干旱区城市化过程中的生态风险评价模型及应用——以河西地区城市化过程为例

城市化是河西走廊可持续发展的必由之路,然而现实中城市化过程与生态环境之间存在着各种各样的矛盾与胁迫,同时也伴随着生态风险的产生,评价城市化过程中诱发的生态风险,并找出各种生态风险变化的规律性,对河西走廊城市未来的健康发展具有重要的现实意义。通过研究城市生态风险的内涵与动因,建立了生态风险评价的数学模型,并利用该模型从不同角度计算出河西走廊7个城市的生态环境风险强度,在此基础上分析了河西城市化过程中生态风险变化的规律性,即河西走廊7个城市的经济城市化诱发的生态风险大于人口城市化和社会城市化诱发的生态风险;农业用水诱发的生态风险大于工业和第三产业用水;流域下游的生态风险大于上、中游地区;从空间上,各城市的综合生态风险呈现出玉门>敦煌>武威>金昌>酒泉>嘉峪关>张掖的位次顺序。

Model andApplication of Ecological Risk Appraisal in the Course of Urbanization in Arid Area

Urbanization is the only way of sustainable development of the Hexi Corridor.Hower,There are various contradictions and coerce between the urbanization course and ecological environment in reality,which also engenders ecological risk.It therefore makes sense to appraise the ecological risk and find its disciplinarian brought out by the urbanization course for future development of cities in Hexi corridors.Natural forces,economy and social activities contribute to the cause of ecological risk.The ecological risk in the urbanization originates mainly from the development of economy and the social activities.On the basis of research on the intension and the cause of the ecological risk,the author sets up the mathematical model for the ecological risk appraisal and then use this model to calculate the intensity of ecological risk of 7 cities in Hexi Corridor from different perspective.On this foundation,the author analysis the regularities of ecological risk change in the urbanization course of Hexi corridor: Ecological risk that the economic urbanization brings out is greater than the ecological risk that population urbanization and social urbanization bring out;The ecological risk brought out by the first industry development is greater than the secondary and tertiary industries;The ecological risk brought out by agricultural water is greater than the industry and the tertiary industry;The ecological risk of the low reaches is greater than the middle and upper reaches;The comprehensive ecological risk of each city demonstrates the precedence order of Yumen >Dunhuang >Wuwei >Jinchang >Jiuquan >Jiayuguan>Zhangye. By careful analysis on the characteristics and laws of the ecological risk in Hexi urbanization course,the author also put forward the countermeasure and ways to dissolving the ecological risk of cities in the Hexi Corridor.These countermeasures includes: Impulse the transition of economic increase to intensive style;Develop the secondary and tertiary industries such as tourism which have relatively low ecological risk in a more cost-effective manner;Improve the proportions of industrial water and reduce the proportion of agricultural water;Stress on the work of the ecological constructions of the lower reaches and the coupling development of each drainage.