Tunisia is one of countries most affected by desertification. Sustainability of its resources, particularly agricultural ones, is closely dependent on it. Studies have multiplied to understand this phenomenon and consequently try to reduce its consequences on society. In recent decades, attempts have been made to find methods of forecasting and predicting desertification. Today, with significant progress made in remote sensing and GIS techniques, there is a better control of data from field, environment and society. This now makes it possible to produce documents that are much more accurate and reliable than before. This paper aims to assess sensitivity to desertification in a region of central Tunisia using remote sensing tools, GIS and guidelines of MEDALUS (Desertification and Land Use in the Mediterranean) model. Integration of different parameters with weighted values in a GIS system resulted in indices of climate, soil, vegetation and management. In almost all cases, indices reveal the preponderance of soils, vegetation, climate and management of moderate and especially poor quality. Overlaying the four indices by multiplying them according to model equation yields the final sensitivity index map. This index shows that study area is in an advanced stage of desertification since most of its surface area (82%) is in critical class. The rest is considered as fragile. Whole region is therefore placed in of high sensitivity classes of desertification. This situation is linked to a very poor vegetation cover, unstructured and low-developed soils, cultural practices based on tillage and high livestock numbers in regard to low natural grazing resources. It is also due to a farming system not taking into account soil natural vulnerability. As natural resources, in current context of exploitation, cannot regenerate so quickly, pressure on environment is remarkable, exacerbating at the same time desertification problem. Continuing with current practices with clear signs of degradation may make situation irreversible in near future. Therefore, immediate action is necessary to stop degradation and preserve future generations’ resources.

中文翻译：

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利用遥感，GIS和MEDALUS方法研究塔尔地区（突尼斯中部）的荒漠化敏感性

突尼斯是受荒漠化影响最大的国家之一。其资源（尤其是农业资源）的可持续性密切依赖于它。为了理解这一现象，研究已成倍增加，因此试图减少其对社会的影响。在最近的几十年中，已经尝试找到预测和预测荒漠化的方法。如今，随着遥感和GIS技术的重大进步，对来自野外，环境和社会的数据有了更好的控制。现在，这使得产生比以前更准确和可靠的文档成为可能。本文旨在使用遥感工具，GIS和MEDALUS（地中海沙漠化与土地利用）模型指南来评估突尼斯中部地区对荒漠化的敏感性。在GIS系统中将具有加权值的不同参数集成在一起就可以得出气候，土壤，植被和管理的指标。在几乎所有情况下，指标都显示出土壤，植被，气候以及中等质量（尤其是劣质）的管理优势。通过根据模型方程将它们相乘来叠加这四个指标，可以得到最终的灵敏度指标图。该指数表明研究区域处于沙漠化的晚期，因为其大部分表面积（82％）处于关键等级。其余被认为是脆弱的。因此，整个地区都属于高敏感度的荒漠化类别。这种情况与植被覆盖率很差，土壤的结构疏松和欠发达，基于耕作的文化习俗以及由于自然放牧资源少的牲畜数量高有关。这也是由于耕作制度没有考虑到土壤的自然脆弱性。由于在当前的开采背景下自然资源无法如此迅速地再生，对环境的压力是巨大的，同时加剧了荒漠化问题。继续采用具有明显退化迹象的现行做法，可能会使情况在不久的将来变得不可逆转。因此，必须立即采取行动以制止退化并保留子孙后代的资源。继续采用具有明显退化迹象的现行做法，可能会使情况在不久的将来变得不可逆转。因此，必须立即采取行动以制止退化并保留子孙后代的资源。继续采用具有明显退化迹象的现行做法，可能会使情况在不久的将来变得不可逆转。因此，必须立即采取行动以制止退化并保留子孙后代的资源。