Xi'an, The Eastern Outskirts Of The Lower Part Of The Lishi Loess Permeability And Groundwater Enrichment Conditions

People has done many researches on the infiltration characteristics of modern surface soil, however vertical strata and water infiltration conditions of loess are rarely done. This study not only has important scientific significance on revealing water permeatbility,water space,vertical variation of water and its causes of the loess, but also has practical significance on identifying groundwater and soil water accumulation conditions in loess and water resources development. So a complete profile was chosen at Xinglin slope in Bailu tableland after detailed filed research, and many samples were collected and infiltration experiments from L1 to S15 layer of the profile were done in this paper. In the laboratory, we made porosity determination, magnetic susceptibility and content of CaCO3 determination. According to the experiments'results, we draw a conclusions as follows:(1) The average of stability infiltration rates of the loess layers at Xinglinpo profile in Bailu tableland is 0.88mm/min, and which of the paleosol layers is 0.36mm/min, the former is grater than the latter.(2) The average infiltration rates and the stability infiltration rates from L6 to S15 layer in Bailu tableland has showed the reducing trend, but there are fluctuations.(3) The experimental data leakages profile of three commonly used fitting formula derived infiltration in Xinglin slope, Empirical formula in the common experience of the three formulas can be generally applied to describe the infiltration characteristics from L6 to S15. The average and standard deviation for every parameter of three experience formula can provide practical reference for agricultural sector and others using the seeping experience formula.(4) The loess layers in Bailu tableland which have coarse grain size composition, large porosity and good aquifer space are easier to form the aquifer; the paleosol layers which have Smaller particle size composition, low porosity and less water space development are easier to form the impermeable layer.(5) CaCO3 TB in research profile exists in the bottom of the paleosol layers. And the CaCO3 TB has compact structure, and water is hard to reach, so it is easy to form the impermeable layer.(6) Magnetic susceptibility and CaCO3 test show as follows, Loess layer with water bearing space and strong permeability developing well is decided by cold-dry climate and rather weak pedogenesis. And paleosol with very weak permeability is decided by moist climate and rather strong pedogenes.