关键词: 硅藻, 种类组成, 生态分布, 长江口

Abstract: GIS has a substantial advantage for the spatial overlay analysis in eco-environmental sensitivity assessment. In this paper, the traditional eco-environmental sensitivity assessment methodology was logically improved by adopting ArcGIS Model Builder to incorporate GIS modules capable of multi-cycle eco-environmental sensitivity assessment, and the assessment capacity of the improved methodology was tested in Qinghai-Tibetan railway area. By identifying environmental problems, determining indices and weights, and preprocessing spatial data, the GIS modules were easy and quick to run. The test results showed that the improved methodology could effectively illustrate the spatial pattern of the eco-environmental sensitivity areas along Qinghai-Tibetan railway. The highly eco-environmental sensitivity areas were mainly near the wildlife pathways on the both sides of the railway, and formed a linear distribution in a larger scale. The accuracy and reliability of our results were validated, and showed a strong compassion to the previous field researches in the region, implying that the improved methodology could supply a technical support for the quick eco-environmental sensitivity assessment of linear construction project.

Key words: Diatom, Species composition, Ecological distribution, Changjiang River estuary