Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China; Danjiangkou Wetland Ecosystem Field Scientific Observation and Research Station, Chinese Academy of Sciences & Hubei Province, Wuhan, 430074, China.
Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China; Danjiangkou Wetland Ecosystem Field Scientific Observation and Research Station, Chinese Academy of Sciences & Hubei Province, Wuhan, 430074, China.
J Environ Manage. 2024 Dec;371:123231. doi: 10.1016/j.jenvman.2024.123231. Epub 2024 Nov 4.
Besides cascade hydropower development, regional socio-economic activities also significantly affect water quality in the drainage region. However, it remains challenging to ascertain the implications of the damming effects and regional sustainability on water quality. This study examined the variations in water quality indicators, including chemical oxygen demand (COD), ammonia nitrogen (NH-N), and total phosphorus (TP), during the cascade hydropower development (both the construction and impoundment periods from 2006 to 2023) in the lower reaches of the Jinsha River (the upper reaches of the Yangtze River). The relationships between land use changes, point and non-point source nitrogen (N) and phosphorus (P) inputs, and water quality and their interconnections with multiple Sustainable Development Goals (SDGs) were analyzed to assess the impacts of regional sustainability on water quality. The COD and NH-N concentrations did not significantly differ between 1-2 hydrologic years before and after dam construction or reservoir impoundment, while the TP concentrations substantially decreased following reservoir impoundment. Land use changes at the riparian scale and point and non-point source N and P inputs in the sub-watershed effectively accounted for variations in NH-N and TP during cascade hydropower development. Factors influencing water quality were closely linked to regional sustainability, including urbanization progress (SDG 11), urban sewage management (SDG 6), agricultural adjustment (SDG 2), and forest restoration (SDG 15). This study underscores the positive influence of regional sustainability on water quality improvement, which is beneficial for developing sustainable hydropower development strategies.
除梯级水电开发外，区域社会经济活动也会显著影响流域的水质。然而，确定大坝效应和区域可持续性对水质的影响仍然具有挑战性。本研究调查了金沙江下游（长江上游）在梯级水电开发期间（2006 年至 2023 年的建设和蓄水期）水质指标的变化，包括化学需氧量（COD）、氨氮（NH-N）和总磷（TP）。分析了土地利用变化、点源和非点源氮（N）和磷（P）输入与水质之间的关系，以及它们与多个可持续发展目标（SDGs）的相互关系，以评估区域可持续性对水质的影响。在大坝建设或水库蓄水前后的 1-2 个水文年内，COD 和 NH-N 浓度没有显著差异，而 TP 浓度在水库蓄水后显著下降。河岸带土地利用变化以及子流域的点源和非点源 N 和 P 输入有效地解释了梯级水电开发过程中 NH-N 和 TP 的变化。影响水质的因素与区域可持续性密切相关，包括城市化进程（可持续发展目标 11）、城市污水处理（可持续发展目标 6）、农业调整（可持续发展目标 2）和森林恢复（可持续发展目标 15）。本研究强调了区域可持续性对水质改善的积极影响，这有利于制定可持续的水电开发策略。
