Study On The Character Of Slop Runoff Of Forests Stand In Jinyun Mountain

Based on the typical forests stand in Yangtze River, the paper study for the process and characteristics of rainfall and runoff of broad-leaved forest, bamboo fores, shrub land and mix forest.The data observed from 2002y to 2007y. By using some mathmatics way, such as stochastic component and relativity, paper shows characteristics in different time scales. By fractal dimension, paper analyzes the runoff parameters.By detrended fluctation analysis (DFA), paper predicts the future of runoff in different forests.Research shows that the average annual rainfall is about 1263.4mm, more concentrated rainfall in the year from April to September, the peak appears in July. Annual rainfall is distributed more evenly, the distribution of relatively stable during the year. Annual rainfall is independently, there is no significant correlation among the years. There are about 170.8d rain days a year, 14.2 days month in the mountain in averag, From July to September, the runoff takes more than 90% in a whole year, that similar in the four types of vegetation, the maximum in July. Mixed forest is the most uneven distribution of run-off during the year, followed by shrub, broadleaved forest and bamboo forest.Research shows, during the process of the impact of vegetation to runoff,that mixed forest has the most obvious extension of the rain forest, followed by broadleaved forest, shrubs, bamboo forest; and broadleaved forest reduce the runoff amount most, followed by shrub, mixed forest, bamboo forest. Water-holding capacity of the four types of forest litter in the order: mixed> broadleaved forest> bamboo forest> shrub. Soil water-holding capacity in the order: mixed> broad-leaved forest> shrub> bamboo forest. Broad-leaved forest canopy interception most, followed by mixed forest, shrubs, bamboo forest.The conclusion shows that the impact factors of mixed forest is: height, a high degree of biodiversity, precipitation (rainfall, rainfall intensity, rainfall duration), litter (the largest holders of water, the thickness), canopy volume, and all the impact factors of broadleaved forest, bamboo forest, scrub is: height a high degree of biodiversity, precipitation (rainfall, rainfall intensity, rainfall duration), litter (the largest holders of water, the thickness), canopy, soil porosity.This study provides theoretical support and technical reference not only for the building of local vegetation to, but also for the accumulation of research in the field of a certain idea of research and analysis tools.