基于RS和GIS的半干旱区城市绿化三维量测算研究——以兰州市安宁区为例

Study on three-dimensional vegetation quantity measurement and calculation of urban greening in semi-arid region based on RS and GIS——Taking anning district of Lanzhou as an example

实地调查测量兰州市主要绿化树种的胸径、冠径、冠高、冠下高、树高等指标,建立常见绿化树种"冠径-冠高"相关方程和树冠绿化三维量计算公式。以1∶2 000数字航空正射影像为数据源,在ARCGIS9.0支持下测算出研究区绿化三维量,计算结果与研究区实际情况相符。研究表明,绿化三维量作为半干旱区城市绿色环境评价的指标,能更好地反映城市绿化和生态环境质量。

Many indices of main tree species in Lanzhou landscaping on site, including the diameter at breast height, crown width, crown height, the height under crown and the height of a tree are measured, and the correlative equation of ＂crown width-crown height＂ and the formulas to calculate three-dimensional vegetation quantity for tree＇s crown are established. By taking 1 ： 2 000 digital aerial orthophoto as its main research data, the three-dimensional vegetation quantity of research area is measured and calcul ated with the help of ARCGIS9.0. The result of calculating correspond with practical situation, which shows that taking three-dimensional vegetation quantity as indices of urban green environmental assessment will better reflect qualities of urban greening and ecological environment.