地面沉降对地下水可采资源的影响

Influence of Land Subsidence on Minable Groundwater Resources

为研究地面沉降对地下水可采资源量的影响,以华北地区沧州市为例,基于Biot固结理论,建立了地下水开采与地面沉降三维变参全耦合黏弹塑性数值模型.分别预测了2019-2030年按现状开采地下水,2031-2040年禁采(方案一);2019-2030年规划开采,2031-2040年禁采(方案二);和2019-2040年地下水持续禁采(方案三)三方案的地面沉降量和各个方案在2041-2050年的地下水可采资源量.结果表明,2041-2050年,方案一、方案二和方案三的地下水可采资源量分别为1.29×10^(8)m^(3)/a、1.35×10^(8)m^(3)/a和1.43×10^(8)m^(3)/a.方案二比方案一的累计地面沉降减少84.4 mm,地下水可采资源量多6×10^(6)m^(3)/a;相较于方案一,方案三发生了88 mm的地面回弹,地下水可采资源量多1.4×10^(7)m^(3)/a.说明了地面沉降严重的情况下,地下水可采资源量相对较少.

In order to study the impact of land subsidence on minable groundwater resources,taking Cangzhou City in North China as an example,based on Biot consolidation theory,a three-dimensional variable-parameter fully coupled viscoelastic-plastic numerical model of groundwater exploitation and land subsidence is established.Regarding groundwater mining from 2019 to 2030 based on current conditions and a ban on mining from 2031 to 2040(scheme 1),compression mining from 2019 to 2030 and a ban on mining from 2031 to 2040(scheme 2),and continuous ban on groundwater mining from 2019 to 2040(scheme 3),the land subsidence of each scheme is predicted,and the minable groundwater resources of each scheme from 2041 to 2050 are reasonably evaluated.Results show:from 2041 to 2050,the minable groundwater resources of scheme 1,scheme 2 and scheme 3 are 1.29×10^(8)m^(3)/a,1.35×10^(8)m^(3)/a and 1.43×10^(8)m^(3)/a,respectively.Compared with scheme 1,the maximum cumulative land subsidence of scheme 2 is reduced by 84.4 mm,and its minable groundwater resources increase by 6×10^(6) m^(3)/a.Compared with scheme 1,scheme 3 achieves a ground rebound of 88 mm,and its minable groundwater resources increase by 1.4×10^(7) m^(3)/a.These fully explain that the amount of recoverable groundwater resources is relatively small under the condition of severe land subsidence.