Study on Impact of Changes of Watershed Geomorphic Features on Runoff
China has been undergoing rapid urbanization, which in turn greatly affects the watershed geomorphology and surface runoff. Estimation of surface runoff is essential for the assessment of runoff potential of a watershed, planning of water conservation measures and reducing the flooding hazards of downstream by utilizing appropriate hydrologic model. Qiantang Estuary, well-known for its giant tidal, has few observed and experimental runoff data. Therefore, Soil Conservation Service Curve Number (SCS-CN) model was used to determinate surface runoff in this study watershed, integrating Geographic Information System (GIS) based on this field’s the long-term data owing to its few data requirements and clearly stated assumptions.Results indicated that rapid urbanization really altered watershed geomorphic features and surface runoff. Simulated data demonstrated that the average annual runoff depth has been increased by 35.85mm from 1975 to 2010, an increase of 1.37×108m3 of total annual runoff volume. It is revealed that the Geomorphic features of watershed is one of the important factors influencing runoff.This study provided significant hydrologic parameters for city flood measures and watershed environment protection.
References
- Su, S.L., Ma, X.Y., Xiao, R: Agricultural landscape pattern changes in response to urbanization at ecoregional scale, Ecological Indicators 40(2014), p.10-18.
- Chen, Q., Song, Z: Accounting for China's urbanization. China Economic Review 30(2014),p.485-494.
- Liu, Y., Huang, X.J., Yang, H., Zhong, T.Y: Environmental effects of land-use/cover change caused by urbanization and policies in Southwest China Karst area -A case study of Guiyang. Habitat International 44( 2014),p. 339-348.
- Jianying, Song.,Jianlong,Wang.,Xiyan,Ren.,Zheng,Sun:Discussion on the Permeability Calculation Method of Permeable Pavement. China Water & Wastewater,Vol.38(2022),No.2,p.34-40.
- Sjöman, J.D., Gill, S.E:Residential runoff -The role of spatial density and surface cover, with a case study in the Höjeå river catchment, southern Sweden. Urban Forestry & Urban Greening 13 (2014) No.2, p.304-314.
- USDA-Soil Conservation Service (USDA SCS): National Engineering Handbook. Section 4. Hydrology. US Department of Agriculture, Soil Conservation Service. US Government Printing Office, Washington(. 1985.), DC.
- Xiaohan,Zhang Guoqing,Sang:Application of SCSCN Model in Runoff Calculation of Small Watershed,YELLOW RIVER,Vol.44(2022),No.5,p.35-40.
- Fuyang Water Conservancy Commission (FWCC):Water Conservancy Records of Fuyang. Hehai University Press(2007). Nanjing.
- Qiantang River Record Compilation Committee (QRRCC):Qiantang River Record. Fangzhi Press ( 2007) , Beijing.