基于土地利用结构变化的沙漠化动态评估——以内蒙古自治区奈曼旗为例

Dynamic Assessment for Desertification Based on the Changes in Landuse Structure: An Example from Naiman Qi of the Inner Mongolia, China

以内蒙古自治区奈曼旗为例 ,在利用遥感和GIS技术获取 1985— 2 0 0 0年间 4个时期土地利用变化资料的基础上 ,引入层次分析方法 ,确定不同的土地利用类型对沙漠化过程影响的权重值 ;并利用倪晋仁等人提出的相关区域土地利用结构特征指标来定量反映针对该地区沙漠化的土地利用结构的综合影响。通过分析研究区土地利用结构特征指针的变化 ,评价沙漠化土地的动态变化 ,为区域发展和规划提供科学的依据。此方法在奈曼旗的应用表明 ,根据不同时期的土地利用结构计算出的土地利用结构特征指标与遥感监测所得的沙漠化土地面积具有明显的负相关性 ,由此所得到的沙漠化动态评估结论与实际监测的结果基本一致 ,说明了该方法的合理性 ,较之其他方法更加省时省力和有效。

Taking Naiman Qi of the Inner Mongolia in the North of China as an example and b ased on the data of landuse changes obtained by remote sensing and GIS in four t ime intervals between 1985—2000, the authors determine the weight values of the influences from different landuse patterns on desertification processes by anal ytic hierarchy process. Furthermore, the integrated influences of landuse struc ture on desertification in the region are quantitatively described using the cha racteristic index of landuse structure put forward by Ni Jinren et al. This met hod can be used to assess the dynamic changes of desertified lands through analy zing the changes in the characteristic index of landuse structure in the study a rea and thereby provide a scientific basis for the developmental planning of the region. The results achieved from this study enrich the assessment method of la nd desertification and have a certain theoretical significance. The application of the method in Naiman Qi showed that the characteristic indexes of landuse str ucture calculated from different periods of landuse structure are negatively cor related with desertified land area obtained by remotely sensed monitoring. The c onclusions obtained from present dynamic assessment of desertification are essen tially coincident with the monitoring results, and thus demonstrate the rational ity and effectiveness of the method.