Regionalization of rainfall thresholds: an aid to landslide hazard evaluation

1998 ◽  
Vol 35 (2-3) ◽  
pp. 131-145 ◽  
Author(s):  
Giovanni Crosta
Geomorphology ◽  
1999 ◽  
Vol 31 (1-4) ◽  
pp. 181-216 ◽  
Author(s):  
Fausto Guzzetti ◽  
Alberto Carrara ◽  
Mauro Cardinali ◽  
Paola Reichenbach

2017 ◽  
Vol 21 (9) ◽  
pp. 4573-4589 ◽  
Author(s):  
Liang Gao ◽  
Limin Zhang ◽  
Mengqian Lu

Abstract. Rainfall is the primary trigger of landslides in Hong Kong; hence, rainstorm spatial distribution is an important piece of information in landslide hazard analysis. The primary objective of this paper is to quantify spatial correlation characteristics of three landslide-triggering large storms in Hong Kong. The spatial maximum rolling rainfall is represented by a rotated ellipsoid trend surface and a random field of residuals. The maximum rolling 4, 12, 24, and 36 h rainfall amounts of these storms are assessed via surface trend fitting, and the spatial correlation of the detrended residuals is determined through studying the scales of fluctuation along eight directions. The principal directions of the surface trend are between 19 and 43°, and the major and minor axis lengths are 83–386 and 55–79 km, respectively. The scales of fluctuation of the residuals are found between 5 and 30 km. The spatial distribution parameters for the three large rainstorms are found to be similar to those for four ordinary rainfall events. The proposed rainfall spatial distribution model and parameters help define the impact area, rainfall intensity and local topographic effects for landslide hazard evaluation in the future.


2002 ◽  
Vol 27 ◽  
Author(s):  
Deepak Chamlagain ◽  
Vishnu Dangol

The paper describes the results of the engineering geological and landslide hazard evaluation studies carried out in and around the Ilam Hydropower Project, eastern Nepal. Various types of mass wasting phenomena such as gully erosion, bank undercutting, and landslides are observed along the Mai Khola, Puwa Khola and road corridors. Gully erosion and bank undercutting are common on the slopes adjacent to streams and gullies. Most of the landslides are located on the slopes of 25° to 40° whereas large rock falls are found on the slopes, which are steeper than 40°. South-facing dip slopes contain large landslides while north-facing slopes seem to be relatively stable. The population of translational slide is dominant in the study area and is found mostly on soil having a depth of 3-6 m. Most of the rock falls are confined in schistose gneiss and highly fractured quartzite. Generally, three sets of joints govern the failure pattern of rockslides. The main triggering factors for mass movement of the area are high intensity of rainfall, rock discontinuities, steep topography, poor vegetation and river scouring. Land use pattern of the area has also equally contributed to initiate the mass movements in the area. The high hazard zones for rock slopes were confined to the steep dip slopes with highly fractured rocks whereas soil slope hazard is confined to fault zones and south facing slope. The soil slope was found to be more hazardous than the rock slope. The main causative factors for the landslide hazard in the study area are steep slope, rock discontinuity, land use pattern, soil depth and rainfall.


2020 ◽  
Vol 9 (1) ◽  
pp. 1966-1971

Slope is a measure of steepness or the degree of inclination of a feature relative to the horizontal plane. One of the phenomenon or incidents of a slope was called as slope failure or landslide. Slope failure was a major natural disaster that had affected the country in terms of injuries, deaths, property damage, destruction of services, public inconvenience and economic as well as financial losses. Slope failure cases were very serious geologic hazard disaster that happened in many countries around the world. The aim of this paper is to determine the category of slope failure in the state of Johor based on Landslide Hazard Zonation (LHZ). Data were calculated by using Total Estimated Hazard (TEHD) value method which considered six factors effecting the slope failure, including lithology; slope steepness, topography, land use class, annual rainfall and type of soil. Data on the factors were collected from Malaysia Public Works Department (JKR) inspection form, website, and secondary data resource. After that weight for each factor were identified by referring to Landslide Hazard Evaluation Factor (LHEF) rating scheme. Then determination of LHZ was done according to TEHD values which have five hazard zones; (1) very low; (2) low; (3) medium; (4) high; and (5) very high. The results of this study found that out of total fifty two cases there were three medium hazard (MH), twenty seven high hazard (HH) and twenty two very high hazard (VHH). Comparison between actual data from JKR and total 52 locations of slope failure in Johor showed that 94% accuracy, TEHD equation could calculate potential slope failure hazards in Johor very well.


2011 ◽  
Vol 28 (2) ◽  
pp. 99-121 ◽  
Author(s):  
K. M. Weerasinghe ◽  
M. Gunaratne ◽  
P. Ratnaweera ◽  
N. M.S.I. Arambepola

Author(s):  
Nur Safrina Syafril ◽  
Wani Sofia Udin ◽  
Arham Muchtar Achmad Bahar

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