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Xi H.,Chinese Academy of Sciences | Feng Q.,Chinese Academy of Sciences | Feng Q.,Alashan Desert Eco Hydrology Experimental Research Station | Liu W.,Tsinghua University | And 6 more authors.
Environmental Earth Sciences | Year: 2010

Water resources is a primary controlling factor for economical development and ecological environmental protection in the inland river basins of arid western China. Groundwater, as the important component of total water resources, plays a dominant role in the development of western China. In recent years, with the utilization ratio of surface water raised, the groundwater recharge rate has been reduced by surface water, and groundwater was exploited on a large-scale. This has led to the decline of groundwater levels and the degradation of eco-environments in the lower reaches of Heihe watershed, especially. Therefore, the study on the groundwater-level change in recent years, as well as simulating and predicting groundwater levels changes in the future is very significant to improve the ecological environment of the Heihe River Basin, coordinate the water contradiction, and allocate the water resources. The purpose of this study is to analyze the groundwater-level variations of the Ejina region basin on a large-scale, to develop and evaluate a conceptual groundwater model in Ejina Basin; according to the experimental observation data, to establish the groundwater flow model combining MODFLOW and GIS Software; simulated the regional hydrologic regime in recent 10 years and compared with various delivery scenarios from midstream; determined which one would be the best plan for maintaining and recovering the groundwater levels and increasing the area of Ejina Oasis. Finally, this paper discusses the possible vegetation changes of Ejina Basin in the future. © 2009 Springer-Verlag.


Xi H.,Chinese Academy of Sciences | Feng Q.,Chinese Academy of Sciences | Feng Q.,Alashan Desert Eco Hydrology Experimental Research Station | Si J.,Chinese Academy of Sciences | And 4 more authors.
Hydrogeology Journal | Year: 2010

Water resources have been overexploited for agricultural irrigation and industrial production in the upper and middle reaches of the Heihe River, northwestern China. Due to inadequate water resources management, the runoff entering into the lower reaches has been continuously reduced in recent years. The Heihe River is the primary recharge source for the groundwater of the lower reaches, so the decrease in runoff has caused the groundwater level to decline. As a result, a series of ecological and environmental problems has now appeared in the lower reaches, including river-flow interruptions, drying up of associated lakes, degeneration of vegetative cover and so on. In view of these issues, the National Water Diversion Project was put into practice in July 2000. It has significantly increased the quantity and frequency of flows entering into the lower reaches of the Heihe River, and has recharged the groundwater and improved the water quality to some degree along the length of the river. The water deliveries have had obvious influences on the groundwater in the lower reaches. The groundwater level increase and groundwater quality improvement have been of great benefit in restoring the ecological environment that was destroyed in past years. © 2009 Springer-Verlag.


Xi H.,CAS Lanzhou Cold and Arid Regions Environmental and Engineering Research Institute | Xi H.,CSIRO | Zhang L.,CSIRO | Feng Q.,CAS Lanzhou Cold and Arid Regions Environmental and Engineering Research Institute | And 8 more authors.
Hydrological Processes | Year: 2015

In arid region, direct infiltration from rainfall contributes little to groundwater compared with localized recharge from streams. How to quantify riverbed infiltration to groundwater systems is an important area of research in hydrology. In this study, saturated permeability coefficient of a riverbed in an arid inland river basin located in the northwest of China was obtained by Guelph Permeameter and laboratory analysis methods. The characteristics of riverbed infiltration and its spatial patterns were analysed using geostatistical method and kriging method. The results showed that the saturated permeability coefficient varied from 0.089 to 2.802m/d, indicating moderate degree of variability. The Guelph Permeameter and laboratory test methods provided consistent estimates of saturated permeability coefficient. There was a strong spatial correlation for Kfs of the riverbed in this study area when Range (A) was less than 0.276°, suggesting that the maximum sampling distance for saturated permeability coefficient of the riverbed was 0.276° under isotropic conditions. The Kfs near the centre of the riverbed was higher than the value near riverbank. The Kfs values decreased in the direction of upstream to downstream in the Heihe River Basin. The riverbed mechanical composition, initial soil water content and bulk density have significant influence up on the riverbed infiltration. Besides, the topographical factors including the width, altitude and distance factors of the riverbed together impacted the riverbed infiltration and the slope of the riverbed and also influenced the riverbed infiltration. © 2015 John Wiley & Sons, Ltd.


Guo X.,CAS Lanzhou Cold and Arid Regions Environmental and Engineering Research Institute | Guo X.,University of Chinese Academy of Sciences | Feng Q.,CAS Lanzhou Cold and Arid Regions Environmental and Engineering Research Institute | Feng Q.,Alashan Desert Eco Hydrology Experimental Research Station | And 3 more authors.
Arabian Journal of Geosciences | Year: 2015

Until now, most studies of the isotopic composition of precipitation in the Extensive Hexi Region have described individual sites. A systematic study considering the regional atmospheric circulation, the complex topography, and the re-evaporation process is lacking. This paper compares and summarizes previous studies in the Extensive Hexi Region, to provide a regional picture of the characteristics of isotopic composition of precipitation and moisture sources. δ18O and δD values exhibit significant seasonal variability, with higher values in summer and lower values in winter due to the seasonality of temperature and moisture sources. The temperature effect is more pronounced in the Extensive Hexi Region than in northwest China. The altitude effects are also evident with a gradient of −0.23 ‰/100 m for δ18O and −1.67 ‰/100 m for δD. But, the d-excess increases gradually with altitude, and the higher d-excess values occur at mountain sampling sites which are attributed to the difference of the secondary evaporation between mountains and plain. Finally, the moisture source in the study area was investigated, and the results show relatively complex patterns: the westerly and polar air masses dominate in winter; however, there are inconsistent results in summer. Whether or not the westerly air mass is the dominant supply of moisture in summer is yet to be determined. Additionally, in the course of reviewing and integrating, some new research questions are identified for future work. © 2014, Saudi Society for Geosciences.


Guo X.,CAS Lanzhou Cold and Arid Regions Environmental and Engineering Research Institute | Guo X.,Alashan Desert Eco hydrology Experimental Research Station | Guo X.,University of Chinese Academy of Sciences | Feng Q.,CAS Lanzhou Cold and Arid Regions Environmental and Engineering Research Institute | And 14 more authors.
Hydrological Processes | Year: 2015

Stable isotopic (δDVSMOW and δ18OVSMOW) and geochemical signatures were employed to constrain the geochemical evolution and sources of groundwater recharge in the arid Shule River Basin, Northwestern China, where extensive groundwater extraction occurs for agricultural and domestic supply. Springs in the mountain front of the Qilian Mountains, the Yumen-Tashi groundwater (YTG), and the Guazhou groundwater (GZG) were Ca-HCO3, Ca-Mg-HCO3-SO4 and Na-Mg-SO4-Cl type waters, respectively. Total dissolved solids (TDS) and major ion (Mg2+, Na+, Ca2+, K+, SO4 2-, Cl- and NO3 -) concentrations of groundwater gradually increase from the mountain front to the lower reaches of the Guazhou Basin. Geochemical evolution in groundwater was possibly due to a combination of mineral dissolution, mixing processes and evapotranspiration along groundwater flow paths. The isotopic and geochemical variations in melt water, springs, river water, YTG and GZG, together with the end-member mixing analysis (EMMA) indicate that the springs in the mountain front mainly originate from precipitation, the infiltration of melt water and river in the upper reaches; the lateral groundwater from the mountain front and river water in the middle reaches are probably effective recharge sources for the YTG, while contribution of precipitation to YTG is extremely limited; the GZG is mainly recharged by lateral groundwater flow from the Yumen-Tashi Basin and irrigation return flow. The general characteristics of groundwater in the Shule River Basin have been initially identified, and the results should facilitate integrated management of groundwater and surface water resources in the study area. © 2015 John Wiley & Sons, Ltd.


Wang Y.,CAS Lanzhou Cold and Arid Regions Environmental and Engineering Research Institute | Wang Y.,Lanzhou University of Technology | Feng Q.,CAS Lanzhou Cold and Arid Regions Environmental and Engineering Research Institute | Feng Q.,Alashan Desert Eco Hydrology Experimental Research Station | And 2 more authors.
Environmental Management | Year: 2013

The Ecological Water Transfer and Rehabilitation Project in the arid inland area of northwest China is an important measure in restoring a deteriorated ecosystem. However, the sustainability of the project is affected by many socio-economic factors. This article examines the attitudes of the local populace toward the project, its impact on the livelihood of the people, and the positive effects of water-efficient agricultural practices in Ejina County. Related data were collected through questionnaire surveys and group discussions. The results identified three critical issues that may influence the sustainability of the project in the study area. The first issue relates to the impact of the project on the livelihood of local herdsmen. The potential for the sustainability of the project is compromised because the livelihood of the herdsmen greatly depends on the compensation awarded by the project. The second issue is that the project did not raise the water resource utilization ratio, which may undermine its final purpose. Finally, the compensation provided by the project considers losses in agriculture, but neglects the externalities and public benefit of eco-water. Thus, appropriate compensation mechanisms should be established and adopted according to local economic, environmental, and social conditions. Some recommendations for improving the sustainability of the project are provided based on the results of this study. © 2013 The Author(s).


Xi H.,Chinese Academy of Sciences | Xi H.,Alashan Desert Eco hydrology Experimental Research Station | Xi H.,Gansu Province Eco hydrology Engineering Research Center | Xi H.,CSIRO | And 16 more authors.
Environmental Earth Sciences | Year: 2016

Ecologic patterns and community succession are generally controlled by hydrologic mechanisms, especially for plant distributions which are sensitive to habitat conditions. The hydrology characteristics of ecosystems mainly influenced plant ecological processes in water and salinity changes. In this paper, we analyzed the composition and characteristic of natural plant community, divided the plant community classes and discussed the effect of water and salinity gradients on plant species and community classes in Ejina Desert Oasis. The results demonstrated that Populus euphratica, Tamarix chinensis and Phragmites communis were the most important plant species that had the highest important values among forest, shrubs and herbaceous. Six plant community patterns were classified by cluster analysis in Ejina Desert Oasis. Species richness and species diversity were the highest near West River and East River channels of the core oasis area. The distributions of plant community were mainly influenced by the following factors: distance from river channel, groundwater level, soil water content, soil salinity and groundwater salinity. The water and salinity factors, which controlled the distributions of plant, were the main driving forces for ecosystem succession. The plant community succession is becoming toward the type of shrub + herb or low shrub with very drought-tolerant from the type of forest + shrub + herb with tall and high water consumption, when habitat conditions change from good to poor. The water gradients had more significant and more directed effect than salinity gradients on plant species and communities. © 2015, Springer-Verlag Berlin Heidelberg.

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