Landscape spatial patterns in the Maowusu (Mu Us) Sandy Land, northern China and their impact factors

Abstract

In environmentally sensitive areas, particularly the arid or semi-arid regions, different factors such as relief and human activity, can greatly influence the landscape on a local scale. Using satellite imageries and field investigations, we have studied the distribution of sand dunes in the Maowusu (Mu Us) Sandy Land in the southern Ordos Plateau, northern China. Key research questions are which factors are critically responsible for the spatial pattern evident in the landscape and what is the relative importance of such factors? We used a new approach, i.e., the Geographical Detector to improve our spatial analysis. Using the combined methods of the Geographical Detector, digital image processing, field investigation and spatial and temporal analysis of the Normalized Difference Vegetation Index (NDVI), we aimed to clarify the causal relations governing the different landform patterns within this Sandy Land and beyond. The primary factors include local relief, drainage, climatically controlled potential plant productivity, wind action and rock type as explanatory parameters x and the landscape properties as the output y. Our results show the quantified links between the spatial distribution of various landscapes and their controlling factors. This study revealed that the climatic potential productivity, local relief and drainage are the key factors in shaping the landscape spatial pattern. Owing to different regional climates and land use histories, the responses to changes of external forcing between the western and eastern parts of the Maowusu Sandy Land are out-of-step. We conclude that the desertification of the eastern part of Maowusu Sandy Land has been mainly caused by human activities while the western part is governed by natural factors.