Volume 40 (2021): Issue 3 (September 2021)

The value of terrestrial carbon sequestration in urban areas, due to lack of vegetation as a carbon sink, is rarely studied. In fact, urban areas have high carbon emission values, which must be minimised. On the other hand, the value of carbon sequestration in urban areas is very dynamic due to natural factors from the environment and non-natural factors from anthropogenic activities. The main objectives of this study are to identify the carbon dioxide sequestration in urban areas, especially in tropical climates, and to determine the dynamics of carbon sequestration in urban areas for a year. The results show that carbon sequestration in tropical urban areas has a significant value compared with urban areas in temperate climates. This condition happens because there are still green open spaces in gardens and agricultural lands. The value of carbon sequestration in this tropical urban area experiences monthly dynamics caused by rainfall variation and anthropogenic activities, such as land conversion and plant type conversion in agricultural lands.

Despite the large amount of information, including books, articles and pristine images of geotourism, there exists no comprehensive study on the collection and classification of them in Iran yet. In this research, for the modelling of geosite watersheds, 1000 articles were surveyed through library research and the models with the highest frequency of use were identified and analysed among a statistical sample of 451 local papers using the Meta-Analysis method, and then the most efficient ones were identified using Delphi and Analytic Hierarchy Process (AHP) methods. The results of this study showed that while the strengths, weaknesses, opportunities and threats (SWOT), Pralong, Reynard, AHP and Pereira models are in the first to fifth-ranked models with the highest frequency, however, Pralong, SWOT, Reynard, Perira and Comanescu models were considered as the most efficient ones in geosite modelling in Iran.

The lack of implementation of the Nationally Appropriate Mitigation Actions (NAMAs) of the non-Annexe I Parties registered in the NAMA Registry of the United Nations Framework Convention on Climate Change (UNFCCC) is a worrying situation in the sense that it is limiting the contributions these NAMA projects would have made towards mitigating global climate change. There is however little research on the reasons behind the lack of implementation of these NAMAs projects and this is the knowledge gap that this paper seeks to fill based on a critical overview of the NAMAs of Ethiopia, Indonesia and Georgia. The source of data for this paper is mainly from the focal persons for the NAMAs of the countries under study, which was obtained via telephone and Skype interviews with the respondents. Our findings show that lack of funding, complicated financial mechanisms, lack of technical expertise, fringe conditions to donor support and policy issues according to the findings of this study are the main hindrances to the implementation of NAMAs. International organisations, donor partners, developed countries and local governments alike are therefore encouraged to channel some of the funds meant for fighting global climate change into sponsoring the NAMAs of poorer countries, as this will see to the successful implementations of these NAMAs and their subsequent impacts on mitigating global climate change. The paper is also timely considering the scarcity of literature on NAMAs related issues.

Merapi Volcano in Central Java, Indonesia, has a high eruption intensity that triggers landscape changes in the form of a river channel evolution. In this paper, the spatial change of river valleys under the influence of sediments deposition in the fluvio-volcanic system is investigated. The data were collected by employing observation, remote sensing image interpretation, literature study and documentation of data from several agencies. The data were analysed using the spatial approach supported by geographic information system (GIS) and remote sensing. The results show that there are many palaeochannels related to fluvio-volcanic processes from the southern to the western sectors of the Merapi volcanic foot. Palaeochannels are mainly distributed next to the main river valleys. This condition correlates with the contributions of the Merapi eruptions. The palaeochannel distribution patterns cluster radially following the distribution pattern of the river valleys. The process that plays the most important role in the evolution of palaeochannels is the deposition of lahar. In sum, this research shows that volcanic activities over a long period of time have provided great and important contributions that have driven the landform evolution. The various changes that occur also reveal the unique morphological characteristics, showing the influence of the volcanic processes.

The prioritisation of catchments, particularly in the context of catchment plans and management programmes, is part of water resources development. In fact, morphometric analysis assisted by geospatial technology is carried out by prioritising sub-catchments according to their natural resource availability characteristics. Information on the geomorphology and erosion factors of the study area is used in the area in the preparation of local models of ungauged sub-catchments, which otherwise lack an adequate hydrological database. The objective of this paper is to use geographic information systems (GISs) in morphometric analysis to prioritise sub-catchments of the Soungrougrou (a tributary of the Casamance River). In this respect, the integrated methodology involving morphometric aspects from geospatial technology is used. To carry out the geospatial research, basic mathematical equations used in a GIS environment were used to measure a series of aspects of hydrology such as flow length, flow length ratio, bifurcation ratio, drainage density, drainage texture, flow frequency, elongation rate, circularity ratio, form factor, relief and relief ratio. The results divided the whole catchment into three priority areas, namely high, medium and low. The results are relevant for establishing soil and water conservation plans in the Soungrougrou basin, as well as adequate groundwater production and management. The high category (sub-basins 6, 8, 14, 17 and 18) is subject to maximum soil erosion, which requires immediate intervention to avoid possible natural hazards.

River floods are distinct because not all of them are destructive and typically affect the people who are living in riverine areas. Therefore, people often refuse to evacuate even when they face imminent danger. River floods are a recurrent phenomenon in Bangladesh. This research aims to analyse the flood evacuation behaviour of riverine people in Bangladesh. A total of 377 households were selected for the questionnaire survey and were interviewed from April 2019 to May 2019. Bivariate and multivariate statistics were employed to analyse riverine people's evacuation behaviour based on their socio-demographic and economic characteristics. This study found that although 82% of the households had received flood warning messages, only 40% had evacuated. Results from multivariate analysis suggested that the age of household heads, their education, whether they are disabled/chronically ill members, their income, the height of floodwater inside the house, and the type of warning messages they receive appear to be key determinants that influenced their decisions regarding evacuation. Elderly household heads had a lower likelihood to evacuate. The results showed a negative association between early warning messages and evacuation. Household with disabled/chronically ill member(s) was associated with a higher likelihood of evacuation. Similarly, higher water depth in the home was associated with evacuation. These findings will be helpful for policymakers to enhance awareness of riverine households.

This study presents the SALBEC – Soil ALBEdo Calculator – a Python library and Graphical User Interface designed to predict the diurnal variation of the clear-sky albedo based on the soil surface properties. Such predictions are becoming more and more necessary with the increasing role of remote measurements. The software uses the following input parameters: the soil spectrum, soil roughness, day of the year (DOY) and sample location. It returns the diurnal albedo variation and, as a unique feature, optimal observation time in the form of tables and graphs as outputs. Models created with the SALBEC were compared with the data acquired under near clear-sky conditions. The comparison shows that the differences between the models and measured data do not exceed the variation of input parameters. The software is directed towards scientists and professionals who require precise estimations of the albedo of soils for different field observation times. Our software is issued as free and open source software (FOSS) and is publicly available at https://github.com/jarekj71/salbec.

In the course of analysing the annual air temperature in Wrocław (TWr), a rapid change of the thermal regime was found between 1987 and 1989. TWr increased by >1°C, a strong, statistically significant positive trend emerged. The analysis of processes showed that strong warming in the cold season of the year (December–March) occurred as a result of an increase in the NAO intensity and warming in the warm season because of increased sunshine duration in Wrocław (ShWr). Multiple regression analysis has shown that the winter NAO Hurrell's index explains 15% of TWr variance, and the ShWr of the long-day (April–August) period 49%, whereas radiative forcing 5.9%. This indicates that the factors incidental to the internal variability of the climate system explain 64% of the TWr variability and the effect of increased CO₂ concentration only ~6%. The reason for this rapid change of the thermal regime was a radical change in macro-circulation conditions in the Atlantic-European circular sector, which took place between 1988 and 1989. The heat, which is the cause of warming in Wrocław, comes from an increase in solar energy inflow (April–August) and also is transported to Europe from the North Atlantic surface by atmospheric circulation (NAO). These results indicate that the role of CO₂ in shaping the contemporary temperature increase is overestimated, whereas the internal variability of the climate system is underestimated.

There have been many studies on rainfall erosivity and erosivity density (ED). However, it was not widely developed in Indonesia as a tropical country and has unique precipitation patterns. They are indicators for assessing the potential risk of soil erosion. The Air Bengkulu Watershed is undergoing severe land degradation due to soil erosion. This study aimed to analyze spatial-temporal in rainfall erosivity and ED based on monthly rainfall data (mm). The data used consisted of 19 weather stations during the period 2006–2020 and which are sparsely distributed over the watershed. The analysis was done by using Arnold's equation. Then, the trend was tested using parametric and non-parametric statistics, and analysed with linear regression equation, and Spearman's Rho and Mann Kendall's tests. The spatial distribution of both algorithms was analysed using the inverse distance weighted (IDW) method based on the geographic information system (GIS). Unlike previous research findings, The long-term average monthly rainfall erosivity and ED revealed a general increase and decreasing trend, whereas it was found to be non-significant when both indices were observed. However, these results indicate a range from 840.94 MJ · mm⁻¹ · ha⁻¹ · h⁻¹ · a⁻¹, 552.42 MJ · mm⁻¹ · ha⁻¹ · h⁻¹ · a⁻¹ to 472.09 MJ · mm⁻¹ · ha⁻¹ · h⁻¹ · a⁻¹ in that November month followed by December and April are the most susceptible months for soil erosion. Therefore, The upstream area of the region shows that various anthropogenic activities must be managed properly by taking into account the rainfall erosivity on the environment and that more stringent measures should be followed in soil and water conservation activities.

Gullies and other forms of erosion have been the greatest environmental problem and catastrophe in most high- and low-income countries. The challenge posed by soil erosion has compromised agricultural productivity, environmental biodiversity and food safety for the world's population. It is important to identify vulnerable areas to soil erosion in each region to initiate remedial measures. This study demonstrates the use of watershed morphometry coupled with weighted sum analysis (WSA) to estimate the soil erosion susceptibility of the Imo River Basin sub-watersheds (SWs) in South-Eastern Nigeria using satellite remote-sensing data and geographic information system (GIS) analysis. To this end, Shuttle Radar Topography Mission (SRTM), a Digital Elevation Model (DEM) with 30 m spatial resolution was used to extract and analyse 18 morphometric parameters including basic, linear, shape and relief. The method of receiver operating characteristics (ROC) curves was used to validate the model's prediction accuracy. This morphometry-based analysis resulted in the SWs being classified into zones of low, medium, high and very high erosion susceptibility. With regard to erosion susceptibility, 41.51% of the basin (2494.68 km²) is in the very high priority zone; while 10.50%, 44.33% and 3.66% of the basin are in the high, medium and low priority zones respectively. Validation of the final erosion susceptibility map showed a prediction accuracy of 81%. The use of satellite imagery and morphometric analysis in this study was cost- and time-effective for identifying areas susceptible to soil erosion.

The authors discuss the Boers (2021) view on the nature of the circulation of the Atlantic Meridional Overturning Circulation (AMOC).

Since the approval of the Brazilian Federal Technical Assistance Law, whose objective is to guarantee adequate technical assistance to the residents of poor areas to improve their homes, several municipalities have implemented programs, not always successful, to improve housing in slums. Aiming to subsidize these programs implementation workflow, the present paper analyses use of drones as a tool to gather information about the physical characteristics slum households in Salvador de Bahia city, Brazil. As an experiment we flight over a single census sector within the Alto das Pombas slum, and after image processing we extracted and organized the collected data, extracting the possible information that could be applied to identify and quantify the most precarious houses that could be prioritized from a health improvement perspective. We conclude that many of the necessary data needed, on the urbanistic scale in Brazilian slums, can benefit from drone photogrammetry at low cost and fast execution.