| Urbanization as the only road to modernization is a symbol of a country's level of development and civilization,and it is the country's greatest internal potential and its phreatic force for progress.As a basic natural resource and a strategic economic resource,water resources are the material basis for sustainable urban development.The rapid development of urbanization is inevitably based on water resources,and groundwater is an important part of water resources.It plays an important role in promoting the rapid development of cities,supporting social and economic development,ensuring the production and living of residents,and maintaining ecological balance.This thesis takes Xi'an as the research object and takes the underground phreatic system as the core to study the Xi'an underground phreatic system's response to the urbanization process and obtains the following research results:(1)Phreatic depth of Xi'an City,2015 Compared with 2001,the 5~10m buried depth area was reduced by 16.77%,nearly 15km2,distributed on the banks along the south bank of the Wei River and on both banks of the Chan River and Ba River;the area of the 10~20m buried depth increased by 15.47%.It is widely distributed in the second and third grade terraces of the Wei River and alluvial fan areas in the south;the buried depth is more than 20m;the high buried depth area is basically stable;and it is distributed from the Wei River water source area to the Sanqiao section and the east suburb Shilipu to the east,etc.The source of Sanzhao Town,Bailuyuan and other places.(2)Compared with 1990,the construction land area increased by 348.23km2,the single dynamic degree was 1.58%,the forest land area increased by 2131.35km2,the single dynamic degree was 2.92%,the cultivated land area decreased by 308.22km2,and the single dynamic degree was-0.36%;In the main city radiation area,the construction land area has increased from 248.69km2 to 447.88km2 with a dynamic degree of 3.2%.(3)Rainfall and flow caused by changes in land use during urbanization 2015 increased by 42.219 million m3 compared with 1990.In the main city radiation area,the rainfall output flow increased by 121.07 million cubic meters,and the rainfall infiltration supply decreased by 276.767 million cubic meters,which is essentially consistent with the dynamic change process of groundwater in Xi'an.(4)The groundwater system responded to the subway.During the construction period,dredging precipitation resulted in a drop in the phreatic level,which caused the ground settlement of the Zhangbabei Road Station to be 5.5~35mm,and the ground settlement of the Yanqingmen Station was 1.6~28.6mm.The inhomogeneity of the settlement was significant.In Well K273 of Metro Line 1,the water level buried in the construction period increased by about 3m,and the depth of water level at the water surface during the operation was reduced by about 2m.(5)The groundwater system responds to artificial water,and the water level in Kun Mingbasin rises at a rate of 0.5m/a.After the Xing Qinggong self-accumulates,the average annual increase of the diving water level reaches 2m or more,and Qu Jiangchi recharges the monthly leakage of groundwater.The amount reaches 63109m3 to 298707m3.(6)The groundwater system responds to disturbances caused by artificial mining,and the depth of groundwater dipping is increased by 4~7m under the mining conditions of Weibin water source area;in 2010,the annual exploitation volume of Wei River water source area is reduced by 2500×104m3,and the water depth deepens.It reaches 5.6m.The depth of water level in the Wei River water source site fluctuates significantly.The overall depth of water level rise at the recovery well point is 5.16 m,and the total depth of the decline well point is decreased by 1.78~4.76 m. |
PDF Full Text Request