塔里木河下游植被生态风险遥感定量评估

QUANTITATIVE ASSESSMENT OF VEGETATION ECOLOGICAL RISK ON THE LOWER REACHES OF TARIM RIVER BY REMOTE SENSING

以我国最大的内陆河——塔里木河下游区段为研究区域,将遥感、地理信息系统等技术手段与模糊数学方法相结合,根据ERA框架和层次分析思想,建立塔河下游植被的生态风险评估指标,运用模糊综合评判的方法进行塔河下游植被生态风险的遥感定量评估.评估结果:①塔河下游的植被生态风险程度较重,普遍都是中度、重度风险;②从英苏到台特玛湖河段植被风险最大;③明显呈现出下游上段植被风险小于下游下段,绿洲内部植被风险小于绿洲外围;④偏离河道越远,植被风险越大.植被生态风险评估数据的获取是采用遥感与地面相结合的方法,这在今后的生态风险评估研究中将有很大的应用潜力.利用RS和GIS技术手段并结合景观生态、模型预测的生态风险评估正处于研究开发阶段,如何把这些方法运用到干旱区特殊环境的生态风险评估之中,将是干旱区环境研究的一个新方向.

Recently Ecological Risk Assessment （ERA） has played an important role in environment science, but shorts a set of integrated methods up to now. In this paper, a methods＇ combination of Fuzzy Synthetic Evaluation,Remote Sensing, Geographic Information System and other advanced methods is used to accomplish a vegetation ecological risk assessment of the lower reaches of Tarim River, which is the longest continental river in China. According to the conceptual frame of ERA and ideology of Analytic hierarchy process （AHP）, we establish an index system, and use fuzzy comprehensive evaluation method to analyze the vegetation ecological risk,then we get results as follows： 1. in the lower reaches of Tadm River, it appears severely, the vegetation generally confronting medium or heavy ecological risks;2.it is severest at the part from Yingsu to Taitema Lake; 3.From the upper segment to the lower segment, external oasis to internal Oasis, it shows a obviously mitigation; 4.The farther apart from the river, the heavier the ecological risk of the vegetation is. The approach used in this paper, using remote sensing to obtain the data which ground approaches cannot get, will have great potential in future for application in ecological risk assessment.Using RS and GIS technology combined with landscape ecology, predicting models in this field is still at the primary stage, and how to apply them in special environment like add areas will be a new direction for research.