土壤水非均匀流动网络特性实验

Experimental research on network characteristics of soil non-uniform flow

土壤中的优先流是指土壤在整个入流边界上接受补给,但水分和溶质绕过土壤基质,只通过少部分土壤体的快速运移.优先流的产生是由于土壤中往往存在大量的根孔、虫孔等大孔隙以及裂隙等.搞清优先流对土壤水分运动的影响,对于深入认识入渗补给过程、准确评价地下水补给资源以及地下水污染分析具有重要意义.本研究采用大分子染色材料(Brilliant Blue FCF)及根据碘与淀粉反应显现出蓝色的原理,设计实施了土壤中非均匀水流运动的室外染显色示踪实验,研究了土壤水非均匀流动模式,验证了优先流的水流通道网络特征.

Preferential flow refers to such a flow transport pattern that water and solute flows round the soil matrixes, which contributes to accelerate the movement velocity in the soil; and soil recharge happens on the whole inlet boundary. Preferential flow is produced by a large number of macropores and fractures in the soil, such as root hole, wormhole. Preferential flow is of great importance to groundwater recharge due to its quick movement. For knowing the process of infiltration recharge , evaluating the recharge source of underground water and analyzing subsurface water pollution, it＇s great significant to research the influence of preferential flow to soil moisture transport. In this study, according to the principle that iodine turns to blue after reacting with starch, outdoor tracer experiments of heterogeneous flow in clay loam are designed, from which the heterogeneous flow patterns are studied; the system from micro-soil structure to macro-flow movement is established.