ANALYSE DU RISQUE D’EROSION HYDRIQUE DANS LE NORD-EST ALGERIEN : IDENTIFICATION DU ZONES VULNERABLES ET APPROCHE DE GESTION DURABLE

Abstract

Soil erosion is among the most critical environmental challenges globally, contributing to the degradation of agricultural land and threatening vital natural resources such as soil and water. This study aims to identify and map areas vulnerable to water-induced erosion in the OuedMellag basin, located in northeastern Algeria. The Revised Universal Soil Loss Equation (RUSLE) was implemented using Geographic Information Systems (GIS), integrating key environmental factors influencing erosion. This methodology allowed for the estimation of annual soil loss and the assessment of its spatial distribution across the basin. The resulting erosion map categorizes erosion intensity into five classes: very low, low, moderate, high, and very high. The highest erosion rates were observed in the southern part of the basin, an area characterized by steep slopes and limited vegetation cover, which enhance surface runoff. The average annual erosion rate was estimated at 1.33 tons per hectare per year. The produced erosion sensitivity map serves as a valuable decision-support tool for developing targeted land management strategies to mitigate erosion risks and guide future control measures in the region. -----------------------------------------------------------------------------

تُعدّ انجرافات التربة الناتجة عن مياه الأمطار من بين أبرز المشكلات البيئية على المستوى العالمي، إذ تؤدي إلى تدهور الأراضي الزراعية وتهدد الموارد الطبيعية من تربة ومياه. تهدف هذه الدراسة إلى تقييم وتحديد المناطق المعرضة لخطر التعرية المائية في حوض وادي ملاق الواقع في شمال شرق الجزائر. تم تطبيق نموذج RUSLE)المعادلة المنقحة لفقدان التربة( باستخدام نظم المعلومات الجغرافية(GIS) ، حيث تم إدماج العوامل المختلفة المساهمة في التعرية لتقدير كمية فقدان التربة وتحديد التوزيع المكاني لها عبر الحوض. تم تقسيم خريطة ا التعرية إلى خمس فئات: ضعيفة جدًا، ضعيفة، متوسطة، قوية، وقوية جدًا.حيث كانت المنطقة الجنوبية اكثر تعرضا للتعرية . وذلك راجعا الى الانحدارات الحادة ضعف الغطاء النباتي الذي يساهم في زيادة جريان المياه السطحية ,وقد قُدّر المعدل السنوي المتوسط للتعرية في حوض وادي ملاق بـ 1.33طن/هكتار/سنة .وتُعدّ خريطة الحساسية للتعرية الناتجة أداة دعم لاتخاذ القرار تهدف إلى وضع استراتيجيات إدارة محسّنة للحد من مخاطر التعرية وتوجيه خطط مستقبلية لمكافحة هذه الظاهرة في المنطقة ---------------------------------------------------------------------------- Soil erosion is among the most critical environmental challenges globally, contributing to the degradation of agricultural land and threatening vital natural resources such as soil and water. This study aims to identify and map areas vulnerable to water-induced erosion in the OuedMellag basin, located in northeastern Algeria. The Revised Universal Soil Loss Equation (RUSLE) was implemented using Geographic Information Systems (GIS), integrating key environmental factors influencing erosion. This methodology allowed for the estimation of annual soil loss and the assessment of its spatial distribution across the basin. The resulting erosion map categorizes erosion intensity into five classes: very low, low, moderate, high, and very high. The highest erosion rates were observed in the southern part of the basin, an area characterized by steep slopes and limited vegetation cover, which enhance surface runoff. The average annual erosion rate was estimated at 1.33 tons per hectare per year. The produced erosion sensitivity map serves as a valuable decision-support tool for developing targeted land management strategies to mitigate erosion risks and guide future control measures in the region.