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Stable isotopes in precipitation can effectively reveal the process of atmospheric water circulation, serving as an effective tool for hydrological and water resources research, climate change, and ecosystem studies. The scarcity of stable isotope data in precipitation has hindered comprehension of regional hydrology, climate, and ecology due to discontinuities on a temporal scale and unevenness on a spatial scale. To this end, we collated stable hydrogen and oxygen isotope data in precipitation from 1930 stations in Eurasia from 1961 to 2022, totalling 51,752 data records. Stable isotopes in precipitation across various regions of Eurasia, as a whole, decrease with increasing latitude and distance from the coast. In the summer, stable isotopes in precipitation are relatively enriched, while in winter, they are relatively depleted. In recent decades, the stable isotope values of Eurasian precipitation show an overall trend of increasing variation with the advancement of years, which is associated with global warming. Geographical location, underlying surface conditions, seasons, and atmospheric circulation are all factors that determine the characteristics of stable isotopes in precipitation. The dataset of stable isotopes in Eurasian precipitation provides a powerful tool for understanding changes in regional atmospheric water circulation and assists in conducting hydrological, meteorological, and ecological studies in related regions. [ABSTRACT FROM AUTHOR]

Stable hydrogen and oxygen isotopes in atmospheric precipitation have the potential to identify abnormal weather events, and climate change will cause more intense and frequent high-temperature events, which already pose a threat to human health and the development of the global economy. Based on precipitation isotope data from 37 high-temperature events that occurred in various global regions between 2010 and 2022, this article examines the impacts of high-temperature events on stable precipitation isotopes. The results show that (1) stable precipitation isotopes are more enriched under the influence of high-temperature events than in the same month of previous years; the slope and intercept of the precipitation local meteoric water line (LMWL) are lower than in the same month of previous years and the global meteoric water line (GMWL); and the precipitation d-excess is lower than the global average. (2) Temperature is the primary meteorological factor that produces abnormal variations in precipitation isotopes under the influence of high-temperature events, and the impact of temperature on precipitation isotopes is significantly amplified (P<0.05). (3) Furthermore, variations in atmospheric circulation patterns, water vapor transport fluxes, regional water vapor background, and surface morphology can lead to regional differences in anomalous variations in precipitation isotopes. This study reveals the impact of high temperatures on precipitation isotopes and their mechanisms, which is instructive for disentangling the influence of high-temperature events on water cycle processes. It may also offer fresh perspectives for the reconstruction of paleo-high-temperature events based on isotopes. [ABSTRACT FROM AUTHOR]

The water cycle has been hampered by urban development and the changes it has made to natural surfaces, especially in arid regions with scarce water supplies. Urbanization has a significant hydrological impact because of the high water demands of urban populations and economic factors. We set up an observational system close to Wuwei City, which is situated in the Shiyang River Basin, to research the effects of urbanization on isotope dynamics within the basin. We sought to clarify any perceptible changes in isotopic patterns by the methodical collecting and analysis of water samples from various water sources. According to our research, landscape dams in urban areas have a substantial impact on the evaporation and penetration of surface water. We have also observed a weaker connection between precipitation, surface water, and groundwater in urban areas, as compared to non-urban regions. Also, our research has demonstrated that metropolitan areas have a quicker catchment cycle and a quicker conversion of rainfall to runoff. These results have important ramifications for managing water resources and urban planning since they offer important insight into the hydrological dynamics of urban areas. In dry regions, where care must be made to the loss of water resources owing to landscape dam evaporation, the barrier impact of urbanization on water body connection is particularly severe. [ABSTRACT FROM AUTHOR]

In the middle and lower reaches of inland river basins of arid regions, human-intensive exploitation directly determines the distribution patterns of plants in arid areas and further determines the patterns of water use and the water cycle in arid regions. However, human activities on vegetation water utilization and the influence of the water cycle process and mechanism are not clear. In this study, seven observation systems were set up to collect samples in the mountainous, oasis and desert areas of the Shiyang River Basin, an arid inland river in central Asia. In order to quantitatively assess the contribution of different potential water sources to plants, stable isotopes of various water bodies in different geomorphic units of the basin were analyzed. The results showed that precipitation and soil water were the main sources of forest trees in mountainous areas, and the farmland vegetation in the middle and lower reaches of the oasis mainly absorbed soil water supplied by irrigation. The desert area forms vegetation in the ecological water transport area, and vegetation mainly absorbs soil water, lake water and groundwater formed by ecological water transport. On the whole, the water use patterns of plants in mountainous areas are not affected by human activities fundamentally, the oasis area is mainly affected by irrigation activities, and the inland river terminal lake area is mainly affected by ecological water transport. Human activities determine the water use patterns in the middle and lower reaches of inland rivers in arid areas. [ABSTRACT FROM AUTHOR]

Mountainous areas are the main water-producing and source areas of rivers. Global climate change is transforming the distribution of plants and forms of water use. Therefore, a clear understanding of evapotranspiration in mountainous forest zone is key for understanding the ecohydrological effect of vegetation and its influence on the water cycle of the watershed. We quantified the evapotranspiration processes in the forest belts of the Qilian Mountains as well as their contribution to runoff yield and concentration based on precipitation, soil water, and plant water samples and experimental data. The study showed that transpiration of Qinghai spruce accounted for the highest proportion of evapotranspiration in the entire Qinghai spruce forest ecosystem, with an average of 79 %, which means that transpiration is much greater than evaporation. Soil water content and air humidity were the dominant factors influencing evapotranspiration in Qinghai spruce forest belts. The growing season of Qinghai spruce is characterized by greater evapotranspiration than precipitation in each month. Consequently, the forest zone does not yield flows in the eastern part of the Qilian Mountains. The warming of global temperatures and human activities are likely to trigger shifts in the distribution areas and evapotranspiration regimes of Qinghai spruce, which in turn will lead to a change in water resource patterns in the basin. [ABSTRACT FROM AUTHOR]