The Measure of Ecological Security Early Warning and the Temporal and Spatial Pattern in Yellow River Delta
以黄河三角洲为例，用PSR模型和熵值法构建预警指标体系，分析2005-2010年生态安全变化，发现东部优于中西部，但整体仍处于三级预警水平。
Ecological security is important for human health,natural resources,and socio-economical development. With the aggravation of environmental pollution,ecological problem in Yellow River Delta area had become the focus of attention. In this paper,as the Yellow River Delta for an example,the PSR model was used to construct the warning index system of Yellow River Delta. The paper carried on analysis to the Yellow River Delta ecological security early warning by entropy method. Three conclusions were as follows. Firstly,during the period of 2005-2010,the ecological environment of Yellow River Delta has been improved gradually,and the value of ecological security early warning value in 2010 was bigger than the one in 2005. Secondly,although ecological environment has been improved,the ecological security level in most areas of Yellow River Delta in 2010 was still in the third grade. Ecological security was not optimistic. Lastly,ecological environment in eastern area of Yellow River Delta was better than the one of the central and western area. The areas of the worst ecological environment basically concentrated in Dongying city and Binzhou city. The transformation of economic development mode,ecological restoration and compensation,the difference of regional spatial control are the necessary measures to improve the ecological environment of Yellow River delta.