Water cycle in substrate-vegetation-atmosphere system of rock slope

The substrate-vegetation system is the primary functional component of eco-engineering for the rock slope protection. The water cycle in the system can influence the engineering and achievement. In this paper,Festuca arundinacea Schreb is selected to study water cycle in substrate-vegetation-atmosphere system with the time domain reflector to investigate in situ for one year stimulating slope with the different surface treatments and the different gradients. The results show that the gradient is the main limiting factor of water cycle in substrate-vegetation-atmosphere system. A rise in gradient leads to a decrease in the actual precipitation receiption of slope and a change in substrate water input. The evapotranspiration from the system decreases with the gradient improving,but the rangeability is small. Under weather conditions of the experiment area,the natural precipitation is sufficient for the vegetation with slopes of 45° and 60°,whereas deficient for the vegetation on a slope of 75°. Runoff happens when the substrate is fully filled with water due to its favorable moisture physical properties. The effect of the precipitation characteristics and the water content of the initial stages in the substrate on the process of runoff is small. Under the same space-time condition,water content in the substrate varies slightly in different treatments. They fallow in the order of spraying concrete slope>limestone>sandstone. The modified engineering measurements of eco-engineering are suggested from the point of water cycle,and provide necessary technical and theoretical support.