Study On The Canopy Hydrologic Characteristics And Data Management System Of Urban Forest In Xiashu Of Jiangsu Province

Rainfall redistribution by crown layer was monitored from May to September in 2003 in the oak and bamboo forests in Xiashu of Jiangsu Province, with its relational vegetation and precipitation characteristics and other meteorological conditions. After analyzing these observed data, the results as follows are got:1. In the oak forest, the canopy interception, throughfall, stemflow during the flood season respectively was 24.79%,73.11%,2.3% of total gross rainfall while in the bamboo forestry, was 19.42%, 76.99%,3.8%.The canopy interception of the oak forest was larger than that of the bamboo forest's, which indicates the canopy interception is not always in line with canopy cover fraction, but is impacted by synthetic affection of vegetal characteristics.2. Comparing the rainfall redistribution in 1990 with in 2003 at the same oak forest research site, we can find that the rate of canopy interception rose from 20.02% to 24.79% with the canopy cover fraction rising from 0.86 to 0.93. This result shows the canopy interception has the increasing tendency with the raise of canopy cover fraction in the same forest.3. Meteorological factors influence the rainfall redistribution by crown layer. The research showed the 8 meteorological factors, including rainfall, air temperature, relative humidity and evaporation capacity during the raining, relative humidity and evaporation capacity of the interval of precipitations, last rainfall, interval days of precipitation, have a good linear regressive relationship with the canopy interception, throughfall and stemflow.4. In the same forest, the canopy interception and throughfall were dominatingly impacted by the same meteorological factors which hadn't the same effect on the stemflow. In the oak forest, the canopy interception and throughfall were mainly affected by the rainfall and evaporation capacity of the interval of precipitions and the stemflow was mainly by rainfall, evaporation capacity during the raining, last rainfall and air tempertature.In the bamboo forest, the mainly impacting meteorological factors for the canopy interception and throughfall are rainfall, last rainfall and air temperature as well as rainfall and air temperature for the stemflow.5. The rainfall redistribution by crown layer is related to some of meteorological factors, especially to the water quantity of precipitation. The throughfall and the stemfall of the bamboo forest are line with the rainfall as well as the canopy interception, stemfall of oak forest, the rate of canopy interception; throughfall and stemfall are in power relationship with rainfall.6. The canopy interception, throughfall, stemfall of both forests were respectively different, which accounts for the characteristics of forest, including the characteristics of forest's canopy affect the rainfall redistribution by crown layer.7. After analyzing the relationship of all kinds of data, build the data management system of foresi: hydrologic research in the urban forest ecoiogic permanent research station in Xiashu Country Jiangsu Province.