Study On The Shallow Groundwater’s Dynamic Of Shihezi Agricultural Area And The Relationship With Ecotope

Groundwater is an important part of water resources, and it is particularly important tothe Northwest District for the relative lack of surface water resource and precipitation. Shihezireclamation area is located in typical arid region of the Northwest, and groundwater resourceis the main source of agricultural irrigation and domestic water. Due to the unreasonabledevelopment and utilization, the level and quality of groundwater is abnormal, so theproblems of groundwater resource have been paid more and more attention. The previousresearches are concentrated on Shihezi City about the level of groundwater, while pay a littleattention to other regions in the reclamation area, the quality of groundwater and ecologicalenvironment effects. This paper researches the temporal and special variation of groundwaterlevel and degree of mineralization, and the factors of groundwater regime by Surfer Softwareand ArcGIS Software, using Kring interpolation, interrelated analysis method of grey system,and inverse distance weighted. Then it studies the distribution of hydrochemical types andpreliminarily discusses the relationships between the dynamic change of groundwater and theecological environment. The main results are as follows:(1)From the temporal and spatial variation analysis of groundwater depth in thereclamation area from2008to2012, we can find that groundwater depth is large, and itchanges differently in different areas. The groundwater depths of121group,142group,145group and148group are on the rise from2011, the variation trend of135group and144group is increasing first, then decreasing, and at last increasing, while the groundwater depthof149group decreases first and then increases; from spring to autumn, the annual variation ofgroundwater depth decreases first, and then increases. By interrelated analysis method of greysystem，we know that the influence of evaporation to groundwater of121group is bigger,then it is rainfall, surface runoff and farm irrigation.(2)According to the distribution diagrams of the groundwater mineralization degree inthe reclamation area from2008to2012, we can see that the mineralization degree is high inthe north area and low in the south area. The mineralization degree of groundwater in2010isrelatively small in each region, and in2012, it reaches the maximum in most regions; FromApril to September, the mineralization degree of groundwater of the reclamation area is in theprocess of deceasing first and then increasing; From the northeast to the northwest, the mainhydrochemical types are Na-SO4·Cl, Na·Mg-Cl·SO4and Na-Cl·SO4, and in the central regionthey are Na-SO4·Cl and Mg-SO4·Cl.(3)From the perspectives of vegetation recession, soil salinization and desertification of the reclamation area, the paper discusses the relationships between the dynamic change ofgroundwater and the ecological environment. For the vegetation, if groundwater depth is toolarge, they will degenerate because of lacking water, resulting in land desertification; if theground water depth is too shallow, it is easy to cause soil salinization, for which thevegetation cannot germinate. Based on this, it puts forward the corresponding countermeasure,providing the basis for the improvement of the ecological environment.The results of this paper are significant to comprehensively mastering the variation trendof groundwater regime, making reasonable plans for exploiting groundwater, and protectinggroundwater resource, and they also provide the theoretical foundation for the sustainabledevelopment of agriculture and ecological environment in the reclamation area.