Study On Forest Hydrological Effects And Optimal Afforest Models Of Artificial Water Conservation Forest

The canopy interception,the litter and the physical and chemical features of the forestland is analysised in Miyun water resource zone.The grey system theory is used to analysis the main factors that affect the run-off coefficient,also the analytic hierarchy process is applied to determine the best area of different trees in Beizhuang district.The conclusion is following:(1) The canopy interception of Robinia Pseudoacacia,Pinus Tabulaeformis and Castanea mollissima reach to the max when the rainfall is 45.5mm,then the canopy interception gradually reduces.The canopy interception rate is first higher then lower with the decrease of the rainfall.The order of the composition of the litter is:leave＞branch＞bark＞fruit.The change scope of the litter accumulation is 3.2-12.62t/hm~2.(2) The TN and Organic matter is becoming lower with the soil depth increasing.The content TP of different forestryland is not significantly.The actual water storage is below:Robinia Pseudoacacia (2664.85t/hm~2,max),wasteland(1329.3t/hm~2,minimum).Yhe effective and lardgest theory soil water storage is below:the mixed forest(189.78mm,280.2mm,max),the wasteland(111.24mm,190.74mm, minimum).The permeability has power relations with the time.(3)The data of the grey correlative degree is below:the canopy density(0.584),the thickness of the litter(0.556),the modified interception(0.576),the soil bulk density(0.64),the largest water storage(0.614).The Pinus Tabulaeformis and Rhus typhina can increase the content of TN in the rainfall. The date is seperately 3.19mg/L,1.91mg/L The inefficient forest should be transformed to efficient mixed forest.The weights of different forests are below:the coniferous forest 0.1845,the broad-leaved forest 0.2540,the mixed forest 0.3798 the bush 0.1153,the economic forest.0.0664...