Study On Methods Of Predicting Land Demand For Construction Use In Land-use Planning

Along with china's economic and social development ,the rapid urbanization process has continued to improve and the land demand for construction use keep increasing. Meanwhile, the land is a limited resources, the expansion of land demand for construction use influence the other categories, especially the farmland. Therefore, it is need to meet the demand for economic development and also maintain an appropriate balance of the land resources in land-use planning.Predicting land demand for construction use is an important part in land-use planning. To give an accurate forecast of the demand for construction use, a full understanding of the different forecasting methods and the analysis of local economic and social situation is needed.This paper introduced the domestic and foreign methods of predicting and related research progress .Study on the theoretical basis of predicting land demand for construction use. Make an analysis of the different characteristics and nature of different forecasting methods.The Leshan city of Sichuan province is researched as an example, on the basic of an analysis of the situation of land for the construction of Leshan city . Many defferent methods are used to predicte the demand of land for the construction .Finally get the following conclusions:(a) The scale of land demand for construction change in Leshan city ,the economy, population are related very closely. Construction land increasing with the total population, non-agricultural population. There is a positive correlation between the expansion of land for the construction and the development of the population. The relations of Construction land and GDP, fixed asset investment are significante. And the rate of land for construction output is increased every year, Land use is from extensive to intensive one.(b) In the practice of a variety of forecasting methods in predicting land demand for construction use of Leshan city we found : As the trend forecasts extends the development trend to the future, but to the place where the current economic and social development in areas are improved rapidly, the growth rate of demand of land for the construction in future is higher than the current growth speed, so the out come may be low, it should be projected as a result of the minimum reference program. Regression analysis needs the original data related to the economy, social development, and other statistical data, also need to find out the main factor of the demand of land for the construction, this method acquires detailed study of basic data, and the user must have a strong background of professional knowledge so that can take a proper control of the relevant factors, that is, to make the other factors remain stable consensus in the process, otherwise, regression analysis is likely to lead to false results. Linear Programming forecast the maximum land demand considerated the economic development of Leshan city. compared to a breakdown forecast the result are slightly excessive, but as the method set up environmental benefits, eco-efficiency etc, It achieve the overall land use planning objectives. Gray model applies not only to the small number of samples, the greater volatility of the series, but faded gray multiple factors interference accumulation, predicted better results. As the gray model predictions are based on an exponential curve trend forecasts, so its results are sometimes high. However, when most of the residual value relative to the majority is positive, it may cause results on the low side. As the breakdown forecast divide the land for the construction into a more detailed categories, more information can be obtained in the relevant departments involved in land use changes. and it combining quantitative and qualitative analysis, the result can reflect the actual demand well.(c) Using several forecast mathods to predicte the demand of construction land of Leshan city .Get tree different projects which are high, middle and low level. Considering to the situation of Leshan city. the demand of construction land of Leshan city is 3,549 hectares during 2006-2010. until 2011, the total amount of construction land achieve to 5,7346hectares. And the demand of construction land of Leshan city is5,971 hectares during 2011-2020.until 2020, the total amount of construction land achieve to 6,3290hectares.