Identifying surface water evaporation loss of inland river basin based on evaporation enrichment model

Abstract

Accurately quantifying the evaporation loss of surface water is essential for regional water resources management, especially in arid and semi-arid areas where water resources are already scarce. The long-term monitoring of stable isotopes (δ 18 O and δ 2 H) in water can provide a sensitive indicator of water loss by evaporation. In this study, we obtained surface water samples of Shiyang River Basin from April to October between 2017 and 2019. The spatial and temporal characteristics of stable isotopes in surface water show the trend of enrichment in summer, depletion in spring, enrichment in deserts and depletion in mountains. The Local Evaporation Line (LEL) obtained by the regression of δ 2 H and δ 18 O in surface water has been defined by the lines: δ 2 H = 7.61δ 18 O + 14.58 for mountainous area, δ 2 H = 4.19δ 18 O − 17.85 for oasis area, δ 2 H = 4.08δ 18 O − 18.92 for desert area. The slope of LEL shows a gradual decrease from mountain to desert, indicating that the evaporation of surface water is gradually increasing. The evaporation loss of stable isotopes in surface water is 24.82% for mountainous area, 32.19% for oasis area, and 70.98% for desert area, respectively. Temperature and air humidity are the main meteorological factors affecting the evaporation loss, and the construction of reservoirs and farmland irrigation are the main man-made factors affecting the evaporation loss.

Effects of urbanization on the water cycle in the Shiyang River basin: based on a stable isotope method

“…At points S3-S5, the correlation of the model simulation is higher, which is because in the middle reaches of the SYR basin, the expansion of urban built-up areas leads to a significant increase in river runoff during the rainy season, and according to the land use data, the land area of the towns in Wuwei has continued to increase by 134.38 km 2 from 2010 to 2018, resulting in the river water showing a cyclical trend comparable to that of the precipitation. Since the 1950s, in order to better utilize water resources, 13 small-and medium-sized reservoirs with a total storage capacity of 900 000 m 3 have been constructed (Ma et al, 2010), increasing the proportion of rainfall in the runoff constituents as a result of the correlation of the model simulation is at a high level at points S6-S9, where, in contrast to the high-elevation areas in the upper reaches, the terrain in the middle and lower reaches of the SYR basin is relatively flat, mainly with cultivated land and deserts, and is less disturbed by human activities (Sun et al, 2021), which further reflects the responsiveness to recent precipitation inputs.…”

Quantifying Recycled Moisture in Precipitation in Qilian Mountains

“…The elevation of the XYR basin ranges from 1510 to 4874 m above sea level. The average annual temperature is 6.3 • C and the average annual precipitation ranges from 200 to 700 mm [8,27]. The upper reaches of the Shiyang River basin are located in the East Asian monsoon crisscross zone, controlled by the East Asian monsoon and plateau monsoon.…”

“…In summer, hot low air pressure appears on the plateau, and the air flows from all directions to the plateau [6], which is a typical continental alpine climate. Vegetation is mainly distributed in areas between 2000 m and 3600 m above sea level; the basin is affected by multiple sources of moisture [6,27].…”

Seasonal variation and influence factors of river water isotopes in the East Asian monsoon region: a case study in the Xiangjiang River basin spanning 13 hydrological years

“…For instance, the river water stable isotopes primarily reflect the characteristics of precipitation, as precipitation input acts as the primary water source (Sprenger et al, 2022;. Moreover, due to varying degrees of evaporative enrichment and mixing processes experienced by different water bodies within a basin, the river water isotopes markedly differ from those of the precipitation input and exhibit distinct seasonality (Jiang et al, 2021;Sun et al, 2021;Das and Rai, 2022). This disparity forms the basis for employing stable isotope techniques to investigate river water generation processes in basins, while the stable isotope techniques were widely used to indicate the water cycle processes (Boral et al, 2019;Xiao et al, 2020;Wu et al, 2021) and find extensive application in hydrometeorology modeling and diagnosis (e.g., Aggarwal et al, 2016;Sinha and Chakraborty, 2019;Zhiña et al, 2022) as well as in paleoclimate reconstruction (e.g., Steinman et al, 2010;Jiménez-Iñiguez et al, 2022;Emmanouilidis et al, 2022).…”