Landslides of the Lance Creek catchment, South Gippsland Hills, Victoria

Tang, Yong Ping.

Landslides of the Lance Creek catchment, South Gippsland Hills, Victoria

Authors

Tang, Yong Ping.

Date

2001

Publisher

University of Melbourne

Affiliation

Science Collected Works

Full item page

Document Type

Masters Research thesis

Access Status

Only available to University of Melbourne staff and students, login required

URI

https://hdl.handle.net/11343/341507

Description

Typescript (photocopy)

School of Earth Sciences

Thesis (MSc) -- University of Melbourne,Faculty of Science, 2002

Includes bibliographical references (leaves 111-114)

Abstract

This study aimed to achieve three objectives: 1) to examine the mechanism and various factors contributing to landsliding, 2) to determine criteria for identifying landslide prone areas, and 3) to suggest guidelines for minimizing the incidence oflandslides. The Lance Creek catchment study area is located in the foothills of the South Gippsland Hills, approximately 200 km southeast from Melbourne, and covers about 13 km2 � In order to achieve the objectives, the study has involved collection and analysis of multiple sets of data: geology, topography, climate, and land use, etc.; farmer interviews, regional mapping of landslides, morphology mapping of landslides; rock, soil and water sampling; perched water and landslide activity monitoring; petrological analysis, rock property tests, .X.R.D. analysis of clay mineralogy, soil triaxial tests and water TDS analysis. This study has identified that slump (involving soil and rock) and earthflow (involving soil) are the two main types of landslides in the study area. The main features of a slump are a main scarp, a head scarp, minor scarps, cracks, ponds, springs and a bulging mass. Slumps are likely to occur on moderately steep to steep (8�-22�) slopes of concave shape of north-west, north, north-east and south-east facing. The main features of an earthflow are a main scarp, minor scarps and a bulging mass. Earthflows are likely to occur on steep (??5�) slopes of convex shape of north-west, north and north east facing. This study has found that there were few landslides before land clearance; over 98% of landslides investigated have happened after land clearance ( <66 years). All landslides have been triggered by severe rainstorm events. This study has also found that the factors controlling landslides of the Lower Cretaceous Strzelecki Group sandstone and mudstone of the study area are rock weathering, geological structure, climate and topography, drainage, land clearance, stock grazing, farm track construction and farm dam construction. Slope of concave shape and bedding dipping coinciding with slope facing are the primary assessment factors of occurrence of slumps. Slope of convex shape is the primary assessment factor of occurrence of earthflows. Angle of slope, aspect of slope, drainage, trees, stock grazing, track and dam are the secondary assessment factors of occurrence for both slumps and earthflows. Subsurface drainage, surface drainage and tree planting are suggested remediation methods for minimizing landsliding. Among these, subsurface drainage is the most efficient. Tree planting is efficient in stabilizing earthflows and small slumps but not for medium and large slumps. Stock should not graze on landslides, slopes with tension cracking, steep (^5�) convex slopes of north-west, north and north-east facing, narrow steep convex slopes between two farm tracks and stream banks. Farm track construction should be discouraged on moderately steep to steep slopes of concave shape with bedding dipping coinciding with slope facing north-west, north, north-east and south-east, or steep convex slopes of north-west, north and north east facing. Farm dam construction should avoid the head of old slips, slips and areas experiencing recent movements.

Keywords

Landslides -- Australia -- Victoria.

Collections

Science Collected Works - Theses