Flow regime changes in the Lancang River, revealed by integrated modeling with multiple Earth observation datasets

Zhang，Xingxing1; Jiang，Liguang2; Liu，Zhaofei1; Kittel，Cecile M.M.3; Yao，Zhijun1; Druce，Daniel3; Wang，Rui1; Tøttrup，Christian3; Liu，Jun4; Jiang，Hou1; Bauer-Gottwein，Peter4

2023-03-01

10.1016/j.scitotenv.2022.160656

SCIENCE OF THE TOTAL ENVIRONMENT   Impact Factor & Quartile

0048-9697

1879-1026

The flow regime change of rivers, especially transboundary rivers, affected by reservoir regulations is evident worldwide and has received much attention. Investigating dam-induced flow regime alterations is essential for understanding potential adverse downstream effects and facilitating dialogue around coordinated water use in transboundary basins, such as the Lancang River Basin (LRB). This study explored the value of combining several types of satellite Earth observation (EO) datasets that monitor different water balance components to constrain the parameter space of lumped conceptual hydrological models. Thus, we aimed to reconstruct the natural flow regimes upstream and downstream of the cascade reservoirs. Specifically, reservoir water storage changes were first estimated using satellite imagery and altimetry datasets. Then, storage changes were combined with hydrological model simulations of reservoir inflow to estimate the regulated flow regime downstream. Our results showed that integrated hydrological modeling combined with EO datasets exhibited better overall performance. Continuous warming and drying of the LRB resulted in a decrease in discharge of approximately 47 %. By comparing the simulated natural and regulated flow regimes, we revealed the pivotal role of the Xiaowan and Nuozhadu reservoirs in regulating natural flows. The wet season shortens (approximately 45 days), the flood peak flattens, and the low flow in the dry season has primarily increases. The two reservoirs attenuated 50 % of the flood peaks in the wet seasons and mitigated droughts by releasing up to 100 % of the natural flows in the dry seasons at the China–Laos border. Overall, these results enhance the understanding of upper reservoir operation, and the approaches can be applied to studies of dammed basins under climate change scenarios when knowledge of the upstream area is limited.

Cascade reservoir Climate change Flow regime Hydrological model Lancang river Sentinel-3 altimetry

SCI

English

Corresponding

Strategic Priority Research Program of the Chinese Academy of Sciences[XDA2006020202] ; National Natural Science Foundation of China[42201037] ; EOForChina project - Ministry of Foreign Affairs of Denmark[18-M01-DTU] ; Chinese Academy of Sciences[E2S20001Y5] ; China Postdoctoral Science Foundation[2022M713122]

Environmental Sciences & Ecology

Environmental Sciences

WOS:000928164100005

ELSEVIER

ENVIRONMENT/ECOLOGY

2-s2.0-85143833963

Scopus

1.Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing,100101,China
2.School of Environmental Science and Engineering,Southern University of Science and Technology,Shenzhen,518055,China
3.DHI-GRAS,Hørsholm,2970,Denmark
4.Department of Environmental Engineering,Technical University of Denmark,Kgs. Lyngby,2800,Denmark

Zhang，Xingxing,Jiang，Liguang,Liu，Zhaofei,et al. Flow regime changes in the Lancang River, revealed by integrated modeling with multiple Earth observation datasets[J]. SCIENCE OF THE TOTAL ENVIRONMENT,2023,862.

Zhang，Xingxing.,Jiang，Liguang.,Liu，Zhaofei.,Kittel，Cecile M.M..,Yao，Zhijun.,...&Bauer-Gottwein，Peter.(2023).Flow regime changes in the Lancang River, revealed by integrated modeling with multiple Earth observation datasets.SCIENCE OF THE TOTAL ENVIRONMENT,862.

Zhang，Xingxing,et al."Flow regime changes in the Lancang River, revealed by integrated modeling with multiple Earth observation datasets".SCIENCE OF THE TOTAL ENVIRONMENT 862(2023).