| Agricultural production risk has become the main limiting factor which restricts regular agricultural production and reasonable land use in our country.With the deepening of research on regional disaster theory and land utilization change,the systematic research combining disaster theory and land utilization has gradually become one of the important research contents of human-land interaction mechanism as well as received widespread attention of domestic and foreign scholars.As is analyzed from the perspective of regional agricultural production risk management and land utilization,land consolidation activity which is of great significance to the risk management and prevention in regional agricultural production involves not only engineering"hard" methods but also regulation planning "soft" measures in disaster risk prevention and control as well as disaster reduction.The research on synthetic evaluation of regional agricultural production risk and the discussion on technological support of agricultural production risk on land consolidation have not only deepened the human cognition degree of the interaction relationship between natural ecology system and economic society system but also enriched the research contents of disaster theory and land utilization change.The two have important theoretical and practical significance for enhancing the integrated management level of regional risk and promoting the regional sustainable development.Based on the above background and with the support of the special scientific research fund of public welfare industry of Ministry of Land and Resources on the topic "Development and Demonstration of Land Consolidation Technology in Taiyuan Area in the Loess Plateau",Guanzhong region,the hard-hit area of agricultural production risk and the key land consolidation area in the Loess Plateau,was selected as the research area to conduct agricultural production risk assessment as well as land consolidation and regionalization research.The interaction mechanism of agricultural production risk and land utilization in Guanzhong region was systematically analyzed on regional scale.The predominant types of main agricultural production risk in Guanzhong region were clarified.The intensive study of agricultural production risk characteristic and spatial pattern rule in Guanzhong region was conducted from the aspects such as the risk of disaster-inducing factors,the vulnerability of hazard-bearing body and the integrated risk of regional agricultural production.The land consolidation and regionalization research based on agricultural production risk assessment was conducted;the consolidation direction,consolidation goal,consolidation emphasis and engineering construction measures of different consolidation areas were emphatically discussed.The paper is divided into seven chapters.The first and second chapters are introduction and theoretical basis of the research.The third chapter is general situation of the study region,which introduces general situation of natural environment and social economy in Guanzhong region as well as selectively analyzes the mutual influence between agricultural production risk and land utilization in the research area.The fourth chapter mainly studies the agricultural production risk types in Guanzhong region as well as researches the spatial pattern characteristic and rule of various risks through appraisal on the main risk types.The fifth chapter is the integrated risk research of agricultural production,which mainly conducts the integrated risk research from the aspects such as the integrated risk of disaster-inducing factor,the vulnerability of hazard-bearing body and the integrated risk of agricultural production.In the sixth chapter,the land consolidation and regionalization research is carried out based on agricultural production risk;the consolidation direction,consolidation goal,consolidation emphasis and engineering construction measures of different land consolidation areas are discussed from the perspective of agricultural risk.The seventh chapter is the research conclusion and prospect.Through the paper research,the following main conclusions have been obtained:The first,five main types of agricultural production risk in Guanzhong region.The main types of agricultural production risk in Guanzhong region are drought,flood,geological disaster,soil erosion and agricultural environmental risk.In terms of the range and degree of hazard,drought risk is the greatest,which is successively followed by flood,geological hazard,soil erosion and agricultural environment risk.The second,significant difference among the spatial distribution characteristics of various types of risk in the agricultural production in Guanzhong region.The research findings have shown that the Guanzhong agricultural drought risk as a whole takes on the spatial distribution situation of "high in the north and low in the south,high in the west and low in the east";the composite index of drought risk is in the scope of 0.12-0.743;the high risk area is mainly distributed in the midstream and downstream area in the middle Weihe River basin;the risk index is averaged as 0.63.The flood disaster risk as a whole gradually decreased progressively towards the both sides from the center of the downstream main current of Weihe River.The high risk area of geological disaster having the composite risk index of not less than 0.45 and the area of 20181km2 is mainly located at the both banks of Weihe River,Jinghe River and Luohe River,the northern loess Liangmao area as well as the southern mountainous region.The soil erosion risk as a whole is higher in the north and south area,lower in the middle of basin area;the soil erosion modulus is 500-2600t/km2.The composite index of quality risk in the agricultural production environment is 0.097-0.567,which has the variation coefficient of 0.486 and presents the inverted"U" distribution in the north-south direction as well as the increase tendency from west to east in the east-west direction.High-risk area having the composite risk index of 0.325-0.567 is mainly distributed in the eastern valley basin area in the research region;the low risk area is in the southern Zhongshan area.The third,agricultural production hazard risk of Guanzhong region was from north to south distribution trend.High-risk areas,the hazard risk index between 0.8 and 1.0,the soil erosion intensity of the risk of geological disasters types of risk-based,low-risk areas are mainly located in the northern foot of Qinling,vulnerable to the risk of soil erosion,geological disasters as the wind.flood risk impact.Starting the vulnerability sexual connotation,disaster exposure,anti-anti-risk ability of the two angles Lin out to selected 14 indicators to construct the the vulnerability evaluation index system.The vulnerability of the study area,agricultural production hazard bearing body showing the South than in the north,east to the west of the distribution characteristics.Agricultural production risk and high risk areas are mainly located of Guanzhong region the south-eastern and northern areas,medium-risk areas in the tableland edge of the area,low-mountain region to the transition zone of the Guanzhong Basin,low-risk areas are mainly distributed in the Guanzhong Basin region.The fourth,agricultural production risk research's support for land consolidation and regionalization.As the composite index of integrated agricultural risk of 0.9 is taken as the threshold value,the Guanzhong region is classified into suitable region and unsuitable region of land consolidation according to the composite index of agricultural production risk.The suitable region having the area of 4.64×104km2 is mainly distributed in the central and southern region.According to the composite risk index of disaster-inducing factors and the vulnerability index of hazard-bearing body,and by virtue of the space and time disposition decision rule in land consolidation,the suitable region can be divided into the short-term prior consolidation area,the short-term reserve consolidation area,the intermediate consolidation area and the forward consolidation area.The short-term prior consolidation area is mainly distributed in the Guanzhong Basin as well as the midstream and downstream area of Weihe River,which mainly include the counties or cities such as Dali,Hancheng and Gaoling;the comprehensive value of disaster-inducing factors is averaged as less than 0.185,and the vulnerability index of the hazard-bearing body is averaged less than 0.40.The forward consolidation area is mainly distributed in the areas such as Feng County,Taibai County and Liyou County.According to the predominant type and risk degree of regional agricultural production risk,the Guanzhong area is divided into 5 land consolidation engineering type areas,namely,the northern geological disaster and drought prevention and control type area,the agricultural environment quality risk and flood disaster consolidation type area in the Weihe River basin,the flood protection and water conservation consolidation type area in the upstream area of Weihe River,the integrated risk consolidation type area in the eastern mountainous region and the geological disaster and soil erosion consolidation type area in the southern hilly area.The land consolidation goal,the consolidation emphasis,the consolidation direction and the engineering measures of risk prevention and control in different types of areas are emphatically discussed. |
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