关键词:  font-size: 10.5pt" face="宋体">生态风险评价；font-size: 10.5pt">PSRfont-size: 10.5pt" face="宋体">模型；模糊综合评价；BPfont-size: 10.5pt" face="宋体">神经网络；煤炭资源型城市；鄂尔多斯市

Abstract:  This paper, based on case study on Ordos city, uses references and GIS to study its natural, social and economic indexes, and applies PSR model to select 24 indexes to establish an index system in assessing ecological risks in study area, which is used to assess the ecological risks in 2005—2015 by means of fuzzy comprehensive evaluation. BP neutral network is employed to set up a prediction model used to predict Ordoss ecological risks in next five years. During 2005—2015, Ordos had undergone a higher risk level in 2005—2008, a general risk level in 2009—2011 and a low level in 2012—2015. Risk levels vary over time, generally showing a good trend. In the future, Ordos's ecological risk level is estimated to decrease in the future, at a low level, down to 5.894 5 in 2017 a general level, and to 6.026 6 in 2020, indicating a low level. Pressure factors to ecological risks mainly include environmental pressure, such as industrial pollution emission, conditional factors are economic and environmental conditions, including the weight of the third industry in GDP and waterfall. Response factors are human response, like college student number per 10 thousand people, and medical bed rate per 10 thousand people. To avoid worsening ecological risks, this paper presents suggestions on controlling population, industrial pollution emission, degradation of grass land and desertification, adding input in health and education.

Key words: ecological risks assessment, PSR model, fuzzy comprehensive assessment, BR neural network, coal city, ordos city