土水比指标在天津沉降区地下水资源管理中的应用

天津地面沉降形势严峻,加强地下水资源管理是控制地面沉降的关键。理论和实践证明,可开采量和临界水位等地下水资源管理指标,其可操作性不强。为此,在综合分析沉降区内地下水开采量和地面沉降所引起的土方损失情况的基础上,提出了一种新的地下水资源管理指标——土水比。研究结果表明:土水比能够指示地面沉降相对于地下水开采的易发性以及沉降区内的地下水资源保障程度;将土水比作为沉降区地下水资源管理的指标,就可以确定出不同级别的沉降易发区域以及地下水资源的保障程度,了解开采条件下地下水资源的补给能力,从而可保证地下水开采不消耗地下水储存资源,有效监控和防治地面沉降。

Application of ratio of soil loss to groundwater-exploitation in groundwater management of Tianjin land subsidence area

Land subsidence occurs at a high rate and with a wide distribution in Tianjin City. Strengthening the management of groundwater resources is the key to controlling land subsidence. It was proved theoretically and practically that the exploitable groundwater and critical water level used as the indexes of environmental capacities of groundwater were not the operational parameters in groundwater management. For this reason, based on comprehensive analysis of the soil loss due to the quantity of exploited groundwater and subsidence of the land, a new index for water environmental capacity is proposed：the ratio of soil loss to groundwater exploitation. The results from this study show that the ratio can indicate the land subsidence readily resulting from groundwater exploitation, and also the guarantee degree of exploration of groundwater resources in the land subsidence area. Using the ratio of soil loss to groundwater-exploitation as a reference index for groundwater management, areas with different degrees of vulnerability to land subsidence and guarantee degrees of extracting groundwater resources can be determined, the supply capacity of groundwater resources under exploitation can be quantified, and therefore extraction of groundwater without consumption of the storage of groundwater resources, can be ensured, enabling the effective monitoring and control of land subsidence.