塔里木河胡杨实现自我恢复的新方法探索

Exploration of New Methods to Realize Self-recovery of Populus Euphonium from Tarim River

针对塔里木河下游地下水位下降造成的胡杨生长胁迫问题,采用柱状换土的方法实现胡杨自我恢复,通过粉土、砂土和粘土三种不同土质的室内竖管法毛细水上升试验,优选出毛细水上升高度高、速度快的土壤用作换土试验,由3粉土不同初始含水率和填筑干密度的毛细水上升对比试验,得出了适宜的换填参数。三组试验表明,各土质中粉土毛细作用最优,^(#)1-(#)4粉土和^(#)7粉细砂20d平均最大上升高度分别为169.5、164.1cm,满足胡杨生长胁迫水位差129cm要求;粒度成分中0.05~0.005mm颗粒含量是决定毛细水上升高度的关键粒组,该颗粒含量越高毛细水上升高度越高;^(#)3粉土作为换填土,当初始含水率分别为3%、8%时,干密度分别为1.50、1.55g/cm^(3)的柱状土毛细水上升效果最好。

Aiming at the problem of populous euphratica growth stress caused by the decrease of underground water level in the lower reaches of the Tarim River,this paper studied the method of column soil exchange to realize the self-recovery of populus euphratica.By means of laboratory standpipe capillary water rising test of silty soil,sandy soil and clay,the soil with high rising height and fast speed of capillary water were selected as the soil changing test.By comparing the rise of capillary water in~#3 silty soil with different initial moisture content and filling dry density,the suitable filling parameters were obtained.Three groups of experiments show that the silty soil has the best capillarity in all soils.The average maximum ascending height of~#1-~#4 silt and~#7 fine sand for 20 days were 169.5 cm and 164.1 cm respectively,which met the requirement of 129 cm difference of water level under the stress of populous euphratica growth.The particle content of 0.05-0.005 mm is the key particle group that determines the height of capillary water.The higher the particle content is,the higher the height of capillary water is.When the initial moisture content of~#3 silty soil was 3%and 8%respectively,the capillary water of columnar soil with dry density of 1.50 g/cm^(3) and 1.55 g/cm^(3) had the best effect.