Research On Space Differentiation Characteristics Of Cultivated Land Resources In Brazil

With the continuous development of the global economy,the rapid development of industrialization, the reduction of cultivated land speed more and more quickly, the per capita arable land decreasing, the relationship between the cultivated land resource and human society gradually beyond a single ethnic and national category, and become the human survival and development environment of space big global issues. Brazil is located in eastern South America, as one of the agricultural product export country of global importance, rich land resources, land reserve volume is very large, the agricultural production potential, the future of Brazil in the international agricultural domain has extremely important strategic significance. With the rising power of global food crisis spread and population, the continuous development of agricultural technology, Brazil plays a more and more important role in the global food trade, in recent years gap of grain is expanding in our country, Brazil has become a major importer of agricultural products in China, therefore, the characteristics of distribution of arable land resources in Brazil has a certain guidance and practical significance for China’s grain trade more effectively to the Brazil.This paper is a research topic in support of the national "973" project "the effects of land use change on a large scale on global climate, with the European Space Agency Globcover data as the basis, according to the satellite emote sensing image interpretation signs, referring to the rivers, lakes, railway and highway, residential and other ancillary data, through the grid by grid discrimination method of human-computer interaction, established in Brazil land use spatial database in 2005, provides the possibility for the characteristic analysis of cultivated land resources. Using the spatial analysis of GIS, statistics the cultivated land area of Brazil interstate,reclamation rate, cultivated land center and geometric center of gravity offset and other indicators, To achieve the analysis of the Brazil interstate differences of structure, regional distribution differences and regional differences of cultivated land spatial features in three aspects, grasp the basic characteristics of the distribution of cultivated land in Brazil. On this basis, the use of DEM digital elevation data and climate with vector data, with the help of GIS space superposition function, further analysis distribution characteristics of cultivated land in different influence factors of space, differentiation characteristics of cultivated land comprehensive mastery of the terrain,also provides scientific basis and support for the rational development and utilization ofreserve cultivated land resources in Brazil; And the further use of the spatial autocorrelation index, reflect the degree of agglomeration of cultivated land space, provide scientific reference for Brazil’s grain trade in China. The main conclusions are as follows:(1)Brazil interstate cultivated area is significantly different, The state of Minas Gerais located in the southeastern and the state of Roraima area ratio located in the northwest corner is up to 62:1; State land reclamation rate range of 0.27%~38.06%, 26 states reclamation rate is divided into five levels, the state data are uniformly distributed, respectively 6, 5, 5, 5, 4, Among them, one level of reclamation rate state have Roraima, Amapa state, the state of para, Amazonas, acre state and Rondonia, five level state have Sergipe, Goias, St Paul Prefecture and Parana Prefecture; Five agricultural economic zone, due to the difference in altitude and climate conditions, Differences of cultivated land distribution of each economic region is obvious, the southeastern reclamation rate is the highest, up to 29.05%, about 2.5 times the national average reclamation rate, area of cultivated land area accounted for 24.30% of the total arable land; Secondly, for the southern region, the reclamation rate of 24.67%, the land area accounts for 6.6% of the total area of the country, while regional relative cultivated land are aratio of 12.59%; The northern area of reclamation rate is the lowest, 2.92%, but its land area accounts for the national total area 45%; The cultivated land center of Brazil located in Goias Federal District of Western Brasilia,relative to the geometric center of gravity, cultivated land center inclined to southeast area, show that the eastern and Southern is gathering area of cultivated land.(2)The vertical distribution of cultivated land in Brazil has distinct layers, the distribution of cultivated land elevation, The vertical distribution of cultivated land in Brazil has distinct layers, the distribution of cultivated land elevation, each elevation range were cultivated land distribution,The domain of cultivated land within the majority in the altitude below 1000 m, where 200-500 m and 500-1000 m is the main distribution area of cultivated land. The range of 1000-1500 m elevation region economy more developed, the reclamation rate is relatively high, above 1500 m rarely distribution of cultivated land; most of the distribution of cultivated land in Brazil is relatively slow,which,(11) natural vegetation and(12) more than half of the arable land is distributed in the 0- 0.43; From the different aspects, the ability to accept the solar radiation is also different,except in the area of cultivated land in Brazil plain less, other area is uniform, the water and heat conditions, on the northern slope of the terrain generation is conducive tothe growth of crops and economic crops, and corresponds to the South and southeast of south slope direction, the reclamation rate is low, do not suitable for farming; Brazil terrain niche index range 0-5.71, terrain niche index of 1, 2, 3 and 4 of the fourdistribution of more than 90% of arable land, and in addition to the 1 level with theterrain increases dominance decreased cultivated land; Differences in climatic conditions of Brazil obviously, northeastern, southeastern and central regions is the main source area of cultivated land resources, cultivated land area of the region accounted for 43.95% of the total arable land, high altitude tropicalclimate zone average reclamation rate is the highest in the six climate zone, up to 30.76%. Less land reclamation equatorial climate zone, the area of cultivated land is corresponding also rarely.(3)Brazil reclamation rate of global spatial autocorrelation analysis, the results show the state of Brazil cultivated land spatial distribution showed a similarity value between thespatial clustering, spatial association is characterized in that: The reclamation rate of higher state tends to adjacent,The reclamation rate of lower state also tends to adjacent; Local spatial autocorrelation results show, the southeastern Minas Gerais, St Paul Prefecture, Rio De Janeiro Prefecture, northeastern state of Bahia and Midwest, South Matoquero state reclamation rate is significantly high aggregation in Brazil, This shows that the relative abundance of arable land resources in five states, plays an important role in agricultural production. Brazil is located in the northern Roraima and Amazonas, acre state, the state and the state of para cultivation rate is significant forlow aggregation, not suitable for arable farming.