Soil And Water Conservation Model And Benefit Monitoring And Assessment Of Karst Rocky Desertification Control

Karst rocky desertification control is an international problem, which is comprehensive superposition of ecological, economic and social problems of the environment reflect in the karst area. For the vulnerability of ecological environment and the gravity of soil and water loss in the karst area in Guizhou province,this paper based on the relevant theories of soil and water conservation and soil and water loss as the guiding ideology, which has an important and practical significance to carry out soil and water conservation model and benefit monitoring and assessment of karst rocky desertification control. This study results selected potential- mild rocky desertification of plateau mountain( Salaxi demonstration site in Bijie) and moderate- strength rocky desertification of plateau valley( Huajiang demonstration site in Guanling-Zhenfeng) as the research sample region from April 2011 to December 2015. We used the field investigation, indoor analysis, literature review and so on, though study the coupling mechanism of soil and water loss of surface and underground in the karst area, determine the evaluation index system of soil and water conservation benefit index factors, construct the evaluation index system of soil and water conservation, summarize and analysis the models of different degrees rocky desertification of soil and water conservation. This work will provide scientific guidance to coordinate the relationship between human and nature and predict the soil and water conservation work in the karst area.(1) Aimed at the specialties of soil and water loss of surface and underground in the karst area, this paper thought that the earth’s surface- underground dual structure and rainfall are the main factors of soil and water loss of surface and underground. The coupling process can be divided into four stages, namely, the rainfall erosion stage, the surface soil erosion stage, the surface and subsurface of soil and water loss and the underground river erosion stage, which the key stage is karst leakage process of soil by the water hole. This study is lack of the underground soil and water loss monitoring data for a long- term. If we want to illustrate the coupling mechanism of soil and water loss of surface and underground in the karst area, which is difficult to put forward a reasonable management plan. Future research should also be carried out more of the underground soil and water loss monitoring, in-depth analysis the rule of underground soil and water loss, establish benefit forecast mode of underground soil and water loss and soil and water conservation management, which can put provide theoretical basis to put forward the concrete techniques of coupling mechanism of soil and water loss of surface and underground.(2) Aimed at the control measures of different rocky desertification of soil and water conservation, we should establish a suitable and sustainable mode system for the characteristics of karst environment. This study puts forward the different rocky desertification of sub- model of coupling for soil and water conservation: soil and water conservation models of potential rocky desertification is economic forest vegetation restoration(I); soil and water conservation models of mild rocky desertification is comprehensive recovery(II); soil and water conservation models of moderate rocky desertification is grassland vegetation restoration(III); soil and water conservation models of intensity rocky desertification is forest vegetation restoration(IV). According to the pattern features of different rocky desertification of soil and water conservation, We should adopt the corresponding technical measures of soil and water conservation, so as to provide scientific basis for desertification control.(3) According to the complexity of karst area, this study established a set of suitable for karst area of evaluation index system of soil and water conservation, which include the ecological benefit index, economic benefit index and social benefit index. It can provide a set of practical evaluation model to evaluate the future ecological environment governance in the karst area. Through a long- term monitoring, the effect of desertification control is obvious. Two demonstration areas of ecological structure had improved to some extent. Salaxi demonstration site in Bijie as a national "twelfth five- year" of new establish demonstration area, because it has completed the assignment design and engineering decorate of demonstration area rocky desertification comprehensive treatment, all aspects of the benefit is not as good as Huajiang demonstration site in Guanling- Zhenfeng. In the future, we should combine with the regional economic development to optimize the control of soil and water conservation engineering space configuration and build the best evaluation index system of soil and water conservation for desertification control in the demonstration area.(4) From 2011 to 2015, with the extension of desertification control time in demonstration areas, all of the ecological benefits indexes have a good direction trend. Average change rule of air temperature is: model I > mode II > mode III > mode IV; Light intensity change is 2011 > 2012 > 2013 > 2014 > 2015; Diversity index, evenness index, dominance index and richness index are increased, and the dominance index increased more obviously, which has showed that mode I < mode II < mode III < mode IV; Soil and water loss is mainly composed of micro and mild degree erosion, area of micro and mild degree erosion accounts for more than 70 % of the whole demonstration area; Soil structure has a good development trend. With the increased of the desertification control time, the second industry and the third industry of the two demonstration area had a growing trend.Farming,forestry,animal husbandry and income proportion of returning farmland to forest industry were basically stable, planting proportion of Salaxi demonstration site in Bijie had increased from 15.09 % to 21.01 % since from 2011 to 2015; planting proportion of Huajiang demonstration site in Guanling- Zhenfeng had increased from 3.46 % to 4.94 % since from 2011 to 2015. Through the rocky desertification control, soil and water conservation benefit of the demonstration area got goo d benefit, which can provide scientific guidance for the soil and water conservation of karst rocky desertification governance in the future.