Showing papers by "Roslan Umar published in 2023"
TL;DR: In this article , the authors determined the habitat distribution patterns of C. quadricarinatus based on the methods of GIS and environmental DNA (eDNA) analysis at Felda Tenang, Terengganu, Malaysia.
Abstract: Cherax quadricarinatus (von Martens, 1868) is a highly invasive species that is resilient and highly adaptable to environmental conditions in new locations. Its presence brings along ecosystem imbalances and causes socioeconomic losses in invaded areas. Due to the destructive behaviour, it is important to conduct preliminary assessment methods and scientific studies especially on its behavioural and dispersal patterns. Thus, this study aims to determine the habitat distribution patterns of C. quadricarinatusbased on the methods of GIS and environmental DNA (eDNA) analysis. The study was done at Felda Tenang, Terengganu, Malaysia. Based on the geographical features and climate conditions of the study area, we theorized that there are fewer and older C. quadricarinatuspresent at higher areas but more and younger C. quadricarinatus at lower areas. We found that 91.67% of the study area to be invaded, thus imploring the need for future mitigation plans to curb their dispersal into new areas. Future studies should also be done to determine the habitat distribution patterns of C. quadricarinatus in other areas.
TL;DR: In this paper , the authors used geographic information systems (GIS) and environmental deoxyribonucleic acid (eDNA) analyses to detect freshwater invasive alien species (IAS) in Southeast Asia.
Abstract: Freshwater invasive alien species (IAS) are non-native organisms that were intentionally or unintentionally released into local water bodies and later harmed the invaded habitat by disrupting the ecological processes. Over the last few years, environmental deoxyribonucleic acid (eDNA) analyses have been used in many studies to detect IAS, with positive results. However, with the help of geographic information systems (GIS), efforts to detect the presence of IAS can be made faster and more efficiently. In this paper, we review the background of IAS in Southeast Asia and management efforts undertaken involving the input of known habitat-specific geographical parameters into GIS mapping. Via this strategy, it is possible to identify and distinguish areas that fit IAS habitat features from those that do not. eDNA analysis can later be applied to confirm the presence of IAS in detected areas, enabling further studies and actions. The presence of IAS in certain areas can be used as an indicator to assess the environmental integrity of native waterways. This combined method is likely the first approach to be applied to the detection of freshwater IAS in local water bodies. Apart from saving energy and resources, embedding GIS and eDNA into the study of IAS not only benefits the ecosystem but also assists locals and authorities in managing and taking necessary enforcement actions to curb further spread.
TL;DR: In this paper , the performance and structural properties of enhanced skinned asymmetric nanofiltration (NF) membranes were experimentally and theoretically analyzed based on the Donnan and steric-hindrance transport mechanism.
Abstract: In this study, the performance and structural properties of enhanced skinned asymmetric nanofiltration (NF) membranes were experimentally and theoretically analyzed. Based on Donnan and steric-hindrance transport mechanism, the relationship of performances and key properties of the fabricated nanofiltration membranes were examined. At the optimum concentration of polymer, the skinned nanofiltration membranes achieved high salt rejection up to 85% and high solutes separation efficacy. Moreover, morphological and modeling analysis discovered that, the optimum membranes produced good pore size and fine key properties with 1.20 nm of pore radius, 4.96 µm of ratio of thickness to porosity (∆x/Ak) and −1.56 of surface charge, ζ as well as uniform pore size distributions. The findings from this study proved that the strategic utilization and manipulation of good membranes material is a simple and good attempt to upgrade the membranes capability and usability which lead towards the application in various membrane separation processes.
TL;DR: In this paper , the spatiotemporal analysis of rainwater quality before and during the movement control order (MCO) implementation due to the COVID-19 pandemic was performed.
Abstract: This study aimed to classify the spatiotemporal analysis of rainwater quality before and during the Movement Control Order (MCO) implementation due to the COVID-19 pandemic. Chemometric analysis was carried out on rainwater samples collected from 24-gauge stations throughout Malaysia to determine the samples' chemical content, pH, and conductivity. Other than that, hierarchical agglomerative cluster analysis (HACA) and discriminant analysis (DA) were used to classify the quality of rainwater at each location into four clusters, namely good, satisfactory, moderate, and bad clusters. Note that DA was carried out on the predefined clusters. The reduction in acidity levels occurred in 11 stations (46% of overall stations) after the MCO was implemented. Chemical content and ion abundance followed a downward trend, indicating that Cl- and Na+ were the most dominant among the anions and cations. Apart from that, NH4+, Ca2+, NO3-, and SO42- concentrations were evident in areas with significant anthropogenic activity, as there was a difference in the total chemical content in rainwater when compared before and during the MCO. Based on the dataset before the MCO, 75% of gauge stations were in the good cluster, 8.3% in the satisfactory cluster, 12.5% in the moderate cluster, and 4.2% in the bad cluster. Meanwhile, the dataset during the MCO shows that 72.7% of gauge stations were in the good cluster, 9.1% in the satisfactory cluster, 9.1% in the moderate, and 4.5% in the bad cluster. From this study, the chemometric analysis of the year 2020 rainwater chemical composite dataset strongly indicates that reduction of human activities during MCO affected the quality of rainwater.
TL;DR: In this paper , public participation in environmental impact assessment has been recognized under Principle 10 of the Rio Declaration on Environment and Development, where the public shall have right to access to information, participate in decision making process and their voice shall be heard.
Abstract: Public participation in environmental impact assessment has been recognized under Principle 10 of the Rio Declaration on Environment and Development. According to Principle 10, the public shall have right to access to information, participate in decision making process and their voice shall be heard. Malaysia has implemented environmental impact assessment under Article 34 of Environmental Quality Act 1973, Article 12 of Sabah Environment Protection Enactment 2002 and Section 11A of Sarawak’s Natural Resources and Environment Ordinance 1993. This paper will look into the public participation in environmental impact assessment in Malaysia, Sabah and Sarawak. Qualitative methodology with analytical, historical and comparative approaches was used in this study. Result indicates that public participation has been mentioned in all three legislations. However, there is no guideline as to the level of participation by the public and how the information shall be delivered to the public.