Spatiotemporal Changes in Hydro-chemistry of Groundwater in Irrigation District within the Kaidu River Basin北大核心CSCD

【Objective】This paper studied the spatiotemporal changes in hydro-chemical properties of groundwater in irrigation districts within the Kaidu River basin, as well as the factors that affect these changes.【Method】Groundwater samples were taken in January, March, July and September in 2017 from the irrigation area in the Kaidu river basin. Spatiotemporal change in hydro-chemical properties of the groundwater and its impacting factors were analyzed using statistics, spatial interpolation, and Piper and Gibbs diagram.【Result】①The groundwater quality was generally good, with low TDS and being dominated by HCO-3, Na+, Ca2+ and SO2-4. The mean TDS was high in winter and low in summer, and it was related to the depth of groundwater table. ② Na+, Ca2+ and SO2-4 varied erratically both in time and space. ③The hydro-chemical type of the groundwater in the studied area was HCO-3-SO2-4-Na+-Ca2+, and remained almost unchanged in the four seasons. ④The rock weathering appears to affect the hydro- chemical propertied of the groundwater most. The impact of human activities was mainly in spring, summer and autumn in the oasis and lakeside region, and it was stronger in irrigation season than in non-irrigation season.【Conclusion】Our results suggest that pumping groundwater for irrigation should be rationally managed and the associated change in chemical properties of the groundwater should be monitored; this applies not only to the studied sites but also to regions on the southern slope of the Tianshan Mountain. © 2019 Authors. All rights reserved.