Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

A combination of natural (tropical latitudes) and human induced (Climate Change, Urban heat island) conditions give rise and exacerbate extreme hot temperatures, but mechanisms are unclear. Land use and land cover change (LULC) is considered one of the main causes of Urban Heat Island (UHI) but its contribution varies depending on local conditions. This study focuses on determining the influence of land use change on the UHI effect in Tuxtla Gutiérrez City by investigating the relationship between LULC and land surface temperature (LST). Through Landsat 5 and Landsat 8 imagery, this study analyzes historical LST. In 2017, the highest LST (>40 °C) occurred in the metal ceiling land class, which is made up of malls with open-air parking zones. This coverage occupied less than 3% of the total city area. Bare agriculture soil (BAS) class, located mainly on the periphery of the city, represented 11% of the city, and reported a mean LST of 35 °C, followed by asphalt roads with 34 °C and concrete ceiling with 32 °C. The lowest LST (< 28 °C), occurred in contiguous areas of trees greater than 3 ha. The LST variation when land use changed from trees to another coverage (1.3 to 3.1 °C) is higher than in the opposite direction (0.1 to 1.2 °C). The elimination or replacement of tress with impervious surfaces are the main causes for LST increase in Tuxtla Gutiérrez.

The analysis of land use and land cover changes represents a key issue for applied geography. In Mexico, even though deforestation prevails at the national level, it coexists with regional processes of forest recovery—the so-called forest transition. Despite an extensive literature on the forest transition in Mexico and in other developing countries, few studies have simultaneously addressed the social and biophysical factors of this phenomenon. Precisely, in the Mixteca Alta region of the Mexican state of Oaxaca, an increase in forest cover has been observed, taking place in the last several decades because of the combination of these factors. In this paper, we analyze land use and land cover changes occurring from 1967 to 2020 in the Mixteca Alta UNESCO Global Geopark (GMA) based on aerial photographs (1967) and satellite images (2020). We found that, during the study period, the area of oak forest increased 59%, pine-oak forest expanded 349%, grasslands declined 39%, agricultural areas decreased 17%, and areas without vegetation diminished 68%. Overall, 5992 hectares of forest were recovered (14.5% of the GMA’s total area). We also determined the main social and biophysical factors associated with this forest transition using three categories of change: no change, reforestation, and deforestation. This analysis was done with 15 meter-resolution raster data. We studied the importance of 21 variables based on a random forest classification. The most important variables associated with the forest transition were distance to the forest, geomorphological landscape, geology, slope, elevation, number of tractors, and mean temperature. The article discusses why the biophysical variables were more important than the social variables.

The agave is a representative plant of natural and anthropic landscapes of many arid and semi-arid regions of Mexico and offers a large number of products, the main ones being tequila and mezcal. For its production, both wild and cultivated magueys are used, so its demand in national and international markets has led to a change in the use of land for its cultivation and it has produced the genetic erosion of its populations. There is no information about their location and abundance, so that it is not possible to create management plans to ensure their permanence. Therefore, in this work is generated a spectral library for A. angustifolia (espadín), A. americana var. oaxacensis (arroqueño) and A. potatorum (tobalá) and other covers associated with the crop, and it was identified the bands of the electromagnetic spectrum where the reflectance of these elements are statistically different, thorough the non-parametric test for independent samples of Kruskal - Wallis and that of Dunn. This information was resampled spectral bands of Sentinel 2A images to evaluate if this satellite is able to identify this species. This was applied in hyperspectral signatures (350-2500nm) taken in three locations of Oaxaca, by a portable spectroradiometer. The results suggest that by using bands 2, 3, 6 and 8 it is likely that both agaves and their associated covers can be classified.

Introduction: The ongoing global pandemic due to the COVID-19 virus has had varying impacts on the quality of life in different regions. This article aims to identify areas of high social vulnerability in the municipalities in Hidalgo with information gathered in 2015. Methodology: The social vulnerability index was calculated by using the principal component analysis technique along with geographic information systems to evaluate its relationship with COVID-19 fatality ratio. Variables were constructed based on information taken from the 2015 Intercensal Survey for municipalities. Results: Two regions, one in the northeast and the other in the southwest of the state of Hidalgo, showed a strong relationship between social vulnerability and the fatality ratio. Conclusions: The variables that best explain social vulnerability in the Municipalities in Hidalgo are those that contemplate population characteristics. The findings could be used in planning social actions so that they not only focus on health care services in order to reduce the impacts of the current pandemic and reduce mortality due to COVID-19 in the most vulnerable sectors in Municipalities in Hidalgo.

The insertion of underdeveloped economies into the global financialization process has been carried out in a context of dependency, the differences of which are discussed under the concept of subordinate financialization. In this scenario, the securitization process is analyzed based on the issuance of mortgage backed securities issued by public housing funds in Mexico, which has energized the social housing real estate market. From the review of the financial reports on the stock certificates (CEDEVIS and TFOVIS), it is established that the sale of mortgage debt has served to be able to grant more mortgage loans to the beneficiaries, which is part of the state subsidiary that supports the private real estate sector, a situation that characterized the massive construction policy of the last two decades.

   Forest fires are a phenomenon that impacts the environment and society. They cause severe adverse effects but also play a role in the natural dynamics of ecosystems. Mexico has a significant incidence of forest fires, with an annual average of more than 400 thousand hectares of burned natural vegetation in recent years. The complex merge of social and environmental causes and effects, and their implications in the territory, make forest fires an ideal topic of study from a geographic perspective. The objective of this work was to analyze the approaches, findings, and research opportunities of Geography regarding the territorial dynamics of forest fires in Mexico. This analysis comprised (1) the compilation of advances in geographic studies on the subject, (2) the discussion of the results of these studies and their relevance, and (3) the identification of challenges and opportunities for future research in this field through a geographic approach.  The methodology consisted of a literature review guided by the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) concept. The SALSA (Search, Appraisal, Synthesis, and Analysis) approach was used to search for information, working with data from the Scopus platform. We considered papers published in geographic journals authored by researchers working in geographic institutions. The selected publications were processed through a bibliometric analysis and content review. The first includes data visualization using graphs, maps created in ArcGIS, and diagrams of scientific collaboration networks developed in the Gephi program.  We identified 41 papers published from 1983 to June 2021. The number of publications has increased in recent years. An increasingly interdisciplinary dynamic is also noted, with publications by academics from other disciplines in geographic journals and articles by geographers jointly with other researchers in non-specialized journals. The disciplines with the largest collaborations are Ecology, Environmental Sciences, Biology, Forest Sciences, Atmospheric Sciences, and Mathematics. This research topic has had an outstanding international orientation, involving scientists from ten countries. Studies have been conducted throughout the country, particularly in central Mexico and the northwest area (Baja California and Sonora). The field most investigated is geospatial analysis (51.3 %), followed by Physical Geography (36.6 %). Meanwhile, Human Geography has been scarcely addressed to date. Analyzing the co-authorship and citation networks, a lack of integration of geographic studies on forest fires in Mexico is observed, especially between studies on Physical and Human Geography.  Geospatial analysis studies have focused mainly on identifying affected areas and hazard modeling using geographic information systems and remote sensing. Additionally, some studies have estimated fire emissions. The primary focus of Physical Geography studies has been the research of fire regimes, mainly using dendrochronological methods. Few studies have also dealt with the effects of fires on the soil and the assessment of forest fuels. Works related to Human Geography have addressed the role of rural communities in fire management, particularly from local case studies.  In conclusion, despite the limited number of geographic studies published in peer-reviewed journals, there are significant contributions and growing interest in this discipline. It is recommended to strengthen geographic studies in this area, consolidate the existing lines of research, and add new approaches through which Geography can make a valuable contribution. Investigating the role of fires in air pollution in large cities, hazard modeling at regional and local levels, the effects of climate change, and the spread of invasive plants is essential. Finally, Geography can make a greater contribution to fire management by leveraging recent advances in this discipline on topics including governance and risk management. 

The management of green areas plays a central role in urban sustainability since vegetation cover has important environmental functions in urban areas. Urban green areas are key elements to improve the well-being of their inhabitants; they are not homogeneous but are differentiated into landscapes with coverages related to historical uses. This article documents the landscapes that are part of green areas in the urban zone of the municipality of Morelia and establish their relationship with the number of inhabitants living in urban areas. The methodology used for the identification and mapping of anthropogenic landscapes as units of analysis and differentiation in the study of vegetation is part of the geoecological approach.  To differentiate these landscapes, we started by identifying the physical-geographic landscapes of the territory as the natural background on which the urbanization process takes place, modifying the original land cover and giving rise to different uses. The land uses in the territory are differentiated by establishing the typology of housing and infrastructures introduced in the physical-geographic landscapes where the city was established and by the modified natural covers that remain in a given moment.  Then, by superimposing the typology of land uses and covers on the differentiation of the physical-geographic landscapes, geoecological units, i.e., spatial-territorial units, are obtained. They facilitate the classification and identification of the anthropogenic  ̶ anthroponatural and anthropic  ̶  landscapes of the territory. Certainly, the main transformative process of these landscapes has been urbanization. To determine the extension of green areas, the Normalized Vegetation Index was calculated for the study area, which was contrasted with the anthropogenic landscape layer to estimate this surface area per landscape unit.  From this, two indicators were established to achieve the proposed objective: the rate of green areas, which shows the percentage of the landscape covered by green areas, and the density of green areas per inhabitant once the population size has been calculated; both indicators are estimated for each class and type of anthropogenic landscape. The results revealed the presence of two classes, 5 subclasses, and 19 types of anthropogenic landscapes, mapped in 437 polygons in the urban area of the municipality, with the predominance of urban anthropic landscapes. From these results, the main function of the landscapes in the territory studied is housing, which covers 70% of the territory. Infrastructure in productive or service facilities in this urban area shows that the primary economic function is related to services; there is low industrial activity, and vegetation and agriculture occupy less than 8% of the area, which will probably be used for urban growth or services. The rate of green areas in the territory of study is low, and the main issue lies in the type of continuous housing landscapes of different densities. Commercial services and technogenic storage landscapes have a low rate of green areas. Separately, the issues with the density of green areas per inhabitant are concentrated in urban landscapes for housing purposes, which are home to 97.79% of the urban population, in particular in continuous housing landscapes of different densities, housing covering large areas, housing colonial-style landscapes (Historic Center), and buildings. In 2020, 87.6% of the urban inhabitants live in landscapes with a density of green areas per inhabitant of less than 10 m2/inhabitant, that is, below the recommended international standards. The methodology used to study the vegetation in the urban area of interest showed the relationship between the types of urban anthropic landscapes and the density of green areas per inhabitant, identifying and differentiating the main issues in the territory studied. The city of Morelia urgently needs a reforestation program based on the differentiation into the anthropogenic landscape units obtained from these indicators. It is imperative to propose innovative projects and technologies in landscapes with a deficit of tree coverage, particularly in the Historic Center landscape.

Immigration from Latin American countries to Canada is a relatively recent phenomenon. Approximately half a million Latin Americans currently live in Canada. They tend to prefer urban areas and settle in Toronto, Montreal, and Vancouver. In the past, smaller and mid-sized cities in the interior of British Columbia were generally off the radar for immigrants, but this has changed since the early 2000s, and the city of Kelowna has gradually emerged as a popular destination, including for immigrants from Latin America. It is a growing population that has received relatively little scholarly attention. This article addresses this research gap by exploring the settlement and housing experiences of Latin American immigrants in the mid-sized city of Kelowna. The study draws on data from questionnaire surveys that were administered to 62 Latin American immigrants in the city of Kelowna in the summer-fall of 2018. The findings revealed that transitioning from their homelands was a stressful and costly experience for participants, particularly with regard to finding affordable housing. They reported enormous financial stress, with most living in unaffordable housing; more than half were spending more than 30% of their monthly income on housing. Participants’ residential mobility and housing searches were constrained in part by low vacancy rates, language barriers, lack of public transportation, and a lack of affordable housing to rent or buy. Immigrants’ unfamiliarity with how subsidized housing works in Canada, including how to access it, combined with a limited supply of this housing, are major challenges.

Changes in land use cause a mosaic of areas in the landscape with different uses and coverage. This condition compromises soil nutrient stocks, especially phosphorus (P). In this sense, this study aimed to determine the concentrations of extractable and total phosphorus in 04 soil classes (Yellow Argisol, Litholic Neosol, Entisol and Planosol), 04 uses and covers (Open Native Caatinga, Dense Native Caatinga, Agriculture and Pasture) of the soil, in 04 depths (0-10, 10-20, 20-30 and 30-40 cm). To determine the extractable P, the Mehlich 1 and colorimetric reading were used. Total phosphorus was determined by sulfur digestion and colorimetry. The results of extractable and total P concentrations were higher for the Argisol and Planosol classes. It was observed that there were reductions in extractable P concentrations between the soil layers as the soil profile deepened. Depths between 0-20 cm generally showed higher concentrations of extractable and total phosphorus in agriculture. Among the four soil classes studied, the highest average values of extractable and total P stocks occurred in Litholic Neosols and Planosols, mainly due to agricultural use. P deficiency has been a limiting factor to agricultural productivity and, especially in the Agreste region of Pernambuco, where the main soil classes under natural cover have low levels of available and total P.

The analysis of tree growth rings has been used to spatially and temporally reconstruct geomorphological processes of the recent past in different environments. Trees have proven to be a reliable source of information in sites of difficult access where data are scarce or non-existent, as in the case of several volcanic gorges in central Mexico. This research was carried out in the Barranca Seca and Ojo Salado located northeast of the Pico de Orizaba volcano, where mass movements (landslides and rockfalls) and lahars were analyzed from samples of three conifers: Pinus hartwegii, Pinus patula and Abies religiosa. The number of tree disturbances associated with mass movement was 29 and the most common were: scars (45%) and Tangential Rows of Traumatic Resin Ducts or TRD (21%). In the case of lahars, the total number of disturbances was 70, and the most frequent were: TRD (61%) and scars (20%). The reconstruction of geomorphological processes was carried out from 1983 to 2018 in sectors A and B. In sector A, 11 rockfall events were dated. In sector B,  6 mass movements were identified  and 11 lahars. In addition, the historical data on hurricanes and tropical storms allowed us to identify the possible triggers of the geomorphological processes studied. The results obtained in this research provide information that may be relevant for the management of Pico de Orizaba National Park.