River ecological flow early warning forecasting using baseflow separation and machine learning in the Jiaojiang River Basin, Southeast China

Hao Chen; Saihua Huang; Yue-Ping Xu; Ramesh S V Teegavarapu; Yuxue Guo; Hui Nie; Huawei Xie; Luqi Zhang

doi:10.1016/j.scitotenv.2023.163571

River ecological flow early warning forecasting using baseflow separation and machine learning in the Jiaojiang River Basin, Southeast China

Sci Total Environ. 2023 Jul 15:882:163571. doi: 10.1016/j.scitotenv.2023.163571. Epub 2023 Apr 21.

Authors

Hao Chen¹, Saihua Huang², Yue-Ping Xu³, Ramesh S V Teegavarapu⁴, Yuxue Guo⁵, Hui Nie⁶, Huawei Xie⁷, Luqi Zhang⁸

Affiliations

¹ College of Hydraulic and Environmental Engineering, Zhejiang University of Water Resources and Electric Power, Hangzhou 310018, China; International Science and Technology Cooperation Base for Utilization and Sustainable Development of Water Resources, Zhejiang University of Water Resources and Electric Power, Hangzhou 310018, China. Electronic address: chenhao@zjweu.edu.cn.
² College of Hydraulic and Environmental Engineering, Zhejiang University of Water Resources and Electric Power, Hangzhou 310018, China; International Science and Technology Cooperation Base for Utilization and Sustainable Development of Water Resources, Zhejiang University of Water Resources and Electric Power, Hangzhou 310018, China. Electronic address: huangsh@zjweu.edu.cn.
³ Institute of Hydrology and Water Resources, College of Civil Engineering and Architecture, Zhejiang University, Hangzhou 310058, China. Electronic address: yuepingxu@zju.edu.cn.
⁴ Department of Civil, Environmental and Geomatics Engineering, Florida Atlantic University, Boca Raton, FL, USA. Electronic address: rteegava@fau.edu.
⁵ Institute of Hydrology and Water Resources, College of Civil Engineering and Architecture, Zhejiang University, Hangzhou 310058, China. Electronic address: yuxueguo@zju.edu.cn.
⁶ College of Hydraulic and Environmental Engineering, Zhejiang University of Water Resources and Electric Power, Hangzhou 310018, China; International Science and Technology Cooperation Base for Utilization and Sustainable Development of Water Resources, Zhejiang University of Water Resources and Electric Power, Hangzhou 310018, China. Electronic address: nieh@zjweu.edu.cn.
⁷ College of Hydraulic and Environmental Engineering, Zhejiang University of Water Resources and Electric Power, Hangzhou 310018, China; International Science and Technology Cooperation Base for Utilization and Sustainable Development of Water Resources, Zhejiang University of Water Resources and Electric Power, Hangzhou 310018, China. Electronic address: xiehw@zjweu.edu.cn.
⁸ Zhejiang Hydrographic Technology Development and Operation Company, Hangzhou 310009, China.

PMID: 37087001
DOI: 10.1016/j.scitotenv.2023.163571

Abstract

Ecological flow early warning is crucial for the rational management of watershed water resources. However, determining of accurate ecological flow threshold and choosing the appropriate forecasting model are challenging tasks. In this study, we initially developed a baseflow separation and Tennant method-based technique for calculating ecological river flow. Then an ecological flow early warning model was created using the machine learning technique based on distributed gradient enhancement framework (LightGBM). Finally, we utilized the framework of Shapley Additive Planning (SHAP) to explain how various hydrometeorological factors affect the variations in ecological flow conditions. The Jiaojiang River basin in southeast China is selected as the study area, and the hydrological stations in upstream of Baizhiao (BZA) and Shaduan (SD) are chosen for key analysis. The results of these applications show that the monthly baseflow frequency of the river ecological flow conditions of the two stations in the dry season is 20 % (7.49 m³/s) and 30 % (4.79 m³/s), respectively. The ecological flow level early warning forecasting accuracy is close to 90 % in the BZA and SD stations during dry and wet seasons. The variations of ecological flow are most affected by evaporation and base flow index. The results of this study can serve as a strong basis for the effective allocation and utilization of locally available water resources.

Keywords: Baseflow; Ecological flow; LightGBM; SHAP framework; Southeast China.