Research On Commonjunctive Sustainability Of Groundwater Resources And Wetlands In Xiongan New Area

In the past 40 years,affected by a series of human activities,the groundwater level in the plain area of Baiyangdian basin has been declining significantly;at the same time,the area of Baiyangdian Wetland,the largest surface water body in the basin,has also been decreasing,and both groundwater resources and wetland surface water resources are facing unsustainable problems of continuous consumption.From the perspective of the conjunctive sustainability of groundwater resources and wetland surface water in Xiongan New Area,based on the remote sensing extraction and analysis of the evolution process of wetland area,this paper quantitatively analyzed and identified the main reasons for the degradation of wetland area,and calculated the ecological water demand of Baiyangdian wetland in different hydrological years;By establishing a numerical model of groundwater flow in the plain area of Baiyangdian basin,the scheme of sustainable utilization of groundwater resources in the basin plain is proposed.Under the background of sustainable regional groundwater resources,based on the future planning of the Xiongan New Area,the exploitable amount of groundwater resources and the amount of water transferred under the joint sustainable development of groundwater resources and wetlands in Xiong'an New Area in the future is calculated.The main achievements of this paper are as follows:(1)An improved humidity component method suitable for remote sensing extraction of Baiyangdian wetland area was proposed,and the evolution process of wetland area of annual sequence scale from 1960 to 2016 was supplemented by constructing the relationship between the extraction of wetland area and Baiyangdian water level.According to the idea of comprehensive identification method,the area of reed and open water was separated and extracted,and the yearly change rule of wetland components was analyzed.(2)The quantitative analysis of the influencing factors of wetland evolution shows that the correlation coefficient between the difference between the inflow runoff and irrigation water volume and the wetland storage variables reached 0.91.The decrease of inflow caused by human activities such as the retaining of upstream reservoir and irrigation area,irrigated farming around the wetland is the main driving factors for the degradation of Baiyangdian wetland area.According to the calculation,the ecological water demand of wetland is 1.69×10~8m~3/a,2.73×10~8m~3/a and 3.57×10~8m~3/a respectively in the wet year,the normal year and the dry year.(3)Based on the numerical model of groundwater flow in the plain area of Baiyangdian basin,through the simulation,prediction and analysis of groundwater level changes and funnel recovery under different policy and plan,a scheme for sustainable utilization of groundwater resources in the plain area of Baiyangdian basin is proposed.Under the scheme,the groundwater recovery amount by river is 1.63×10~8m~3/a,the water-saving and limited mining measures reduce the groundwater exploitation amount of 5.68×10~8m~3/a and 1.60×10~8m~3/a respectively.During the 30years of simulation and prediction period,the groundwater level in the plain area of Baiyangdian basin no longer decreased and the funnel recovered slowly.(4)Under the background of sustainable utilization of groundwater resources in plain area of Baiyangdian basin,the exploitable amount of groundwater resources in Xiongan New Area is 1.78×10~8m~3/a,and the amount of water transferred in the near,medium and long term planning period of the Xiongan New Area is 5.60×10~8m~3/a,9.77×10~8m~3/a and 9.97×10~8m~3/a respectively.