Spatial Pattern Analysis of Water-Driven Land Cover Change in Aridzone, Northwest of China

As a good indicator reflecting the interaction between human activities and ecological environment, landuse and land cover change has been studied for decades. The focuses of current researches are from whether a change has happened to what cause the change and how will change in the future. Many forces will drive environmental change of the earth. Water is one of the most significant factors for living things, especially in an arid environment. The study of land cover change with dynamic change of water resource can give us a better understanding on land cover change and the change reasons. This study attempts to find the spatial pattern of land cover change driven by water in an aridzone in the northwest of China and try to find a balance between economic development and sustainable development of environment for the fragile region. Since land cover change at that place is mainly due to the extension and abandon of farmland, two main land cover classes are considered in this study-the farmland and non-farmland. Based on the post-classification method, a change trajectory has been established to rebuild the history of land cover changes. In order to quantifying the impacts of water supply, two class-level metrics, Normalized Landscape Shape Index (NLSI) and Area Weighted Fractal Dimension Index (AWFDI), are adopted as tools which can measure the spatial distribution of changes. The result shows that farmland extension in that region is close to extreme due to the restriction of water supply. With the proposed approach, we can get a better understanding of the impacts of human activities or natural resources on land cover change.