基于3S 的榆林市土地利用/覆盖变化 生态效应定量研究

基于遥感数据, 运用3S 技术及多种生态经济学方法测算不同土地利用/覆盖情景下的生 态服务价值, 并分析其影响因素, 构造土地利用变化生态效应指数和土地利用变化生态效应度等 指标定量测评区域土地利用/覆盖变化的生态效应。研究结果表明: (1)榆林市1987、1999 和2002 年生态系统服务总价值分别为237.58 亿元、173.43 亿元和283.69 亿元, 并存在区域差异。整个研 究期间(1987～2002 年), 南、北六县耕地生态服务价值比重不断缩减, 林地、草地生态服务价值比 重不断增加, 但北六县以林地增加为最, 南六县以草地增加为最, 且在1999 年后增速加剧。(2)除 土地利用变化外, 气候波动对榆林市生态服务价值变化的影响更不容忽视。(3)除榆阳、神木、米脂 外, 其余空间尺度的各区域在后一阶段( 1999～2002 年) 的土地利用变化的生态效应高于前一阶 段(1987～1999 年); 在前一阶段, 北六县土地类型间流转导致生态价值变化较南六县强烈; 而后一 阶段正好与之相反。

Quantitative Study on Response of Ecosystem to Land Use/Cover Changes in Yulin Ar ea Based on 3S Technology

The technologies of 3S and various economic analysis methods for ecosystem service evaluation were employed, and regional total ecosystems’service values for different spatial scales in Yulin Area were calculated. Then, the factors that impact regional total ecosystems service values have been analyzed and the indexes employed to quantitatively evaluate the response of ecosystem to land use/cover changes were established. The results are as follows:① In 1987, 1999 and 2002 the total ecosystems’services values of Yulin Area were 237.58 billion yuan, 173.43 billion yuan and 283.69 billion yuan, respectively. But it varied with the spatial variation in Yulin Area. During the whole study period, there is a decrease in terms of the proportions of the services values of farmland and an increase in terms of that of woodlands and grasslands in the Northern- Six- County as well as in the Southern- Six- County, but the sharpest increase in the Northern- Six- County was woodlands, while that in the Southern- Six- County was grasslands. ②Both the land use/cover changes and climate fluctuation are mainly responsible for the changes of regional total ecosystems’service values yearly. Thus, only when the influence of climate fluctuation yearly is eliminated, can the response of ecosystems to land use/cover changes be evaluated more objectively. This was exactly indicated by the results of response indexes of ecosystems to land use/cover changes. ③For most of regions of different spatial scales, the response degree of ecosystems to land use/cover changes during the latter period was higher than that during the former period; and during the former period, changing of total ecosystems services values resulted from land use/cover changing in Northern- Six- County was more dramatic than that in Southern- Six- County, while it was vice verse during the latter period.