Chin J Plan Ecolo ›› 2006, Vol. 30 ›› Issue (5): 732-742.DOI: 10.17521/cjpe.2006.0095

• Research Articles • Previous Articles     Next Articles

STUDY OF SOIL PREFERENTIAL FLOW IN THE DARK CONIFEROUS FOREST OF GONGGA MOUNTAIN, CHINA

NIU Jian_Zhi; YU Xin_Xiao; ZHAO Yu_Tao; ZHANG Dong_Sheng; CHEN Li_Hua; ZHANG Zhi_Qiang   

  1. Key Laboratory of Soil and Water Conservation & Desertification Combating of Ministry of Education, Beijing Forestry University, Beijing 100083, China
  • Online:2006-09-30 Published:2006-09-30

Abstract:

Background and Aims Preferential flow is the physical phenomenon of rapid transport of water and solutes in soil. It occurs in most soils and determines field_ scale transport of contaminants in soils, thereby contributing to groundwater pollution.
Methods Research on preferential flow involves studying the mechanism of soil water movement and can answer key questions that could not be explained by Darcy’s law and Convective_Diffusive Equation in early hydrological research. Experimental or technological analyses are difficult because this movement is not detected easily. Preferential flow increases the difficulty and complexity of there search due to non_equilibrium, regional characteristics and the involvement of many influencing factors. To date, the mechanism of the movement of preferential flow has not been properly defined. This study involved
detailed research on the influencing factors of preferential flow, using a soil column experiment in combination with dye_tracer analyzes in the root zone of the dark coniferous ecosystem in the upper drainage of the Yangtze River. Factors examined included rainfall processes, growth characteristics and water movement states of litter, moss, roots and soil. 
Key Results The soil of the research area is porous with large pores, and rainfall is low in amount and intensity and long_lasting. The soil also has thick litter and moss and is rich in roots. Therefore, the Gongga Mountain ecosystem may have preferential flow. Water transport has opened up preferential flow pathways along soil pores and root channels, forming a water channel in litter, moss and soil. 
Conclusions Soil will be transported continuously along these channels with longtime rainfall.