دانلود رایگان مقاله انگلیسی چارچوب مفهومی برای ارزیابی کیفیت زیست محیطی فضای سبز شهری: مشهد - اشپرینگر 2018

Abstract

This study evaluates the green space ecological quality with regard to its spatial properties. It investigates how the spatial properties of green space patches afect ecological aspects of municipal green spaces of Mashhad in Iran. The importance and necessity of this investigation is to develop a concept to evaluate the quality of urban green patches based on the perspective and method of landscape ecology. In accordance with our objectives, the quality concept is defned by quantitative (size, area, density) and qualitative (shape, complexity, connectivity) factors as referred to spatial confguration and composition of landscape structure. However, to have a better understanding of the quality concept, we explored the relationship between landscape variables and ecological quality by spatial analysis and correlation tests. We (1) drew the urban green space map by images processing, (2) quantifed landscape metrics for the green space patches, (3) analyzed and represented the metric value spatially, (4) calculated ecological quality and drew the grade map, (5) measured the Pearson correlation coefcients and linear regression between ecological quality and each landscape metric. Results of this study provided the evidence to study ecological quality by integrating metrics map and analyzing spatial heterogeneity in Mashhad city. Results showed that the extent and continuity of the green spaces were too low to efectively support some key ecological services. Additionally, the Pearson’s correlation coefcients and linear regression revealed strong relationships between ecological quality and most landscape metrics except LSI. Although it was expected that the qualitative variables of green space had higher infuence on the ecological quality, quantitative variables had the highest efect due to the origin and nature of the green patches.

4 Conclusion

Urban green space has widespread usage and many benefts for quality of human life. However, climate restriction and urban development features and policies have infuenced the urban green space ecological quality in Mashhad city. In this study, we also used and examined a conceptual framework to measure green space ecological quality in Mashhad by landscape metrics and spatial analysis. The proposed patch metrics in terms of composition and confguration have informed us about function of urban green patches separately. However, when the analytic hierarchy process (AHP) was used and integrated landscape metrics map along with GIS, we were able to study the quality of green space patches. In fact, the green space ecological quality has provided evidence for the green space quality by spatial analysis of heterogeneity in Mashhad. Therefore, the results reveal that green spaces of Mashhad have low relative frequency, and patches of green spaces have undesirable conditions in terms of spatial composition and confguration. Statistically, the results of quality analysis demonstrate a signifcant diference between the minimum (10.96) and maximum (403.427) values in the spatial map. This means that there is a notable diference between the points with low and high ecological quality in the study area. In addition, average of quality values equal to 109.268 and standard deviation (SD) equal to 80.9125. Average and standard deviation are two closely related concepts measuring how “spread out” of a distribution or a data set value is. According to the descriptive statistics, we can imply that heterogeneity exists in distribution ecological quality values.