Assessment of environmental changes induced by internally displaced person (IDP) camps in the Darfur region, Sudan, based on multitemporal MODIS data

Abstract

Darfur's complex conflict situation led to large-scale internal displacement of people with significant implications for the environment as well as for the conflict situation itself. Time series analyses of medium-resolution satellite data for monitoring large regions were carried out over a longer period to detect the impact of camps for internally displaced persons (IDPs) on their surrounding environment. Four regions of interest were defined in the Darfur region, Sudan, which cover the main and most dynamic IDP camps of the region and are characterized by different environmental conditions. Hotspots of anthropogenic impacts on the vegetation are revealed based on the Seasonal Kendall test applied to quality-enhanced enhanced vegetation index and normalized difference vegetation index Moderate Resolution Imaging Spectroradiometer time series. Overlaying the resulting trend pattern with the locations of IDP camps suggests significant impact on the vegetation, especially -but not exclusively -in those areas with very high population densities. A comparison of the temporal development of the detected hotspots with precipitation and population figures over the investigated period help differentiate between natural and human-induced impacts. Subsequent to the analysis of the medium resolution data, the resulting trends in vegetation cover were correlated with changes detected with very-high-resolution satellite imagery for the two areas around Zalingei and Zam Zam. Areas of decreased vegetation cover in the resulting trend pattern can be correlated with logging of trees as well as removal of shrubs and grass, while positive changes in vegetation cover are related to agricultural land expansion.

Vegetation changes attributable to refugees in Africa coincide with agricultural deforestation

“…For example, an evaluation of the changes in landscape within 90 km of Darfur camps in 2001-2007 illustrated a regeneration of vegetation in the rural residences of the displaced while an intensification of agricultural practices in the urban periphery [15]. Extending the temporal coverage to 2010 and refining the spatial resolution to 250 m indicates that the deleterious impacts on vegetation are quite concentrated in the areas surrounding the camps [18]. In utilizing data at a greater spatial resolution, our study may underestimate the scale of agricultural deforestation induced by refugees.…”

“…In addition to testing the refugee effect on the condition of natural vegetation, we test a second hypothesis: refugee camps lead to the expansion of agricultural land [18][19][20]. Refugee camps offer additional sources of cheap labor and attract capital investment, such as the expansion of road networks [21][22][23][24][25][26][27].…”

“…Refugee camps offer additional sources of cheap labor and attract capital investment, such as the expansion of road networks [21][22][23][24][25][26][27]. Both features can strengthen farmers' access to cheaper inputs and auxiliary output markets reinforcing incentives to cultivate more land [28][29][30]. However, refugees themselves have at times been responsible for the conversion of forest to agriculture due to their volition to continue farming in host regions [28].…”

“…Both features can strengthen farmers' access to cheaper inputs and auxiliary output markets reinforcing incentives to cultivate more land [28][29][30]. However, refugees themselves have at times been responsible for the conversion of forest to agriculture due to their volition to continue farming in host regions [28]. Qualitative studies identify the use of unsustainable, customary practices and shortened fallowing cycles as a means of compensation for meager land allotments through existing programs initiated within camps [8,10].…”

An Earth Observation-based Approach for the Assessment of the Environmental Impact of Refugee and IDP Camps

“…Evidence has shown that for these reasons such camps often have significant impacts on the environment (e.g. HAGENLOCHER et al 2012, KRANZ et al 2015. Severe deforestation, desertification, land degradation, unsustainable groundwater extraction, and water pollution are impacts that can be observed in the surroundings of many camps, often within a radius of up to 15 km.…”