冻融作用对WEPP模型细沟可蚀性参数的影响OA
Effect of freeze-thaw cycles on rill erodibility parameters in WEPP model
[目的]探究冻融循环作用对WEPP模型估算细沟可蚀性参数的影响规律,为提高模型在季节性冻融区侵蚀预测的精度提供科学依据.[方法]以东北典型黑土区农耕地土壤为研究对象,设置不同放水流量(1,2,3 L/min)、冻融循环次数(0,1,3,5,10次)及初始土壤含水量(质量含水量16.5%,24.8%和33.0%),通过控制条件室内模拟冲刷试验,研究冻融循环作用与初始土壤含水量共同作用对细沟剥蚀率和可蚀性变化的影响,并基于实测临界剪切力评估WEPP模型细沟可蚀性参数在冻融循环作用下的可靠性.[结果](1)冻融循环次数和初始土壤含水量对黑土细沟剥蚀率具有显著影响(p<0.01).随着冻融循环次数和初始土壤含水量的增加,细沟剥蚀率逐渐增大,且在1次冻融循环作用下增幅最大,3～5次冻融循环作用后趋于稳定.此外,初始土壤含水量的升高加剧了冻融循环作用对剥蚀率的影响.(2)黑土细沟平均可蚀性值为3.6×10-3 s/m,冻融循环作用使其增加1.84倍.未冻结条件下,WEPP模型表现出较好的拟合效果;而在冻融循环作用下,WEPP模型对临界剪切力呈整体高估现象,平均高估幅度为58.59%.[结论]冻融循环作用显著增加细沟剥蚀率和可蚀性,且初始土壤含水量的升高加剧了这一影响,此外,冻融循环作用下WEPP模型估算可蚀性参数的不确定性增大.
[Objective]This study investigates the effects of freeze-thaw cycles on the rill erodibility parameters estimated by the Water Erosion Prediction Project(WEPP)model,aiming to provide a scientific basis for improving the model′s accuracy in predicting erosion in seasonal freeze-thaw regions.[Methods]Agricultural soil from a typical black soil region in Northeast China was selected as the research object.Different water discharge rates(1,2,3 L/min),number of freeze-thaw cycles(0,1,3,5,10 cycles),and initial soil moisture contents(16.5%,24.8%,and 33.0%by mass)were set.Laboratory simulated scouring experiments under controlled conditions were conducted to investigate the combined effects of freeze-thaw cycles and initial soil moisture on rill erosion rates and erodibility variations.Additionally,the reliability of the WEPP model′s rill erodibility parameters under freeze-thaw cycles was evaluated based on measured critical shear stress.[Results](1)Both the number of freeze-thaw cycles and initial soil moisture content significantly influenced rill erosion rates(p<0.01).As the number of freeze-thaw cycles and initial soil moisture content increased,the rill erosion rate progressively increased,with the greatest increase observed after the first freeze-thaw cycle,followed by stabilization after 3～5 cycles.Moreover,an increase in initial soil moisture content intensified the effect of freeze-thaw cycles on the erosion rate.(2)The average rill erodibility of black soil was 3.6×10⁻3 s/m,which increased by 1.84 times under freeze-thaw cycles.Under unfrozen conditions,the WEPP model demonstrated satisfactory fitting performance.However,under freeze-thaw cycles,the model generally overestimated critical shear stress,with an average overestimation of 58.59%.[Conclusion]Freeze-thaw cycles significantly increase rill erosion rates and erodibility,with higher initial soil moisture content intensifying these effects.Furthermore,the WEPP model demonstrates increased uncertainty in estimating erodibility parameters under freeze-thaw cycles.
Zhang Zhiyi;Wang Bin;Wang Wengang;Liu Yicheng;Zhou Xiao
School of Soil and Water Conservation,Beijing Forestry University,Beijing 100083,ChinaSchool of Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China||National Forest Ecosystem Observation and Research Station of Jinyun Mountain,Three-Gorges Reservoir Area(Chongqing),Beijing Forestry University,Beijing 100083,ChinaSchool of Soil and Water Conservation,Beijing Forestry University,Beijing 100083,ChinaSchool of Soil and Water Conservation,Beijing Forestry University,Beijing 100083,ChinaSchool of Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China
农业科技
临界剪切力冻融循环作用初始土壤含水量WEPP模型细沟可蚀性
critical shear stressfreeze-thaw cyclesinitial soil moisture contentWEPP modelrill erodibility
《水土保持研究》 2026 (1)
54-62,70,10
国家自然科学基金项目"复杂界面冻融—融雪—渗流多场耦合驱动的黑土区沟道侵蚀动力机制"(42477338)
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