scholarly journals Assessment and mapping of desertification sensitivity with MEDALUS model and GIS – Case study: basin of Hodna, Algeria

2018 ◽  
Vol 36 (1) ◽  
pp. 17-26 ◽  
Author(s):  
Fouzia Boudjemline ◽  
Ahcene Semar
Keyword(s):  
Anthropogenic Factors ◽  
Risk Category ◽  
Mountain Areas ◽  
Area Index ◽  
Sensitive Areas ◽  
The North ◽  
Environmentally Sensitive Areas ◽  
Environmentally Sensitive ◽  
Low Sensitivity

AbstractIn Algeria, desertification risk is one of the main environmental and also social and economic problems. As much as 20 million hectares of northern Algeria are highly exposed and vulnerable to desertification with large areas falling into his ‘severe’ risk category, because the present massive destruction of vegetation and soils. This study aimed to use geographic information system (GIS) for mapping environmentally sensitive areas to desertification based on Mediterranean Desertification and Land Use (MEDALUS) approach in basin of Hodna, Algeria. Sensitivity is estimated with a modification of the MEDALUS environmentally sensitive area index (ESAI) which identifies such areas on the basis of an index (ESAI) that incorporates data on environmental quality (climate, vegetation, soil) as well as anthropogenic factors. This methodology allows the classification of land in critical, fragile and potentially sensitive areas. The results obtained show that 61% of the area is classified potentially sensitive to low sensitivity. These areas are particularly located in mountain areas. Spatially, the areas sensitive to degradation are as well in the lower region of the Hodna in Highlands consisting mostly of steppe route. The factors that could explain these variations of sensitivity are related mainly to changes in precipitation between the North and the South altitude and pressure of the population and livestock.

Threats to environmentally sensitive areas from peri-urban expansion in Mauritius

2015 ◽  
Vol 42 (3) ◽  
pp. 256-267 ◽  
Author(s):  
D. S. HAMMOND ◽  
V. GOND ◽  
C. BAIDER ◽  
F. B. V. FLORENS ◽  
S. PERSAND ◽  
...  
Keyword(s):  
Urban Expansion ◽  
Bimodal Distribution ◽  
Spatial Proximity ◽  
Environmental Services ◽  
Tropical Islands ◽  
Sensitive Areas ◽  
Environmentally Sensitive Areas ◽  
Environmentally Sensitive ◽  
Global Growth

SUMMARYRapid population growth and economic change on the tropical islands of Mauritius have led to one of the highest rates of urban build-out in the world. Pressure on many of the island's natural features and resources increasingly risks further degradation to the environmental services that they provide to the country. Fourteen types of marine and terrestrial environmentally sensitive areas (ESAs) are critical to the nation's sustainable development. Twelve of these ESA types are currently at risk of degradation, owing to their spatial proximity to built-up areas (BUAs) and current use designation. There was a bimodal distribution in proximity; eight of the 12 ESA types analysed had an area-weighted modal peak < 500 m from the nearest BUA, and four ESAs had a modal peak 2–3 km from the nearest BUA. Six coastal and marine ESAs had limited protection from urban expansion and over-use. The Mauritian experience reflects trends that are emerging across many tropical developing countries, where the bulk of future global growth in urban area is expected to occur. The approach detailed in this case study is replicable and may be useful in assessing degradation risk as a result of urban expansion in other island countries.

scholarly journals Assessment of the Vulnerability to Drought and Desertification Characteristics Using the Standardized Drought Vulnerability Index (SDVI) and the Environmentally Sensitive Areas Index (ESAI)

Resources ◽  
2018 ◽  
Vol 8 (1) ◽  
pp. 6 ◽  
Author(s):  
Demetrios Tsesmelis ◽  
Christos Karavitis ◽  
Panagiotis Oikonomou ◽  
Stavros Alexandris ◽  
Constantinos Kosmas
Keyword(s):  
Natural Resources ◽  
Vulnerability Index ◽  
Natural Phenomenon ◽  
Anthropogenic Factors ◽  
Drought Vulnerability ◽  
Current Effort ◽  
Sensitive Areas ◽  
Environmentally Sensitive Areas ◽  
Environmentally Sensitive ◽  
The One

The degradation of natural resources at an intense rate creates serious problems in the environmental systems particularly with the compounding effects of climatic vagaries and changes. On the one hand, desertification is a crucial universal, mostly an anthropogenic environmental issue affecting soils all over the world. On the other hand, drought is a natural phenomenon in direct association with reduced rainfall in various spatial and temporal frames. Vulnerabilities to drought and desertification are complex processes caused by environmental, ecological, social, economic and anthropogenic factors. Particularly for the Mediterranean semi-arid conditions, where the physical and structural systems are more vulnerable, the abuse and overuse of the natural resources lead to their degradation and ultimately, if the current trends continue, to their marginalization. The scope of the current effort is trying to find any common drivers for the pressures of both processes. Thus, the vulnerabilities to drought and desertification are comparing by using the Standardized Drought Vulnerability Index (SDVI) and the Environmentally Sensitive Areas Index (ESAI). The indices are calculated from October 1983 to September 1996 in Greece. Greece is prone to desertification and it is often experiencing intense droughts, thus it presents an almost ideal case study area. The results may indicate that the most important factor for such procedures is the deficits in water resources, either due to lower than usually expected rainfall or to higher societal water demand.

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