The Assessment of Urban Ecological Environment in Watershed Scale

Urban ecological environment is closely related to the harmonious development of the region. The interaction between ecological environment of the city and the watershed where it locates is less considered in current study. In this paper, making use of multisource data with remote sensing data as the main data source and according to the "Technical Standard for Evaluation of Ecological Environment" (HJ192-2015) promulgated by Ministry of Environment Protection, we accomplished the quality assessment of ecological environment of Yanhe watershed in 250m x 250m pixel unit with synthetical index method. Based on this, we also combined demographic data, DEM data of Yanhe watershed to analyze the interaction between urban ecological environment and ecological environment status of the entire watershed. The results showed that: 1) The ecological environment quality levels of urban areas in Yanhe watershed were mainly "poor" and "worse", and the farther from the urban area, the better quality level of ecological environment in general, which indicated the existence of the city exerted stress on the ecological environment; 2) The ecological environment of the city at higher altitude was in poorer condition, indicating that the distribution of the topography of the watershed had a certain impact on the ecological environment of the city; 3) By comparing the distribution of the ecological environment quality of different cities in the watershed, the more concentrated population density of the city, the greater scope of the poorer ecological environment, indicating that human activities had great influences on the urban ecological environment. We can conclude that it is necessary to consider the interaction between urban ecological environment and watershed ecological environment where the city locates, so as to provide new ideas for the construction and protection of the ecological environment of the city. (C) 2016 Published by Elsevier B.V.