Evaluation of water erosion loss on the northern slope of Tianshan Mountains under tourism disturbance: Taking west Baiyanggou watershed mountain scenic spot as an example

In order to explore the effect of tourism disturbance on the mountain scenic spot in west Baiyanggou watershed, we quantitatively estimated the economic loss of water erosion under different disturbance intensities, and then analyzed the change law of water erosion economic loss. The relationship of tourism disturbance with soil physical and chemical properties and vegetation coverage was also evaluated, based on data collected in the national soil erosion survey and the Chinese Soil Loss Equation(CSLE) and water erosion economic loss evaluation model. The results showed that under different tourism disturbance intensities, the soil physical and chemical properties and vegetation coverage were significantly different. Compared with the no disturbance sites, the decrease of soil water content, saturated water content, and soil porosity in severe sites were 51.67%, 32.23%, and 13.30%, respectively. The contents of soil available N, P, and organic matter decreased with increasing disturbance intensity, but the content of soil available K tended to increase. The vegetation coverage of the light, moderate, and severe disturbance sites decreased by 14.18%, 43.32%, and 92.35%, respectively, compared with the control group. With the increase of tourism disturbance intensity, the values of soil erodibility K and biological measure B increased significantly, and soil erosion also significantly increased(P4 yuan·hm-2·a-1 and 2.49×104 yuan·hm-2·a-1 in moderate and severe sites, respectively. Vegetation coverage was the most sensitive to water erosion economic loss. Every 1% reduction in vegetation coverage lead to 4.98×104 yuan increasing in water erosion economic loss. The study also indicated that tourism disturbance intensity is a key factor affecting the water erosion intensity and economic loss in mountain scenic spots. Therefore, to control the intensity of tourism disturbance, it should be combined with the analysis of soil erosion parameters, strengthening the management of soil exposure, the use of plant trample resistant vegetation, and assessment of tourism carrying capacity.