The Study Of Runoff Control Effect By Urban Trees And Its Application Strategy

Trees are an important part of the urban ecosystem.For a long time,the landscape architecture professional regards the trees as the design elements in the landscape construction.The water profession ignores the impact of trees on the urban rainfall runoff.This all ignores the functionality of the trees themselves.In fact,it is a common but neglected rainwater control facility that the trees use their own interception,transpiration,and infiltration to control the runoff during rainfall.However,how do the trees control the impact of runoff? What impact does the tree have on low-impact development and design in Sponge City? How to effectively use this part of the amount of rainwater control in the construction of the sponge city? This series of questions is the core issue of this article.This research reviewed the basic research and applied research of rainwater control functions of trees and summarized the rainwater control function components of trees,and the range and law of rainwater control effectiveness under different experimental conditions.At the same time,the U.S.as an example,In the developed countries,how to practically apply trees in rainwater management has been combed.The valuable practical experience of the United States and a relatively perfect planning standard system provide templates for the application of trees in the construction of sponge cities in China.In order to further discuss the effect of forest canopy interception on the control of runoff in relation to the actual conditions of urban garden trees in China,eight canopy interception monitoring experiments of common garden tree species were conducted in the Xicheng Campus of Beijing University of Architecture.The interception rates of different canopies and canopy interception volumes were studied.The influencing factors were discussed.In order to study the effects of canopy interception on the runoff of the entire study area in the experiment,a method for estimating the runoff control rate of interception production of forest canopy was proposed,and the influencing factors of the runoff control rate of interception production of forest canopy were discussed.Combining the canopy interception rules and annual rainfall historical data obtained from the experiment,statistics were made on the relationship between the canopy interception and annual runoff total control rate,rainfall control volume and other indicators and parameters,and the canopy interception versus urban runoff was proposed.The method of estimating the control effect is based on the current design methods of the sponge city design or the construction status of the pilot cities.The effects of canopy interception on stormwater runoff control and practical engineering significance are analyzed from the micro,medium,and macro scales.Finally,a systematic analysis of obstacles and strategies in the application of sponge-tree urban trees was conducted.It is hoped that the tree planting will be integrated into the construction of the sponge city from the aspects of guidelines,planning and standards systems.