scholarly journals Investigation of Basin Characteristics: Implications for Sub-basins Level Flood Peak and Vulnerability Assessment

Author(s):  
Rajeev Ranjan ◽  
Pankaj R. Dhote ◽  
Praveen K. Thakur ◽  
Shiv P. Aggarwal

Abstract Flood vulnerability is a significant component in assessing the probable degree of damage to various exposures in hazard conditions. In this study, a semi-distributed event-based hydrological model and indicator-based method were applied to evaluate the sub-basin level flood vulnerability using the Geographical Information System (GIS). The flood peak discharge of each sub-basin corresponding to the 2014 extreme flood of the Jhelum river was related with different sub-basins characteristics (terrain, hydrological, land use and soil) using a theoretical framework under an indicator-based method. The calibrated (2014) and validated (1992, 1997) hydrological model showed Nash-Sutcliffe Efficiency (NSE) of 0.98 and (0.99, 0.99) at relatively upstream gauging station Sangam against optimized Curve Number (CN) scaling factor of 0.98. The Anantnag and Kulgam districts, exhibiting multiple sub-basins contributing to the Sangam gauging station, are falling into a highly vulnerable category located in the Jhelum basin's southern part, Greater Himalayan Range. It was also revealed that sub-basins at the upstream of the Jhelum basin are more vulnerable compared to downstream area, where sub-basin W810 (Greater Himalayan), Anantnag district draining at Sangam gauging site is found as most vulnerable among the all other sub-basins. However, hydrological characteristics control the most vulnerable sub-basin peak discharge rather than other characteristics such as terrain, soil, or Land Use. Outcomes of the study will be helpful in prioritizing the flood mitigation planning not only with respect to the hydrological boundary (sub-basin level) but also with administrative district boundaries. The proposed method is generic and can be applied to any flood-prone river basin.

Hydrology ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 58
Author(s):  
Ahmed Naseh Ahmed Hamdan ◽  
Suhad Almuktar ◽  
Miklas Scholz

It has become necessary to estimate the quantities of runoff by knowing the amount of rainfall to calculate the required quantities of water storage in reservoirs and to determine the likelihood of flooding. The present study deals with the development of a hydrological model named Hydrologic Engineering Center (HEC-HMS), which uses Digital Elevation Models (DEM). This hydrological model was used by means of the Geospatial Hydrologic Modeling Extension (HEC-GeoHMS) and Geographical Information Systems (GIS) to identify the discharge of the Al-Adhaim River catchment and embankment dam in Iraq by simulated rainfall-runoff processes. The meteorological models were developed within the HEC-HMS from the recorded daily rainfall data for the hydrological years 2015 to 2018. The control specifications were defined for the specified period and one day time step. The Soil Conservation Service-Curve number (SCS-CN), SCS Unit Hydrograph and Muskingum methods were used for loss, transformation and routing calculations, respectively. The model was simulated for two years for calibration and one year for verification of the daily rainfall values. The results showed that both observed and simulated hydrographs were highly correlated. The model’s performance was evaluated by using a coefficient of determination of 90% for calibration and verification. The dam’s discharge for the considered period was successfully simulated but slightly overestimated. The results indicated that the model is suitable for hydrological simulations in the Al-Adhaim river catchment.


2013 ◽  
Vol 13 (3) ◽  
pp. 583-596 ◽  
Author(s):  
M. Coustau ◽  
S. Ricci ◽  
V. Borrell-Estupina ◽  
C. Bouvier ◽  
O. Thual

Abstract. Mediterranean catchments in southern France are threatened by potentially devastating fast floods which are difficult to anticipate. In order to improve the skill of rainfall-runoff models in predicting such flash floods, hydrologists use data assimilation techniques to provide real-time updates of the model using observational data. This approach seeks to reduce the uncertainties present in different components of the hydrological model (forcing, parameters or state variables) in order to minimize the error in simulated discharges. This article presents a data assimilation procedure, the best linear unbiased estimator (BLUE), used with the goal of improving the peak discharge predictions generated by an event-based hydrological model Soil Conservation Service lag and route (SCS-LR). For a given prediction date, selected model inputs are corrected by assimilating discharge data observed at the basin outlet. This study is conducted on the Lez Mediterranean basin in southern France. The key objectives of this article are (i) to select the parameter(s) which allow for the most efficient and reliable correction of the simulated discharges, (ii) to demonstrate the impact of the correction of the initial condition upon simulated discharges, and (iii) to identify and understand conditions in which this technique fails to improve the forecast skill. The correction of the initial moisture deficit of the soil reservoir proves to be the most efficient control parameter for adjusting the peak discharge. Using data assimilation, this correction leads to an average of 12% improvement in the flood peak magnitude forecast in 75% of cases. The investigation of the other 25% of cases points out a number of precautions for the appropriate use of this data assimilation procedure.


2017 ◽  
Vol 63 (No. 6) ◽  
pp. 245-253 ◽  
Author(s):  
Khaleghi Mohammad Reza

In recent decades, due to rapid human population increases and in its results, destructive effects of anthropogenic activities on natural resources have become a great challenge. Land use and vegetation are important factors in soil erosion and runoff generation. This study was performed to assess the effects of different amounts of forest cover on the control of runoff and soil loss in the Talar basin, which is located in Mazandaran province, using a runoffrainfall model, geographical information system (GIS) and remote sensing (RS) to determine the hydrologic effects of deforestation on the Talar watershed (north of Iran). A runoff-rainfall model has been presented using GIS (HECGeoHMS) and hydrologic model (HEC-HMS). Land use changes (deforestation) and anthropogenic activities (roads and impervious surfaces development) were evaluated using RS techniques and satellite images. We used the Soil Conservation Service and Curve Number methods for hydrograph simulation and runoff estimation, respectively. First, a model was performed and optimized. Afterward, the optimized model was evaluated by other six events of floods (model validation). According to the obtained results, the runoff generation potential has been increased in the Talar watershed due to deforestation during the last forty years. Land use changes cause an increase in runoff volume and flood peak discharge.


2019 ◽  
Author(s):  
David Dziubanski ◽  
Kristie J. Franz ◽  
William Gutowski

Abstract. Hydrologic modeling studies most often represent humans through predefined actions and fail to account for human responses under changing hydrologic conditions. By treating both human and hydrologic systems as co-evolving, we build a socio-hydrological model that combines an agent-based model (ABM) with a semi-distributed hydrologic model. The curve number method is used to clearly illustrate the impacts of landcover changes resulting from decisions made by two different agent types. Aiming to reduce flooding, a city agent pays farmer agents to convert land into conservation. Farmer agents decide how to allocate land between conservation and production based on factors related to profits, past land use, and willingness. The model is implemented for a watershed representative of the mixed agricultural/small urban area land use found in Iowa, USA. In this preliminary study, we simulate scenarios of crop yields, crop prices, and conservation subsidies along with varied farmer parameters that illustrate the effects of human system variables on peak discharges. High corn prices lead to a decrease in conservation land from historical levels; consequently, mean peak discharge increases by 6 %, creating greater potential for downstream flooding within the watershed. However, when corn prices are low and the watershed is characterized by a conservation-minded farmer population, mean peak discharge is reduced by 3 %. Overall, changes in mean peak discharge, which is representative of farmer land use decisions, are most sensitive to changes in crop prices as opposed to yields or conservation subsidies.


Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 676
Author(s):  
Crispin Kabeja ◽  
Rui Li ◽  
Jianping Guo ◽  
Digne Edmond Rwabuhungu Rwatangabo ◽  
Marc Manyifika ◽  
...  

In the original article, there was a mistake in Figure 1 as published [...]


2022 ◽  
Vol 11 (1) ◽  
pp. 40
Author(s):  
Hanyong Lee ◽  
Min Suh Chae ◽  
Jong-Yoon Park ◽  
Kyoung Jae Lim ◽  
Youn Shik Park

Changes in rainfall pattern and land use have caused considerable impacts on the hydrological behavior of watersheds; a Long-Term Hydrologic Impact Analysis (L-THIA) model has been used to simulate such variations. The L-THIA model defines curve number according to the land use and hydrological soil group before calculating the direct runoff based on the amount of rainfall, making it a convenient method of analysis. Recently, a method was proposed to estimate baseflow using this model, which may be used to estimate the overall streamflow. Given that this model considers the spatial distribution of land use and hydrological soil groups and must use rainfall data at multiple positions, it requires the usage of a geographical information system (GIS). Therefore, a model that estimates streamflow using land use maps, hydrologic soil group maps, and rain gauge station maps in QGIS, a popular GIS software, was developed. This model was tested in 15 watersheds.


Water ◽  
2017 ◽  
Vol 9 (6) ◽  
pp. 360 ◽  
Author(s):  
Ljubomir Gigović ◽  
Dragan Pamučar ◽  
Zoran Bajić ◽  
Siniša Drobnjak

Floods are natural disasters with significant socio-economic consequences. Urban areas with uncontrolled urban development, rapid population growth, an unregulated municipal system and an unplanned change of land use belong to the highly sensitive areas where floods cause devastating economic and social losses. The aim of this paper is to present a reliable GIS multi-criteria methodology for hazard zones’ mapping of flood-prone areas in urban areas. The proposed methodology is based on the combined application of geographical information systems (GIS) and multi-criteria decision analysis (MCDA). The methodology considers six factors that are relevant to the hazard of flooding in urban areas: the height, slope, distance to the sewage network, the distance from the water surface, the water table and land use. The expert evaluation takes into account the nature and severity of observed criteria, and it is tested using three scenarios: the modalities of the analytic hierarchy process (AHP). The first of them uses a new approach to the exploitation of uncertainty in the application of the AHP technique, the interval rough numbers (IR’AHP). The second one uses the fuzzy technique for the exploitation of uncertainty with the AHP method (F’AHP), and the third scenario contemplates the use of the traditional (crisp) AHP method. The proposed methodology is demonstrated in Palilula Municipality, Belgrade, Serbia. In the last few decades, Palilula Municipality has been repeatedly devastated by extreme flood events. These floods severely affected the transportation networks and other infrastructure. Historical flood inundation data have been used in the validation process. The final urban flood hazard map proves a satisfactory agreement between the flood hazard zones and the spatial distribution of historical floods that happened in the last 58 years. The results indicate that the scenario in which the IR’AHP methodology is used provides the highest level of compatibility with historical data on floods. The produced map showed that the areas of very high flood hazard are located on the left Danube River bank. These areas are characterized by lowland morphology, gentle slope, sewage network, expansion of impermeable locations and intense urbanization. The proposed GIS-IR’AHP methodology and the results of this study provide a good basis for developing a system of flood hazard management in urban areas and can be successfully used for spatial city development policy.


2021 ◽  
Vol 11 (7) ◽  
Author(s):  
Ashish Rawat ◽  
M. P. S. Bisht ◽  
Y. P. Sundriyal ◽  
S. Banerjee ◽  
Vidushi Singh

AbstractQuantitative morphometric analysis of Dhanari watershed has been done using remote sensing and Geographical Information System (GIS). The impact of climate, lithology, tectonics, structural antecedents, vegetation cover and land use on hydrological processes is assessed by quantifying geomorphic parameters. The Dhanari River (a tributary of the Bhagirathi River) and its tributaries Dhanpati Gad and Kali Gad forms Dhanari watershed covering 91.8  Km2 area. Several geomorphic aspects viz. linear, areal, relief were computed to comprehend potentials of soil erosion, groundwater, flood vulnerability and the geomorphic response of watershed. LISS-III image is used to generate the Land Use and Land Cover (LULC) map and assess the watershed dynamics. Values of computed hypsometric integral and morphometric parameters viz. drainage density ($$D_{{\text{d}}}$$ D d ), stream frequency ($$F_{{\text{s}}}$$ F s ), stream length ratio ($$L_{{{\text{ur}}}}$$ L ur ), bifurcation ratio ($$R_{{\text{b}}}$$ R b ), rho coefficient (ρ), drainage texture ($$D_{{\text{t}}}$$ D t ), circularity ratio ($$R_{{\text{c}}}$$ R c ), relief ratio ($$R_{{{\text{hl}}}}$$ R hl ), elongation ratio ($$R_{{\text{e}}}$$ R e ), form factor ($$F_{{\text{f}}}$$ F f ), basin shape ($$B_{{\text{s}}}$$ B s ), drainage intensity ($$D_{{\text{i}}}$$ D i ), compactness coefficient ($$C_{{\text{c}}}$$ C c ) and infiltration number ($$I_{{\text{f}}}$$ I f ) have shown a moderate and steady erosion rate, with low groundwater potential and low to moderate flood vulnerability in the watershed. Hypsometry presents a dependable geomorphic parameter to understand the erosion and geomorphic response of a watershed to hydrological processes. Hypsometric integral value (0.51) of Dhanari watershed suggests a mature topography with steady erosion in the watershed.


2012 ◽  
Vol 60 (3) ◽  
pp. 206-216 ◽  
Author(s):  
Pavla Pekárová ◽  
Aleš Svoboda ◽  
Pavol Miklánek ◽  
Peter Škoda ◽  
Dana Halmová ◽  
...  

Estimating Flash Flood Peak Discharge in Gidra and Parná Basin: Case Study for the 7-8 June 2011 FloodWe analyzed the runoff and its temporal distribution during the catastrophic flood events on river Gidra (32.9 km2) and Parná (37.86 km2) of the 7th June 2011. The catchments are located in the Small Carpathian Mountains, western Slovakia. Direct measurements and evaluation of the peak discharge values after such extreme events are emphasized in the paper including exceedance probabilities of peak flows and of their causal flash rainfall events. In the second part of the paper, plausible modeling mode is presented, using the NLC (Non Linear Cascade) rainfall-runoff model. Several hypothetical extreme flood events were simulated by the NLC model for both rivers. Also the flood runoff volumes are evaluated as basic information on the natural or artificial catchment storage.


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