基于CA-Markov模型的喀斯特地区县域生态系统服务价值动态模拟

【目的】评估贵州喀斯特典型地区土地利用及生态系统服务价值变化趋势,为退耕还林(草)工程的实施提供理论支撑。【方法】在"3S"技术支持下,以贵州省普定县1999年、2003年、2009年和2015年4期Landsat遥感影像为主要数据源,根据CART决策树模型分类结果,提取普定县土地利用/覆被及景观格局信息,对1999—2015年间生态系统服务价值进行动态评估;在此基础上结合CA-Markov模型,预测普定县2021年土地利用景观格局及生态系统服务价值变化趋势。【结果】1999—2015年间,研究区生态系统服务价值平稳增加,其中林地、农田和水域3类景观的生态系统服务价值占总价值的90%以上,是生态系统服务主体。在土地利用生态系统单项服务价值方面,水源涵养、土壤形成与保护和废物处理这3项生态服务功能合计贡献率在50%左右。【结论】贵州普定县域生态系统服务价值变化的主要驱动因素是退耕还林(草)政策的实施。2021年普定县生态系统服务价值总量为9.58亿元,比2015年减少约0.3亿元,说明现有退耕还林政策下,普定县生态系统服务价值在未来5年呈下降趋势。

Dynamic simulation of future ecosystem service value in Puding County,Guizhou Province based on CA?Markov model

Objective]Exploring the variations in land use and ecosystem service value in a typical Karst land area in Puding County plays an important role in the implementation of a"grain?for?green" restoration project.Method]We de?termined land use/land cover and landscape patterns based on the classification results of a CART decision tree using"3S" technology. The ecological system services values for the period of 1999 to 2015 were estimated based on the eco?logical principles. Combined with a CA?Markov model, the land use pattern and ecological system services value of 2021 was predicted. Result]The ecological system services value steadily increased from 1999 to 2015. The forest, field and water landscape areas were the largest part of the ecological system services, collectively providing more than 90% of the total ecological system services value. Water conservation, soil formation and protection, and waste disposal were almost 50% of the total contribution to total land?use ecosystem service values.Conclusion]The leading factor in the changes in ecological system service value in the study area was the grain?for?green project. Results of the forecast showed that the total ecological system services value of Puding County in 2021 would be 9.58 billion Yuan, a decrease of 0.3 billion Yuan compared to 2015.