下辽河平原地区历史地面沉降情况研究

STUDY ON THE HISTORY OF LAND SUBSIDENCE IN LOWER LIAOHE RIVER PLAIN

地面沉降不但影响到下辽河平原地区的经济生产,而且导致湿地逐年退化,对生态环境产生非常严重的影响.该区域没有监测网络,无法知道具体的沉降范围和大小.为了查清下辽河平原历史地面沉降状况,有效地服务于地方经济发展和环境改善,首次在下辽河平原区域提出了地形图比对方法.通过搜集不同时期地形图,对同一高程点进行比对,结果表明下辽河平原地区围绕着油田集中采油区和地下水集中开采区,存在地面沉降现象,最大沉降量达到3 m.地形图比对有效地解决了下辽河平原无法确定沉降范围和量级的困难,是一种在没有监测网络的情况下,掌握工作区地面沉降情况的良好方法.

The ground subsidence in Lower Liaohe River Plain, which results in the degradation of wetlands, has seriously impacted on not only the local economy, but also the ecological environment. Without a monitoring network, the scopes and sizes of the subsidence in this region are not clearly known. In order to find out the historical land subsidence in Lower Liaohe Plain so as to effectively improve the local economy and environment, the terrain map matching method is put forward. By collection of topographic maps of different periods, the elevations for the same spots are compared. The result shows that the land subsidence does exist in and around the concentrated areas of the oil fields and the groundwater exploitation, with maximum subduction up to 3 m. The topographic map matching effectively solves the problems of determination of scope and magnitude of subduction in the Lower Liaohe Plain. It is a practicable method to know the subsidence situation without the network monitoring data.