Search Results (2)

This study presents a comprehensive analysis of the temporal variations in the area and evapotranspiration (ET) of five key lakes on the Qinghai–Tibet Plateau: Qinghai Lake, Hara Lake, Eling Lake, Gyaring Lake, and Ulan Ula Lake. Utilizing remote sensing data from Landsat satellites over the period from 1986 to 2022, we examined the dynamic changes and identified significant correlations and lag effects between lake area and regional ET. Distinct temporal patterns and sudden changes in lake areas and ET were observed, with Qinghai Lake showing an upward trend in the summer area and a mutation in 2020, while ET exhibited a mutation in 2021. Cyclic characteristics were observed, with significant correlations noted during specific periods, indicating a strong positive phase relationship between lake area and ET. This research contributes to the sustainable development and ecological protection efforts in this ecologically fragile region. Full article

Proper water use requires its monitoring and evaluation. An indexes system of overall water use efficiency is constructed here that covers water consumption per 10,000 yuan GDP, the coefficient of effective utilization of irrigation water, the water consumption per 10,000 yuan of industrial value added, domestic water consumption per capita of residents, and the proportion of water function zone in key rivers and lakes complying with water-quality standards and is applied to 31 provinces in China. Efficiency is first evaluated by a projection pursuit cluster model. Multidimensional efficiency data are transformed into a low-dimensional subspace, and the accelerating genetic algorithm then optimizes the projection direction, which determines the overall efficiency index. The index reveals great variety in regional water use, with Tianjin, Beijing, Hebei, and Shandong showing highest efficiency. Shanxi, Liaoning, Shanghai, Zhejiang, Henan, Shanxi, and Gansu also use water with high efficiency. Medium efficiency occurs in Inner Mongolia, Jilin, Heilongjiang, Jiangsu, Hainan, Qinghai, Ningxia, and Low efficiency is found for Anhui, Fujian, Jiangxi, Hubei, Hunan, Guangdong, Guangxi, Chongqing, Sichuan, Guizhou, Yunnan, and Xinjiang. Tibet is the least efficient. The optimal projection direction is a* = (0.3533, 0.7014, 0.4538, 0.3315, 0.1217), and the degree of influence of agricultural irrigation efficiency, water consumption per industrial profit, water used per gross domestic product (GDP), domestic water consumption per capita of residents, and environmental water quality on the result has decreased in turn. This may aid decision making to improve overall water use efficiency across China. Full article