Quantitative Study Of Urban Temperature Regulating Service Based On “Source-Sink” Landscape Pattern

Rapid urbanization process makes a lot of artificial buildings replaced the natural surface. It changes the physical properties of city underlying surface and the urban thermal environment and enhances the “urban heat island effect”. The pattern process of urban landscape deeply affects the supply and demand of urban ecosystem services.Therefore, the study chooses the rapid urbanization area-western Shenzhen as research area, based on the theory of “source-sink” landscape to quantitative research the effect of landscape pattern to the function of temperature regulation. The main contents and research conclusions are as follows:(1)We created “source-sink” landscape identification method based on the temperature regulation service. For temperature regulation service, according to the theory of “source-sink”, with the temperature relationship between the landscape and the surrounding environment as the basis of “source-sink” landscape identification based on the urban landscape classification and equidistance surface index buffer analysis, then to determine the “source” and “sink” landscape. This method can better reflect the landscape characteristics of temperature regulating services and relationship between pattern and process.(2) The areas of “source” landscape are about 379 square kilometers(2005),533(2010) square kilometers and 525(2013) square kilometers, respectively. The areas of “sink” landscape are about 454(2005) square kilometers, 365(2010) square kilometers and 433(2013) square kilometers. The supply distance of temperature regulating service is calculated based on temperature gradient equidistance buffer analysis. the supply distance of the temperature regulation service in three periods is150 m(2005), 180 m(2010) and 210 m(2013), respectively.(3) In this paper, we estimate the temperature regulating theory value based on the area of “source” landscape, and combined with the “sink” landscape within the buffer area to estimate the actual service value. The theory value is 16.63 billion yuan/a, 23.73 billion yuan/a, 37.5 billion yuan/a of 2005, 2010 and2013 respectively.The actual services value is 3.04 billion yuan/a(2005), 3.27 billion yuan/a(2010) and4.31 billion yuan/a(2013), respectively. The result is lower than the predecessors’ research results and it shows that previous calculation result is higher than the actual value. The distance between “source” landscape and “sink” landscape is closer and closer. It may be the main reason for more and more value of temperature regulating service from 2005 to 2013.(4) Through the analysis of calculation of the shape index and size index, the value and the supply distance of service of the individual pixels are the smallest. As the increase of area, the value and the supply distance are gradually increasing. In shape index analysis, the service value of “source” landscape of shape index 2-4 is the greatest, “source” landscape of shape index more than 10 is the second. The supply distance of service from “source” landscape of shape index 1 is the shortest, and the supply distance of service from “source” landscape of shape index more than 1 are about 90 m.