Tree Canopy Coverage And Distribution Rule Of Built-up Area In Puxi Of Shanghai

In this paper, RS and GIS technology was used to analyze characteristics of the tree canopy coverage in built-up area of Shanghai Puxi., the study area covers360km2, and based on ring road system of the city, that all study area was divided into3regions, or inner region (the area inside of inner ring road), which covers7812hm2middle region(the area between inner ring and middle ring road), which covers11196hm2; outside region (the area between middle ring and outside ring road), which covers16992hm2.The conclusions are as follows:(1) According to types of land use, the built-up area could be classified into12functional areas:residential square, industrial area, commercial region, school yard, farmland, roads and pavement ground, urban forest patch, green belt, park, water, airport and unused land. The are total218of16hm2sample plots at satellite image were picked up, which were4117hm2. In the all sample area,1758.22hm2was identified as residential square and accounted to50.43%of land;371.75hm2for Industrial area, accounted to10.66%;324.48hm2for roads and rigid pavement area, a accounted to9.30%;306.63hm2for urban forest patches, accounted to8.79%;186.85hm2for general green belt, accounted to5.36%;184.15hm2for commercial area, accounted to5.28%;139.83hm2for farmland, accounted to r4.01%;69.02hm2for school yard, accounted to1.99%;697.80hm2for Parks, accounted to1.94%;31.11hm2for water surface, accounted to0.89%,;25.15hm2for unused land, accounted to0.72%and22.01hm2for airport, accounted to0.63%.(2) The total area of tree canopy cover was8241.82hm2in study area, which accounting to tree canopy coverage (TCC) of22.8%. The tree canopy coverage for different types of land use was compared in the paper and the results showed that: park area had the highest tree canopy coverage, which was up to53.72%, the others followed in order:urban forest patch (50.72%)> general green belt(34.60%)> school yard (24.13%)> residential square (21.87%)> farmland (19.58%)> commercial area (18.50%)>industrial region (15.29%)> road (8.78%)> unused land (3.19%).(3) The land area of inner region accounted to21.7%of entire study area, middle region reached to31.1%, and outside region occupied as to47.2%; then the TCC for these3regions was26.45%、21.92%、and21.90%respectively, this pattern showed a trend in generally that TCC increased from inner region to outside region. However, TCC for the land of residential square showed a increased trend from inner region to outside region, The industrial land area in the different regions was significantly increased from inner to outer, The road area commercial and school yard showed a trend of increasing, but they only accounted for a low proportion.(4) The land of residential square was accounted to50.43%of whole study area. Its tree canopy coverage was in a suitable range, and almost up to21.87%. For three different regions of inner、middle and outer, their area were respectively accounted to69.73%,60.93%and37.14%, the tree canopy coverage of them were26.16%,22.28%and18.21%respectively.(5) The area of road land and rigid pavement in Shanghai Puxi accounted for9.3%of the total area. For3different regions of inner、middle and outer, their area occupancy was9.45%,10.35%and9.45%; Their tree canopy coverage were10.16%,9.50%and7.72%.(6) There were55public parks, with a total area of697.8hm2in the study area, which according for1.94%of total land area, appearing on the low occupation. The tree canopy coverage for most parks was lower, and average was53.72%. There were22parks in inner region with the total area of142.52hm2, accounting to20.4%of study area; There were24parks in middle region with the total area of246.41hm2, accounting for35.31%;and anothers9parks in outer region, with a total area of308.67hm2, accounting for44.23%.(7) The author estimated total8.1million trees growing in the study area, and0,368million tree in parks. Potential tree plant opportunity was estimated to0.59-0.98million trees in the study area, if it will do so the potential canopy coverage could reach to24.56%～25.67%at least,0.482million trees could be planted in outer region、0.312million in middle region and0.188million in inner region respectively.