不同入渗水量下的西南喀斯特地区人工林土壤优先流特征  

Characteristics of Preferential Flow of Artificial Forest in Karst Areas of Southwest China under Different Infiltration Amounts

作　　者：管凝 程金花[1,2] 侯芳 沈子雅 曾合州 赵梦圆 秦建淼 GUAN Ning;CHENG Jin-hua;HOU Fang;SHEN Zi-ya;ZENG He-zhou;ZHAO Meng-yuan;QIN Jian-miao(Jianshui Research Station,School of Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China;Key Laboratory of National Forestry and Grassland Administration on Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China)

机构地区：[1]北京林业大学水土保持学院,云南建水荒漠生态系统国家定位观测研究站,北京100083 [2]北京林业大学水土保持国家林业和草原局重点实验室,北京100083

出　　处：《土壤通报》2023年第3期587-595,共9页Chinese Journal of Soil Science

基　　金：国家自然科学基金项目(32071839)资助。

摘　　要：【目的】研究不同入渗水量下的西南喀斯特地区人工林的优先流现象,明确入渗水量对优先流程度的影响,对当地人工林的保护具有重要意义。【方法】通过野外染色示踪实验以及图像处理技术,获得优先流在竖直和水平方向上的形态特征,以及染色面积比随土层深度的变化情况,并提取优先流比等5个特征参数作为优先流评价指标,运用均方差决策法对不同入渗水量下的优先流程度进行综合评价。【结果】喀斯特地区人工林下的土壤中存在优先流现象,25 mm入渗水量下的优先流主要沿竖直方向运动,而60 mm入渗水量下的水流横向运动活跃。当入渗水量为25 mm和60 mm时,土壤染色面积比分别为5.72%和27.92%,且三次函数能够较好地拟合喀斯特地区马尾松人工林在大雨和暴雨条件下的染色面积比与土壤深度间的关系。当入渗水量由25 mm提高至60 mm时,基质流深度、平均最大入渗深度和长度指数均显著提高,优先流比和染色形态变异系数显著降低。25 mm入渗水量下的优先流指数为0.52,高于60 mm入渗水量下的0.46。【结论】充足的外部供水会降低喀斯特地区人工林下的优先流程度,减少土壤水分的快速漏失。[Objective]The phenomenon of preferential flow in southwest karst plantations under different infiltration volumes is needed to make sure and to clarify the influence of infiltration volume on the degree of preferential flow,which is of great significance for the conservation of local plantations.[Method]Through field dyeing tracing experiment and image processing technology,the morphological characteristics of preferential flow in the vertical and horizontal directions and the variation of dyeing area ratio with soil depth were obtained,and five characteristic parameters,such as preferential flow ratio,were extracted as the preferential flow indices,and the mean square difference decision method was applied to comprehensively evaluate the degree of priority flow under different infiltration water volumes.[Result]Preferential flow existed in the soils of karst plantations,with preferential flow at 25 mm infiltration mainly moved in the vertical direction,while lateral flow was active at 60 mm infiltration.The ratios of soil dyed area were 5.72%and 27.92%for infiltration of 25 mm and 60 mm,respectively,and the cubic function was able to fit well the relationship between the dyed area ratio and soil depth in karst plantations under heavy and stormy rainfall conditions.When the infiltration volumes were increased from 25 mm to 60 mm,the matrix flow depth,average maximum infiltration depth and length index were significantly increased,while the preferential flow ratio and variation coefficient of dyeing morphology were significantly reduced.The preferential flow index was 0.52 at 25 mm infiltration,higher than 0.46 at 60 mm infiltration.[Conclusion]Adequate external water supply will reduce the degree of preferential flow and reduce rapid soil moisture loss under planted forests in Karst areas.

关 键 词：优先流 喀斯特地区 染色示踪实验 人工林 入渗水量 

分 类 号：S714.7[农业科学—林学]