The Land Suitability Analysis Of Nanyang Downtown

City park as the only vitality green infrastructure in city, is the carrier of city spiritual civilization and ecological civilization construction. Rational layout of city park green space, can improve the city environment quality and residents’ happiness. However, planning the layout of Park involved many factors,such as ecological environment factor, social factor, cultural factor and economic factor. Can’t attend to one thing without neglecting the other in the traditional park planning system, it is difficult to have a scientific and reasonable planning standards for reference. The park land suitability analysis can be very good for the planners to provide a scientific basis for reasonable. The park land suitability analysis is combined with the park property and effect of park planning to seek the most appropriate changes to the park land from the land in city. This thesis is based on this purpose, as the downtown area of Nanyang for an example, to explore the appropriate standard for city park in Nanyang downtown.Through field investigation and literature review, to understand the present situation of green space construction of urban park in Nanyang downtown.Found the problem is that:1.Nanyang city park is mainly distributed in the river and the accessibility of park is low. Leading to the old city and the South Bank of the river is serious lack of green space.2. Park green space layout imbalance,which lead to the park green area per capita is 5.3%.and there has lot’s of difficulties to increase new parks in the old city area.This area’s building and population are density. so that the house demolition is difficult.3. Nanyang has a long history.But lot’s of cultural relics were surrounding buildings. Which lead to the cultural atmosphere is very weak. 4. The park green space is smaller and the characteristics are not outstanding.There has lot’s of small gardens and street parks.but little of comprehensive park in the central downtown.Referring to the theory of land suitability analysis by Mcharg and "layer cake" model. Owen land suitability analysis principle and the "layer cake" model,through the investigation and analysis,we summed up the approprite criteria of the park land suitability evaluation criteria. The criteria selected 6 evaluation factors: 1.the accessibility of park. 2.the nature of land use. 3.building height. 4.cultural sites. 5.natural water. 6.analysis of urban heat island.In the yaaph platform, using analytic hierarchy process, experts give those factors’ weight. In the Arcgis9.3 platform, using raster overlay operation, draw the park of Nanyang land suitability analysis map. Through the analysis, we found the land suitability distribution rules of Nanyang city: the highest land suitable for regional level are mainly distributed in the edge of the city, the suitability in the city centre is low, the suitability to the south bank of Baihe river is higher.