根据模糊物元理论建立了城市化的生态预警模型,将警报级别分为无警、轻警、中警、重警和巨警5级,并从资源预警、生态预警和环境预警3个方面构建河西走廊城市化进程中的生态环境预警指标体系,设立了预警参照标准与预警界限、警灯、警度,对河西走廊进行了实证分析。结果发现,河西走廊及五大地市按照预警指数从大到小的顺序依次为:张掖市、武威市、金昌市、河西走廊、嘉峪关市和酒泉市。其中,河西走廊的生态用水比重、植被覆盖率、人均环境保护费用和万元产值工业S02排放量的景气指数最高,处于重警状态;城市工业用地定额、城市居住用地定额、万元产值工业废水排放量和万元产值工业粉尘排放量的景气指数最低,均处于轻警状态;其它指标均处于中警状态。可见,相对于土地资源和环境污染因素而言,水资源和生态条件已经对河西走廊的城市化产生了较强的束缚作用。
An ecological early-warning model to evaluae the process of urbanization was set up based on fuzzy matter element theory. The alarm signals were divided into five grades, namely, non-alert, light alert, middle alert, heavy alert and giant alert. Taking Hexi Corridor in Gansu Province as an example, we set up an index system of the ecological early-warning in the process of urbanization and established the early warning standards, limits, lights and degrees. The results showed that the order of ecological early warning exponent of Hexi Corridor and the five cities is shown as the following: Zhangye, Wuwei, Jinchang, Hexi Corridor, Jiayuguan and Jiuquan. The boom exponents of ecological water proportion, vegetation coverage, environmental protection costs per capita and output value of industrial SO2 emissions per 10 000 Chinese yuan in Hexi Corridor are the highest. It shows that these exponents are in a heavy alert state. The boom exponents of urban industrial land ration, urban residential land ration, output value of industrial wastewater and dust emissions per 10 000 yuan in Hexi Corridor are the lowest. These exponents are in a light alert state. And the other exponents are in a middle alert state. Clearly, in relation to land resources and environmental factors, water resources and ecological conditions have played a strong role in the shackles of the urbanization in Hexi Corridor.