地下水开采引起的平原灌区地面沉降的数值模拟

Numerical simulation of groundwater exploitation on land subsidence in plain irrigated area

针对地下水开采引起地面沉降的问题,以达西渗透定律和太沙基的一维固结理论为基础,设置两种布井方案,采用Processing Modflow软件模拟分析绥滨县290农场平原灌区的地面土体-水位变化。结果表明,模拟区域北部及东北部地下水位变化明显,中心区域水力坡度变化较大,地下水漏斗形状较为明显。整个应力期内,地下水位变化与地面沉降变化呈正相关性,单井出水量对地面沉降影响较大。开采总量相同、布井中心位置设9眼井且以240 m间距向四周均匀分布30眼井,地下水位线下降量与地面沉降量均较小,且趋势发展缓慢。该研究为地下水开采科学布井提供了参考依据。

This paper discusses the effort to address the land subsidence due to groundwater exploitation.The study drawing on Darcy,s penetration law and Tai-Sky,s one-dimensional consolidation theory is focused on the coupling calculation of the soil-water level changes in plain irrigated of Suibin County 290 farm using Processing Modflow software to calculate,and set up two types of well arrangement for simulation analysis.The simulation results show that there is a significant groundwater level change in the north and northeast of the simulated area;a greater change in the hydraulic gradient in the center area;the more obvious occurrence of the underground water funnel;the presence of a positive correlation between groundwater level change and land subsidence change during the entire stress period,and a great influence the single well output has on land subsidence;and the occurrence of a smaller change both in groundwater level subsidence and the surface subsidence,as in the case where there are the same total amount of mining and large density,along with a slower developing trend.The research may provide a reference for the scientific development of groundwater mining.