The aggregation degree evaluation of urban park green space based on convolution method

Abstract

To fully reflect radiation effects of urban park green space (UPGS) service functions and obtain UPGS aggregation degree (AD) produced by a combination of UPGS in a local area and adjacent ones, the UPGS AD evaluation method for grid units and entire urban area were established based on a convolution operation. Based on high spatial resolution remote sensing images, UPGS maps of 37 cities in Shandong Province were constructed. Then, urban areas were segmented by 500鄄m grids and GIS technology, thereby obtaining UPGS grid maps. At the same time, a 3伊3 AD evaluation convolution mask was constructed and UPGS AD in each grid unit was attained by the convolution operation. Based on the calculation of UPGS AD in each grid unit, two evaluation factors were selected, namely the area ratio of urban space for which AD at each grid was zero, and AD standard deviation of all grids whose AD was larger than zero, for UPGS AD evaluation model construction of the entire urban area. The graded value of the two factors was acquired according to the distribution of UPGS AD in each grid unit of the study area. Using the two factors, the UPGS AD evaluation model of the entire urban area was constructed by a weighted overlay method. Dongying and Tai忆an were taken as typical examples for UPGS AD evaluation. The study result showed that the UPGS AD evaluation method of each grid unit based on convolution calculation could quantify the UPGS radiation effect in adjacent grids well. The method obtained AD values produced by the