对“用调整地下水开采层次方法控制地面沉降”的质疑

Discussion to the paper "control the land subsidence by adjusting the exploitation stratum of groundwater"

据不完全统计,至今我国已有90余个城市和地区相继发生不同程度的地面沉降,长江、黄河、珠江三角洲、华北平原、松辽平原及沿海许多地区,地面沉降正在发生和发展之中,尤其以上海为中心的长江三角洲及以天津为中心的华北平原,成为我国两片最大的沉降地区。地面沉降对这些地区社会和经济的可持续发展带来严重影响。几十年来,这些地区一直将“调整地下水开采层次”作为控制地面沉降措施之一。该文章认为“调整地下水开采层次”并非一种理想的控沉措施,不仅值得商榷,甚至为应该被否定的控沉措施。依据:①一般情况下,随深度增加,地层的压缩性会渐下;但是开采同量的地下水,其水位下降的速率及幅度深部含水组比浅部含水组要大的多,两者引起的沉降量不会有明显的差别;②从地下水开采资源组成与地面沉降关系分析,含水层深度越深,其中的压密释水量所占的比例也越大,造成的地面沉降也越严重;③地层的物理力学性质及固结状态,随深度的增加,也不完全是越来越好。

Up to now, according to incomplete statistics, ground subsidence occurred with different degree in 90 cities or regions in China. Land subsidence developes in Yangtze River Delta, Yellow River Delta, Pearl River Delta, Northern China plain, Songliao plain and other areas along the sea coast. Particularly, the Yangtze River Delta, regarding Shanghai as the center, and northern China plain, regarding Tianjin as the center, become the biggest land subsidence regions in our country. Ground subsidence affects the continuous development of society and economy seriously in these regions. In the past decades, ＂adjusting the stratum of groundwater＂ was considered as one of the useful measures for controlling the land subsidence. But in this discourse the authors don＇t think it is an ideal control measures. And even should be negated. The basis is ： 1. Usually, with the increasing of depth, the compressibility of strata will be monished. But when we mine commensuration groundwater, the falling velocity water level and range of the deep hydrous stratum are bigger than the shallow hydrous stratum. And the quantity of subsidence is not obvious different. 2. Analyzing the relation between the stratum of groundwater and land subsidence, with the depth of aquifer bed increased, the proportion that the released water because of compressibility of strata possessed become bigger, and it cause land subsidence more serious. 3. The physical and mechanical properties and the consolidation state of stratum do not become better with the depth increased.