TY - JOUR
T1 - Influence of river cross-section data resolution on flood inundation modeling
T2 - Case study of Kashkan river basin in western Iran
AU - Geravand, Fatemeh
AU - Hosseini, Seiyed Mossa
AU - Ataie-Ashtiani, Behzad
PY - 2020/5
Y1 - 2020/5
N2 - In this study, a coupling of a hydrologic and hydraulic model was utilized to assess the impacts of river geometry data resolution on the flood inundation characteristics in a data-scarce environment. Hydrological modeling incorporates soil conservation service curve-number (SCS-CN) and the geomorphologic based instantaneous unit hydrograph model (GIUH) to compute the direct runoff hydrograph in Kashkan river basin located in western Iran. 1D HEC-Geo-RAS model was used and performed to simulate inundation extent of 100-yr floods (~1800 m3/s) along 40 km reach of Kashkan river with a ground survey of river cross-section (2000 cross-sections, each including 500 data-points). The effect of cross-section spacing (20 m to 5000 m) and dataset resolution along cross-section (5–500 points) on 100-yr (~1800 m3/s) flood inundation extent area (FIA), average flow depth (FD), and velocity (FV) in river centerline were scrutinized. Results indicate that coarser cross-section spacing (20–5000 m) showed an overestimating tendency to simulate FIA (~5.75%), FD (391.34%), and FV (31.2%). While increasing grid resolution (5–500 points) on cross-section tends to underestimate of FIA (17.84%),FD (84.13%), and FV (49.12%). The predominant effect of cross-section spacing on FIA, FD, and FV was found compared to the number of data-points on a cross-section. Results of this study could potentially be considered as a baseline for mapping of flood inundation extent in the environment that ground or remotely sensed high-resolution topographic data of river cross-section are scarce while making a trade-off between model accuracy, computational time, and cost of data compilation is crucial.
AB - In this study, a coupling of a hydrologic and hydraulic model was utilized to assess the impacts of river geometry data resolution on the flood inundation characteristics in a data-scarce environment. Hydrological modeling incorporates soil conservation service curve-number (SCS-CN) and the geomorphologic based instantaneous unit hydrograph model (GIUH) to compute the direct runoff hydrograph in Kashkan river basin located in western Iran. 1D HEC-Geo-RAS model was used and performed to simulate inundation extent of 100-yr floods (~1800 m3/s) along 40 km reach of Kashkan river with a ground survey of river cross-section (2000 cross-sections, each including 500 data-points). The effect of cross-section spacing (20 m to 5000 m) and dataset resolution along cross-section (5–500 points) on 100-yr (~1800 m3/s) flood inundation extent area (FIA), average flow depth (FD), and velocity (FV) in river centerline were scrutinized. Results indicate that coarser cross-section spacing (20–5000 m) showed an overestimating tendency to simulate FIA (~5.75%), FD (391.34%), and FV (31.2%). While increasing grid resolution (5–500 points) on cross-section tends to underestimate of FIA (17.84%),FD (84.13%), and FV (49.12%). The predominant effect of cross-section spacing on FIA, FD, and FV was found compared to the number of data-points on a cross-section. Results of this study could potentially be considered as a baseline for mapping of flood inundation extent in the environment that ground or remotely sensed high-resolution topographic data of river cross-section are scarce while making a trade-off between model accuracy, computational time, and cost of data compilation is crucial.
KW - Cross-section data resolution
KW - Data-scarce environment
KW - Flood inundation
KW - HEC-Geo-RAS
KW - River basin modeling
UR - http://www.scopus.com/inward/record.url?scp=85079890360&partnerID=8YFLogxK
U2 - 10.1016/j.jhydrol.2020.124743
DO - 10.1016/j.jhydrol.2020.124743
M3 - Article
AN - SCOPUS:85079890360
SN - 0022-1694
VL - 584
JO - Journal of Hydrology
JF - Journal of Hydrology
M1 - 124743
ER -