黄土高原不同降雨强度下生物土壤结皮对坡面流水动力参数的影响  

Effects of Biological Soil Crust on Dynamic Parameters of Slope Flow Under Different Rainfall Intensities in the Loess Plateau

作　　者：张宝琦 王兵 许欢欢[2] 张慧妮 马金龙 Zhang Baoqi;Wang Bing;Xu Huanhuan;Zhang Huini;Ma Jinlong(Xifeng Soil and Water Conservation Scientific Experimental Station,Yellow River Water Conservancy Commission,Qingyang,Gansu 745000,China;State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Institute of Soil and Water Conservation,Northwest A&F University,Yangling,Shaanxi 712100,China;Institute Soil and Water Conservation,CAS&MWR,Yangling,Shaanxi 712100,China)

机构地区：[1]黄河水利委员会西峰水土保持科学试验站,甘肃庆阳745000 [2]西北农林科技大学水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨凌712700 [3]中国科学院水利部水土保持研究所,陕西杨凌712700

出　　处：《水土保持研究》2024年第3期128-134,共7页Research of Soil and Water Conservation

基　　金：国家自然科学基金面上项目“坡面土壤分离与泥沙输移耦合关系对生物结皮发育的响应机制”(42377352);国家自然科学基金面上项目“黄土高原疏伐强度对刺槐人工林能水平衡的影响机制”(42271042)。

摘　　要：[目的]明确不同降雨强度下生物土壤结皮对坡面流水动力参数的影响,进一步评估生物结皮的水土保持功能。[方法]以黄土高原典型藻结皮和苔藓结皮为研究对象,系统研究了60,90,120,150,200 mm/h雨强下生物土壤结皮对坡面流水动力参数的影响。[结果](1)所有雨强下藻结皮和苔藓结皮坡面流流型均为层流,除200 mm/h雨强下苔藓结皮坡面流为急流外,所有雨强下藻结皮和苔藓结皮流态均为急流;(2)藻结皮在90,120,150,200 mm/h雨强下流速、径流量和径流系数分别是60 mm/h雨强的1.76~3.9,4.89~9.26,3.91~4.13倍,苔藓结皮则为1.34~2.56,5.86~13.81,2.46~4.26倍,流速和径流量均随雨强呈线性函数增加(R^(2)≥0.85,p<0.01),径流系数呈幂函数增加(R^(2)≥0.49,p<0.05);(3) 60,90,120,150,200 mm/h雨强下藻结皮阻力系数和曼宁糙率系数变化范围分别为0.15~0.74,0.01~0.03,苔藓结皮则为0.82~3.02,0.03~0.06,阻力系数和曼宁系数均随雨强成指数函数降低(R^(2)≥0.47,p<0.05);(4)降雨强度与生物结皮种类均与坡面水动力参数显著相关。所有雨强下,藻结皮坡面流速显著高于苔藓结皮(11.77%~118.31%),而径流量、阻力系数和曼宁系数则低于苔藓结皮(1.41%~37.55%,53.32%~90.42%和38.08%~73.00%)。[结论]生物结皮对黄土高原坡面流水动力参数有较大影响,未来应加强生物结皮对坡面流水动力参数的研究。研究对于黄土高原生物土壤结皮坡面流水动力参数特征具有重要意义,可对精准侵蚀预报模型提供理论支撑。[Objective]The aims of this study are to elucidate the vital role of biological soil crust in slope flow dynamic parameters under different rainfall intensities,and evaluate the soil and water conservation function of biological soil crust.[Methods]Cyanobacteria and moss crusts were chosen as the typical model crusts to assess the effects of biological soil crusts on slope flow dynamic parameters under rainfall intensities of 60 mm/h,90 mm/h,120 mm/h,150 mm/h,and 200 mm/h,respectively.[Results](1)Under all the tested rain intensifications,both flow patterns on the slopes with the Cyanobacteria and the moss crust present a laminar type.In addition,the flow patterns on the slopes with Cyanobacteria and moss crust show a rapid type under all tested rain intensities except for rapid flow type on the slope with the bryophyte crust flow under 200 mm/h rain intensification.(2)At 90,120,150 and 200 mm/h rainfall intensity,the velocity,runoff,and runoff coefficient on the slope with the Cyanobacteria under other rain intensities are 1.76~3.9,4.89~9.26,and 3.91~4.13 times of those under the rainfall intensity of 60 mm/h,respectively,while the same evaluation is applied to the moss crust,the parameters are 1.34~2.56,5.86~13.81,and 2.46~4.26,respectively.Additionally,the flow velocity and runoff increase linearly with the rainfall intensity(R^(2)≥0.85,p<0.01),and the runoff coefficient increases linearly with the power function(R^(2)≥0.49,p<0.05)。(3)Under the rainfall intensities of 60,90,120,150 and 200 mm/h,the drag coefficient and Manning roughness coefficient on the slope with Cyanobacteria vary in the range of 0.15 to 0.74 and 0.01 to 0.03,respectively,while the drag coefficient and manning roughness coefficient the slope with moss vary from 0.82 to 3.02 and 0.03 to 0.06,respectively.With increase of rainfall intensity,the drag coefficient and Manning coefficient decrease exponentially(R^(2)≥0.47,p<0.05).(4)Rainfall intensity and biological crusts are strongly correlated with slope hydrodynamic parameters.Under

关 键 词：藻结皮 苔藓结皮 降雨雨强 水动力学 黄土高原 

分 类 号：S157.1[农业科学—土壤学]