Optical and radar remote sensing data for forest cover mapping in Peninsular Malaysia

This study aims to map forest cover in Peninsular Malaysia using satellite images as deforestation is of concern in the recent decades, and is an important environmental issue for the future too. The Carnegie Landsat Analysis System‐Lite (CLASlite) program was used in this study to detect forest cover in Peninsular Malaysia using Landsat satellite data. The results of the study show that CLASlite algorithm misclassified some oil palm, rubber and urban areas as forest vegetation. A reliable forest cover map was produced by first combining Landsat and ALOS PALSAR images to identify oil palm, rubber and urban areas, and then subsequently removing them. The HH and HV polarization data of ALOS PALSAR (threshold method) could detect oil palm plantations with 85.26 per cent of overall accuracy. For urban area detection, Enhance Build up Index (EBBI) using spectral bands from Landsat provided higher overall accuracy of 94 per cent. These methods produced a forest cover reading of 5 914 421 ha with an overall classification accuracy of 94.5 per cent. The forest cover (including rubber areas) detected in this study is 0.38 per cent higher than the percentage of 2010 forest cover detected by the Forestry Department of Peninsular Malaysia. The technique described in this paper presents an alternative and viable approach for updating forest cover maps in Malaysia.     

The Spatial Structure of Zooplankton Communities of Pedu Reservoir, Malaysia

A total of 22 species of zooplankton were identified from 8 sampling stations located in the limnetic zone of Pedu reservoir.The zooplankton community was dominated by rotifers (11 species),followed by cladocerans (9 species) and copepods (2 species).Four species of zooplankton comprised of 3 rotifers,Brachionus quadridentata,Brachionus caudatus and Keratella cochlearis and one cladoceran,Ceriodaphnia cornuta were present at all sampling stations.Species richness was highest at Station 2 (17 species) followed by Station 4 and Station 8 (14 species),Station 5 (15 species),Station 7 (11 species),Station 6 (10 species),Station 3 (9 species) and Station 1 (7 species).With an exception of water transparency,all other water quality parameters such as temperature,dissolved oxygen,conductivity,pH and total dissolved solids were not significant when compared between sampling stations.The study found that station 5 which was located in a calm strait,protected from strong wave and wind was a suitable area for zooplankton growth and establishment.Factors supporting the findings included highest water transparency (3.4 m),rich in species numbers (15 species),high diversity index (0.950) and evenness index (0.808).     

Foregrounding technology over politics? Media framings of federal elections in Malaysia

Mainstream and alternative media play an important role in circulating powerful narratives within and often beyond a country's borders. This article specifically examines how Malaysia's media have framed the relationship between information and communication technologies (ICTs) and the country's electoral process. To this end, the authors conducted a content analysis of selected domestic mainstream and alternative media sources for two weeks before and two weeks after Malaysia's last three federal elections – 1999, 2004 and 2008 – to gauge how coverage has changed over time with shifts in the local political landscape and growing ICT access and usage.     

Seismological Activities in Malaysia

In this paper,the development of the National Seismic Network of Malaysia is described firest.Then,the maximum intensities on the Modified Mercalli(MM) scale experienced by Peninsular Malaysia and East Malaysia and the damage to man-made structures caused by earthquakes are analyzed.Finally,the seismicrisk management and strategy to mitigate seismic risk in Malaysia are outlined.     

Identification of trends in Malaysian monthly runoff under the scaling hypothesis

Abstract

Statistical tests have been widely used for several decades to identify and test the significance of trends in runoff and other hydrological data. The Mann-Kendall (M-K) trend test is commonly used in trend analysis. The M-K test was originally proposed for random data. Several variations of the M-K test, as well as pre-processing of data for use with it, have been developed and used. The M-K test under the scaling hypothesis has been developed recently. The basic objective of the research presented in this paper is to investigate the trends in Malaysian monthly runoff data. Identification of trends in runoff data is useful for planning water resources projects. Existence of statistically significant trends would also lead to identification of possible effects of climate change. Monthly runoff data for Malaysian rivers from the past three decades are analysed, in both five-year segments and entire data sequences. The five-year segments are analysed to investigate the variability in trends from one segment to another in three steps: (1) the M-K tests are conducted under random and correlation assumptions; (2) the Hurst scaling parameter is estimated and tested for significance; and (3) the M-K test under the scaling hypothesis is conducted. Thus the tests cover both correlation and scaling. The results show that the number of significant segments in Malaysian runoff data would be the same as those found under the assumption that the river flow sequences are random. The results are also the same for entire sequences. Thus, monthly Malaysian runoff data do not have statistically significant trends. Hence there are no indications of climate change in Malaysian runoff data.

Citation Rao, A. R., Azli, M. & Pae, L. J. (2011) Identification of trends in Malaysian monthly runoff under the scaling hypothesis. Hydrol. Sci. J. 56(6), 917–929.     

Tropical residual soil as compacted soil liners

A series of laboratory tests was conducted on a tropical residual soil, which is widespread and readily available over a considerable part of Peninsular Malaysia, to assess whether it could be compacted as hydraulic barriers in waste disposal landfills. Index properties, swelling potential, cation exchange capacity (CEC), compaction characteristics, and hydraulic conductivity of the soil indicate that it is inorganic, very plastic, inactive (activity <0.75), moderately expansive (modified free swell index is about 3.06), and of fair attenuation capacity (for inorganic contaminants). For hydraulic conductivity measurement, the soil was compacted in rigid-wall permeameter moulds at a variety of water contents and compactive efforts and then permeated with de-aired tap water. The results of hydraulic conductivity tests illustrate that hydraulic conductivity lower than 1×10^–7 cm/s can be achieved using a broad range of water contents and compactive efforts, including water contents dry of optimum. Its shrinkage and strength properties show that it has minimal potential to shrinkage and has adequate strength to support the overburden pressure imposes by the waste body. These findings suggest that the residual soil can be potentially utilized as compacted soil liner material.     

Interstadial records of the last glacial period at Pantai Remis,Malaysia

Two eustatic high sea stands during the last glacial period are recognised at Pantai Remis. These highstands, lower than present-day sea-level, are tropical manifestations of the ameliorating interstadial climate during the Weichselian/Devensian/Wisconsin glaciation in the Northern Hemisphere. The earlier highstand corresponds to a sea-level of 14.6 m below mean sea-level (MSL). It is interpreted as synchronous with Oyxgen Isotope Stage 5a and is correlated with other known sea-level curves in other parts of the world. The younger high sea stand, dated 55810 ± 1140 to 53870 ± 1400 yr BP, indicates sea-level of 4.3 m below MSL. It represents an interstadial equivalent that lasted for at least 2000 yr, whereas the earlier interstadial period indicates a minimum duration of twice this amount or very likely even longer, as reflected from the thickness of the accumulated deposits. The palynological records indicate that during interstadial times, climatic stability in the tropics is attained and was sufficiently long for vegetation to thrive and develop. The palynofloral constituents of the earlier interstadial phase at Pantai Remis showed the establishment of vegetation in a coastal setting, initiated by Pandanus swamp forests. Simultaneously, mangrove swamp flourished in the lower lying parts of the area, hence the presence of direct tidal influence is evident. Both the Pandanus and mangrove swamps were succeeded by mixed freshwater swamp forests of a Campnosperma–Calophyllum assemblage. Subsequently a slightly open and somewhat drier mixed swamp forest prevailed, marked by the increase in fern spore representation. The later interstadial phase showed shorter vegetation successions, which commenced on the landward edge of a mangrove swamp forest. The mangrove was successively replaced by strand forest, as indicated by domination of Casuarina equisetifolia. The palynological assemblages in both the interstadial periods indicate similarity to the present-day coastal vegetation. This implies that during the interstadials the climate in the lowlands of Peninsular Malaysia and presumably throughout the equatorial region, was as that prevailing today. © 1997 John Wiley & Sons, Ltd.     

(In)Formal memoryscapes and the unma(s)king of a Malaysian war heroine

The geographical literature on the politics tied to formal commemorations of the past is a burgeoning one. Yet, there has been less attention paid to similar practices undertaken by nonstate agents seeking to ensure that what is written out of official history is not forgotten. This paper explores how and why the story of Sybil Kathigasu, a woman who played a salient role in the resistance movement against the Japanese during the Second World War in Perak, Malaysia, has been peripheralized within formal memory making even as it has been informally revived elsewhere. It specifically suggests that, while the sidelining of her story may be the product of the tendency of the state of Perak to downplay its war past, Sybil's gender, race and political ideologies have also made it more difficult for her to be embraced as a ‘national’ heroine. Drawing on a private museum that was set up in her honor in Papan, the paper also reveals how factors impeding her formal remembrance also have implications for alternative efforts to recover her story. More broadly, the paper offers insights into women's absences in Malaysian public memory, and argues the need for more emphasis on memoryscapes ‘from below’ as a means of nuancing local remembrance politics.