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The pastoral resources in eastern Sudan are changing under the combined impact of increasing anthropogenic activities such as clearance of natural vegetation and the effect of state policies that favour crop farming against pastoralism. Remotely sensed data are used to detect spatial and temporal changes from 1979 to 2009 in the land use/land cover (LULC) across three study sites. Areas of natural vegetation have been reduced from 26.1% in 1979 to 12.6% in 1999 and further to 9.4% in 2007. The majority of this reduction went into agricultural land. Local knowledge of pastoralists on their perceived changes in plant species is obtained. Major LULC trends are progressive degradation and loss of grazing areas, loss of biodiversity and depletion of other ecological support provided by natural vegetation. Declining rainfall, land clearance due to agricultural expansion, overgrazing and herbicide applications by crop farmers are identified as underlying forces changing plant species in the region. The study revealed that pastoralists have considerable knowledge and experience in dealing with degradation and climate variability. However, pastoralists are marginalized in decisions concerning expansion of large-scale agriculture at the expense of pasture land. Their lack of education and other basic services restricts the pastoralists' potential to adapt to the new situation.

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In the Gadarif Region of Sudan, destruction of the natural vegetation for agricultural expansion is one of the major causes of the degradation of renewable resources and the environment. This study identifies and analyses the farmers' attitudes and perceptions towards agricultural land degradation and abandonment. The cross-sectional data collected from ten key informants and 41 large-scale farmers focussed on the degradation and abandonment of mechanized agricultural land. The results of the study show that the respondents are well aware that soil degradation is in various forms are taking place on their cultivated agricultural land. This is based on their perception and interpretation of indicators such as weed infestation, poor soil fertility and soil compaction. Continuous cropping, mono-cropping, rainfall shortage and the use of inferior seeds are the main reasons of land degradation as indicated by farmers. The main measures acknowledged to maintain and improve land productivity are repeated soil ploughing, abandonment/fallow periods and crop rotation.The study adduces evidence of widespread land degradation. The mitigation measures followed by the farmers may though not be sufficient to restore the soil fertility. The application of appropriate chemical fertilizers, sound crop rotation and long fallow periods can be recommended. Any management and research intervention regarding the problem of land degradation should; however, be concerted with the farmers' knowledge.

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Recently, object-oriented classification techniques based on image segmentation approaches are being studied using high-resolution satellite images to extract various thematic information. In this study different types of land use/land cover (LULC) types were analysed by employing object-oriented classification approach to dual TerraSAR-X images (HH and HV polarisation) at African Sahel. For that purpose, multi-resolution segmentation (MRS) of the Definiens software was used for creating the image objects. Using the feature space optimisation (FSO) tool the attributes of the TerraSAR-X image were optimised in order to obtain the best separability among classes for the LULC mapping. The backscattering coefficients (BSC) for some classes were observed to be different for HH and HV polarisations. The best separation distance of the tested spectral, shape and textural features showed different variations among the discriminated LULC classes. An overall accuracy of 84 % with a kappa value 0.82 was resulted from the classification scheme, while accuracy differences among the classes were kept minimal. Finally, the results highlighted the importance of a combine use of TerraSAR-X data and object-oriented classification approaches as a useful source of information and technique for LULC analysis in the African Sahel drylands.

This paper focuses on the dynamics of pastoralist herd mobility in West Darfur State, Sudan, a region affected by persistent conflict. The paper examines the annual cycle and seasonal trajectories of mobility for camels, cattle, and sheep, comparing mobility patterns by livelihood specialisation and reviewing the mobility of multi-species herds. Using social research tools and remote sensing livestock tracking technology, the study found diverse livestock mobility patterns within the region. Conflict and insecurity have reduced the freedom and flexibility of these movements. Persistent insecurity combined with climate shocks have led to adaptations, including changes in herd species composition and owner preference, and a shift from long to short-distance mobility closer to the home area. Ultimately these changes have undermined the resilience of the pastoral system. The paper considers the implications of these changes in pastoralist mobility for humanitarian needs, building livelihood resilience and promoting peaceful integration with other users of natural resources.