天津滨海新区围海造陆对沿海低地浅层地下水环境的影响

摘要

天津滨海新区被提到国家总体发展战略后，随着经济持续发展、城市化进程不断加速及产业转移，进行了大规模围海造陆，在拓展土地空间的同时，也造成了相当多的环境问题。利用滨海新区由陆到海的3条水文地质剖面获取的地下水动态变化监测数据和土壤含盐量测试结果，开展了围海造陆对沿海低地浅层地下水环境的影响研究。结果显示：①受围海造陆影响，对应的沿海低地浅层水位已经出现由陆到海逐渐增高的现象，造成地下水位反向倾斜，阻碍了地下水径流和排泄；②由陆到海浅表土壤全盐量出现逐渐增高的特征，在浅层地下水反向径流作用下，东部区域大量的盐分将被携带至沿海低地，使沿海低地盐渍化程度加重，严重影响到湿地保护和生态建设；③围海造陆对海岸带生态环境的影响是一个长期缓慢的过程，应持续监测近岸海域和陆域沿海低地生态环境的变化情况，以便提出合理的修复建议。%Since Tianjin Binhai New Area was incorporated in the national development strategy, the construction of this new area has increased the landuse and hence caused considerable environmental problems as a result of large-scale land reclamation with sus⁃tainable development of economics and acceleration of urbanization and industrial transfer. In this study, the authors used three hydro⁃geological sections from the land to the sea to obtain the monitoring data of groundwater dynamic variations and soil salt contents, and discussed the environmental consequences of shallow groundwater in coastal lowland influenced by land reclamation. Overall, three conclusions have been reached:(1) Under the influence of land reclamation, the shallow water level in coastal lowland has grad⁃ually increased from the land to the ocean, causing the reverse tilt of groundwater level, which hinders the groundwater run off and drainage;(2) The salt content of topsoil gets higher from the land to the sea, and a large amount of salt is carried from eastern regions to the coastal lowlands, which makes the salinization more serious and wrecks the wetland protection and ecological construction;( 3) Land reclamation impact on the ecological environment of the coastal zone is a long slow process, and hence a continuous monitor⁃ing mechanism of the ecological environment changes in the coastal lowlands and waters should be set up so as to put forward reason⁃able suggestions for rehabilitating the ecosystem.