黑龙江省水源地优先流区与基质流区土壤特性分析

Analysis on Soil Characters of Preferential Pathways and Soil Matrix in Water-source Area of Heilongjiang Province

以黑龙江省东部山地天然次生林为研究对象,采用野外染色示踪和统计分析相结合的方法,应用Photoshop Cs5,Image pro Plus6.0图像处理软件,分析天然次生林下优先流区和基质流区土壤特性差异。结果表明:黑龙江省东部山地天然次生林土壤优先流现象极为明显,主要以大孔隙流、指流以及管流为主。表层土壤孔隙间的连通性好,水分运动过程变得相对均匀,不易于发生优先流。10—45cm土层范围内,染色路径不再整体均匀扩散,表现出明显的优先运移特征,产生优先流,并表现出了一定的环绕特性。从土壤表层到底层,染色区非毛管孔隙度比未染色区高0.3%~2.0%。非毛管性孔隙可视为大孔隙,是产生优先流的主要原因。0—40cm土层范围内,染色区土壤饱和持水量、毛管持水量和田间持水量均高于未染色区,染色区土壤容重均低于未染色区。20—40cm是该地区天然次生林土壤产生"优先路径"最明显的土层。在此范围内优先流区土壤入渗速率明显大于基质流区,证明该区土壤特性差异是黑龙江省东部山地天然次生林优先流产生的主要原因。

This paper took the soil characteristics between preferential flow and matrix of natural secondary forests at eastern mountainous region in Heilongjiang province as research object.By using the field dye tracer method and Image processing software.The results showed that：The phenomenon of soil preferential flow was very obviously in natural secondary forests at eastern mountain in Heilongjiang province.There were mainly macropore flow,mean flow and pipe flow.The soil pore connectivity was unimpeded in surface.Water movement process became relatively uniform.So the preferential flow was not easy to occur.Within the range of 10—45cm soil layer,the dyeing path was no longer a whole uniform diffusion.There was obviously preferential migration and certain surround characteristics.From surface to bottom of soil,the non-capillary porosity of staining region was 0.3%—2.0% higher than unstained area.Meanwhile,non-capillary porosity was considered as main reason for the generation of preferential flow.In the range of 0—40cm soil layer,the water holding capacity,capillary capacity and field capacity in the dyeing area were higher than those of unstained area,the soil bulk density was on the contrary.The priority path was most obviously in 20—40cm of soil in natural secondary forest.In this area,the infiltration rate of preferential flow area was significantly higher than that of matrix.And it proved that the difference of soil characteristic was the main reason of soil preferential flow of natural secondary forest at eastern mountain in Heilongjiang province.