季节性河道渗漏野外试验研究

Field Experimental Study on Infiltration in Seasonal River Channels

为研究季节性河流大沽河河道的渗漏规律,以包气带水分运动理论为基础,在大沽河上、中游建立有代表性的试验场,进行野外现场入渗试验,研究不同包气带岩性下河道的入渗能力。结果表明:干涸河道入渗过程可分为非稳定入渗和稳定入渗两个阶段;包气带的水理性质影响着河床的入渗规律,大沽河河道上游的入渗率比中游的入渗率大,上游和中游南沙梁村试验场的稳定入渗率分别为0.028cm/s和0.023cm/s;非稳定入渗过程为1.5～2.0h,其入渗量占总渗漏量的比例较小,并随时间逐渐减少,用稳定入渗率计算大沽河行洪期河道的渗漏量是可行的。

In order to find the leaking laws of seasonal Dagu River in Shandong Province,some typical test sited were established in the upper and middle reaches of the Dagu River,and the field infiltration experiments were conduced based on the theory of water movement in vadose zone. Capacities of infiltration in riverbed in different vadose zones were studied. The results show that the infiltration process in the dry riverbed could be divided into two stages,i.e. the unstable infiltration and stable infiltration; the infiltration in the riverbed was affected by the hydraulic properties of vadose zone,and the infiltration rate in the upper reaches was higher than that in the middle reaches. The stable infiltration rates in the upper and middle reaches were 0.028 and 0.023 cm/s respectively. The process of unstable infiltration varied in a range of 1.5-2.0 hours,the proportion of infiltration was low in the total leakage,and it was gradually decreased with the time. Therefore,it is feasible to calculate the total leakage by using the stable infiltration rate in riverbed in flood season.