黄河上游生态脆弱区城市增长边界划定——以临夏回族自治州为例

Delimitation of urban growth boundary in ecologically vulnerable areas in the Upper Yellow River:Take Linxia Hui Autonomous Prefecture as an example

黄河流域是我国重要的生态屏障和经济区,其上游水源涵养区对黄河流域的生态可持续发展起着决定性的作用。因此,科学统筹城乡发展、合理划定城市增长边界(UGB),对于黄河流域生态保护与城市高质量发展具有重要意义。以黄河上游典型城市临夏回族自治州为研究对象,基于土地利用及相关遥感数据,运用遥感生态指数(RSEI)、生态敏感性分析评估了临夏回族自治州的生态质量,并在此基础上,结合CA-Markov对比分析了有无生态环境质量评价条件下未来城市增长边界发展情况。结果表明:(1)2005—2015年,临夏回族自治州生态环境整体较差且逐年下降,2015年生态质量(RSEI)结果降至最低(0.38)。同时,生态敏感性也从中度敏感变为低度敏感。(2)2005—2015年,研究区城市扩张面积增长6.04 km^(2),通过CAMarkov模拟得到的2030年城市建设用地规模为95.88 km^(2),超出规划面积3.2 km^(2),城市扩张未得到有效约束。(3)RSEI-CA-Markov模拟2030年的城市建设用地为90.36 km^(2),小于政府规划面积2.32 km^(2),符合城市可持续发展要求。因此,基于RSEI-CA-Markov划定的黄河上游生态脆弱地区UGB具有更强的城市管理能力,有利于引导和实现城市可持续发展,也可对中国其他生态脆弱城市生态—经济协调发展提供参考依据。

The Yellow River Basin is an important ecological barrier and economic zone in China,and its upstream water-conserving areas play a decisive role in the sustainable ecological development of the Yellow River Basin.Therefore,scientific coordination of urban and rural development and reasonable delineation of urban growth boundary(UGB)are of great significance for ecological protection and high-quality urban development in the Upper Yellow River Basin.This paper takes Linxia,a typical prefecture-level city in the upper reaches of the Yellow River,as the research object,and assesses its ecological quality based on land use and related remote sensing data using remote sensing ecological index(RSEI)and ecological sensitivity analysis.On this basis,the future urban growth boundary development with and without ecological quality assessment conditions is analyzed in combination with CA-Markov comparison.The results show that:(1)From 2005 to 2015,the overall ecological environment of the study area was poor and decreased year by year,and the ecological quality(RSEI)result dropped to the lowest(0.38)in 2015.Meanwhile,the ecological sensitivity changed from moderate to low sensitivity.(2)The urban expansion area increased by 6.04 km^(2),and the scale of urban construction land in 2030 obtained by CA-Markov simulation was 95.88 km^(2),which exceeded the planned area by 3.2 km^(2),and the urban expansion was not effectively restrained.(3)Simulation of RSEI-CA-Markov shows that the urban construction land in 2030 is 90.36 km^(2),which is smaller than the planned government planning area of 3.3 km^(2),and meets the requirements of urban sustainable development.Based on this,the designated UGB has stronger urban management capabilities.The delineation of UGB in the ecologically fragile area in the Upper Yellow River is conducive to guiding and realizing sustainable urban development,which can also provide reference for the sustainable development of other ecologically fragile cities in China.