Tinjauan awal potensi ketidakstabilan cerun dan cirian fiziko-kimia tanah di Cameron Highlands, Pahang : Preliminary survey on potential slope instability and soil physico-chemical characteristic in Cameron Highlands, Pahang

Geologically Cameron Highlands was formed by a granite batholith intruding into the older sedimentary rocks. Intrusion of this acidic igneous rock formed metasedimentary rocks and other metamorphic rocks as roof pendants. The schist had been highly weathered, coloured bright grey to dark grey having fine to medium size grains with an obvious foliation. Meanwhile the granitic rock is composed of quartz, feldspar and biotite and/or tourmaline grains. Most of the road slopes cut across the granite body and slope instability survey was carried out based on type of failure, geometry and physico-chemical properties of soil slopes. Field observations showed that most of the failed slopes were soil slopes, and the slip that occurred were either shallow slip or deep slide types. Among the factors that influenced slope instability were slope geometry such as slope height and steep slope gradient, friable features of the weathering profile and the lack of surface vegetation cover. This rendered the slope surface exposed to the direct raindrop impact. Surface water run-off has also caused the development of erosion gullies on soil slope surface. Physico-chemical properties of slope material such as particle size distribution, pH, organic matter content, iron oxide content, water content, true and bulk density, and porosity were also influential in slope stability of the slopes investigated. Low soil pH (acidic) of all the slopes examined decreased iron oxide content of soil which acted as a cementing agent to soil aggregates. This has caused the soil aggregate to become weaker and easier eroded

Potential of Normalized Difference Vegetation Index for Mapping of Soft Clay Area in Paddy Fields of Kedah, Malaysia

Mapping of soft clay area in paddy fields uses remote sensing and GIS technique is the fastest way to obtain an accurate location of soft clay in a large scale area. It can be an alternative way to change conventional method like in-situ observation that is expensive and labor intensive. Therefore, this study aimed to investigate the normalized difference vegetation index (NDVI) to map soft clay area in paddy fields Kedah, Malaysia. To analyze soft clay area comprehensively, the study was carried out in three different periods; before paddy planting, after paddy planting and harvest. Ground-truth data of soft clay area was collected from study area during fieldwork activity and compared with NDVI values that produced from Landsat 8 image. Result of study showed NDVI map in period of before paddy planting could be a good indicator for mapping soft clay area because it gave a higher accuracy value than the other periods, with overall accuracy (85%) and kappa coefficient (0,84). Total area of soft clay from the highest value was showed in period of before paddy planting (1.856,97 ha), followed by after paddy planting (656,73 ha) and harvest (401,85 ha) periods, respectively

Soil erosion assessment in Tasik Chini Catchment using remote sensing and gis techniques

Over many years, forested land transformation into urban, agriculture and mining areas within Tasik Chini Catchment become more intense. These activities have negatively affected the catchment through soil erosion and increased the amount of sediments that deposited into the lake. Hence, the present study aimed to estimate soil erosion risk within Tasik Chini Catchment integrating the Revised Universal Soil Loss Equation (RUSLE) model and remotely sensed geospatial data. The multispectral imagery from LANDSAT 8 was used to provide up to date information on land cover within the catchment. The result shows the majority of Tasik Chini Catchment is classified at very low class ( 150 ton ha−1 yr−1) with total area of 120.04 ha (2.30%). Tasik Chini Catchment is very susceptible to soil erosion especially on northwest and southeast regions, where the main sources of soil loss come from the agricultural, new settlements and mining activities. To conclude, the estimation of soil erosion model using remotely sensed data can be used to build sustainable development strategy within Tasik Chini Catchment in the future

Agricultural Land Evaluation Using GIS-Based Matching Method in Highland Areas for Oil Palm Cultivation

Oil palm (Elaeis guineensis) is one of the commodity crops and is mostly found in tropical lands. This study aimed to analyze the current and potential land suitability for oil palm using the geographic information system (GIS) technique. The study was conducted in the Ranau District, Sabah State, Malaysia. Field activity was carried out to collect soil samples and land information in the study area. Land suitability was then assessed using the matching method and GIS software was employed to produce a land suitability map for oil palm. The results indicated that the current land suitability classes in the study area were highly suitable (S1) with a total area of 99,118 ha (27.4%); moderately suitable (S2) with 110,108 ha (30.4%); marginally suitable (S3) with 109,533 ha (30.2%); currently not suitable (N1) with 2,728 ha (0.7%) and permanently not suitable (N2) with 40,693 ha (11.3%). Meanwhile, the potential land suitability classes showed 198,206 ha (54.7%) for S1; 123,281 ha (34%) for S2 and 40,693 ha (11.3%) for N2. Suitable areas that could be planted with oil palm included the gently sloping flank and the low gradient slope margin. Availability of nutrients and work capability were the dominant limiting factors in the study area. The outputs of this study recommend that the Ranau District has the potential for oil palm although it still needs land improvements for sustainable oil palm cultivation

Mechanical characteristics of developed brick from drinking water sludge under different firing temperatures and rice husk ash contents

There is a considerable interest in making alternative bricks using wastes. Firing temperature has been significantly improved the mechanical qualities of bricks. The aim of this study was to investigate into the impact of firing temperature and rice husk ash content on the mechanical properties of drinking water sludge bricks (DWS). Two types of bricks were produced; bricks made of 100% DWS (DWS100) and bricks with 80% DWS and 20% RHA (DWS80). These samples were subjected to different thermal variations of 300 °C and 700 °C for three hours. The unfired brick samples were also prepared for reference. The volume changes of the DWS100 bricks increased as the firing temperature climbed up to 500 °C, before dropped at 700 °C. A similar behaviour was also exhibited by DWS80 bricks, however it shrunk at earlier temperature of 500 °C. At 500 °C and 700 °C, the density of bricks decreased dramatically, with DWS80 bricks consistently being lesser than DWS100 bricks. The water absorption of DWS80 brick began to decrease at 500 °C, a lower temperature than that of DWS100, as the firing temperature climbed. RHA-added bricks (DWS80) were anticipated to absorb more water than DWS100 bricks, but this did not occur. This presumably induced by the constriction of clay mineral structure rather than organic matter removal at high temperature per se. The compressive strength increased with the increase in temperature. It can be inferred that RHA can decrease the compressive strength of RHA-added bricks, despite the fact that a higher fire temperature significantly increased their strength

Kesan suhu dan bahan tambah abu terbang terhadap pencirian mekanik bata daripada sisa rawatan air mentah

Penggunaan semula sisa dalam pembangunan bata giat diusahakan dan beberapa pengubahsuaian dilakukan bagi menghasilkan produk bata yang berkualiti baik dan selamat. Suhu merupakan antara faktor yang mempengaruhi cirian mekanik bata. Oleh itu, objektif kajian ini adalah untuk melihat pengaruh suhu dan abu terbang (RAM) terhadap sifat mekanik bata yang dihasilkan daripada campuran sisa rawatan air mentah (RAM). Dua jenis sampel bata disediakan melibatkan bata 100% sisa RAM (RAM100) dan bata campuran 80% sisa RAM dan 20% AT (RAM80). Kedua-dua jenis sampel dikenakan suhu pembakaran berbeza (tanpa bakar, 500 °C, 700 °C) selama tiga jam. Ujian larutresap turut dilakukan bagi mengenal pasti kepekatan logam berat yang hadir dalam bata. Pencirian mekanik bagi penyusutan linear menunjukkan peningkatan dengan pertambahan suhu. Kehadiran sisa AT meningkatkan nilai penyusutan linear yang lebih tinggi berbanding bata berasaskan RAM (RAM100) apabila suhu meningkat daripada 350 kepada 700 °C. Nilai ketumpatan kedua-dua jenis bata turut menyusut dengan peningkatan suhu namun meningkat semula pada suhu yang lebih tinggi (700 °C). Kedua-dua jenis bata juga menunjukkan peningkatan penyerapan air dengan peningkatan suhu. Kehadiran AT turut mengurangkan nilai serapan air berbanding bata RAM100. Kekuatan mampatan bata meningkat dengan peningkatan suhu dan bata RAM100 menunjukkan corak peratus peningkatan yang ketara berbanding bata RAM80. Namun, daripada perspektif peratusan, kehadiran AT menunjukkan peratusan pertambahan kekuatan mampatan yang ketara berbanding bata RAM100. Daripada hasil ujian larutresap dan cirian mekanik yang dilakukan, sisa rawatan air dan abu terbang berpotensi digunakan sebagai bahan asas dalam pembangunan bata dan beberapa pengubahsuaian diperlukan bagi mencapai piawaian yang ditetapkan sebagai bahan binaan alternatif

Developing and mechanical properties of low fired and geopolymer bricks from drinking water sludge with different contents of added fly ash

Raw water treatment and coal-based power generation facilities produce a high level of waste to the environment annually. A low recycling scheme has worsened the situation and wastes usually end up in a landfill. Further environmental degradation could be prevented by re-utilising wastes for the production of alternative bricks. Additionally, the development of low-fired brick from wastes can comparatively reduce energy consumption during the firing stage. Geopolymer has successfully replaced ordinary portland cement (OPC) without bargaining its mechanical quality. This study aimed to investigate the effect of fly ash (FA) content and geopolymerization on mechanical characteristics of brick developed from drinking water sludge (DWS). A set of brick samples was fired at 500 oC while another set of samples was prepared under a high alkaline condition to produce geopolymer bricks. Resultantly, both sets of samples demonstrated a decrease in linear shrinkage and increased density with more content of FA. For fired brick samples, the water absorption decreased from 38.6% to 33.3% before rising again at 45% of FA content. However, a continuous decrease was displayed by geopolymer brick as FA increased. The compressive strength of fired bricks showed a decreasing trend as FA content increased and vice versa for the geopolymer brick. The compressive strength of geopolymer bricks increased from 1.22 MPa to 3.63 MPa at 45% of FA content. Comparatively, geopolymer bricks demonstrated higher strength than fired bricks. These results reflect the advantage of the incorporated wastes and geopolymerisation in developing alternative brick for sustainable resources and a better environment

Lineament mapping in a tropical environment using Landsat imagery

Remote sensing has proved to be a useful tool in lineament identification and mapping. This study demonstrates the use of multispectral Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper Plus (ETM +) satellite data obtained over two acquisition dates in 1990 and 2002 for lineament interpretation in a Malaysian tropical environment. A digital elevation model (DEM) was generated to improve the interpretation. We found that most of the major orientations in the field station could be successfully detected from the remotely sensed imagery. The results from the study show that the remote sensing technique is capable of extracting lineament trends in an inaccessible tropical forest

Pengaruh Hasil Tani Organic Compound (HTOC) Terhadap Sifat Fisik dan Kimia Tanah di Lahan Sawah yang Bertanah Asam Sulfat

Tanah asam sulfat umumnya tidak sesuai untuk produksi tanaman, kecuali tanah itu telah diamandemen. Riset ini dilakukan untuk meneliti pengaruh material amandemen tanah, Hasil Tani Organic Compound (HTOC) terhadap sifat fisik dan kimia tanah asam sulfat di lahan sawah, Kedah Malaysia. HTOC dibuat dari beberapa komponen utama yaitu zeolite, kieserite, asam humat dan serbuk kayu karet dengan rasio spesifik. Nilai pH pada tanah asam sulfat adalah sangat rendah yang dapat mengurangi produktifitas tanaman padi. Aplikasi HTOC dapat meningkatkan nilai pH dan kapasitas pertukaran kation (KPK) tanah. Dalam penelitian ini, sampel tanah asam sulfat diperlakukan dengan lima jenis perlakuan variasi dosis HTOC yaitu Plot T0 kontrol (0 t/ha HTOC), T1 (0.25 t/ha HTOC), T2 (0.5 t/ha HTOC), T3 (0.75 t/ha HTOC) dan T4 (1 t/ha HTOC). Dosis HTOC yang paling optimum untuk meningkatkan kualitas tanah asam sulfat adalah 1 t/ha HTOC. Hasil penelitian menunjukkan bahwa nilai sifat fisik dan kimia tanah meningkat sejajar dengan bertambahnya dosis HTOC yang diperlakukan terhadap tanah. Nilai pH dan KPK tanah dilaporkan paling tinggi pada Plot T4 (5.47 dan 12.75 cmolc/kg) dan paling rendah pada Plot kontrol (3.62 dan 8.55 cmolc/kg). Secara kesimpulannya, aplikasi HTOC ini dapat meningkatkan kualitas tanah asam sulfat untuk penanaman padi secara signifikan dengan cara meningkatkan sifat fisik dan kimia tanah terseb