Spatial Heterogeneity of Driving Factors of Wind Erosion Prevention Services in Northern China by Large-Scale Human Land-Use Management

Large-scale human land-use management is an effective method for ecosystem restoration and wind erosion prevention service (WEPS) improvement. However, the spatial differences of driving factors and the feedback in subsequent management have received less attention. This study analysed the temporal and spatial changes in the WEPS in northern China from 2000 to 2015, classified the driving modes between the WEPS and environmental factors, distinguished the main driving factors, and proposed suggestions for successive projects. The results showed that, compared with 2000, the amount of WEPSs in 2015 increased by 12.60%, and forest and grassland in the WEPS-increased area was 1.34 times that in the declining area. There were east–west differences in the driving mechanism of WEPS improvement. In addition to climatic and topographic factors, the western division was mainly affected by changes in vegetation quality, whereas the eastern division was affected by the combined influence of vegetation quality and quantity. This study shows the necessity of land-use management and project zoning policies, and provides a reference for policy formulation and management of large-scale ecological projects.

Wind Erosion, Climate Change, and Shelterbelts

Wind erosion is a widespread phenomenon causing serious soil degradation. It is estimated that about 28% of the global land area suffers from this process. Global climate changes are expected to accelerate land degradation and significantly affect the intensity of wind erosion. Shelterbelts are linear multi-row planting strips of vegetation (trees or shrubs) established for numerous environmental purposes. Shelterbelts are a specific type of agroforestry system which could reduce soil degradation (soil erosion). Shelterbelts mitigate greenhouse gas through trees storing carbon (C) in their above- and below-ground biomass, wherefore they are highlighted as one of the potential ways to mitigate climate change. The purpose of this chapter is to present wind erosion as a land degradation problem, especially in line with climate changes and the present concept of vegetation establishment in the form of shelterbelts for long-term multi-functional provision of ecosystem services, in particular carbon sequestration.

Damage Assessment of Concrete under Wind-Sand Load

In this paper, a numerical model of wind-sand flow is established to explore the influence of wind-sand flow parameters on the stress state of the concrete. According to the contact mechanics theory, the wind erosion critical pressure of concrete members and the corresponding stress state of concrete are analyzed. A wind erosion damage assessment index based on stress fatigue theory is proposed.

Evaluation of Desertification Severity in El-Farafra Oasis, Western Desert of Egypt: Application of Modified MEDALUS Approach Using Wind Erosion Index and Factor Analysis

Desertification is a serious threat to human survival and to ecosystems, especially to inland desert oases. An assessment of desertification severity is essential to ensure national sustainable development for agricultural and land expansion processes in this region. In this study, Index of Land Susceptibility to Wind Erosion (ILSWE) was integrated with a Modified Mediterranean Desertification and Land Use (MEDALUS) method and factor analysis (FA) to develop a GIS-based model for mapping desertification severity. The model was then applied to 987.77 km2 in the El- Farafra Oasis, located in the Western Desert of Egypt, as a case study. Climate and field survey data together with remote sensing images were used to generate five quality indices (soil, climate, vegetation, land management and wind erosion). Based on the FA, a weighted value was assigned to each index. Five thematic layers representing the indices were created within the GIS environment and overlaid using the weighted sum model. The developed model showed that 59% of the total area was identified as high-critical and 38% as medium-critical. The results of an environmentally sensitive area index suggested by the original MEDALUS model indicated similar results: 18.37% of the total area was classified as high-critical and 78.73% as medium-critical. However, the sensitivity analysis indicated that weights derived from FA resulted in better performance of the developed spatial model than that derived from the original MEDALUS method. The proposed model would be a suitable tool for monitoring vulnerable zones, and could be a starting point for sustainable agricultural development in inland oases.