南水北调济东明渠农田浸没问题研究

Study on Farmland Inundation Problem of Jidong Open Channel of the South-to-North Water Diversion Project

摘要:

南水北调济东明渠是山东省内重要输水通道,在运行过程中,渠道外局部农田受到一定的浸没影响。文章针对济东明渠某段堤内农田地下水浸没问题,根据农作物根系长度及土壤中毛细水上升高度的不同确定了轻微浸没和严重浸没两种程度的地下水临界埋深。基于GeoStudio软件下的SEEP/W模块构建了非饱和-饱和渗流数值模型,运用现状运行工况下的实测资料验证了模型的可靠性,并对设计水位和加大水位两种工况进行了渗流仿真运算,得到渠道在3种工况下输水运行时研究区内地下水位埋深的分布情况;研究了输水运行水位抬升对浸没面积的影响及其变化趋势,得出产生浸没的主要原因为渠道未进行防渗措施、截渗沟、农田排水系统不完善等,并提出建议。

Abstract:

The Jidong Open Channel of the South-to-North Water Diversion Project is an important water diversion corridor in Shandong Province. During operation, partial farmland outside the channel is affected by inundation. Aiming at the groundwater inundation of farmland inside the dike along a section of the Jidong Open Channel, this paper determines the critical groundwater burial depths for slight and severe inundation according to crop root length and capillary water rise height in soil. An unsaturated-saturated seepage numerical model is established by adopting the SEEP/W module of Geo-Studio software. The reliability of the model is verified by measured data under current operating conditions. Seepage simulation calculations are carried out under design water level and increased water level working conditions, and the distribution of groundwater burial depth in the study area under three water diversion operating conditions is obtained. The influence and variation trend of rising water transportation level on inundated area are studied. It is concluded that the main causes of inundation are lack of channel anti-seepage measures, imperfect interception drainage ditches and farmland drainage systems, corresponding suggestions are put forward.