• Energy Research

Understanding the supply–demand relationships and driving mechanisms of ecosystem services (ES) provides a theoretical foundation for sustainable ecosystem management. This study utilized Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) models and geographical detectors to quantify the spatial–temporal patterns of the supply, demand, and supply–demand ratio of ESs such as water yield, soil conservation, and carbon sequestration, along with their driving factors, in the Shanxi section of the Yellow River Basin. The results show that: (1) From the year 2000 to 2020, although the supply and demand of water yield, soil conservation, and carbon sequestration fluctuated, they generally increased during this period of time. In comparison to ecosystem services from the year 2000 to 2020, the supply of water yield exceeded the demand in 2020. The supply, demand, and supply–demand ratio of ESs exhibited notable spatial heterogeneity. (2) The most notable factors influencing the supply–demand ratio of water yield varied between 2000 and 2020. In 2000, construction land was the most important factor, while in 2020, cropland had the greatest impact. However, the primary factors affecting the supply–demand ratio of soil conservation and carbon sequestration remained the same in 2000 and 2020. Forestland was the primary factor in 2000, while construction land was the primary factor in 2020. (3) Considering interaction factors, the interaction factors between construction land and precipitation had the greatest impact on the supply–demand ratio of water yield in 2000, while the interaction between forestland and cropland had the greatest impact in 2020. The interaction between cropland and shrubland had the greatest impact on the supply–demand ratio of soil conservation in 2000, whereas the interaction factors between construction land and forestland had the greatest impact in 2020. The interaction between construction land and shrubland had the greatest impact on the supply–demand ratio of carbon sequestration in 2000, while the interaction between construction land and cropland had the greatest impact in 2020. Overall, the interaction between construction land and various land-use factors had the strongest explanation for the supply–demand ratio of ecosystem services. This study can serve as a reference for the comprehensive development and utilization of the Shanxi section of the Yellow River Basin.

Hydropower, although an attractive renewable energy source, can alter the flux of water, sediments, and biota, producing detrimental impacts in downstream regions. The Mekong River illustrates the impacts of large dams and the limitations of conventional dam regulating strategies. Even under the most optimistic sluicing scenario, sediment load at the Mekong Delta could only recover to 62.3 ± 8.2 million tonnes (1 million tonnes = 10 9 kilograms), short of the (100 to 160)–million tonne historical level. Furthermore, unless retrofit to reroute sediments, the dams are doomed to continue trapping sediment for at least 170 years and thus starve downstream reaches of sediment, contributing to the impending disappearance of the Mekong Delta. Therefore, we explicitly challenge the widespread use of large dead storages—the portion of the reservoirs that cannot be emptied—in dam designs. Smaller dead storages can ease sediment starvation in downstream regions, thereby buffering against sinking deltas or relative sea level rises.