Malaysian Journal of Tropical Geography (MJTG)

SPATIOTEMPORAL VARIATION OF PARTICULATE MATTER (PM) 2.5 CONCENTRATION IN THE INDONESIAN MARITIME CONTINENT

Sat, 29 Jun 2024 00:00:00 +0800

Indonesia is recognized as the country with the highest level of Particulate Matter (PM) 2.5 pollution in Southeast Asia. This study aims to investigate the spatial and temporal variations of PM2.5 concentrations in the Indonesian maritime continental region (IMC) over a span of 38 years (1980-2018), based on seasonal and El Niño-Southern Oscillation (ENSO) phenomena. The data used are surface PM2.5, rainfall, wind components at 850 hPa pressure, and fire hotspot points in the IMC region. The results showed higher PM2.5 anomalies in summer (JJA) compared to winter (DJF). There is a positive PM2.5 anomaly during the JJA period and a negative anomaly during the DJF period in the IMC region, which is caused by particle deposition by rain. Seasonal wind patterns carry pollutants from urban areas and hotspots towards the countryside, significantly increasing PM2.5 concentrations in rural areas. Riau and South Sumatra provinces show the highest hotspot density on Sumatra Island, Central Kalimantan and West Kalimantan provinces show the highest hotspot density on Kalimantan Island, and southern Papua has the highest hotspot density on Papua Island. The peak number and density of hotspots in Sumatra, Kalimantan, and Papua occurred in September. The rainfall patterns in IMC are closely linked to ENSO years. During El Niño years, rainfall decreases, and the atmosphere tends to become drier, leading to an increase in hotspots. These hotspots contribute to elevating the concentrations of PM2.5, as observed in 1997/1998 and 2015/2016 when the region experienced its highest hotspot density and a corresponding rise in PM2.5 levels. This association underscores the complex interplay between climatic phenomena, atmospheric conditions, and air quality dynamics in the Indonesian context.

ASSESSMENT OF LANDSLIDE VULNERABILITY REGARDING TNB ASSETS IN BUKIT ANTARABANGSA

Sat, 29 Jun 2024 00:00:00 +0800

The assessment of vulnerability to landslides is crucial for effective risk management, especially for infrastructure and human lives. This study aims to evaluate the vulnerability of landslides toward Tenaga Nasional Berhad (TNB) assets in Bukit Antarabangsa, an area known for susceptibility to slope and landslide failures. The TNB assets include substations and pylon towers. Substations were selected based on their proximity to slopes and a landslide inventory within a 50-meter distance. The study uses an Indicator-Based Method (IBM) to quantify the vulnerability level, allowing for a systematic and comprehensive analysis. The IBM involves selecting and assessing key indicators that reflect the physical aspects of vulnerability. These indicators are grouped into clusters, each corresponding to specific indicators and sub-indicators, and then integrated into a geospatial model for the vulnerability assessment. The Bukit Antarabangsa assessment revealed that the Athenaeum Condo substation exhibits very high vulnerability to landslides, while the entire pylon tower generally demonstrates a lower vulnerability level. This assessment provides TNB with critical information to make informed decisions, implement mitigation measures, and prioritize actions to minimize potential risks and maintain service reliability. The study's significance lies in its valuable contribution to infrastructure safety against landslides, safeguarding communities, and ensuring the continuity of essential utilities during natural disasters.

INFLUENTIAL ELEMENTS IN THE DEVELOPMENT OF IRAN'S URBAN POPULATION

Rahimberdi Annamoradnejad, Taher Safarrad — Sat, 29 Jun 2024 00:00:00 +0800

Urbanization is the concept of increasing urban population and the number of cities in a region. The growing trend of urbanization in developing countries is one of the challenges of today's world due to the occurrence of problems and its negative consequences. This article analyses the spatial distribution of Iran's urban areas and the factors affecting it, examines the rate of change in the country's urban population over 6 decades, and finally predicts the change in the country's urban population until 2030. The main question of the research is how urbanization in Iran has changed over the last 6 decades (1956-2016) and what factors have influenced it. The results showed that urbanization in Iran, as in most developing countries, has grown rapidly in recent decades, with the country's urban population increasing more than tenfold over the past six decades. The reasons for the rapid growth of the urban population in Iran can be listed as follows: the massive migration of villagers to urban areas, the development of industries in big cities, land reforms, the occurrence of the Islamic Revolution, the Iraq-Iran war, the continuation of the centralization process, regional inequalities in the country, the tendency of Afghan immigrants to live in the city and the implementation of some inappropriate laws, such as the abolition of the population criteria for turning a village into a city, the high natural population growth rate in the cities due to the suspension of the family planning program.

TEMPORAL ANALYSIS OF VEGETATION COVER CHANGES IN NORTHEASTERN PART OF NIGERIA’S SUDAN SAVANNAH

Afolayan, O.S — Sat, 29 Jun 2024 00:00:00 +0800

Survival of teeming population in sub-Saharan Africa necessitates conversion of natural vegetation to farmland in an unsustainable manner leading to environmental degradation and subsequently, the threat to food security. The study aims at analyzing of vegetation cover changes in Nigeria’s Sudan savannah agroecological zone. Landsat images of Yamaltu-Deba town with periodic interval of 10 years between 1990-2020 were acquired at 30 m spatial resolution and 16 bit of radiometric resolution was analyzed using Arc GIS. Image processing and data analysis was used to determine the trend pattern of vegetation cover changes. While NDVI was used to classify the vegetation into high, low, moderate, no vegetation and water body, overlay analysis was used to produce vegetation cover change map. The study discovered reduction in high vegetation at the rate of -9.32% in 1990 to -29.81% in 2020 while low vegetation cover changes increased from 4.09% in 2000 to 50.01% in 2020. In conclusion both high and moderate vegetation cover have been reducing at alarming rate resulting to increase in low vegetation cover. Therefore the study hereby recommended the need for incorporation of spatial integration of soil nutrient improve tree into the farming system and legislation against all form of deforestation.