基于PSR模型的凌河口湿地生态系统健康评价与预警研究

凌河口湿地自然保护区是辽河流域主要的湿地保护区域。选取1995年、2000年、2005年、2009年和2014年TM影像作为研究的数据源,在3S技术平台支撑下构建了凌河口湿地空间信息数据库,获取了5个时期的景观格局指数。运用PSR数学模型,从压力、状态、响应3个方面选取10个评价指数,构建了凌河口湿地生态系统健康评价指标体系;采用AHP方法确定各项指标权重指数,应用逻辑斯蒂增长模型(Logistic growth model)对各个单项指标进行单因子评价,最后用计算CEI的综合评价法对5个时期湿地的生态健康情况进行综合评价。结果表明:1995年、2000年生态系统健康指数为0.642、0.617,凌河口湿地生态系统状态为比较健康;2005年、2009年和2014年生态健康指数为0.524、0.436和0.405,凌河口湿地生态系统处于亚健康的状态,应及时采取措施对该研究区进行生态系统保护。最后通过选取基于灰色系统理论的预测模型,构建凌河口湿地生态健康预测模型GM(1,1),对模型进行精度检验,发现灰色绝对关联度、后验差比值和小误差概率的精度检验等级均为一级,预测模型精度较为理想,因此采用GM(1,1)模型对凌河口湿地进行生态系统健康预测研究。预测结果表明:未来20年的湿地生态健康值分别为:0.357、0.321、0.291、0.267,研究区处于一般病态,并有向病态发展的趋势,生态健康面临愈来愈严重的威胁,对湿地进行保护和管理刻不容缓。

Study on ecosystem health evaluation and risk assessment for Linghekou wetlands based on a PSR model

As one of the Liaoning nature reserves, the Linghe estuary wetland is an important component of the Liaohe Delta. Data from TM images in 1995, 2000, 2005, 2009 and 2014, were used to build a spatial information database of the Linghekou Wetland Nature Reserve and determine landscape dates of 5 periods using 3S technology. In this study, we evaluated Linghekou wetland ecosystem health using the purpose-built Linghekou wetland ecosystem health evaluation based on the Press-Status-Response (PSR) concept model. We used the expert evaluation index combined with the AHP evaluation to comprehensively evaluate the use of a logistic growth model for each index based on the assessment of a single index. The ecosystem health values were 0.642 and 0.617 in 1995 and 2000, respectively, indicating that the ecosystem health was better in 1995 than 2000; the ecosystem health values were 0.524, 0.436, and 0.405 in 2005, 2009 and 2014, respectively, which showed that the ecosystem was in a sub-healthy state and some necessary measures should to be immediately taken. Based on this study, we used the Grey prediction model to build a wetland ecosystem health prediction model and tested the model for accuracy. The correlation and mean square error ratio and the small error probability were primary concerns; the model accuracy was high enough to effectively predict the ecosystem health of the Linghekou wetland. The prediction values for the Linghekou wetland ecosystem health were 0.357, 0.321, 0.291 and 0.267 in 2019, 2024, 2029 and 2034. The wetland ecosystem health was in a general poor state and this trend is expected to worsen. Ecosystem health threats are very serious and necessitate more protection and management of wetland ecosystems to ensure their survival.