宝鸡市生产建设项目降雨侵蚀力算式及应用研究

Research and application of rainfall erosivity equations for the production and construction projects in Baoji City

加强生产建设项目水土流失防护是新时代水利部门工作的重点。利用2016-2018年宝鸡市周边30个气象站点日降雨数据,基于《生产建设项目土壤流失量测算导则》给出的R_(r)、R_(m)和R_(n) 3种降雨侵蚀力算式,分别评价不同算式的计算精度并给出推荐次序,在此基础上,分析宝鸡市生产建设项目降雨侵蚀力时空分布特征。结果表明:水土保持方案编制单位应优先选择R_(n)算式,其次是R_(r)算式,不宜使用R_(m)算式;利用本研究提出的R_(n)-R_(r)混合算式计算得到了年降雨侵蚀力等值线图和查找表,可分别满足线型和点型生产建设项目的需求;2016-2018年宝鸡市年降雨侵蚀力值在887.94~4276.88 MJ·mm/(hm^(2)·h)之间变化,且均从北向南逐渐增大;宝鸡市降雨侵蚀力存在两个高值区和两个低值区。本研究成果可为宝鸡市乃至关中天水经济区水土保持方案编制提供科学依据。

Soil erosion control for production and construction projects has become the focus of water conservancy entities in new era.Based on the daily rainfall data of 30 weather stations in Baoji and its neighbouring regions from^(2)016 to 2018,we calculated rainfall erosivity using R_(r),R_(m) and R_(n) equations,which were introduced from Guidelines for Measurement and Estimation of Soil Erosion in Production and Construction Projects.Then the recommending order of the equations was given on the basis of the prediction precision,and the temporal and spatial distribution characteristics of rainfall erosivity of Baoji production and construction projects was analyzed.Results showed that R_(n) equation was recommended as the first option in the design of water and soil conservation schemes,whereas R_(m) equation was the least favorable,thus R_(r) fell in between R_(n) and R_(m).The combination equation of R_(n)-R_(r) was then proposed to obtain the contour line and lookup table of rainfall erosivity,in order to meet the demands of the production and construction projects of linear and point types respectively.Rainfall erosivity during 2016-2018 ranged between 887.94 and 4276.88 MJ•mm/(hm^(2)•h),which showed an increasing trend from north to south in Baoji City.There were two high value zones and two low value zones of rainfall erosivity distributing in Baoji City.This study can provide some reference for the design of water and soil conservation scheme for Baoji and Guanzhong-Tianshui economic zone.