武威绿洲城镇化的生态效应情景分析

绿洲是人地关系地域系统研究的典型地区,城镇化是影响绿洲生态系统稳定性的重要人类活动之一,选择合理的城镇化模式对绿洲地区可持续发展至关重要。本文以石羊河流域武威绿洲为研究区,采用情景分析方法,对该地区常规城镇化和快速集约型城镇化两种情景的生态效应展开系统动力学模拟。结果表明：在快速集约型城镇化情景下,到2025年,武威绿洲年农业用水将控制在6×108 m3以内,相比目前水平可节约3×108～4×108 m3,生产和生活对生态用水的占用也将相应减少,年总用水量将控制在8×108 m3以内,水资源供需矛盾可得到缓解,下游民勤绿洲生态退化可得到有效控制;而在常规城镇化情景下,水供需矛盾将继续恶化,无法遏制石羊河下游生态退化趋势。因此,快速集约型城镇化模式是维持武威绿洲及石羊河流域生态系统稳定性的可取城镇化模式之一。

Scenario Analysis on Ecological Effects of Urbanization in the Wuwei Oasis, China

Urbanization is one of the important human activities affecting the oasis ecosystem,so it is essential for the government in the oasis area to choose reasonable urbanization mode. In this article, we took the Wuwei Oasis in the Shiyanghe River Basin as case study area,dynamically simulated the ecological effects under two typical urbanization modes through the method of scenario analysis. The results showed that,under the rapid-intensive urbanization mode,agricultural water consumption of the Wuwei Oasis could be limited in 6×108 m3 and 3×108-4×108 m3 agricultural water would be saved campared to the current level,production and living water consumption would also be reduced correspongdingly,and the total water consumption would not be more than 8×108 m3 in 2025. As a result,the gap between the supply and demand of water resources would be narrowed,and the ecological degradation of the Minqin Oasis in the lower reaches of the Shiyanghe River Basin would be effectively controlled. Otherwise,under the conventional urbanization mode,it would be difficult to effectively solve the water problems and to alleviate the ecological degradation of the Shiyanghe River Basin. Therefore,the rapid-intensive urbanization would be one of desirable modes for maintaining the stability of the ecosystem in the Wuwei Oasis and the Shiyanghe River Basin.