The Study On Quantitative Health Evaluation Of Eco-economy System At Longtan Small Watershed

In the present study, Longtan small watershed in the Longzhong semi-arid loess hilly and gully region was taken as research object. Based on the science investigation, status quo analysis and development prediction, a series of indexes were selected from the point of vigor, organization and resilience and three facets of ecology, economy and society on eco-economy system in Longtan small watershed. The index system of heath evaluation on eco-economy system was established by the method of Analytic Hierarchy Process (AHP), and made the quantitative health evaluation on eco-economy system at Longtan small watershed, to measure the health status and find the mainly obstacle facets to influence the health development, then the science countermeasures and suggestions were offered. The main results are as following:(1) The total number is 244 plant species which belong to the 56 families including 3 families, 12 species of the class Gymnospermae, and 53 families, 232 species of the class Magnoliophyta. Mainly of these plants are belong to the drought-tolerant and alkali-resistance herbage and shrub. The abundance of different vegetation life-form in the sunny and cloudy slope at watershed is perennial herb>annual herb>shrub>tree, and the richness is cloudy slope>sunny slope. The abundance of different vegetation life-form in ditch slope at watershed is perennial herb>annual herb>shrub, and there is no tree. The percentage of perennial herb at total plant is the biggest, and the shrub and the tree are appeared at the form of pure forest.(2) The typical natural vegetation communities at Longtan small watershed include the formation of Ajania fruticulosa, Thymus mongolicus,Pyrethrum pulchrum Ledeb.,Artemisia sacrorum,and Stipa bungeana. The typical artificial vegetation communities in Longtan small watershed include the forest of Pinus tabulaeformis, Caragana korshinskii,Platycladus orientalis, Medicago sativa-Amygdalus davidiana or Armeniaca vulgaris var.ansu. Compared to in the sunny and semi-sunny slope, the coverage of vegetation and the diversity of species are better than in the cloudy and semi-cloudy slope, and the levels of vegetation communities in the cloudy and semi-cloudy slope are more than in the sunny and semi-sunny slope at Longtan small watershed.(3) The influences which the vegetation and the site conditions to the plant diversity indexes are the following: the influence which the vegetation to the Margalef and the Shannon-wiener indexes is significant, and to the Pielou index is not obvious. There are significant influences which the aspect of slope to the three plant diversity indexes is, and the influence which the slope position to the three indexes is not obvious.(4) The present study investigated and evaluated the structure status of the household eco-industrial system in Longtan small watershed. The results including: the management mode of high income level household is labor export + characteristic planting, the management mode of middle income level household is labor export + characteristic planting + breeding industry, and the management mode of low income level is labor export + traditional planting + breeding industry.(5) The comprehensive evaluation health index of the watershed is from 0.6000 in 2007 to 0.738 in 2009, it showed that the health condition of watershed has been in the benign cycle condition from better condition. The average evaluation indexes of three item levels in the past years are showed that vigor evaluation index(0.325)>organic structure evaluation index(0.213)>resilience evaluation index(0.132). The growth of resilience evaluation index is the fast at the three indexes in the past years, and it is 39.09%. The growth of organic structure evaluation index is less than others, and it is 14.07%.(6) Based on the analysis of obstacle degree, the main factors which hinder the health development of small watershed are the primary productivity on grassland, land productivity, farmer net income per capita, the number of livestock per household, output-input ratios, commodity rate of farm produce, and labor productivity.(7) Based on the comprehensive analysis about ecology, economy and sustainable development, it is found that at present the best management mode is labor export + characteristic planting + breeding industry in household eco-industrial system. In the long term, to change the former and single management mode in household eco-industrial system, and to develop compound management mode will have a direct and active effect on promoting the sustainable development in the field of ecology and economy at small watershed in loess hilly and gully region.