Research On The Rainfall Distribution Of Different Forests In Beijing Miyun Reservoir Area

According to the contents of this study, selected two experimental forests, in the zone of water resource conservation forest in Miyun, Beijing. There were two kinds of stands pure stands and mixed stands (the mainly dominant tree species orientalis, cork oak and live oak). respectively, it was a experception about the precipitation in two kinds of stands, analysis and comparison of rainfall interception, throughfall and stemflow in two experimental plots within different species of Pinus tabulaeformis and mixed; to study the rainfall interception in the trial period about a typical rainfall; compare the litters rainfall interception of two kinds of stands; and compare the soil moisture and physical properties of the two kinds of stands; Finally, use of the correction of the Gash analytical model to simulate the canopy interception of Pinus tabulaeformis and explore the applicability of the model in the experimental area.In two experimental Forest study area, Observed the rainfall interception by July to October,2010, combined with indoor experimental data, to analyze all the data obtained the following results:(1) Different species of canopy rainfall interception capacity was different, the sizes of the retention capacity of this study4species were:pine> vitae> Live Oak> cork oak. In the study of4kinds of trees there was a significant linear relationship between throughfall, stemflow and the rainfall outside of the forest.(2) Analysis the typical rainfall during the study period obtained:canopy not only in space to distribute rainfall into canopy interception, throughfall and stemflow but also in time, in different time periods because of the amount of rainfall, rainfall intensity, and other meteorological factors the distribution of rainfall may be different.(3) Observed the litter interception of two forests, combined with lab experiments, and come to get the data of litter maximum water-holding capacity and rainfall interception in different tree species. Litter maximum water-holding and rainfall interception of pine was1.5mm and33.25mm, the mix was1.6mm and31.69mm.(4) Analysis the soil physical properties, soil moisture and soil infilturation situation in different stand of forest. By comparing, in the test area, the tatio of the diameter of0.25mm to0.5mm soil aggregates was lower than>0.5mm; the aggregates of pine form0.5mm to5.0mm was in larger proportion, in the mixed, form0.5mm to2.0mm and gravel accounted for a larger proportion; the soil bulk density and storage capacity of pine was larger than the mixed; the initial infiltration rate of mixed was greater than the pine, while the anerage penetration rate and the total of penetration were less than the pine forest.(5) Use the correction of the Gash analytical model to simulate the canopy interception of the pine and expore the applicability of the model in the experimental area. Compare simulated and measured values and obtained that simulated and measured values are consistent. The relationship was that:y=1.329x-1.64R2=0.988Therefore we can get that the model can apply to the pine of the area canopy interception simulation.