基于CA-Markov的江汉平原生态系统服务价值动态模拟*——以湖北省潜江市为例

DYNAMIC SIMULATION OF FUTURE ECOSYSTEM SERVICES VALUE IN JIANGHAN PLAIN BASED ON CA MARKOV*——A CASE STUDY OF QIANJIANG CITY

关键词:  生态系统服务价值土地利用变化模拟时空变化多准则评价转移适宜性图集TM数据

Key words:  ecosystem services value  land use change simulation  spatio temporal variability  multi criteria evaluation  transition suitability image collection  TM image

摘要:

［目的］江汉平原为典型快速城市化区域，文章以地处江汉平原腹地的潜江市为例，研究其土地利用及生态环境发展趋势，旨在指导土地利用规划及生态经济协调发展，为类似区域提供参考。［方法］以1995—2015年5期土地利用矢量图为基础数据，采用修正的生态服务价值当量系数计算各年份生态系统服务价值（Ecosystem Services Value，ESV），绘制空间分布图，分析其时空变化特征。并采用CA-Markov模型对2035年土地利用空间格局进行模拟，分析2015—2035年ESV变化趋势。［结果］2000年前后城镇化速度差异明显，总体上生态用地在不断减少，潜江市土地利用方式有待转型； 1995—2015年，潜江市ESV变化呈现“急速增加—锐减—恢复增加”的模式，水域面积变动是ESV变化的根本原因； 面积起伏不大的耕地对生态系统稳定十分重要，但林地、湿地、草地生态服务价值占比都有减小的趋势，表明生态环境发展并不乐观； 1995—2015年ESV空间分布发生了显著变化，高值区逐渐以返湾湖为中心集聚分布，并存在向南扩大态势，低值区呈条带状分布于中心城区； 敏感性指数计算结果表明计算结果较为科学； CA-Markov模型模拟结果表明， 2015—2035年，生态用地数量增加，土地利用结构趋于优化，但耕地大幅减少，ESV由4731亿元下降至4666亿元，减幅为137%。［结论］以潜江市为代表的区域生态环境发展不容乐观，政府应加强对水资源、耕地的保护，推行环境友好型土地利用方式，推动生态文明建设。

Abstract:

Jianghan Plain is a typical place of rapid urbanization. We take Qianjiang city, which is located in the hinterland of Jianghan plain, as an example to get a deeper understanding of land use and ecological environment development. Our intention is to guide local land use planning and coordinate development of ecology and economy, and provide reference for similar areas. Using the land use vector map from 1995 to 2015, we conducted the assessment on Ecosystem Services Value(ESV) in Qianjiang city based on the revised ecological services value equivalent coefficient. And we produced the ESV spatial distribution map in Qianjiang city from 1995 to 2015 through Geographic Information System(GIS) in order to analyze spatio temporal variability of ESV. In addition, we adopted CA Markov model to simulate the spatial pattern of land use in Qianjiang city in 2035, thus the changing trend of ESV from 2015 to 2035 was analyzed. The results indicated that difference of urbanization speed before and after 2000 was obvious, and the ecological land area presented clearly a decreasing tendency on the whole, which meant land use pattern in Qianjiang city need to be transformed. Besides, the changing process of ESV in Qianjiang city showed a pattern of "rapid growth sharp reduction renewed growth" mainly due to fluctuations in the area of water. We noticed that ESV of cultivated land had little change and cultivated land was therefore of great significance to the stability of ecosystems. However, the ESV proportion of forest, wetland and grassland performed a dropping trend, implying the development of ecological environment in Qianjiang city was not optimistic. Furthermore, spatial distribution pattern of ESV had undergone significant changes. And regions with high ESV were gradually concentrated and distributed around the "Fanwan" lake, providing a southward expansion tendency, while regions with low ESV were distributed in the city center. Sensitivity analysis demonstrated that ESV was inelastic to the equivalent coefficient, accordingly the results were considered to be scientific. At last, the simulation results produced by CA Markov model showed that from 2015 to 2035 the ecological land area would increase and the land use structure tended to become more optimized, but meanwhile the cultivated land area was dropping sharply. The ESV in 2035 will decrease to 4.67 billion Yuan from 4.73 billion Yuan in 2015, a decline of 1.37%. In conclusion, ecological environment development in places similar to Qianjiang city is not optimistic, so government should strengthen the protection of water resources and cultivated land, and adopt environmentally friendly land use policy to promote ecological civilization.