The Runoff Process In The Small Watershed Of The Typical Steppe Region In Inner Mongolia Province

In order to research the differences of soil infiltration of different vegetation types in Duo Lun county typical steppe region, Soil infiltration process was simulated to analysis their characteristics and differences through field investigation and soil infiltration test and manual water discharge experiment. on the basis of soil infiltration study, This paper discusses the process and mechanism of basin runoff and the prediction model was constructed for the theoretical basis of the discharge runoff and rainwater resources use. The results indicated that:(1) The initial and stable soil infiltration rate in different vegetation types and slope were in the same order:sunny slope grassland>the top of slope grassland>the midslope grassland>the roof of slope grassland>the midslope prunus armeniaca>the shady slope shrub lespedeza; The range of which was about3.578to4.854mm/min and0.813to1.072mm/min.(2) There was significant difference of Soil infiltration process. the soil infiltration rate of grassland falls down slowly in the early stage and rapidly after5minutes, until it reaches the stable infiltration rate, but the rate of infiltration of the forest land was always drop down slowly.(3) The soil infiltration characteristics of different vegetation type in DuoLun county typical steppe region can well reflected and described with Horton model, Kostiakov model and Philip model; But horton model getted the best fitting effect; The value of R2were in the range of0.813to0.870,0.916to0.972,0.693to0.775.(4) Along with the increase of raininess, runoff duration is reduced gradually, runoff deep and runoff coefficient increase gradually in each samples. Runoff pred-iction model were constructed based on motion wave model and Horton infiltration model in the study area, the result was that had higher precision.