Search Results (3)

In this research study, we use Landsat-5, -7, and -8 thermal remote sensing technology to analyze the urban heat mapping of the Greater Beirut Area (GBA) in Lebanon. The investigation is conducted within a time frame that spans over three decades from 1990 to 2020. For each year, we calculate the normalized difference vegetation index (NDVI) and land surface temperature (LST) statistics. Also, a spatial-temporal analysis is conducted to relate heat mapping in GBA to the topography based on the altitude. Overall results show that the temperature in GBA has increased over three decades, with an increase in the vegetation and urban LST by 1.10 °C and 1.26 °C, respectively. Results also show that green areas are cooler than urban areas. Local analyses show that vegetation and altitude have a cooling effect, with temperatures dropping in the high and green mountains. Full article

On 4 August 2020, a strong explosion occurred near the Beirut seaport, Lebanon and killed more than 200 people and damaged numerous buildings in the vicinity. As Amonium Nitrate (AN) caused the explosion, many studies claimed the release of large amounts of NO₂ in the atmosphere may have resulted in a health hazard in Beirut and the vicinity. In order to reasonably evaluate the significance of NO₂ amounts released in the atmosphere, it is important to investigate the spatio-temporal distribution of NO₂ during and after the blast and compare it to the average day-to-day background emissions from vehicle and ship traffic in Beirut. In the present study, we use Sentinel-5 TROPOMI data to study NO₂ emissions in the atmosphere close to the affected area prior, during, and after the Beirut explosion (28 July–8 August 2020). Analysis shows an increase in NO₂ concentrations over Beirut up to about 1.8 mol/m² one day after the explosion that was gradually dissipated in about 4 days. Seven days before the blast (on 28 July 2020) NO₂ concentration was, however, observed to be up to about 4.3 mol/m² over Beirut, which is mostly attributed to vehicle emissions in Lebanon, ships passing by the Beirut seaport and possibly the militant activities in Syria during 20–26 July. It is found that the Beirut blast caused a temporarily and spatially limited increase in NO₂. The blast mostly affected the coastal areas in Lebanon, while it did not have much effect on inland regions. TROPOMI data are also analyzed for the Greater Cairo Area (GCA), Suez Canal, Egypt, and in Nicosia, Cyprus to confirm the effect of human activities, vehicles, and ship traffic on NO₂ emissions in relatively high and relatively low populated zones. Full article

A particular challenge for undertaking urbanization mapping of Beirut is the absence of a unified understanding of the city. Migration, informal settlements, a lack of urban planning, political corruption, as well as internal conflict have made this task even harder. The population in Lebanon is unevenly distributed among regions, where one third of the population resides in the Greater Beirut Area (GBA), whereas it occupies only 233 km² (2% of Lebanon’s total area). The Greater Beirut Area is subject to pressures arising from population growth and economic expansion. This study aims to follow the evolution of urbanization from 1963 till 2005 by processing and interpreting topographical maps and satellite images acquired by different space platforms. Satellite imagery change analysis shows that average annual urban growth surpassed 1.8 km²∙yr⁻¹. Actually, a variety of factors triggers urban growth in the GBA (i.e., transportation, public policies, economic activities and environmental variables). The logistic regression method has been applied to model future urban growth in the region of Greater Beirut. Consequently, an urban growth scenario map has been generated. To validate our results, we compared an urban map derived from RapidEye satellite acquired in 2010 to our model’s outcome of the same year. The output shows a satisfactory rate of success (~61%). This research aims to provide policy makers and urban planners in Lebanon an essential decision tool to support upcoming urban planning in this study area or in others major cities in Lebanon. Full article