基于熵突变理论的滇东南典型岩溶湿地生态脆弱性演变研究

Puzhehei Karst wetland, located in southeast of Yunnan, is a typically sensitive and fragile ecosystem in China. Because of the excessive human activity and Karst geomorphological features, its wetland ecosystem is getting more fragile and difficult for protection and remediation. As the less nutrients and water content, but high calcium concentration of the Karst region soil, its ecosystem is more difficult to remediate. Lots of relavant scientists have been keeping sustainable focusing on the research of Karst wetland succession mechanism and driving factors, which pushes the study to a hot topic around world. However, three key scientific difficulties need be solved: (1) the characteristic disturbance factors of fragile ecosystem for Karst wetland are still for identification; (2) the degration of ecosystem and driving force mechanism of Karst wetland is urgently been enhanced for supplement and improvement; and (3) the quantitive assessment system for Karst wetland ecosystem is limited to face the systematically evidenced research purpose. Puzhehei wetland, a typical Karst region in Yunnan province, is taken as a case study. Based on the data collection, field investigation and monitoring, relevant digital information tool utilization and mathematic model establishment, the comprehensive research work operation as:(1) with the applying GIS and RS tool, the dynamic evaluation and temporal and spatial variation of Puzhehei Karst wetland succession trend will be declared through over 40 years relative data analysis; (2) under the land use and eco-system investigation and monitoring, the human and nature disturbance factors of Puzhehei Karst wetland degradation will be classed and accurate revision will be revised for deeply understanding of the Karst wetland degradation reasons; and (3) after applying the theory of entropy of information and catastrophe, the ecologically identified mathematics model could be established for ecological landscape evaluation of Karst wetland. With the accomplishment of research, several results will be achieved as: (1) statement of Puzhehei Karst wetland degradation trend and mechanism; (2) identification of its key human and nature disturbance factors; (3) establishment of suitably mathematic model and carrying out the parameter mode for key driving factors of Karst wetland assessment; and (4) optimization for ecosystem and landscape of Karst wetland. It is believed that the findings and the approach proposed in this study will provide more interesting and useful hints to support effective Karst wetland protection, management and designing.

普者黑岩溶湿地是我国滇东南生态系统最敏感的区域之一，研究其生态脆弱性演变机制及其驱动因子对生态系统恢复具有重要意义。但目前存在3个方面的难题急需解决：岩溶湿地脆弱生态系统特征性干扰因子需要准确识别；岩溶湿地生态系统退化机制急需补充和完善；岩溶湿地脆弱生态系统演变量化评价体系需构建。本项目以云南典型喀斯特地貌，丘北普者黑岩溶湿地为研究对象，基于GIS和RS的研究方法，系统分析近40年普者黑岩溶湿地演变趋势，在野外调查、遥感影像分析等特征性干扰因子初步识别后，通过建立以信息熵、突变理论等非线性科学理论为主导的普者黑岩溶湿地生态系统定量化表征体系，以实现对其生态脆弱性演变机制及驱动因子准确判定。本研究将系统阐述岩溶湿地的退化演替及特征性驱动因子，建立驱动因子的量化分析模型并进行生态脆弱性评价，从而进一步补充完善生态脆弱性研究理论，并为普者黑及其他岩溶湿地的保护提供理论参考和技术指导。

本研究从土地利用动态度和景观格局指数变化方面分析该研究区景观格局类型演变特征及规律。在此基础上，利用层次分析法和熵突变理论模型，对生态脆弱性时空演变进行评价。主要研究结果如下：.（1）30年间普者黑流域建筑用地和农地面积不断增加，湿地和未利用地面积持续减少，林地和园地呈现波动变化；不同情景模拟预测下土地利用类型之间的转移方式各异，情景Ⅰ下，湿地和农地是土地流转的主要来源，主要流向乡镇居民用地；情景Ⅱ下，建筑用地、未利用地的增加占用部分农地和林地；情景Ⅲ下，农地转化为建筑用地、林地和湿地是普者黑岩溶湿地流域未来主要的土地利用方式;.（2）1990~2015年普者黑流域景观结构发生了较大变化，农地和林地的干扰度较高，普者黑流域不同土地利用景观损失度变化显著，其中农地和未利用地损失度较大，依次达到0.5422和0.5514，湿地、建筑用地和林地次之，园地损失度最小，损失度指数仅为0.1197；1990~2015年研究区生态风险空间分布差异较大，1990~2005年较低生态风险所占比例最大，而2005~2015年期间生态风险主要表现为中生态风险等级，生态风险在缓慢增加；.（3）2006~2015年普者黑岩溶湿地流域生态脆弱性综合指数逐渐减小，从5.34下降到4.37，生态脆弱性等级综合表现为中度脆弱；2006~2015年普者黑流域生态脆弱性时空分布格局较散乱，极度脆弱区由普者黑流域下游向上游转移，且极度脆弱区面积由5 617.09 hm2减少到3 015.27 hm2，生态脆弱性恶化趋势有所缓解；2006~2015年普者黑流域生态环境熵值这十年内发生了多次突变，比较10年间三个阶段的突变特征值：第二阶段（2009~2012年）的突变特征值>第一阶段（2006~2008年）突变特征值>第三阶段（2012~2015年）突变特征值，自然因素和人为因素的叠加是研究区生态脆弱性变化的原因;.（4）选择生物多样性保护、水源涵养、产品提供三个因子进行生态服务功能重要性评价，将普者黑流域划为三大生态功能区，即西部农林生态农业建设功能区、东部生态旅游功能区、南部湿地生态保护功能区，并对三大功能区又进行细化共分为六个生态功能小区。