Optimizing Height Above Nearest Drainage parameters to enable rapid flood mapping in North Carolina

Frontiers in Water, Journal Year: 2024, Volume and Issue: 5

Published: Jan. 5, 2024

Surface water flooding represents a significant hazard for many infrastructure systems. For example, residential, commercial, and industrial properties, wastewater treatment facilities, private drinking wells, stormwater systems, or transportation networks are often impacted (i.e., in terms of damage functionality) by events. large scale events, knowing where to prioritize recovery resources can be challenging. To help communities throughout North Carolina manage flood disaster responses, near real-time state-wide rapid mapping methods needed. In this study, Height Above Nearest Drainage (HAND) concepts combined with National Water Model river discharges enable Carolina. The modeling system is calibrated using USGS stage-discharge relationships FEMA 100-year maps. calibration process ultimately provides spatially distributed channel roughness values best match the available datasets. Results show that system, when calibrated, reasonable estimates both stage (or corresponding surface elevations) extents. Comparing HAND maps Wake County shows an agreement 80.1% 76.3%, respectively. non-agreement locations, extents tend overestimated as compared underestimated, which preferred context identifying potentially Future research will focus on developing transfer estimate locations lack data needed calibration.

Language: Английский

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Dam breach analysis and flood inundation mapping of Dire Dam, using HEC-HMS and HEC-RAS models

Sustainable Water Resources Management, Journal Year: 2024, Volume and Issue: 10(2)

Published: Feb. 5, 2024

Language: Английский

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Integrated assessment of flood susceptibility and exposure rate in the lower Niger Basin, Onitsha, Southeastern Nigeria

Frontiers in Earth Science, Journal Year: 2024, Volume and Issue: 12

Published: June 17, 2024

Background Various methods have been utilized to investigate and mitigate flood occurrences, yet there is a paucity of literature on factors, such as soil compositions, that contribute persistent flooding in river basins like the Lower Niger catchment, specifically at Onitsha. Furthermore, study seeks furnish essential geospatial data concerning vulnerability, risks, exposure rates Catchment area, situated Onitsha, southeastern Nigeria. Materials Soil samples were collected from 10 specific locations identified through GPS ground-truthing techniques. Additionally, satellite imagery Landsat Enhanced Thematic Mapper (ETM +) was utilized, with supervised classification employed extract feature classes. Analysis operations conducted using IDRISI software, resulting creation digital elevation models (DEMs), susceptibility maps, flood-risk zones. Results revealed predominant composition area comprises sandy (84.8%), silt (8.1%), clayey (7.1%) soils. Utilizing these characteristics alongside relevant aerial data, determined various scales delineate most flood-vulnerable zones basin. It found certain areas, accommodating population exceeding 79,426 across 2,926.2 ha, particularly susceptible flooding. Notably, major markets Bridgehead, Textile, Biafra highly susceptible, varying degrees risk. The prevalence soil, which facilitates increased rainwater infiltration but also prone rapid saturation runoff, likely contributes heightened areas. Conclusion Geospatial analysis employing remote sensing indicates high lower River Basin around Urgent mitigation efforts are imperative, necessitating establishment zoned areas equipped effective drainage systems safeguard vulnerable populations.

Language: Английский

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Unravelling flash flood dynamics of Song watershed, Doon Valley: key insights for floodplain management

Geomatics Natural Hazards and Risk, Journal Year: 2024, Volume and Issue: 15(1)

Published: Aug. 2, 2024

The Himalayan foothills are highly prone to rainfall induced flash floods. This research focuses on the August 19–20, 2022 flood event in Song watershed of Doon valley, Uttarakhand caused significant damages buildings and a road bridge. study aims assess intensity through simulation semi-distributed hydrological model by utilizing data, land use soil data. Further, hydrographs generated modelling were used simulate hydrodynamic estimate depth. Pre post-flood inundation assessments conducted using PlanetScope Sentinel-1 imagery. Furthermore, development activities river courses analyzed Google earth Bing maps high resolution Cumulative observations revealed 344 mm Rishikesh 225 Sahastradhara 19–20 for 24 hrs, contributed peak discharge 2679 m3/s at outlet. simulated depth depicted 4.81 m damaged Thano-Bhogpur satellite imagery showed 182 expansion cross-sectional width Maldevta after flood. A 5.36 sq. km. area observed throughout entire catchment two days post Analysis high-resolution imageries increasing floodplains catchment, which got affected findings indicate urgent need floodplain management implementing comprehensive risk plans including early warning systems, land-use regulations based hazard zonation resilient infrastructure mitigate future exposure society.

Language: Английский

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Flood Risk Mapping of Kamla River Basin using HEC-RAS 2D Model

Advances in Engineering and Technology An International Journal, Journal Year: 2023, Volume and Issue: 3(1), P. 31 - 45

Published: Dec. 15, 2023

Flood is a natural disaster that occurs repeatedly in Nepal and causes significant losses terms of life property particularly low land areas around the river courses. Kamla basin highly susceptible to flooding had experienced many disastrous floods past. mitigation measures generally consists two main methods which are structural non-structural methods. Nowadays, importance using nonstructural method such as flood hazard map risk increasing because environmental economic aspects. In this study, assessment was carried out for River basin. Floods simulated HEC-RAS 2D hydraulic model. The prepared simulation result by classifying into four level, corresponding different inundation depth. exposed elements considered vulnerability assessments building, population agriculture area. Finally, evaluate risk, wards under study area 25year,50year 100-year return period events based on product weightage. study’s findings may help planning management plain region avoid future likely disasters.

Language: Английский

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Analisa Genangan Banjir Sungai Gembong Pasuruan Menggunakan Aplikasi Hec-Ras 2D

Jurnal Teknologi dan Rekayasa Sumber Daya Air, Journal Year: 2024, Volume and Issue: 4(1), P. 754 - 766

Published: Jan. 14, 2024

Banjir merupakan keadaan dimana suatu daerah tergenang air dalam jumlah yang besar, Sungai Gembong sungai membelah Kota Pasuruan dan pada tahun 2008 terjadi banjir ekstrim dengan kala ulang 25 membuat fasilitas umum pemadaman listrik sementara. Mengingat pentingnya untuk kehidupan di Pasuruan, studi ini dimaksudkan mendapatkan informasi mengenai debit terjadi, luas genangan kondisi penampang 50 tahun. Data dibutuhkan melengkapi antara lain adalah data hujan, maksimum, DEM, Gembong. Studi dimulai analisis kualitas hujan lalu merubah menjadi rancangan tahun, dilakukan pemodelan aplikasi HEC-RAS sebaran DAS Pemodelan hidraulik menggunakan 6.2 Analisa 2D simulasi unsteady flow mengetahui Dari analisa hidrologi didapatkan metode Hidrograf Satuan Sintetik Nakayasu sebesar Q25th = 125.32 m3/det Q50th 142.442 total 158.44 ha, 170.11 ha

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Analisis Banjir pada Polder Sunter Timur II dengan Menggunakan HEC-RAS (Ras Mapper)

Teras Jurnal Jurnal Teknik Sipil, Journal Year: 2024, Volume and Issue: 14(1), P. 39 - 39

Published: March 25, 2024

Abstrak Banjir di Jakarta menimbulkan kerusakan dan kerugian, menjadi latar belakang dilakukannya analisis banjir Polder Sunter Timur II yang disajikan dalam makalah ini. Wilayah hilir terbagi 43 sistem polder salah satunya adalah II. Studi ini bertujuan untuk mendapatkan luas daerah rencana Analisis hidrologi menggunakan software HEC-HMS HEC-RAS (Ras Mapper). Data input digunakan pemodelan yaitu Digital Elevation Model (DEM) , hidrograf, peta penggunaan lahan. Daerah tangkapan air sebesar 1,328 km 2 . Hasil simulasi didapat debit kala ulang 5, 10 25 tahun 185 m 3 /dt, 208,7 234,3 /dt. menunjukkan dengan 857,08 Ha, 885,62 979,59 Ha. Kata kunci: banjir, polder, hidrologi, HEC-HMS, Abstract Flood in cause damage and losses are the reason for flood analysis of East presented this paper. Downstream area is divided into systems one them Polder. This study aims to obtain plan. Hydrological using Input data used modeling (DEM), hydrograph, land use map. Catchment The result 5-, 10- 25-year return period discharge /s, 234 /s. results show that with Keywords: flood, system, hydrology analysis,

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Open-access digital elevation model (DEM) selection for flood inundation modelling using HEC-RAS in Capital City of Nusantara

IOP Conference Series Earth and Environmental Science, Journal Year: 2024, Volume and Issue: 1343(1), P. 012036 - 012036

Published: May 1, 2024

Abstract Flood is a classic but complex issue in most regions of Indonesia. Nusantara, the future capital Indonesia, now undergoing construction site continues to experience flooding due high intensity rainfall. To overcome this challenge, identification flood points those areas needs be done. Digital Elevation Models (DEM) are important component modeling inundation data-sparse areas. High-accuracy DEMs have been found give better estimation availability such data very limited. Therefore, open-access DEMs, as SRTM, DEMNAS, and MERIT-Hydro, common choices used Each set may provide varying model outcomes, different processing methods. These results often lead confusion which result should subsequent studies. In study, Nusantara will generated using HEC-RAS hydraulic with 25-, 50-, 100-year return period rainfall events. The was obtained by calibrating Global Precipitation Measurement (GPM) satellite rain data. various conditions, MERIT-Hydro tends present higher depths. Followed DEMNAS SRTM lower On other hand, use variation gives linear increase depth for model. While decline increment occurred models when two big year periods were applied. This research can considered development planning.

Language: Английский

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Investigation of Soil Liquefaction and Flooding as a Hydrological Risk for Disaster Risk Reduction in the Construction of Water Reservoirs

Published: Jan. 1, 2024

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Language: Английский

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Numerical simulation of flow characteristics in nonprismatic compound channels

Water Practice & Technology, Journal Year: 2024, Volume and Issue: 19(7), P. 2532 - 2550

Published: June 8, 2024

ABSTRACT The assessment of the flow characteristics river systems is a very intricate undertaking in development hydraulic models for purposes flood control and floodplain management. Therefore, it essential to use simulation order calibrate verify experimental results. In this study, Hydrologic Engineering Centre's – River Analysis System (HEC-RAS) used validate distribution velocity shear stress different converging compound channels. Two separate regimes were assessed validation based on data obtained from channels with angles θ = 5°, 9°, 12.38°. projected values two relative depths (β 0.15 0.20) exhibit similar pattern variation as empirical observations are marginally lower than recorded values. This suggests that HEC-RAS model accurately estimates disparity between simulated outcomes shows discrepancy less 10%. Hence, implications our results suggest while dealing nonprismatic rivers, advisable take into account methodology focused problem-solving might potentially inform infrastructure watercourses.

Language: Английский

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