基于RS、GIS的城市化流域土地利用的生态风险研究——以松花江干流哈尔滨段为例

以城市化流域-松花江干流哈尔滨段为例,基于RS和GIS技术,分析研究区土地利用变化及结构特征基础上,引入生态风险指数。利用空间分析方法对采样点生态风险指数进行空间插值,生成生态风险程度空间分布及变化特征图,以揭示城市化背景下土地利用的生态风险时空演变特征、变化规律及形成机理,最大限度地降低城市化过程中土地利用风险水平。结果表明:18年来研究区生态风险主要以中等程度为主,高生态风险区的比例最小,较高、较低生态风险区面积变化量最大;建成区和城郊过渡带为高、较高生态风险的分布区,低、较低生态风险集中分布于植被覆盖度高的林地和水域、草地及灌木林地等,高、低生态风险存在着明显的过渡地带;耕地→居民工矿用地和耕地→林地是略微变差型和略微变好型的主要土地利用转换轨迹;较低生态风险区的重心偏移量最大,高生态风险区最小,分别为12.31、0.57km。

Study on Ecological Risk of Land Use in Urbanization Watershed Based on RS and GIS: A Case Study of Songhua River Watershed in Harbin Section

The urbanization watershed of Songhua River in Harbin section was as example, using RS and GIS technology, the ecological risk index （ER1） was constructed based on the analysis of land use change and structural characteristics. The spatial distribution and change characteristics of ERI distribution map that obtained using block Kriging from the samplings were analyzed, which to reveal the spatial temporal evolution characteristics, change rules and formation mechanisms of ecological risk based on land use on the background of urbanization, to reduce the land use risk in greatest extent during urbanization process. The results showed that： the moderate ecological risk level was major and the proportion of high ecological risk was lowest, the change volumes of high and low ecological risk were greatest, the high and extremely high ecological risk was focused on the urban region and Peri-urban transition zone, the region of low and extremely ecological risk was mainly located in forest land with higher vegetation, water bodies, grassland ,shrub land and so on, meanwhile, the transition zone from high to low ecological risk was very obvious, cropland cultivated land and cropland -forestland were the major transform trajectory for the region of slightly worth and slightly better, the gravity shift volume of extremely low ecological was greatest, while, the high ecological was least, which accounted for 12.31 km and 0.57 km, respectively.