Researches On Accessibility Of Urban Public Park By GIS Network Analysis

As a main natural landscape elements and recreational place, Urban Public Parkis an important component of Urban Green Space System, and it’s an importantsymbol to measure the city construction and civilization. Besides, it plays a vital rolein improving the ecological environment of the city, the quality of life and thebuilding city image. At present, in the construction of the urban green space theproblem is how to build a perfect urban green space system and yield the greatestreturns on investment. Park green space accessibility is one of the important indexesin urban green space system planning, which is used to measure the service capacity theservice radiation level of the park. So the theme of the academic study has particulartheoretical and pragmatic meaning.In the paper, by digitizing the maps, it take Landsat TM spectrum data satelliteimage map of July2009, and the overall plan graph of Zhengzhou city (2009-2020),as a reference, supported by remote sensing (RS) and geographical informationsystem (GIS), it gets vision planning vector databases of the city road, the park greenspace and the rivers. Then it contrasts the digital vector map with Google Earth highresolution remote sensing image and makes a judgment, correct the object with thefield survey according to the survey. And then it classifies the different types of parkgreen space to different layer, to obtain more accurate vector map status databaseabout Road, Parks and Rivers of Zhengzhou City.We build the network analysis models by the road network system with the spacenetwork analysis module in ArcGIS, under the backgrounds of the status and futureplans, being based on the vector map of Zhengzhou that we had drawn, through thetraffic cost calculation method to calculate the various sections of the resistance value,and in each road junction with30s resistance time value. Then by analyzing andcalculating the accessibility of City park green space in Zhengzhou, we got theaccessibility range chart (5,15,30,60minutes) and all kinds of park green spaceservices range chart, based on the exits as source point respectively, overlaid and clipped them with city administrative region on technology platform on GIS. Theresearch estimates the rationality of green space in current and in future ofZhengzhou，and it makes proposals for the improvement of green space constructionsin the area with bad accessibility condition:1.appropriately increase the parkentrance;2. See the seam and insert green, and actively develop small green;3. Properdevelopment of green roofs and rational planning of road network structure.The innovation points of the paper are as follows: first, use the vector data modelto deal with network accessibility; second, dynamic analysis the accessibility of theurban area of Zhengzhou; third, the breadth-first search algorithm is introduced to thegreen space accessibility analysis.