| Forest canopy interception plays a significant role in hydrological processes and water balance of a watershed. Moreover, the spatial heterogeneity of throughfall further complicates the hydrological processes and thus could significantly effects hydrological behavior if not properly addressed. Forests could not only influence the amount of rainfall arrived on the soil but also cause the unevenly distribution of rainfall due to for canopy spatial heterogeneity. Spatial heterogeneity of throughfall and interception are not only important factors on studying the circulation of water and nutrient on a forested hill-slope, but important parameter of hydrology model based on physical processing.Forty raingauges were installed evenly at grid size of 2m×2m (along contour lines and perpendicular to the contour lines) under a Chinese Pine (Pinus tabulaeformis) plantation canopy located on a hillslope of 32 degree in Miyun Reservoir watershed in 2004. Through analyzing by geo-statistics, we found the scale of observed data was within thoughfall's spatial self-correlation scale. So we adjusted the grid to 8m×8m. In 2004, 5 standard trees were selected to measure the stemflow in 20 trees by means of different diameter at breast height, while in 2005, 24 standard trees were selected in 155 trees. LI-COR LAI-2000 Canopy Analyzer was used to measure the leaf area index and cover at those 40 points where raingauge installed and standard trees in 2004 and 2005, respectively. Both traditional statistics and geo-statistics were used for the research and spatial heterogeneity analysis of throughfall was performed by using Geo-Statistical tool in ArcGIS.Traditional statistical analysis shows that the coefficient of variation (Cv) of throughfall tends to be declined as rainfall quantity and rainfall intensity increases. Throughfall Cv will be achieved its maximum value close to the LAI Cv value at 0.18 after canopy was... |
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