The infiltration rate is an important parameter in soil, hydrological, ecological and agricultural studies. It plays the main role as the input parameter in models for water flow and solute transport in the vadose zone. In this study, Multilayer Artificial Neural Network "ANN" using the backpropagation algorithm was selected to estimate the steady infiltration rate covering different types of Libyan soils. The activation function was selected LOGSIG in the middle and exit layers. The input data were the percentage of sand, silt and clay, bulk density, saturated hydraulic conductivity and the volumetric water content in soil at -10 kPa. The performance of the ANN models was evaluated against a set of data that never seen by the model during the training phase. Multivariate linear regression model (MLR) based on the percentage of silt, saturated hydraulic conductivity and volumetric water content in soil at -10 kPa was also developed to determine infiltration rate for evaluation purpose. The results obtained in this study showed a good agreement between the measured data and the ANN simulated. The values of mean absolute error and root mean square error were slightly smaller in ANN steady infiltration rate model compared to the developed Multivariable linear regression model to estimate the infiltration rate. Although the results of these comparisons encourage the using ANN in practice, it would be valuable to have large local soil database from many different sites, in order to make a stronger assessment of the ANN models.
Ahmed Ibrahim Ekhmaj(10-2010)

Boolean approaches to land suitability treat both the spatial units and the value ranges as clearly defined. This is to ignore the continuous nature of land properties as well as the differences and uncertainties in measurement. The objective of this paper was to compare two approaches to land suitability evaluations; Parametric and Fuzzy Multi-Criteria Methods to model the opportunities for olive production in Jeffara Plain of Libya. In this paper a number of soil and landscape criteria were identified and their weights specified as a result of discussions with local experts. The Fuzzy MCE approach was found to be better than the parametric approach. The Fuzzy MCE approaches accommodate the continuous nature of many soil properties and produce more intuitive distributions of land suitabilities value for olive. The results of Fuzzy MCE showed that the majority of the study area is highly suitable for olive production, while the results obtained from the use the parametric method showed that most of the study area is moderately suitable for olive production.
Mukhtar Mahmud Elaalem(1-2013)

أجريت الدراسة لتقييم مختلف عمليات مقاومة الانجراف المائي، بمنطقة تارسين الملاصقة لمنطقة العربان من الناحية الجنوبية، و الواقعة جنوب شرق منطقة غريان، والتى تتضمنت اقامة المدرجات التعويقية الحجرية بالمجارى المائية الصغيرة وبسفوح الوديان، وإقامة المدرجات الترابية ببعض المواقع القابلة للزراعة والمتأثرة بالانجراف. بينت النتائج ايجابيات عمليات مقاومة الإنجراف المائي وحفظ التربة والمياه. إن تلك الانشاءات قد تعرضت للترسيب عبر السنين،الأمر الذي يتطلب تنظيف المدرجات بمعدل (129.88- 519.4) سنة، من أقل إلى أعلى ارتفاع لتلك المدرجات (50-200) سم، بعدد مرات تنظيف (16.4-4.16) منذ بداية اقامة المدرجات حتى عام 2020م، وأن التربة قد تتعرض للانجراف بصورة أسوأ إذا لم يتم الاهتمام بالمدرجات الحاجزة لمياه الأمطار. أظهرت الدراسة أيضاً أن تربة المنطقة تتعرض للتعرية الريحية بإزالة الغطاء النباتي الطبيعي عن طريق الرعي الجائر والاحتطاب، وعدم تعويضه بنباتات أخرى ملائمة للبيئة، الأمر الذي يوثر سلبياً على التوازن البيئي بين مكونات البيئة في منطقة الدراسة. arabic 126 English 0
يوسف محمد الغزيلي, المنتصر بالله مختارمحمد القريقني, د. أحمد إبراهيم خماج(3-2021)