基于MRSEDI与CA Markov的延河流域生态环境质量评价及预测

Evaluation and Prediction of Ecological Environment Quality in YanheRiver Basin Based on MRSEDI and CA⁃Markov

为探索快速准确评价和预测生态环境质量的普适方法,以延河流域为例,采用1998年、2004年、2010年、2016年6—9月的LandsatTM/OLI遥感影像数据,选取土壤侵蚀指数SEI、建筑裸土指数NDSI、湿度指数WI、植被指数NDVI计算改进型遥感生态距离指数MRSEDI,对1998—2016年生态环境质量进行评价,并采用CA-Markov模型对生态环境质量进行模拟预测。结果表明:①改进型遥感生态距离指数MRSEDI能够综合多指标信息、较为准确地反映延河流域生态环境状况,可作为生态环境质量评价的指标;CA-Markov模型兼具CA模型模拟复杂系统空间变化的能力和Markov模型长期预测的功能,可用于模拟预测流域生态环境质量。②延河流域生态环境质量在空间上具有西北低、东南高的特征,1998—2016年负向指标SEI和NDSI均呈下降趋势、正向指标WI和NDVI均呈上升趋势,MRSEDI流域均值从0.873提高到1.376,流域生态环境质量整体上明显上升,但存在局部生态环境质量退化现象。③未来延河流域生态环境质量将整体持续上升,但流域北部和中部生态环境极度脆弱区生态环境质量仍然较差,因此生态建设尤其石油、天然气、煤炭开采区的生态恢复须长期坚持。

In order to explore the method of quickly and accurately evaluating and predicting the ecological environment quality, taking YanheRiver Basin as an example and using Landsat TM/ OLI remote sensing image data from June to September in 1998, 2004, 2010 and 2016,the modified remote sensing ecological distance index MRSEDI was established by soil erosion index SEI, normalized difference build⁃up andsoil index NDSI, wetness index WI and normalized difference vegetation index NDVI, using it to evaluate the ecological environment qualityfrom 1998 to 2016. The CA⁃Markov model was used to simulate and predict the ecological environment quality. The results show that a. theimproved remote sensing ecological distance index MRSEDI can synthesize multi⁃index information, accurately reflect the ecological environ⁃ment of Yanhe River Basin, and can be used as an index of ecological environment quality evaluation;CA-Markov model has both the abilityof CA model to simulate the spatial changes of complex systems and the long⁃term prediction function of Markov model, and can be used tosimulate and predict the ecological environment quality of river basins. b. The eco⁃environmental quality of Yanhe River Basin is low innorthwest and high in southeast. From 1998 to 2016, the negative indicators SEI and NDSI show a downward trend, while the positive indica⁃tors WI and NDSI show an upward trend. The average value of MRSEDI watershed is increased from 0.873 to 1.376, and the overall eco⁃envi⁃ronmental quality of the watershed is increased obviously, but the eco⁃environmental quality is deteriorated in some areas. c. In the future,the ecological environment quality of Yanhe River Basin will continue to rise as a whole, but the ecological environment quality of extremelyfragile areas in the north and middle of the basin is still poor. Therefore, ecological construction, especially the ecological restoration of oil,natural gas and coal mining areas must be persisted for a long time.