000 m), two soil texture datasets, and two land use databases to model 12 past flash-flood events in southeastern France. The skill of the hydrological simulations is assessed using conventional data (discharge measurements from operational networks) and proxy data such as post-event surveys and high-water marks. The results show significant differences between the experiments in terms of both the simulated river discharge and the spatial runoff, whether at the catchment scale or at the local scale. The spatial resolution has the largest impact on the hydrological simulations. In this study, it is also shown that the soil texture has a larger impact on the results than the land cover.

scholarly journals Evaluation of sub daily satellite rainfall estimates through flash flood modelling in the Lower Middle Zambezi Basin

2018 ◽  
Vol 378 ◽  
pp. 59-65 ◽  
Author(s):  
Thomas Matingo ◽  
Webster Gumindoga ◽  
Hodson Makurira
Keyword(s):  
Flash Flood ◽  
Daily Rainfall ◽  
Flash Floods ◽  
Rain Gauge ◽  
Hydrological Modelling ◽  
Probability Of Detection ◽  
Time Step ◽  
Flood Modelling ◽  
Satellite Rainfall ◽  
Rainfall Estimates

Abstract. Flash floods are experienced almost annually in the ungauged Mbire District of the Middle Zambezi Basin. Studies related to hydrological modelling (rainfall-runoff) and flood forecasting require major inputs such as precipitation which, due to shortage of observed data, are increasingly using indirect methods for estimating precipitation. This study therefore evaluated performance of CMORPH and TRMM satellite rainfall estimates (SREs) for 30 min, 1 h, 3 h and daily intensities through hydrologic and flash flood modelling in the Lower Middle Zambezi Basin for the period 2013–2016. On a daily timestep, uncorrected CMORPH and TRMM show Probability of Detection (POD) of 61 and 59 %, respectively, when compared to rain gauge observations. The best performance using Correlation Coefficient (CC) was 70 and 60 % on daily timesteps for CMORPH and TRMM, respectively. The best RMSE for CMORPH was 0.81 % for 30 min timestep and for TRMM was 2, 11 % on 3 h timestep. For the year 2014 to 2015, the HEC-HMS (Hydrological Engineering Centre-Hydrological Modelling System) daily model calibration Nash Sutcliffe efficiency (NSE) for Musengezi sub catchment was 59 % whilst for Angwa it was 55 %. Angwa sub-catchment daily NSE results for the period 2015–2016 was 61 %. HEC-RAS flash flood modeling at 100, 50 and 25 year return periods for Angwa sub catchment, inundated 811 and 867 ha for TRMM rainfall simulated discharge at 3 h and daily timesteps, respectively. For CMORPH generated rainfall, the inundation was 818, 876, 890 and 891 ha at daily, 3 h, 1 h and 30 min timesteps. The 30 min time step for CMORPH effectively captures flash floods with the measure of agreement between simulated flood extent and ground control points of 69 %. For TRMM, the 3 h timestep effectively captures flash floods with coefficient of 67 %. The study therefore concludes that satellite products are most effective in capturing localized hydrological processes such as flash floods for sub-daily rainfall, because of improved spatial and temporal resolution.

scholarly journals A Remote Sensing Contribution to Flood Modelling in an Inaccessible Mountainous River Basin

2018 ◽  
Author(s):  
Alamgeer Hussain ◽  
Jay Sagin ◽  
Kwok P. Chun
Keyword(s):  
Remote Sensing ◽  
River Basin ◽  
Agricultural Land ◽  
Flash Flood ◽  
Regional Scale ◽  
Flood Mitigation ◽  
Disaster Mitigation ◽  
Observation Data ◽  
Flood Modelling ◽  
The World

Flash flooding, a hazard which is triggered by heavy rainfall is a major concern in many regions of the world often with devastating results in mountainous elevated regions. We adapted remote sensing modelling methods to analyse one flood in July 2015, and believe the process can be applicable to other regions in the world. The isolated thunderstorm rainfall occurred in the Chitral River Basin (CRB), which is fed by melting glaciers and snow from the highly elevated Hindu Kush Mountains (Tirick Mir peak’s elevation is 7708 m). The devastating cascade, or domino effect, resulted in a flash flood which destroyed many houses, roads, and bridges and washed out agricultural land. CRB had experienced devastating flood events in the past, but there was no hydraulic modelling and mapping zones available for the entire CRB region. That is why modelling analyses and predictions are important for disaster mitigation activities. For this flash flood event, we developed an integrated methodology for a regional scale flood model that integrates the Tropical Rainfall Measuring Mission (TRMM) satellite, Geographic Information System (GIS), hydrological (HEC-HMS) and hydraulic (HEC-RAS) modelling tools. We collected and use driver discharge and flood depth observation data for five river sub-stream areas, which were acquired in cooperation with the Aga Khan Rural Support Program (AKRSP) organization. This data was used for the model’s calibration and verification. This modelling methodology is applicable for other regional studies especially for rough mountainous areas which lack local observations and river discharge gauges. The results of flood modelling are useful for the development of a regional early flood warning system and flood mitigation in hazardous flood risk areas. The flood simulations and prepared connected video visualization can be used for local communities. This approach is applicable for flood mitigation strategies in other regions.

scholarly journals Assessing the impact of resolution and soil datasets on flash-flood modelling

2018 ◽  
Author(s):  
Alexane Lovat ◽  
Béatrice Vincendon ◽  
Véronique Ducrocq
Keyword(s):  
Land Cover ◽  
Soil Texture ◽  
Flash Flood ◽  
Grid Cell ◽  
Coupled System ◽  
High Water ◽  
Catchment Scale ◽  
Flood Modelling ◽  
Flood Simulations ◽  
The Impact

Abstract. The present study assesses the impacts of the grid resolution and the descriptors of soil texture and land cover on flash-flood modelling at local and basin scales. The ISBA-TOP coupled system, which is dedicated to Mediterranean flash-flood simulations, is used with two grid-cell sizes (300 m and 1000 m) and various soil datasets to model 12 past flash-flood events in southeastern France. The skill of the hydrological simulations is assessed using conventional data (discharge measurements from operational networks) and proxy data such as post-event surveys and high-water marks. The results show significant differences between the experiments in terms of both the simulated river discharge and the spatial runoff, whether at the catchment scale or at the local scale. The spatial resolution has the largest impact on the hydrological simulations. In this study, it is also shown that the soil texture has a larger impact on the results than the land cover.

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