| The Loess Plateau is a region where water and soil erosion is the most serious in china, an important way of soil and water conservation in this region is small watershed comprehensive management. In this thesis, according to the problems of measures allocation existed in working of small watershed management, under the guidance of theories that contain the expansion of niche theory, the system theory, the soil and water conservation study, the runoff control of soil and water conservation theory and so on, Anjiagou watershed and Jiuhuagou watershed in Gansu province as experiment research bases, a systematic research have be done on the principles of the para allocation of soil and water conservation measures of small watershed, the technology and mode of the para position allocation of soil and water conservation vegetation measures and runoff regulation engineering of small watershed, and that benefit of extension and application, main conclusions achieved are presented as follows:(1) This paper presents new concept for the para position allocation of soil and water conservation measures of small watershed. On the basis of introducing and referencing concept of the niche and the resource-state, combined with work characteristics of soil and water conservation, respectively expounded the meanings of the niche of soil and water conservation demand, the environmental resources state and the para position allocation of soil and water conservation, points out that para position allocation of soil and water conservation distributed level is according to energy level of niche of soil and water conservation demand and environmental resources state, through the analysis on suitability degree of niche of soil and water conservation demand and environmental resources of harness areas, that measures of soil and water conservation are chosen, which are suitable with its characteristic of niche of soil and water conservation demand and environmental resources state; through engineering measures change environmental resources state, the stress degree of restrictive factor on soil and water conservation measures is eliminated or mitigated, the ecological condition which soil and water conservation measures of small watershed need is satisfied, it is achieved that the prevention measure demand state and the resources state are suitable each other, anastomosis mutually.(2) The model of para position allocation of soil and water conservation measures of small watershed is constructed in this paper, the level of para position allocation of soil and water conservation measures which is described by the author contains nine aspects, that are respectively the macroscopic para position allocation, the spatial para position allocation, the plant para position allocation, the engineering para position allocation, the cultivation para position allocation, the technical para position allocation, the management para position allocation, the timing para position allocation and the facility para position allocation.(3) This paper presents the pattern of para position allocation of soil and water conservation vegetation measures of small watershed. Ecological niche suitability assessment model is used to carry out calculation analysis and evaluation of the various land-use measures from niche fitness of microclimate, soil moisture and plant production capacity, analyses appropriate index to improve soil and water conservation measures and its application, it was proved that in measures, terrace> slope farmland, slope farmland>grassland; in the slope aspect, shady slope>sunny slope; in the slope position, about ecological niche suitability index of terrace and grassland in sunny slope, middle>lower>upper; about ecological niche suitability index of terrace and grassland in shady slope, upper > middle > lower. On the basis of this analysis, puts forward"the pattern of para position allocation of soil and water conservation vegetation measures of small watershed in the 5th Sub-Area of Gully and Hilly Regions on Loess Plateau".(4) Ecological niche suitability of vegetation measures at different topographic position in small watershed is analysed , soil moisture at different topographic position in farmland and grassland,the shady slope are higher than the sunny slope, and raises along with the slope position rises; terrace , grassland and shrub cause the soil moisture to reduce obviously, and there is obvious soil layer desiccation, that lead to reduce its niche fitness of moisture, become a bottleneck that affecting plant growth and development. About the niche fitness of hydrothermal climate resource in terrace, grassland, shrub , farmland and waste hillside, the shady slope are higher than the sunny slope, and niche fitness of measures in upper, middle and lower parts of slope decreases along with the slope position rises; the niche fitness of grassland is high, and the niche fitness of terrace is higher than that of slope farmland.(5) According to the research on allocation of key issues about ecology water use in runoff collecting and artificial vegetation, an optimal design is proposed about runoff collecting project which contains inter-slope earth-edge terraces, funnel type, swallow-tail type and bamboo-joint type runoff collecting pit and so on. Practice shows that all the measures of runoff collecting project can make the survival rate of trees reach 83%-98%; the grass production in inter-slope earth-edge terraces reaches 1000-7000kg/hm2 in four years continuously, the author proposes a pattern of para position allocation of soil and water conservation vegetation measures and runoff regulation and control project in the 5th Sub-Area of Gully and Hilly Regions on Loess Plateau.(6) The author investigates and summarizes the governance and industrialization model of popularization and application in two demonstration watersheds. Anjiagou watershed and Jiuhuagou watershed are advanced models of soil and water conservation which produced at different period and have its own specialties and advantages. Anjiagou watershed as small watershed of outskirts, forms a governance model which is agriculture, animal husbandry land mosaic allocation of vegetation measures and engineering measure matching each other, and the for economic development of basin, forms a industrial structure model that taking agriculture , industry and sidelines as a main body. Jiuhuagou watershed as a kind of model of combination of small watershed soil and water conservation government and the poverty alleviation development in typical semi-arid mountains area, forms a set of treatment method that is optimum combination and para position allocation of engineering measure, plant measure and cultivation technique, and it is mainly comprehensive utilization system of runoff regulation and control, a multi-function, multi-objective, high benefit comprehensive protection system of soil and water conservation is constructed, that supports the plant by the project, guarantees the project by the plant, guarantees the economy by the ecology, promotes the ecology by the economy.(7) The author analyzed and evaluated the social economy and the ecological benefit of small watershed management. The results showed that: First, it is remarkable on water and sediment reduction benefits. By the end of 2007, the harnessment degree in Anjiagou watershed reached 79.33%, the coverage rate of vegetation is 40.07%.The soil erosion modulus in Anjiagou watershed. drops to below 1000 t/km2 which is allowable value of soil erosion; The runoff modulus reduces 81.95%.The harnessment degree in Jiuhuagou watershed reached 86.3%, the coverage rate of vegetation is 57.1%, the annual soil erosion modulus in Jiuhuagou watershed is 915t/ km2; the water and sediment reduction benefits respectively reduces 90.8% and 83.06%. Second, harness and development promotes mutually, total output value is steadily increasing, agriculture, forestry and animal husbandry increase simultaneously. Anjiapo village have a foothold agricultural production, using suburb superiority, develops vigorously rural service industry, makes income of watershed increase rapidly. From 2002 to 2007 the average annual agriculture total output value is 1.1228million, agriculture and service industry occupy99.22% of the total output value in Jiuhuagou watershed; through comprehensive controlling and production structure adjusting in Anjiapo village watershed, The agricultural land reduces 38.5%, the forest and animal husbandry land grows 137.5%. Third, the social benefits are remarkable. In Jiuhuagou watershed, the land productivity is 3051.45 Yuan/hm2, the labor productivity is 24.17 Yuan / man-days, the per capita national income is 1486Yuan/people, the step of shaking off poverty and becoming rich has accelerated significantly, and the peasant households that have had adequate food and clothing have reached more than 85%; sets up models which constructs ecological environment and gets rid of poverty and becomes rich to build of well-off society in the same type areas, and it plays a demonstration leading role. |
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