Abstract
Urbanization has become an important contributor for thermal condition, and the temperature has been increased in not only large city also medium city as well. In order to improve the environment, several methods have been applied. One of them is use of tree's cooling function: trapping direct sunshine and evapotranspiration. Therefore it is very important to estimate vegetation fraction in the city. Previous researches have already shown several methods to estimate vegetation fraction. In this study, the characteristic of those parameters are discussed to identify the optimum index to estimate vegetation fraction in the city, where vegetation distribution is heterogeneous in vitality and distribution pattern.
