Influence of cenozoic geology on mass movement and sediment yield response to forest removal, North Westland, New Zealand

O'Loughlin, C.L.; Pearce, A.

doi:10.1007/bf02634757

Cited by 69 publications

(30 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Perhaps less sediment would have entered the stream if the rainstorm had occurred a few weeks later. It may be that, even with detailed local studies of the erosion risk (e.g., O'Loughlin & Pearce 1976), accurate quantitative predictions of all the changes in these features, particularly in small catchments, will never be possible, and the best that can be done is a general assessment of changes that could occur. The data presented here could then be of value, particularly with respect to the Nelson region.…”

Section: Discussionmentioning

confidence: 99%

Effects of logging on stream environments and faunas in Nelson

Graynoth

1979

New Zealand Journal of Marine and Freshwater Research

104

View full text Add to dashboard Cite

The effects of various logging practices on stream environments and faunas were studied at the Golden Downs State Forest in Nelson. Comparisons were made between the features of a control stream with an unmodified forest catchment and three streams whose catchments had been affected by different logging practices. Measurements were made of stream flow, water temperature, stream bed sedimentation, suspended sediment and dissolved solids concentrations, and the abundance of benthic invertebrates and fishes.Clearfelling to the stream's edge, together with inappropriate roading and bridging techniques, caused great changes in stream environments and faunas. Excessive amounts of waste timber and soil entered streams and stream bed loads, and suspended sediment and dissolved solid concentrations increased. In comparison to the control stream water temperatures increased in summer by up to 6.5 c c and decreased in winter by as much as 2.5°c. In one stream the benthic invertebrate fauna was greatly modified; there was a reduction in the abundance of Plecoptera and certain Ephemeroptera nymphs, and an increase in the abundance of oligochaetes. chironomids, and Deleatidium nymphs. Fishes, Galaxias divergens and Anguilla dieffenbachi, were also reduced in numbers in this stream.In January 1971 numerous brown trout (Salmo trutta) and other fishes died in the Motueka River, and there are indications that this was due in part to low dissolved oxygen concentrations following excessive sedimentation of the river bed caused by unsatisfactory logging practices. In general, the physical and chemical changes found in the stream environments were similar to those found overseas, but those noted in the invertebrate and fish fauna were rather different, e.g., logging had different effects on the abundance of Diptera, Ephemeroptera, and Trichoptera, and on trout survival and migration. The data collected will be of some value in assessing the effects of this type of logging on other streams and their biotas in the Nelson region.A protective buffer strip of unlogged vegetation was left alongside one stream and the remainder of the catchment was clearfelled. In comparison to the other streams there was relatively little change in the aquatic environment and fauna. Although stream flows and nitrate concentrations were considerably higher than in the control stream, these differences may have been natural and not a consequence of the logging operations. Similar results have been found overseas, and it is concluded that provided measures are taken to reduce erosion, buffer strips will be effective in reducing the effects of logging operations on stream environments and their faunas in other forests throughout New Zealand.

show abstract

Section: Discussionmentioning

confidence: 99%

Effects of logging on stream environments and faunas in Nelson

Graynoth

1979

New Zealand Journal of Marine and Freshwater Research

104

View full text Add to dashboard Cite

show abstract

“…These models may compute a factor of safety (FOS; i.e., a ratio between resisting and driving forces) as an indicator of the mechanical state and landslide susceptibility [O'Loughlin and Pearce, 1976;Wu et al, 1979;Casadei et al, 2003]. Hydrological effects on FOS are typically expressed as functions of seepage flow and rainfall rate [Montgomery and Dietrich, 1994;Fernandes et al, 2004] or by explicit solution of the Richards equation (for unsaturated flow) to estimate effects of pore pressure evolution [Iverson, 2000;Simoni et al, 2008;Arnone et al, 2011].…”

Section: Introductionmentioning

confidence: 99%

Rainfall-triggered shallow landslides at catchment scale: Threshold mechanics-based modeling for abruptness and localization

2013

View full text Add to dashboard Cite

[1] Rainfall-induced shallow landslides may occur abruptly without distinct precursors and could span a wide range of soil mass released during a triggering event. We present a rainfall-induced landslide-triggering model for steep catchments with surfaces represented as an assembly of hydrologically and mechanically interconnected soil columns. The abruptness of failure was captured by defining local strength thresholds for mechanical bonds linking soil and bedrock and adjacent columns, whereby a failure of a single bond may initiate a chain reaction of subsequent failures, culminating in local mass release (a landslide). The catchment-scale hydromechanical landslide-triggering model (CHLT) was applied to results from two event-based landslide inventories triggered by two rainfall events in 2002 and 2005 in two nearby catchments located in the Prealps in Switzerland. Rainfall radar data, surface elevation and vegetation maps, and a soil production model for soil depth distribution were used for hydromechanical modeling of failure patterns for the two rainfall events at spatial and temporal resolutions of 2.5 m and 0.02 h, respectively. The CHLT model enabled systematic evaluation of the effects of soil type, mechanical reinforcement (soil cohesion and lateral root strength), and initial soil water content on landslide characteristics. We compared various landslide metrics and spatial distribution of simulated landslides in subcatchments with observed inventory data. Model parameters were optimized for the short but intense rainfall event in 2002, and the calibrated model was then applied for the 2005 rainfall, yielding reasonable predictions of landslide events and volumes and statistically reproducing localized landslide patterns similar to inventory data. The model provides a means for identifying local hot spots and offers insights into the dynamics of locally resolved landslide hazards in mountainous regions.Citation: von Ruette, J., P. Lehmann, and D. Or (2013), Rainfall-triggered shallow landslides at catchment scale: Threshold mechanics-based modeling for abruptness and localization, Water Resour. Res., 49,[6266][6267][6268][6269][6270][6271][6272][6273][6274][6275][6276][6277][6278][6279][6280][6281][6282][6283][6284][6285]

show abstract

“…For example, analysis of aerial photographs of landslides in Pyeongchang, Gangwon Province, Korea, during 2006 by the Korea Forest Research Institute (KFRI) demonstrated that landslides occurred six times more frequently in logged areas and monoculture forests than in mixed or natural forests. In addition, landslide frequency and area have been reported to increase drastically 3-10 years post-logging [Bishop and Stevens, 1964;Endo and Tsuruta, 1969;O'Loughlin and Pearce, 1976].…”

Section: Intoructionmentioning

confidence: 99%

Estimating Soil Reinforcement by Tree Roots using the Perpendicular Root Reinforcement Model

Kim

Lee

Combalicer

et al. 2010

IJECE

View full text Add to dashboard Cite

Tree roots are generally understood to reinforce soil by increasing soil shear strength. However, few studies have quantified soil reinforcement by tree roots. This study estimated soil reinforcement by larch [Larix kaempferi (Lamb.) Carrière] and Korean pine (Pinus koraiensis Siebold et Zucc.) roots using the perpendicular root reinforcement model. Root area ratio (RAR) and root tensile strength were measured for each species to apply to the model. RAR ranges were 0.02-0.27% for larch and 0.08-0.23% for Korean pine. The root tensile strengths of larch and Korean pine ranged from 5.8-38.8 MPa and 8.3-75.6 MPa, respectively. The model indicated that roots increased soil shear strengths by as much as 3.9-28.2 kPa for larch and 13.5-35.4 kPa for Korean pine, implying that roots have substantial effects on slope stability. Moreover, results from the perpendicular root reinforcement model can be practically applied with a relevant reduction factor, considering the simplicity and limitations of the model.

show abstract

Influence of cenozoic geology on mass movement and sediment yield response to forest removal, North Westland, New Zealand

Cited by 69 publications

References 1 publication

Effects of logging on stream environments and faunas in Nelson

Effects of logging on stream environments and faunas in Nelson

Rainfall-triggered shallow landslides at catchment scale: Threshold mechanics-based modeling for abruptness and localization

Estimating Soil Reinforcement by Tree Roots using the Perpendicular Root Reinforcement Model

Contact Info

Product

Resources

About