| Title: | Hydrological modeling of karst watershed containing subterranean river using a modified SWAT model: A case study of the Daotian River Basin, southwest China |
| Authors: | Geng, X., C. Zhang, F. Zhang, Z. Chen, Z. Nie and M. Liu |
| Year: | 2021 |
| Journal: | Water |
| Volume (Issue): | 13(24) |
| Pages: | |
| Article ID: | 3552 |
| DOI: | 10.3390/w13243552 |
| URL (non-DOI journals): | |
| Model: | SWAT (modified) & SWAT |
| Broad Application Category: | hydrologic only |
| Primary Application Category: | karst geological effects |
| Secondary Application Category: | calibration, sensitivity, and/or uncertainty analysis |
| Watershed Description: | 99.21 km^2 Daotian River, a tributary of the Baifu River (and larger Wujiang River System) located in the Qixingguan District, Bijie City, Guizhou Province, China. |
| Calibration Summary: | |
| Validation Summary: | |
| General Comments: | |
| Abstract: | Karst watershed refers to the total range of surface and underground recharge areas of
rivers (including subterranean rivers and surface rivers) in karst areas. Karst water resources, as the
primary source of domestic water supply in southwest China, are vital for the social and economic
development of these regions. It is greatly significant to establish a high-precision hydrological
model of karst watershed for guiding water resources management in karst areas. Choosing the
Daotian river basin in the Wumeng Mountains of Southwest China as the study area, this paper
proposed a method for simplifying karst subterranean rivers into surface rivers by modifying the
digital elevation model (DEM) based on a field survey and tracer test. This method aims to solve
the inconsistency between the topographical drainage divides and actual catchment boundaries
in karst areas. The Soil and Water Assessment Tool (SWAT) model was modified by replacing
the single-reservoir model in the groundwater module with a three-reservoir model to depict the
constraints of multiple media on groundwater discharge in the karst system. The results show that
the catchment areas beyond topographic watershed were effectively identified after simplifying
subterranean rivers to surface rivers based on the modified DEM data, which ensured the accuracy of
the basic model. For the calibration and two validation periods, the Nash–Sutcliffe efficiencies (NSE)
of the modified SWAT model were 0.87, 0.83, and 0.85, respectively, and R2 were 0.88, 0.84, and 0.86,
respectively. The NSE of the modified SWAT model was 0.09 higher than that of the original SWAT
model in simulating baseflow, which effectively improved the simulation accuracy of daily runoff. In
addition, the modified SWAT model had a lower uncertainty within the same parameter ranges than
the original one. Therefore, the modified SWAT model is more applicable to karst watersheds. |
| Language: | English |
| Keywords: | karst watershed; modified SWAT; runoff simulation; karst subterranean river |