Effects of Land Use and Climate Change on Groundwater and Ecosystems at the Middle Reaches of the Tarim River Using the MIKE SHE Integrated Hydrological Model

Abstract

Abstract:The Tarim basin is a unique ecosystem. The water from the Tarim River supports both wildlife and humans. To analyze the effects of both land use and climate changes on groundwater, a research site was established at Yingibazar, which is a river oasis along the middle section of the Tarim River. A hydrological survey was performed to assess the general water cycle in this area with special emphasis on groundwater replenishment as well as the impact of agricultural irrigation on the riparian natural vegetation with respect to salt transport and depth of groundwater. Although high-resolution input data is scarce for this region, simulation of water cycle processes was performed using the hydrological model MIKE SHE (DHI). The results of the calibrated model show that natural flooding is the major contributor to groundwater recharge. There is also a close interaction between irrigated agricultural areas and the adjacent natural vegetation for groundwater levels and salinity up to 300 m away from the fields. Furthermore, the source of water used for irrigation (i.e., river and/or groundwater) has a high impact on groundwater levels and salt transportation efficiency. The ongoing expansion of agricultural areas is rapidly destroying natural vegetation, floodplains, and their natural flow paths. Our results show that more unstable OPEN ACCESSWater 2015, 7 3041annual Tarim floods will occur in the future under the background of climate change. Therefore, integrated hydrological simulations were also performed for 2050 and 2100 using MIKE SHE. The results confirm that after the glaciers melt in the Tian Shan Mountains, serious aquifer depletion and environmental degradation will occur in the area, causing great difficulties for the local people.

Relating Water Use to Tree Vitality of Populus euphratica Oliv. in the Lower Tarim River, NW China

“…Logger installation, sensor design and measurement principles were provided in detail in Keilholz et al [24,35].…”

“…However, in terms of water shortage in this region, the insurance of long-term water transferring and the virtuous cycle of ecological environment depends on the rational and efficient usage of limited water resources, which includes the scientific allocation of water for irrigated agriculture, nature and ecosystem conservation, as well as for industry, oasis settlements and human well-being [4,[21][22][23][24]. Therefore, it is important to estimate the water use of riparian forests in the lower Tarim River for providing scientific reference to the water management authorities.…”

Water in Central Asia: an integrated assessment for science-based management

“…In a global perspective, Central Asia is one of the regions with the highest proportion of discharge formed in mountain areas (Viviroli and Weingartner 2004). One of the most prominent examples is the Tarim River, which is almost entirely fed by precipitation in its mountainous headwater zone, which sharply contrasts with the hyperarid deserts farther downstream (Keilholz et al 2015). High mountain zones are not only important source areas for Central Asia's streams, but glaciers and snow pack also provide an intermediate storage of water resources.…”

Nitrogen and phosphorus transformations and balance in a pond-ditch circulation system for rural polluted water treatment

“…In that case, physically based models, which are independent of historical statistics and are able to change the model depending on modification of the specific parameters according to changes in the environmental factors, are necessary in order to provide a more confident prediction. Consequently, predictions employing the MIKE SHE model have become more and more popular in recent years, as in studies of the impact of past and future land-use changes on hydrological processes related to the complex surface-groundwater interactions in the watershed of the Elbow River, covering an area of 1238 km in Alberta (Wijesekara et al, 2014); a simulation study demonstrating how the composition and configuration of land use measures affect discharge at the catchment outlet differently in response to storms of different sizes (Kalantari et al, 2014); an assessment of the respective impacts of land use change and climate change on decadal streamflow through use of three complementary models (Wang et al, 2013); a predction of land use and climate change influence on groundwater and ecosystems at the middle reaches of the Tarim River (Keilholz et al, 2015).…”