| The development of mountain wind farms will destroy the integrity of the mountain slopes,and the slope with broken stones formed by the random abandonment of earth and stone have the characteristics of poor stability,poor soil,poor site conditions,difficult construction,and difficult ecological restoration.When the lower part of the high and steep slope with broken stones is unprotected,a large area of yellow block and strip-shaped non-point source pollution will be formed under the action of hydraulic erosion,which will bring serious soil erosion problems.Therefore,the ecological restoration of soil and water conservation of high and steep slope with broken stones in mountain wind farms has become the focus and research hotspot.In view of the above problems,this paper selects the wind power projects built and under construction in Hunan Province to conduct field investigations,summarizes the characteristics of soil erosion and erosive factors of mountain wind farms,and uses the principal component analysis method to screen out the soil and water effects on the broken stones-laden slope.The dominant factors of loss are:geotechnical composition,slope length and slope aspect.Four typical high and steep broken stones slopes were selected by cluster analysis.According to"function+lithology+slope aspect+slope length",the four-stage Site type naming.In order to provide a stable physical base for the growth of ecological restoration plants,a fuzzy comprehensive evaluation method based on entropy weight method and AHP to determine weights was established to evaluate the stability of typical high and steep broken stones-laden slopes,and the obtained evaluation results and mechanical analysis The results obtained by the method are the same,which shows that this method can quickly and efficiently evaluate the objects of high and steep broken stones-laden slopes.Based on the principle of "plants as the mainstay and engineering as the supplement",an ecological restoration system for high and steep broken stones slopes with optimal allocation of "grass,shrubs and vines" is constructed.First,the native plants in the study area were counted,and then 27 kinds of slope protection plants suitable for growth on the broken stones slope were selected based on plant growth performance,stress resistance and reinforcement,including 13 kinds of herbs,7 kinds of shrubs,and 7 kinds of vines,kind,Finally,the pioneer plants that are both dominant species and native species are screened out,and plant configurations suitable for the establishment of each microsite type unit are designed.In order to rationall yutilize the broken stones hanging resources on the slope,the orthogonal experiment was designed to observe the plant growth index and the physical and chemical properties of the substrate,and to test the effect of the mixed ratio of the hanging broken stones,soil conditioner and compound fertilizer on the rapid regreening of plants.The experimental results show that:The primary and secondary factors affecting plant germination in the early stage were:soil conditioner>substrate>compound fertilizer:the primary and secondary factors affecting plant growth in the growth period were:substrate>soi]conditioner>compound fertilizer.It is proved that 70%hanging broken stones,30%planting soil.5%soil conditioner.0.6‰ compound fertilizer,and bagged plant seeds to form ecological bag slope protection is a feasible means for the resource utilization of slope hanging broken stones.Based on the above analysis and research,taking the two broken stones-laden slopes in Ningyuan Wind Farm as an example,according to the ecological priority slope fixing measures,the unstable broken stones-laden slopes are set up with cutting steps according to the geotechnical composition and slope;The slope is divided into micro-site type units with steps at all levels,and the ecological restoration construction plan is designed:spraying and planting grass in the upper part,digging holes in the middle to plant bagged nutrient seedlings mainy vines,and setting up ecological bag slope protection with improved substrates in the lower part. |
