Probabilistic landslide susceptibility and factor effect analysis   总被引：18，自引：0，他引：18  

S Lee  Jasmi Abdul Talib 《Environmental Geology》2005,47(7):982-990

The susceptibility of landslides and the effect of landslide-related factors at Penang in Malaysia using the geographic information system (GIS) and remote sensing data have been evaluated. Landslide locations were identified in the study area from interpretation of aerial photographs and from field surveys. Topographical and geological data and satellite images were collected, processed, and constructed into a spatial database using GIS and image processing. The factors chosen that influence landslide occurrence were: topographic slope, topographic aspect, topographic curvature and distance from drainage, all from the topographic database; lithology and distance from lineament, taken from the geologic database; land use from Landsat Thermatic Mapper (TM) satellite images; and the vegetation index value from SPOT HRV (High-Resolution Visible) satellite images. Landslide hazardous areas were analyzed and mapped using the landslide-occurrence factors employing the probability–frequency ratio method using the all factors. To assess the effect of these factors, each factor was excluded from the analysis, and its effect verified using the landslide location data. As a result, all factors had relatively positive effects, except lithology, on the landslide susceptibility maps in the study area.  相似文献   

Late Jurassic–Early Cretaceous closure of the Mongol-Okhotsk Ocean demonstrated by new Mesozoic palaeomagnetic results from the Trans-Baïkal area (SE Siberia)     

Jean-Pascal Cogné  Vadim A. Kravchinsky  Nadir Halim  Fatim Hankard 《Geophysical Journal International》2005,163(2):813-832

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Persistence of road runoff generation in a logged catchment in Peninsular Malaysia     

Alan D. Ziegler  Junjiro N. Negishi  Roy C. Sidle  Takashi Gomi  Shoji Noguchi  Abdul Rahim Nik 《地球表面变化过程与地形》2007,32(13):1947-1970

Measurements of saturated hydraulic conductivity (K_s) and diagnostic model simulations show that all types of logging road/trail in the 14·4 ha Bukit Tarek Experimental Catchment 3 (BTEC3) generate substantial Horton overland flow (HOF) during most storms, regardless of design and level of trafficking. Near‐surface K_s(0–0·05 m) on the main logging road, skid trails and newly constructed logging terraces was less than 1, 2 and 34 mm h^?1, respectively. Near‐surface K_s on an abandoned skid trail in an adjacent basin was higher (62 mm h^?1), owing to the development of a thin organic‐rich layer on the running surface over the past 40 years. Saturated hydraulic conductivity measured at 0·25 m below the surface of all roads was not different (all <6 mm h^?1) and corresponded to the K_s of the adjacent hillslope subsoil, as most roads were excavated into the regolith more than 0·5–1 m. After 40 years, only limited recovery in near‐surface K_s occurred on the abandoned skid trail. This road generated HOF after the storage capacity of the upper near‐surface layer was exceeded during events larger than about 20 mm. Thus, excavation into low‐K_s substrate had a greater influence on the persistence of surface runoff production than did surface compaction by machinery during construction and subsequent use during logging operations. Overland flow on BTEC3 roads was also augmented by the interception of shallow subsurface flow traveling along the soil–saprolite/bedrock interface and return flow emerging from the cutbank through shallow biogenic pipes. The most feasible strategy for reducing long‐term road‐related impacts in BTEC3 is limiting the depth of excavation and designing a more efficient road network, including minimizing the length and connectivity of roads and skid trails. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

A review on mechanism and future perspectives of cadmium-resistant bacteria     

S. Z. Abbas  M. Rafatullah  K. Hossain  N. Ismail  H. A. Tajarudin  H. P. S. Abdul Khalil 《International Journal of Environmental Science and Technology》2018,15(1):243-262

Since the last few decades, cadmium anthropocentric sources have been increased drastically. Various chemical and physical approaches for cadmium remediation have been proposed, but these techniques are quite expensive, not healthy for the environment and not efficient at the low concentration of cadmium. Thus, in the last few years, the cadmium removal by biological approaches has received a great interest. Many bacteria can resist against high concentration of cadmium through different mechanisms. The cadmium-resistant bacteria can be grouped into three levels. The main group consists of bacteria which efflux the cadmium from the cells. The bacteria of the other two groups are capable of detoxifying or binding cadmium. The cadA and cadB gene systems are involved in efflux mechanism, and these encode different efflux pump proteins, while the functional groups such as amine, carboxyl, phosphate and hydroxyl facilitate cadmium binding to bacterial surface such as chemisorption. Many enzymes are involved in the detoxifying the cadmium and make the membrane impermeable against cadmium. This paper also reviews the industrial application of cadmium-resistant bacteria and the future perspectives of genetic engineering, bioelectrochemical system, microbial aggregates and biosorption of cadmium by algae.  相似文献   

Hydrogeochemistry and groundwater quality assessment of the multilayered aquifer in Lower Kelantan Basin,Kelantan, Malaysia     

Anuar Sefie  Ahmad Zaharin Aris  Mohammad Firuz Ramli  Tahoora Sheikhy Narany  Mohd Khairul Nizar Shamsuddin  Syaiful Bahren Saadudin  Munirah Abdul Zali 《Environmental Earth Sciences》2018,77(10):397

Continual expansion of population density, urbanization, agriculture, and industry in most parts of the world has increased the generation of pollution, which contributes to the deterioration of surface water quality. This causes the dependence on groundwater sources for their daily needs to accumulate day by day, which raises concerns about their quality and hydrogeochemistry. This study was carried out to increase understanding of the geological setup and assess the groundwater hydrogeochemical characteristics of the multilayered aquifers in Lower Kelantan Basin. Based on lithological data correlation of exploration wells, the study area can be divided into three main aquifers: shallow, intermediate and deep aquifers. From these three aquifers, 101 groundwater samples were collected and analyzed for various parameters. The results showed that pH values in the shallow, intermediate and deep aquifers were generally acidic to slightly alkaline. The sequences of major cations and anions were Na⁺ > Ca²⁺ > Mg²⁺ > K⁺ and HCO₃^? > Cl^? > SO₄^2? > CO₃^2?, respectively. In the intermediate aquifer, the influence of ancient seawater was the primary factor that contributed to the elevated values of electrical conductivity (EC), Cl^? and total dissolved solids (TDS). The main facies in the shallow aquifer were Ca–HCO₃ and Na–HCO₃ water types. The water types were dominated by Na–Cl and Na–HCO₃ in the intermediate aquifer and by Na–HCO₃ in the deep aquifer. The Gibbs diagram reveals that the majority of groundwater samples belonged to the deep aquifer and fell in the rock dominance zone. Shallow aquifer samples mostly fell in the rainfall zone, suggesting that this aquifer is affected by anthropogenic activities. In contrast, the results suggest that the deep aquifer is heavily influenced by natural processes.  相似文献   

Precipitation pattern modeling using cross-station perception: regional investigation     

Sadeq Oleiwi Sulaiman  Jalal Shiri  Hamed Shiralizadeh  Ozgur Kisi  Zaher Mundher Yaseen 《Environmental Earth Sciences》2018,77(19):709

Establishing robust models for predicting precipitation processes can yield a significant aspect for many applications in water resource engineering and environmental prospective. In particular, understanding precipitation phenomena is crucial for managing the effects of flooding in watersheds. In this research, a regional precipitation pattern modeling was undertaken using three intelligent predictive models incorporating artificial neural network (ANN), support vector machine (SVM) and random forest (RF) methods. The modeling was carried out using monthly time scale precipitation information in a semi-arid environment located in Iraq. Twenty weather stations covering the entire region were used to construct the predictive models. At the initial stage, the region was divided into three climatic districts based on documented research. Initially, modeling was carried out for each district using historical information from regionally distributed meteorological stations for calibration. Subsequently, cross-station modeling was undertaken for each district using precipitation data from other districts. The study demonstrated that cross-station modeling was an effective means of predicting the spatial distribution of precipitation in watersheds with limited meteorological data.  相似文献   

Prediction of river bank erosion and protection works in a reach of Chenab River,Pakistan     

Muhammad Ashraf  Abdul Sattar Shakir 《Arabian Journal of Geosciences》2018,11(7):145

The impacts of floods on river bank erosion are generally significant in the alluvial river reaches. This paper presents the prediction of the river bank erosion along the right bank in the reach of Chenab River (starting from downstream of Marala Barrage) where excessive erosion had been reported. The bank erosion is predicted due to flow/flood events of 2010 by coupling the output from the two-dimensional numerical model to the excess shear stress approach. The predicted bank erosion was compared with the one estimated from Landsat images. The Landsat ETM+ images were processed in the ArcGIS software to assess the external bank erosion. The results show that the excess shear stress approach underpredicts the bank erosion. Therefore, the erodibility coefficient was modified by forcing the best agreement between predicted and estimated (i.e., from Landsat images) bank erosion which was used for further analysis. The results reveal that coupling the output from the numerical model to the excess shear stress approach (by modifying the erodibility coefficient) predicts the river bank erosion with a reasonable level of accuracy, thus helpful to identify the locations for the protection works. The predicted river bank erosion presents good coefficient of determination (R²) of 0.82 when compared with the estimated bank erosion from Landsat images. The findings of the present study will help to implement the river protection works at the identified locations in the selected reach of River Chenab and will also act as a guideline for similar river reaches.  相似文献   

Assessing flood inundation mapping through estimated discharge using GIS and HEC-RAS model     

Ernieza Suhana Mokhtar  Biswajeet Pradhan  Abd Halim Ghazali  Helmi Zulhaidi Mohd Shafri 《Arabian Journal of Geosciences》2018,11(21):682

Water discharge is the main parameter in hydraulic modeling for flood hazard assessment. However, the unavailability of data on discharge and observed river morphologies resulted in erroneous calculations and irregularities in flood inundation mapping. The objectives of this study are (i) to investigate uncertainties of hydraulic parameters (width, cross-sectional depth, and channel slope) used in discharge equation and (ii) to examine the influence of estimate discharge on water extent and flood depth with different boundary conditions on interferometric synthetic aperture radar (IFSAR) and modified IFSAR DEMs. Sensitivity analysis was conducted with the Monte Carlo simulation method to generate random data combinations. Bjerklie’s equation was used to calculate discharge based on the three variables, and Manning’s n was substituted into the Hydrologic Engineering Center River Analysis System (HEC-RAS) model. TerraSAR-X was used to distinguish existing flood water bodies and normal water extent. The uncertainty of the combined variables was assessed with the likelihood measures such as F-statistic, mean absolute error, root mean square error, and Nash–Sutcliffe efficiency which compares observed and predicted inundated area as well as flood water depth simulated using the HEC-RAS model.  相似文献   

Smooth particle hydrodynamics modelling of liquid-sediment system and coastal wave breaker     

Ng  Fei Chong  Zawawi  Mohd Hafiz  Azman  Aqil  Abas  Aizat  Razak  Norizham Abdul  Aziz  Nurhanani A.  Zahari  Nazirul Mubin 《Ocean Dynamics》2022,72(2):99-114

Ocean Dynamics - In this paper, a two-phase coastal liquid-sediment system and a wave breaker were numerically simulated using a particle-based smooth particle hydrodynamics (SPH). To verify the...  相似文献   

Seismic response of a four-storey RC school building with masonry-infilled walls     

Kok Tong Tan  Hashim Abdul Razak  Dagang Lu  Yanjun Li 《Natural Hazards》2015,75(1):141-161

This paper focuses on the evaluation of the effect of masonry-infilled walls on the seismic response of a four-storey RC school building. Numerical simulation is presented with respect to the building with and without masonry-infilled walls. The simulation employed force-based fibre elements for beams and columns, and a single equivalent diagonal strut to represent the masonry infill. The numerical model was verified through comparison with shake table test results. It was found that the presence of masonry-infilled walls has significant influence on the global response of the structure. Although the displacement of the structure with infilled wall is reduced in the in-plane direction, it was increased in both in-plane and out-of-plane directions when the infilled walls experienced loss in serviceability.  相似文献