基于SCS-CN模型的半干旱黄土高原区秸秆炭覆盖集雨垄径流预测

垄沟集雨种植是缓解我国半干旱黄土高原区干旱、水土流失和土壤侵蚀的主要雨养农业技术.小流域水文模拟通常采用径流曲线数(Soil conservation service curve number,SCS-CN)模型.在标准SCS-CN模型中,由于径流曲线数CN值取值未考虑土壤水分动态变化,导致径流预测产生不合理的突变.以...

Runoff estimation of ridge-furrow rainwater harvesting with maize straw biochar application based on soil conservation service curve number(SCS-CN)model in semiarid regions of China

Ridge-furrow rainwater harvesting(RFRH)planting is the main rain-fed agricultural technology to address drought,water loss,and soil erosion in the Loess Plateau of central Gansu Province,China.Selecting suitable runoff estimation can effectively improve the utilization of water resources in this region.This paper analyzes the feasibility of the soil conservation service curve number(SCS-CN)model by considering the ridges with maize straw biochar application as the research object in the RFRH system.The runoff curve number(CN),as a basic input parameter of the SCS-CN model,is significantly affected by the antecedent moisture condition(AMC).The CN values,as categorical variables of three AMCs,do not consider the dynamic process of soil moisture between drought and wetness resulting in unreasonable sudden jumps in runoff estimation for the original development of the SCS-CN model.Thus,the modified curve number(MoCN)method proposed by Wang has been made to correct CN value based on continuous function between CN and AMC.The results showed that:(1)The CN values for the MoCN model is higher than the CN values for the SCS-CN model because the AMC value of the MoCN model is different from the SCS-CN model.(2)The runoff discharge measured and estimated by the MoCN model achieved relatively better agreement.Compared with the standard SCS-CN model,the Nash-Sutcliffe coefficient(Ef)of the MoCN model increased from 40%to 275%,and the correlation coefficient(r)of the MoCN model increased from 1%to 20%.Thus,the runoff estimation by the MoCN model is more reasonable and feasible in the RFRH system.This study provides a reference for an efficient utilization of water resources and soil and water conservation in this region.