The Loess Tableland Area Land Bearing Capacity Of The Dynamic Analysis

Land is the basis of survival and development to human, and it is play an important key role of the sustainable development of economy and environment.Land carrying capacity indicates a area can continue to support the population within some environment conditions, it play some early warning function to development of the whole area society, economy and environment. In this paper, we choose the Loess Tableland which is typical landforms of the Loess Plateau to researching. With the help of ArcGIS and the geography records of Xi’an, Xian Yang、Bao Ji、Wei Nan and Tong Chuan, we extract the area of the Loess Tableland. Then we use statistical data and survey data of land use of each villages and towns, with the help of the model of GM (1,1) and the statistical analysis software of DPS, we study on land use, population, main crop yield, sowing area and land carrying capacity of the Loess Tableland over the years, and carries on the forecast. There are main conclusions are as follows:(1) The change of land use dynamic characteristicsFrom1999to2009, the decrease of farmland of72256hm2, unused land and grassland are also decrease, unused land by26861hm2, grassland reduce1277hm2, the increased mainly construction land, forest land and gardens, which were increased by28496hm2,44323hm2,847hm2. Between1999and2009, with the changes of cultivated land the biggest, followed by forest land, construction land and unused land, the last is grassland and garden; In the Loess Tableland, the cultivated land and unused land to reduce, thus forest land and construction land are increase, it shows that the policy of returning farmland to forest play an important key to the Loess Tableland, and the increase of the construction land shows that the Loess Tableland expanding city and actively developing economy.From the dynamic degree of land use, the dynamic of the size of the absolute value for:forest land> unused land> construction land> cultivated land> grassland> garden, the biggest degree of land use for forest land, the smallest for garden, forest land is32.5times of the garden. Therefore, between1999and2009, the largest dynamic degree is forest land, so the role that the policy of returning farmland to forest is obvious; Among construction land, cultivated land in unused land, there are conversion is more obvious, so their dynamic degree of land use the absolute value of relatively large. (2) The growth of population, cultivated land continues to declineBy the end of2009, the Loess Tableland area total population reached10033210, mainly in the agricultural population, the non-agricultural population accounted for24.42%. Compared1992with2009population of the Loess Tableland each county, and with the improvement of people’s living standard and the changes a process to accelerate of city, we can see that rural population gradually moved to the city, the city population are increasing year after year, the city has also been in the expanded state. According to the prediction model, we can predict the population in2015,2020and2030of the Loess Tableland are:10371549,10674418, and11298986.Between1998and2009, the cultivated land area and planting area of grain crops are declined; the cultivated land by885360hm2declined to814201hm2by the end of2009, the planting area of grain crops by1015838hm2descend to900209hm2. The grain output is decline between1998and2001, from2001to2009showed a rising trend; the yield of grain per unit area is rise in general. The population of the Loess Tableland continued to increase, per capita grain decreased first and then increased, in1998the per capita has food for413kg, in2001, for328kg, by the end of2009the per capita has food for419kg, thus the per capita possession of cultivated land area was reduced during this period.(3) The change characteristics of land carrying capacityThe change of land carrying capacity of the Loess Tableland is more than the balance-critical overload-overload-critical overload-more than balance between1998and2009.If people consume the grain is some certain condition, the LCC value is proportional to grain output, the area which grain output is higher, LCC is bigger and can carry more population; or LCC is small, the land carry capacity is also small. In LCCI respect, taken Yan Ta district, Wang Yi district and Jin Tai district for example, the LCCI value of less than1, they are in the state of overload. Similar to Xing Ping county and Chang An district, the LCCI value close to1, they are in a relatively balanced state. Similar to Qin Du district, Qi Shan County, Fu Feng County and Feng Xiang County, the LCCI value greater than1, their carrying capacity of land in a state of abundance. The land carrying capacity of the Loess Tableland is differentiation serious of two stages, serious overloading region becoming more and more serious and surplus area becoming more and more surplus. (4) The land carrying capacities are richAccording to the model of prediction, it shows that:the Loess Tableland can provide1.17million tones of grain to the other areas, can carry more than expected population of2.93million people and grain yield per hectare is6334kg, the land carrying capacity is1.28, the state of the Loess Tableland is the surplus state. If the trend continues to develop, the land carrying capacity will be further increased, by2020and2030, the land carrying capacities are1.34and1.54, and the state of the Loess Tableland is the surplus state, too.In the paper, we using the qualitative and quantitative method to research the land carrying capacity, and according to anglicizing the change of land carrying capacity in the past and at present in the Loess Tableland, so we can predict the land carrying capacity of the Loess Tableland in the future. Therefore, we could give some advices to resolve the contradiction between population, land and environment, and it helps to identify the factors that constraints the sustainable development of land resources. Under the certain land resources premise, causes it to produce the bigger social economy effect. According to anglicizing and predicting the development situation of population, farmland and planting areas of grain crops, we could provide a basis for the local government to make project of land use planning and grain production planning. In addition, according to anglicizing the land carrying capacity of the typical region of the typical landscape, it also provides some ideas to others areas for studying in the future.