Land Slide : A Key Problem in Uma Uya Project Risk Controlling
In this paper, using landslide risky zones best possible places to arrange the buildings and equipments were found in Uma Uya project. The risky zones of the project is achieved and presented. Uma Uma project is a multipurpose project. Uma Oya is a major tributary of Mahaweli Ganga originating from Nuwara Eliya. The Oya traverses Welimada and Kandaketiya in Badulla district. Its confluence with Mahaweli Ganga is just above the Rantabe reservoir. Landslides are aggravated by human activities. Activities include deforestation, cultivation and construction. Main causes can be vibrations from machinery, blasting, earthwork which alters the shape of a slope, removal of deep rooted vegetation and construction. As it can be seen from results the main risky zones are located at high levels of the site. It is clear from results that about %30 of the site zones are involved in high risky landslide. While, about %50 of zones are low risky zones and about %20 of zones are no risky zones. Thus, site mobilization in such zones is dangerous.
Landslide Morphology and Processes on Santa Cruz Island, California
An episode of unusually intense rainfall triggered over a thousand landslides on Santa Cruz Island, California, during the winter of 1977-78. These included large, deep-seated failures, composite mudflows, and hundreds of shallow soil slips. In this study, landslide occurrence is examined in relation to lithologic, pedologic, topographic, and vegetational conditions. Their effects on soil permeability, water movement patterns, and shear strength are found to be related to landslide morphology and process.
The role of early lithification in development of chalky porosity in calcitic micrites: Upper Cretaceous chalks, Egypt
Abstract Petrological and geochemical examination of Upper Cretaceous chalks from the Abu Roash area and Bahariya Oasis (Egypt) provide insights into factors which control porosity development in fine-grained calcitic carbonates. Petrological studies indicate that primary skeletal fabrics of coccoliths and foraminifera in micrites of Abu Roash are well preserved. In contrast, primary skeletal fabrics of the Bahariya Oasis chalks are pervasively altered. Geochemical analysis of these chalks reveals a striking contrast in composition. The high porosity chalks at Bahariya Oasis have depleted isotopic values ( δ 13 C = −5.0‰, δ 18 O = −8.9‰ PDB ) and low concentrations of trace elements (Sr and Na). In contrast, the low porosity chalks at Abu Roash are less depleted in terms of their isotopic values ( δ 13 C = 1.0‰, δ 18 O = −4.0‰ ) and possess elevated concentrations of Sr, Na, Fe and Zn. Importantly, fracture and collapse veins, present only at Abu Roash, are filled with calcite whose δ18O value is coincident with that of altered micrites at Bahariya Oasis. The lithic fragments cemented by this calcite, however, retain compositions identical to other lithified limestones at Abu Roash. Differences in fabric and chemistry of the pelagic marine micrites observed between Abu Roash and Bahariya Oasis reflect the degree of early lithification and compaction prior to exposure and meteoric diagenetic alteration associated with regional Late Cretaceous/pre-Eocene subaerial unconformity.