Hydrochemical assessment of the largest desert reservoir in arid oasis area in Asia

Yang

et al. 2019

Water

Self Cite

Along with the growth of the population and economic and social development, water consumption in the upper-middle reaches of inland rivers is increasing, which has resulted in long-term cutout in the lower reaches of the river, shrinkage and drying up of the wetlands around the terminal lakes, and has caused a series of ecological problems at the same time. In order to protect the fragile ecological environment, comprehensive harnessing projects have been carried out in many inland river basins in China, in which adopting ecological water conveyance to rehabilitate degraded terminal lakes and wetlands is an important means. From June 2014 to October 2017, the water in the upper-middle reaches of the Shiyang River Basin and the lake water of the terminal lake after ecological water conveyance was sampled. The effects of ecological water conveyance on the characteristics of surface water and groundwater were analyzed using, for example, the Piper triangle diagram, Gibbs boomerang envelope model, and mixing diagram. After ecological water conveyance, the ion concentration of water in Qingtu Lake was higher overall, and ion concentration of water in the unstable catchment was higher than that of the stable catchment. The time variation was characterized as high in the summer half year and low in the winter half year. The water of Qingtu Lake is of high and large salinity, and its hydrochemical type is Na-SO 4 (Cl), which is obviously different from the water in the middle-upper reaches of the Shiyang River Basin. The effects of silicate weathering and evaporation crystallization are the main factors leading to the high ion concentration in the water of Qingtu Lake. Ecological water conveyance and the strong evaporation of arid areas have intensified the salinization of water and soils in Qingtu Lake. Meanwhile, implementing the ecological water conveyance policy in the terminal lake has also led to shortage of water resources for agricultural irrigation in the middle reaches of the Shiyang River Basin. The serial negative ecological effects of the ecological water conveyance should be emphasized.

Section: Hydrochemistry Characteristics After Ecological Water Conveycontrasting

confidence: 56%

mentioning

confidence: 99%

Effects of Ecological Water Conveyance on the Hydrochemistry of a Terminal Lake in an Inland River: A Case Study of Qingtu Lake in the Shiyang River Basin

Yang

et al. 2019

Water

Self Cite

“…For each sampling, the samples were collected from the water surface till 30 cm depth (0-30 cm). Three replicate samples were taken from each spot and packed into pre-acidified polyethylene bottles (Zhu, Zhang, He, Zhou, & Feng, 2018). During transport to the laboratory, the samples were stored in a dark refrigerator at 4 C. DOC was measured within 1 week of collection.…”

Section: Study Areasmentioning

confidence: 99%

Dissolved organic carbon transport in the Qilian mountainous areas of China

Wan

Yong

et al. 2020

Hydrological Processes

Self Cite

The Dissolved Organic Carbon (DOC) content of rivers is the most significant part of the carbon cycle migration in the basin under consideration, and it is the basis for a comprehensive understanding of the regional carbon cycle. In this study, we periodically collected samples from four monitoring stations in the Xiying River Basin of the Qilian Mountains in the northern Qinghai-Tibet Plateau. We calculated the fluxes of organic carbon in the rivers within the study area and have discussed the influencing factors of DOC concentration in these rivers. The results showed that: (a) The DOC concentration and transport flux of the Xiying river showed significant seasonal changes. The DOC concentration during summer and autumn was higher than that in winter and spring, and the output flux in summer and autumn accounted for approximately 88.3% of the total annual output. (b) Precipitation runoff has a higher DOC concentration than meltwater runoff. Climate factors, river-water chemical characteristics, and seasonal frozen-soil changes in the river basin have significant effects on the river DOC concentration and transport flux. (c) Larger runoff causes higher DOC concentrations in rivers. Runoff is the primary means of carbon migration in the inland river basin. Carbon migration is significant from the upstream to the middle and downstream sections of the inland river basin.

“…It flows for a distance of 260 km from Qilian Mountains in the south to Tenger Desert in the north (Shi et al, 2002). The total area of the catchment is about 41.6 × 10 3 km 2 (Zhu et al, 2018). The terrain of the basin slopes sharply from southwest to northeast, with Qilian Mountains in the south, diluvial plains and Gobi in the middle, and flood plains and deserts in the north (Zhu et al, 2020).…”

Section: Study Areamentioning

confidence: 99%

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

Sun

Zhang

et al. 2021

Hydrological Processes

Self Cite

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.