黄土高原适于造林的雨水收集系统设计方法

根据黄土高原地区降水缺乏的自然条件 ,该文提出了 30 0mm到 6 0 0mm地区用于造林的集水设计与施工方法 .这种集水系统由不同形式、大小的种植区与产流区组成的微型集水区形成 ,其设计依据主要是降雨、产流区的径流系数、来自树木和土壤的蒸散、土壤水分亏缺及降水资源环境容量等等 .经过YJG(有机硅化学处理 )处理的产流区、拍光压实产流区和自然坡面的径流系数分别为 0 8 0 89,0 2 3 0 36 ,0 0 8 0 10 根据彭曼法计算的土壤水分亏缺量在 5 0mm到 30 0mm之间 .在降雨量为 4 0 0mm的地区经过YJG处理之后用材林每株林木的产流面积为 3 4m2 ,经济树种为 8 10m2 ;经过压光拍实处理之后用材林每株林木的产流面积为 6 8m2 ,经济树种为 10 12m2 ;自然坡面对于用材林每株林木的产流区面积为 8 10m2 ,经济树种为 12 15m2 采用这种系统经过YJG处理产流区、拍光压实产流区和保持自然坡面的微型集水区中树木的蒸腾量分别是总集水量的 4 7 6 5 % 5 3 31% ,2 4 10 % 36 93%和 18 6 5 % 2 9 5 5 % .这种大面积应用于黄土高原地区的系统被称为径流林业 .

Design Method of Rainwater Harvesting System for Afforestation in Loess Plateau

On the basis of natural conditions of lack of rainfall on the Loess Plateau, this paper presents a method of design and construction in rainwater harvesting system for afforestation, which is suitable to the regions of 300 600?mm rainfall. The system consists of micro catchments of various forms and sizes that include planting areas, where trees are planted and trapped runoff, and contributing areas, where overland flow are produced by rainfall. The design is based on rainfall, runoff coefficients of contributing areas, evapotranspiration of trees and soil surface, water deficiency of soil, and environmental capacity of precipitation in the region, and so on. Runoff coefficient of contributing areas with YJG (organic silicon chemical treatment), compacted surface soil slope and natural slope micro catchments, are 0 8 0 89, 0 23 0 36, and 0 08 0 10 respectively. According to the Penman method, the soil water deficiency varies from 50?mm to 300?mm. In the region of 400?mm precipitation, the contributing area treated with YJG is 3 4?m 2 for timber forests, 8 10?m 2 for cash trees respectively; the contributing area treated with compacted soil surface is 6 8?m\+2 for timber forests, 10 12?m 2 for cash trees respectively; the contributing area of natural slope is 8 10?m 2 for timber forests, 12 15?m 2 for cash trees respectively. Transpiration from trees of micro catchment in YJG, compacted surface soil and natural slope treatment is by 47 65% 53 31%, 24 10% 36 93%, and 18 65% 29 55% of total rainfall (rainfall and harvested rainwater) respectively after the system was applied in the region. This system, which has been widely practising on the Loess Plateau, is now known as runoff forestry.