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The spatial distribution of groundwater exploitation potential is crucial to the sustainable management of groundwater resources in arid regions. In this study, an effective approach is developed using a geographical information system (GIS) associated with the Dempster-Shafer (D-S) theory to explore the groundwater exploitation potential based on eight factors (i.e., slope, topography, distance to a river, canal density, lithology, land use, soil type, and groundwater depth)based on pumping test data. Different groundwater exploitation potential zones from the output map are classified as follows: very high (0.67–0.96, 8% of the total area), high (0.45–0.67, 8%), moderate (0.27–0.45, 14%), low (0.13–0.27, 24%), and very low (0.02–0.13, 46%), in the Hotan River basin of the Kunlun Mountains, China. The groundwater exploitation potential is highest in a gravel plain in the piedmont and gradually decreases from the piedmont to the desert. The predicted spatial variability of groundwater exploitation potential can explain 71% of the measured pumping test data. The uncertainty of the groundwater exploitation potential map ranges from

The ecosystem along the lower reach of Tarim River has been undergoing remarkable changes due to the ecological water conveyance activity since 2000. To improve the scientific basis of riparian restoration, the clearing understanding of the dynamic of eco-hydrological system and the feedback between hydrological and ecological components are needed. A fully distributed eco-hydrological model combines a hydrology component based on the modified MODFLOW, with a vegetation dynamic component described by Verhulst logistic equation. The validation of the eco-hydrological model using groundwater well observation, river stage observation and remote sensing data demonstrated that the good capability of the model in simulating the dynamic of the eco-hydrological system in lower reach of Tarim River. The interaction between the hydrological component and ecological component has been revealed through water balance analysis and scenario studies. Vegetation has a significant impact on groundwater evapotranspiration, groundwater storage change and groundwater depth, while groundwater depth is a critical feedback variable that determines the vegetation dynamics, which is shown by observation and simulation result. The eco-hydrological model represented in this study could help to groundwater dependent ecosystem restoration and protection, particularly for riparian ecosystem.

Groundwater is widely recognized as the most significant water resource for irrigation and drinking purposes in the extremely-arid inland river region. However, land use is a major force altering the hydrological processes over a range of temporal and spatial scales. Therefore, understanding the interaction between land use and groundwater processes will definitely contribute to formulate a regional sustainable development strategy and recognize the impact of land use on the groundwater flow regime in the Tailan River basin. A numerical simulation of groundwater level for the inland river basin and scenario analysis under land use using FEFLOW is presented. Spatial data of the regional land use were processed using GIS, and the effects of land use on groundwater level were simulated. The amount of irrigation water and pumped groundwater have the most remarkable influences on groundwater level as main source/sink factors. Their variations were simulated according to the irrigation systems with different crops. Other factors including percolation and evapotranspiration of precipitation and condensed water jointly exerted influences on groundwater level. Changes to farmlands had the greatest impact on Tailan River basin for groundwater level, and unused land and Gobi had the least impact on groundwater level. Groundwater level maintained a decreasing trend in the irrigated zone, and increasing groundwater pumping would further intensify the water shortage in Tailan river basin. This coupled effects resulted from land use and extensive groundwater pumping were considered as the major human-induced factors influencing the groundwater system in the extremely-arid inland river basins. The results can provide useful support for land use. Understanding hydrological processes at the watershed level is essential in land use and water resource planning and management, and the proposed approach can be used as a management and planning tool for evaluating the local and overall impacts of land use management on the surface and groundwater flow regimes.

Temporal changes in soil CO2 efflux rate was measured by a canopy gap method in a temperate natural shrub forest in the Central Asian Desert. Soil CO2 efflux rate in situ was correlated with key soil biotic (e.g. fungal, bacterial and actinomycetes populations) and abiotic (e.g. soil moisture, temperature, pH and organic carbon concentration) variables. Root and rhizosphere respiration originating from soil organic matter decomposition (Rd) were estimated from Rc (soil respiration under the crowns of Haloxylon ammodendron) and Rg (soil respiration in the gaps between H. ammodendron) of H. ammodendron. Contribution of root and rhizosphere respiration (Rr) to total soil respiration ranged from 13% to 94% during the growing season. Correlations of Rr with soil temperature and moisture were significant, but Rd was not significantly correlated with soil temperature and moisture. Microbial biomass, pH, soil organic carbon (SOC), total nitrogen (TN) and calcium carbonate (CaCO3) were analyzed in the soil. Rd with soil biomass and SOC were significantly correlated, whereas Rr was not significantly correlated with soil biomass and SOC. Effects of pH value, TN and CaCO3 on the two components of soil respiration (Rr and Rd) were not significant. Taken together, the data suggest that factors affecting seasonal changes of respiration were different between the two components of soil respiration: Rr was more sensitive to changes of temperature and moisture than Rd.