Geomagnetic anomalies and regional geology in India along 18° N parallel     

B Satyanarayana Murty  Mohd Ghyasuddin  B S Josyulu 《Journal of Earth System Science》1982,91(1):75-77

The mobile geomagnetic measurements made during 1970–73 by NGRI across the Indian Peninsula between Alibag and Kalingapatnam have been examined. It is noticed that the meanZ values after normal correction and the long periodZr/Hr ratio reveal different levels on the three different geological provincesviz., the Deccan traps, peninsular granites and the easternghat metamorphics.  相似文献   

Can devolution and rural capacity trigger de-urbanization? Case studies in Kenya and Malaysia respectively     

Andrew Munya  Nur Huzeima Mohd Hussain  Mugwima B. Njuguna 《GeoJournal》2015,80(3):427-443

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Prediction of long-term settlement on soft clay using shear wave velocity and damping characteristics     

Mohamad Nor Omar  Colin Peter Abbiss  Mohd. Raihan Taha  Khairul Anuar Mohd. Nayan 《Engineering Geology》2011,(4):259

This paper presents a method of calculating long-term settlement of a loaded pad on soft clay at Klang, Selangor, Malaysia where the soil model is treated as an anelastic material of viscoelastic property. Initially, an elastic shear modulus (G) value from shear wave velocity profiles of the seismic tests from spectral analysis of surface wave (SASW) and continuous surface wave (CSW) tests was obtained. A value of damping (D) at an equivalent elastic strain is then calculated from the hysteresis of the plate load tests corrected to equivalent strain using the Damping–Strain formula. The calculated elastic settlement and its equivalent damping are then used to calculate the long-term settlement by applying the generalised viscoelastic formula. Comparisons to traditional methods of settlement predictions were made and the viscoelastic formula has shown better agreement to the observed settlement. Further modification of the settlement formula is introduced to improve the settlement accuracy to 10%.  相似文献   

Establishment of Avicennia marina mangroves on accreting coastline at Sungai Haji Dorani, Selangor, Malaysia     

Noraini Mohd. Tamin  Rozainah Zakaria Roslan Hashim  Yu Yin 《Estuarine, Coastal and Shelf Science》2011,94(4):334-342

Avicennia marina saplings were established within a restoration area at Sg. Hj. Dorani, Malaysia between May and August 2010. Sapling establishment was achieved following the construction of segmented and hard breakwater as mitigating measure against coastal erosion. Geostructures known as brush faschines were installed within the restoration area as secondary sediment and seed traps. There was a steady increase in the sand content of the soil from 5% in November 2008 to 18% in May 2010. The dominant soil content was silt but it fluctuated and declined slightly over the same period, between 80% in November 2008 and 72% in May 2010. The accreting shoreline behind the breakwater had stabilised within 18 months. Subsequently, the first batch of A. marina wild seedlings or wildings was established on the mud surface in September 2009. Only about 10% of these wildings survived and showed high survival rate (90%) over the next eight months. Wildings that were naturally established near mother trees showed good growth performance. No wilding was established after the fruiting season in August 2010 as all seeds that were dispersed into the restoration area were washed away by September 2010. Tall, A. marina wild saplings (1 m) planted within the restoration area showed higher survival rate (80%) compared to planted saplings of Rhizophora apiculata (30%). Final planting of a thousand 1 m tall A. marina wild saplings was carried out from June 2010, in clumps of 20 and in 1 m × 1 m spacing. By the end of September 2010 clusters of regenerating A. marina mangroves about 1.5 m tall were successfully established on the accreting coastline.  相似文献   

The relationship between the shear strength and water retention curve of unsaturated sand at different hydraulic phases     

Albadri  Wael M.  Noor  Mohd Jamaludin Md  Alhani  Israa J. 《Acta Geotechnica》2021,16(9):2821-2835

Acta Geotechnica - This technical paper focuses on evaluating the shear strength of unsaturated sand at drying, wetting and alternate drying–wetting cycles, as well as the correlation between...  相似文献   

Micro-level perception to climate change and adaptation issues: A prelude to mainstreaming climate adaptation into developmental landscape in India     

Naveen P. Singh  Bhawna Anand  Mohd Arshad Khan 《Natural Hazards》2018,92(3):1287-1304

Climate change adds another dimension of challenges to the growth and sustainability of Indian agriculture. The growing exposure to livelihood shocks from climate variability/change and limited resource base of the rural community to adapt has reinforced the need to mainstream climate adaptation planning into developmental landscape. However, a better understanding of micro-level perceptions is imperative for effective and informed planning at the macro-level. In this paper, the grass-root level perspectives on climate change impacts and adaptation decisions were elicited at farm level in the Moga district of Punjab and Mahbubnagar district of Telangana, India. The farmers opined that the climatic variability impacts more than the long-term climate change. They observed change in the quantum, onset and distribution of rainfall, rise in minimum as well as maximum temperature levels, decline in crop yield and ground water depletion. The key socio-economic effects of climate change included decline in farm income, farm unemployment, rural migration and increased indebtedness among farmers. In order to cope with climate variability and change thereon, farmers resorted to adaptation strategies such as use of crop varieties of suitable duration, water conservation techniques, crop insurance and participation in non-farm activities and employment guarantee schemes. Farmers’ adaptation to changing climate was constrained by several technological, socio-economic and institutional barriers. These include limited knowledge on the costs–benefits of adaptation, lack of access to and knowledge of adaptation technologies, lack of financial resources and limited information on weather. Besides, lack of access to input markets, inadequate farm labour and smaller farm size were the other constraints. Further, on the basis of the grass-root elicitation a ‘Need-Based Adaptation’ planning incorporating farmers’ perceptions on climate change impacts, constraints in the adoption of adaptation strategies and plausible adaptation options were linked with the most suitable ongoing programmatic interventions of the Government of India. The study concluded that micro-level needs and constraints for various adaptation strategies and interventions should be an integral part of the programme development, implementation and evaluation in the entire developmental paradigm.  相似文献   

Groundwater and surface-water utilisation using a bank infiltration technique in Malaysia   总被引：1，自引：1，他引：0  

Mohd Khairul Nizar Shamsuddin  Wan Nor Azmin Sulaiman  Saim Suratman  Mohamad Pauzi Zakaria  Kamarudin Samuding 《Hydrogeology Journal》2014,22(3):543-564

Bank infiltration (BI) is one of the solutions to providing raw water for public supply in tropical countries. This study in Malaysia explores the use of BI to supplement a polluted surface-water resource with groundwater. Three major factors were investigated: (1) contribution of surface water through BI to the resulting abstraction, (2) input of local groundwater, and (3) water-quality characteristics of the resulting water supply. A geophysical method was employed to define the subsurface geology and hydrogeology, and isotope techniques were performed to identify the source of groundwater recharge and the interaction between surface water and groundwater. The physicochemical and microbiological parameters of the local surface-water bodies and groundwater were analyzed before and during water abstraction. Extracted water revealed a 5–98 % decrease in turbidity, as well as reductions in HCO₃ ^?, Cl^?, SO₄ ^2?, NO₃ ^?, Ca²⁺, Al³⁺ and As concentrations compared with those of Langat River water. In addition, amounts of E. coli, total coliform and Giardia were significantly reduced (99.9 %). However, water samples from test wells during pumping showed high concentrations of Fe²⁺ and Mn²⁺. Pumping test results indicate that the two wells used in the study were able to sustain yields.  相似文献   

Evaluation of heavy metal contamination in groundwater samples from Kapas Island,Terengganu, Malaysia   总被引：1，自引：0，他引：1  

Noorain Mohd Isa  Ahmad Zaharin Aris  Wan Ying Lim  Wan Nor Azmin Wan Sulaiman  Sarva Mangala Praveena 《Arabian Journal of Geosciences》2014,7(3):1087-1100

An attempt has been made to delineate the hydrochemistry for a small island based on the major ions and heavy metal concentrations. In this investigation, six sampling campaigns were conducted to measure the concentrations of major ions (Ca, Mg, Na, K, HCO₃, Cl, and SO₄) and heavy metals (Zn, Cr, Pb, Mn, As, and Cu) in groundwater samples collected from seven sampling stations (boreholes) located on Kapas Island, Terengganu, Malaysia. The distribution of major ions is illustrated by a piper plot where Ca–HCO₃ is the dominant type. In addition, the concentrations of heavy metals demonstrate that Mn shows as being the highest concentrated heavy metal in the groundwater sampled in the sampling campaigns; the average Mn content in groundwater sampled was 54.05 μg/L. However, a comparison of the heavy metal (Mn, Cr, Zn, As, Pb, and Cu) concentrations in groundwater samples with the Drinking Water Quality Standard prescribed by World Health Organization reveals that none of these heavy metals exceeded the recommended threshold limits. The principal component analyses (PCA) extracted four components that control the groundwater chemistry. Components 1 and 2 from the PCA analyses extracted approximately 52.11 % of the total variance, which represent the heavy metals (As and Mn) and physical parameters (pH, redox potential, electrical conductivity, temperature, and total dissolved solids). Based on the output of the PHREEQC hydrogeochemical software, several species of heavy metals exist, in which the dominant species found are Mn²⁺, PbCO₃, Cu(OH)₂, and Zn⁺.  相似文献   

Long-Wavelength Elastic Wave Propagation Across Naturally Fractured Rock Masses   总被引：1，自引：1，他引：0  

Mohd Mustaqim Mohd-Nordin  Ki-Il Song  Gye-Chun Cho  Zainab Mohamed 《Rock Mechanics and Rock Engineering》2014,47(2):561-573

Geophysical site investigation techniques based on elastic waves have been widely used to characterize rock masses. However, characterizing jointed rock masses by using such techniques remains challenging because of a lack of knowledge about elastic wave propagation in multi-jointed rock masses. In this paper, the roughness of naturally fractured rock joint surfaces is estimated by using a three-dimensional (3D) image-processing technique. The classification of the joint roughness coefficient (JRC) is enhanced by introducing the scan line technique. The peak-to-valley height is selected as a key indicator for JRC classification. Long-wavelength P-wave and torsional S-wave propagation across rock masses containing naturally fractured joints are simulated through the quasi-static resonant column (QSRC) test. In general, as the JRC increases, the S-wave velocity increases within the range of stress levels considered in this paper, whereas the P-wave velocity and the damping ratio of the shear wave decrease. In particular, the two-dimensional joint specimen underestimates the S-wave velocity while overestimating the P-wave velocity. This suggests that 3D joint surfaces should be implicated to obtain the reliable elastic wave velocity in jointed rock masses. The contact characteristic and degree of roughness and waviness of the joint surface are identified as a factor influencing P-wave and S-wave propagation in multi-jointed rock masses. The results indicate a need for a better understanding of the sensitivity of contact area alterations to the elastic wave velocity induced by changes in normal stress. This paper’s framework can be a reference for future research on elastic wave propagation in naturally multi-jointed rock masses.  相似文献   

Wind energy potential assessment using Weibull distribution with various numerical estimation methods: a case study in Mersing and Port Dickson,Malaysia     

Safari  Muhammad Aslam Mohd  Masseran  Nurulkamal  Majid  Muhammad Hilmi Abdul 《Theoretical and Applied Climatology》2022,148(3-4):1085-1110

Theoretical and Applied Climatology - In this study, the Weibull distribution with various numerical estimation methods is utilized for the assessment of wind energy potential in Mersing and Port...  相似文献