Aquifers Properties: Specific Yield and Specific Retention In an aquifer with a water table (unconfined aquifer), the volume of water released from groundwater storage per unit surface area of aquifer per unit decline in the water table is known as the specific yield, S y . also known as the drainable porosity. Hydrologists divide water in storage in the ground into the part that will drain under the influence of gravity (called specific yield) and the part that is retained as a film on rock surfaces and in very small openings (called specific retention). The physical forces that control specific retention are the same forces involved in the thickness and moisture content of the capillary, fringe. fig.1
Aquifers Properties: Porosity (n) The porosity of a soil or rock is that fraction of a given volume of material that is occupied by void space, or interstices. Porosity, indicated by the symbol ( n ), is usually expressed as the ratio of the volume of voids. Most rocks naturally contain a certain percentage of voids that can be occupied by water. Fig. 1 Porosity (n)
stalactites Sannur Cave is characterized by the presence of geological formations known as Stalactites and Stalagmites in a perfect beautiful formed over millions of years, about 60 million years ago dates back to the Era of Middle Eocene. Leakage of aqueous solutions of calcium carbonate saturated through the roof of the cave and then evaporated, leaving the mineral salts that accumulated in the form of deposits of stalactites and stalgmites. Sannur cave extends a distance of about 700 m, breadth about 15 m and depth is about 15 m. It’s Located in Beni Suef province, Egypt. about 70 kilometres southeast of the city. The cave is important to the scarcity of such natural formations “Egyptian Alabaster” as it is of great importance for researchers, Geologists, and Caving fans. Location: كهف وادي سنور في بني سويف من أجمل الكهوف التي رأيتها في حياتي. ما تراه في الصور هي أحجار جيرية نتجت عن عمليات التبخر من مياه الينابيع الحارة داخل الكهف، أو من عمليات ترسيب بطئ من قطرات ال...
Comments
Post a Comment