Modelling and assessment of wind erosion risk by geomatics approach "case of Laghouat (Algeria)"

الموضوعات

علوم تطبيقية وتكنولوجية

الملخص

Wind erosion is one of the most serious environmental problems in Algeria that threatens the human activities and socio-economic development;it is an interaction of biological, ecological, and socioeconomic dimensions. It constitutes a major risk and a main physical factor of sandy desertification that threaten farmland, urban and oases areas in arid and semi-arid regions. This study aims to determine the areas most affected by wind erosion risk and understand the dynamic of sand at a regional scale. Soil analysis, remote sensing, climatic, vegetal-cover, and topographic data were used in a geographic information system (GIS), using multi-criteria analysis (MCA) to map wind-erosion risk (Rwe) in Laghouat. The approach was based on modelling the risk and incorporating topographic and climatic effects. The maps were coded according to their sensitivity to wind erosion and to their socio-economic potential, from low to very high. The results indicated that severe wind erosion affects mainly all the southern parts and some parts in the north of , wind-erosion hazard (Hwe) is very high in 43% of the total area, and which was affected mainly by natural parameters such as soil, topography, and wind. The product of the hazard and the stake maps indicated the potential risk areas that need preventive measures; this was more than half of the study area. Different fuzzy operators (AND, OR, SUM, PRODUCT, and GAMMA) are applied to generate wind erosion hazard sensitivity map. Success rate curves reveal that the fuzzy gamma (γ) operator with taking γ-value equal to 0.9 is the best prediction accuracy with an area under curve of 85.2%. The resulting wind-erosion sensitivity map delineates the area into different zones of five relative sensitivity classes: very high, high, moderate, low and very low. The estimated result was verified by field measurements and the high statistically significant value of a chi-square test. , mineralogical and analysis were carried out in order to identify the probable source and mode of origin of the sand of the study area. Grain size analysis shows that most of the sand is medium to fine-grained, moderately well sorted, symmetrical . The analysis of grain surface features by scanning electron microscope (SEM) showed that quartz grains demonstrate a variety of surface textures indicating mechanical and chemical processes developed during transportation of these grains in environments, respectively, reflecting the mixed mode of formation of this sand. Sand dune movement is a hazardous phenomenon in creates major threat on the existing land use and land cover as well as developmental plans. Temporal and spatial simulation of sand movement using sand index shows the preferred directions of the moving sand and the areas more affected by sand accumulations. Three dates of satellite imageries were used TM; 1987 and 2003, OLI; 2017. The quantification of sand dune movement and direction has, indeed, enabled to determine the major threat on the exiting land use and land cover as well as the newly developmental projects.

روابط وملفات

التعريف والنوع

رقم الوثيقة

09e1a33c-46f8-478e-a0ef-e17e655e6b53

رقم العقد

0

نوع الوسائط

Crawler

نوع المحتوى

الرسائل العلمية

صيغة المصدر

رسائل دكتوراة

نوع الملف

word

أسماء الملفات

1370259_1.docx, 1370259_2.pdf

بيانات النشر

ألقاب المؤلفين

[{"name_ar":" Djouher Saadoud","title_ar":"اعداد","title_en":"Preparation"},{"name_ar":"Guettouche M.S","title_ar":"اشراف","title_en":"Supervision"}]

اللغة

English

المصدر والدورية

اسم المصدر

Modelling and assessment of wind erosion risk by geomatics approach "case of Laghouat (Algeria)"

المحتوى والصفحات

عدد الصفحات

0

كلمات الباحثين

Erosion éolienne, Géomatique, Géomorphologie, Laghouat, LANSAT, Logique floue, Spectrométrie

إشراف وإعداد

الإشراف

Guettouche M.S

الإعداد

Djouher Saadoud

الاقتباسات الببليوغرافية