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

Contemporary history consistently confirms that earthquakes are a natural phenomenon of significant social impact. In reality, seismic episodes, especially in urban settings, trigger a series of alterations in everyday life that are extremely difficult to predict. This reality is far more severe in developing countries, characterized by financial structures that fall short to respond to major natural disasters.In the Caribbean region, studies to estimate socioeconomic losses resulting from the effects of natural phenomena are scrace, especially as related to earthquakes. This limitation restrains the proposals for risk mitigation plans for potential risk scenarios.This investigation examines the foreseen socioeconomic losses associated with a moderate-intensity earthquake affecting San Cristóbal City, western Cuba. On 23 January 1880, this town was affected by an earthquake of magnitude 6.0 Richter Scale and intensity of VIII degrees MSK, the 23 January 1880, which destroyed a large portion of the infrastructure of the time.  The study area has been at the core of several investigations in the 21st century; particularly, works have addressed geotechnical and tectonic aspects. Its history is sufficient to evolve to issues directly linked to local risk management, especially to estimate the socioeconomic impact under a hypothetic seismic scenario similar to the one experienced in 1880.The methodology used allows a simple quantitative expression of potential socioeconomic damage in an urban scenario facing moderate-intensity earthquakes, and uses the "urban block" as the basic information unit. This study assumes the unified definitions put forward in the meeting on Natural Disasters and Vulnerability Analysis held in 1979 as theoretical framework. The methodological bases set in this meeting laid the general guidelines and basic elements to consider in order to estimate the potential human losses and effects on economic activities, should a disaster occur. More recent works have reinforced the methodology, including aspects such as resilience, scientific and technological capacity of communities, and exposure time, among other elements.This work precisely defines seismic hazard levels according to local geological characteristics for return (T) periods of 100 and 475 years. Subsequently, household infrastructure damage levels are estimated using cadastral information and damage probability matrices elaborted by the National Center for Seismic Research of Cuba.This research focuses exclusively on the analysis of the household sector. The map of structural vulnerability contains a comprehensive database of essential attributes, such as type of structure, technical condition, number of inhabitants per type of structure, area occupied by each structure, and number of levels, among others. At the same time, it does not ignore the existence of other elements exposed, which can be perfectly considered for future research, including presence of public buildings (hospitals and schools), and even other public structures such as bridges.According to the current conditions of structural vulnerability and the estimated seismic hazard levels, 5,680 homes are expected to be damaged to some extent should  an earthquake similar to the one in 23 January 1880 occur. Likewise, and depending on the distribution of inhabitants in the urban space, 67 people are expected to become homeless, 59 may be hurt, and one person may die.Finally, the results obtained are considered to be consistent with the urban scenario studied and given the seismic hazard level in the Caribbean region, with the products obtained being a significant contribution for the local management of seismic risk.  Also, we consider that the methodology used serves as a model for other locations in the Caribbean area lacking basic estimates of potential damage for earthquake scenarios.

This paper reports the results of the project "Spatial Analysis of Landscape Configuration in Three Protection and Management Areas of Bogotá D.C.: Formulation of Integrated Landscape Management Guidelines for Improving Ecosystem Services". The project was carried out by the Biodiversity and Ecosystem Services research team at the Scientific Subdirectorate of Bogotá Botanical Garden. The project analyzes landscape elements and their potential linkages to strategic management areas related to the Fucha basin: the Bosque Oriental de Bogotá Forest Protection Reserve and the Priority Public Occupation Areas of the Franja de Adecuación, a buffer zone between the city and the eastern hills. The main objectives of the study were to identify the zones with less availability of urban green areas and show a increasing these areas could expand the spaces suitable for supplying cultural ecosystem services.The study followed the "Model for Studying Landscapes in Mountainous Zones" methodological approach. This model examines three landscape dimensions: verticality, horizontality, and transversality. Verticality addresses the multiple elements of the landscape along the river axis; horizontality analyzes the organization pattern and spatial configuration of the landscape; and transversality assesses the relationships between landscape elements by means of network and proximity analyses.Landscape elements of the Fucha river basin were analyzed using geographic information system tools and field work. The river has been channeled in the urban portion of its basin, where the main land-use is residential, especially along the riverbank in the middle basin, where large green areas and parks with recreational infrastructure exist. By contrast, the lower part of the urban basin harbors mainly industrial and commercial sectors, characterized by constructions standing very close to the canal, few green spaces, and presence of solid waste. In the upper middle basin, groups of street dwellers live along the canal, along with small settlements and self-construction neighborhoods. The upper basin corresponds to the forest reserve, where the vegetation cover includes shrublands, secondary forest and moorland, interspersed with patches of eucalyptus and pine plantations, and some acacias at the edge of the reserve.Landscape metrics were calculated and analyzed using the ArcGIS IndiFrag tool. These showed that 61% of the landscape elements correspond to urban areas or artificial surfaces, including commercial, residential, industrial, service and recreation areas, urban facilities and public spaces, canals, roads and railways. The remaining 39% corresponds to undeveloped areas such as urban green areas, water bodies (wetlands and rivers), unbuilt areas, and protected areas. Aggregation metrics showed that, although industrial uses occur in high density, they do not comprise a large number of buildings; therefore, they correspond to units located in a specific sector to the center of the urban basin. The most widely scattered elements are recreational spaces, urban facilities, and green areas, which show a low probability of occurrence is the landscape. The analysis of the expansion of urban green areas toward unoccupied areas revealed that a ~50% increase does not contribute to better meet the demand, given the current distribution of landscape elements in the urban basin.The connections with the lowest displacement costs between urban green areas were analyzed using the ArcGIS Matrix Green tool. Three critical sectors demanding attention were identified. The first is located in the lower basin, where small urban green areas are found with no connections with large green areas. The second sector is located in the middle basin, where a recently developed urban zone, along with a low availability of spaces for developing green areas were identified. The third is located in the northeast part of the middle basin, characterized by the lowest availability of green areas and no spaces available for their development. Finally, the upper part of the basin has been identified as an area that could supply cultural ecosystem services for the city, and potential access routes to that zone were identified by conditioning the connections with the slope.

Landsat imagery is one of the world’s longest-running and most widely used high-resolution collections. To make extensive use of this vast archive, platforms such as Google Earth Engine are necessary to reduce processing time and facilitate analyses. This study aimed to identify the Landsat scenes acquired between 1972 and 2017 covering the Mexican territory that are available through Google Earth Engine. The query was conducted on the Tier 1 raw scenes imagery collection (as these are the images with the lowest geospatial error between scenes) using a Javascript program in the Google Earth Engine platform. For each scene the query obtained information on the sensor, acquisition date, Landsat key (path/row), and cloudiness percentage over the Earth's surface. The information obtained was processed in R 3.5.1.Data acquisition took approximately 10 seconds, which shows the enormous processing power of Google Earth Engine. A total of 146 Landsat keys are necessary to encompass the entire Mexican territory with scenes acquired by the sensors Landsat 1-MSS through Landsat 3-MSS, and 134 keys are necessary for scenes recorded by sensors Landsat 4 MSS, TM and Landsat 8 OLI. We gathered a total of 89,649 scenes acquired between 1972 and 2017 covering the country. However, the number of scenes available for a given year varied widely; only 9 scenes were found for 1972 (0.06 images per path/row, on average), and 5403 for 2017 (40.32 images per path/row, on average). Over this period, the number of scenes available increased in those years when a new sensor started operations (e.g., 1984, 1999, and 2013) and when the Landsat archive was centralized by the USGS (in 1993). By contrast, the number of scenes available decreased in those years when a satellite ceased operations (e.g., 2012).The sensors that acquired the greatest number of scenes were Landsat 5 TM (38,897 scenes), followed by Landsat 7 ETM+ SLC-off (31,254) and Landsat 8, although with a significantly smaller number (12,796). In addition, almost half of scenes had less than 50% cloudiness over the Earth's surface, although when examined by path/row, it is clear that the driest areas of the country had a lower cloudiness vs. more humid zones. By design, Landsat images should cover the entire Earth's surface since 1972; however, for many areas of the world, including Mexico, the oldest scenes are usually very scarce for the following reasons: lack of reception and/or storage facilities in those regions; lack of proper storage practices; the scenes did not meet the quality standards for inclusion in the Tier-1 collection. Therefore, characterizing the collection of Landsat scenes actually available for the country contributes to understand the true possibilities that this archive provides for studying the Mexican territory.The results of this study are expected to guide future investigations using Landsat imagery to explore the Mexican territory, by providing information on the number of scenes actually available per year and their cloudiness condition. Finally, in order to foster the Google Earth Engine for image processing, a JavaScript routine to build annual mosaics of the highest quality Tier-1 surface reflectance data available was written and made available to any user. This routine is supplemented by a brief tutorial in Spanish that aims to provide an introduction to Google Earth Engine and promote its use in Spanish-speaking countries.

Conservation areas are surfaces that play an indispensable role for the human population by virtue of the multiple environmental and ecosystem services that benefit people and have a direct impact on long-term social, economic and environmental well-being. While conservation areas may or may not represent protected areas, a strategy that has been followed for their protection has been the decree of protected natural areas. This article analyzes the change in land use during the last 20 years that occurred in the Zone Subject to Ecological Conservation Cuxtal Reserve, located to the South of the city of Merida, Yucatan, Mexico. In 1993, the Reserve was decreed as a protected natural area of municipal competence with an extension of 10,757 hectares. However, it was until 2004 that it had a management program which was modified and updated in its entirety after 14 years in 2018. The Reserve, due to its location in the urban periphery of Mérida, faces constant pressure from the date of its creation due to real estate speculation and land use change caused by the expansion of the urban area and, to a lesser extent, by the natural growth of the eight population centers within the Reserve. The phenomenon of loss of forest cover and change of land use within the Reserve occurs mainly due to the lack of proper management and the lack of compliance with current regulations, which is expressed in the loss of conservation areas that the Reserve must protect. In this work, a temporary analysis is carried out to know the changes that the coverage occupied by the low deciduous forest, the herbaceous, shrub and tree secondary vegetation during the period from 1995 to 2015 has undergone. The temporal analysis included the manual interpretation of vegetation types and land use from aerial photos of 1995, 2005 INEGI orthophotos and SENTINEL 2015 satellite image. A digital geographic base was generated that was processed in the QGIS 2.18® and ARCGIS 10.6® programs, from which maps of the South of the municipality of Mérida and the Cuxtal Reserve were obtained. For each of the dates analyzed, the calculation of surfaces of the categories considered was performed and rates of change of vegetation and land use were obtained. The Reserve has lost vegetation cover due to urban expansion and irregularities in civil construction and housing developments. In 20 years, the low forest went from occupying 73.4% of the protected area to 43.9%, which means a loss of forest cover of 3,180.8 hectares. Urban expansion, infrastructure and services registered the largest increase within the Reserve, as it increased from 723.0 hectares in 1995 to 1,864.1 hectares in 2015, representing a growth of 1,141.1 hectares. The area occupied by secondary or recovering vegetation and to a lesser extent agricultural use and perennial crops increased from 2,142.8 hectares to 4,224.7 hectares, which means an increase of 2,081.9 hectares. In the period 1995 to 2005, the forest area of the Reserve decreased, since a loss of 1,566.3 hectares of low deciduous forest and secondary tree vegetation was estimated. From 2005 to 2015, 840.6 hectares were deforested. Housing use in the first period increased by 347.7 hectares and in the second the increase was 1,141.1 hectares. It is clear that the Reserve has not had due compliance with current regulations as it has not been possible to meet the proposed conservation objectives for the protected natural area. There are still vegetation relics that add 3,000 hectares of deciduous forest that have changed to vegetation in a state of recovery of less than 10 years. It is necessary that urban public policies and instruments for regulating land use recognize that the Cuxtal Reserve is the most important water source for the metropolitan area of Mérida, which has a vegetation cover that contributes to the conservation of regional biodiversity and includes populations in vulnerable situations. It is essential to carry out the timely monitoring of the Reserve’s management program, generate sustainable productive alternatives for local residents, as well as to have greater efficiency and effectiveness in the regulation of the land use of the Cuxtal Reserve and areas of influence. 

This research seeks to identify groundwater recharge and discharge areas in the administrative aquifers of the Ayuquila-Armeria river basin in the states of Jalisco and Colima, Mexico. The Ayuquila-Armeria river basin is one of the 15 most important of the 100 rivers running across the Pacific slope, and is among the 43 most important rivers at the country level. The regional climate is warm-humid in lowlands and subhumid temperate in highlands, with a summer rainy season (June to October) and a dry season the rest of the year. The basin shows a striking relief: from sea level to 4260 m a.s.l. at Nevado de Colima. The identification of these areas was based on a multi-criteria analysis of surface indicators of recharge and discharge areas supported by the flow systems theory (FST). This allows a systemic view of the environment, integrating various elements of nature, in addition to acknowledging groundwater and geological agent that causes a wide variety of processes and manifestations on the surface. The integration of Geographic Information Systems (GIS) and the Multi-Criteria Analysis (MCA) made possible to evaluate the potential recharge/ discharge at the regional level by analyzing physical variables such as lithology, soil, relief, slope, vegetation, precipitation, and a topographic humidity index. In the study area, the territory with high recharge potential ranges from 21% to 80%; the area with low and very low recharge potential, from 4% to 30%. The main potential recharge areas are located in the upper portion of mid-elevation and low mountains covered by pine-oak, oak, and tropical deciduous forests, and grasslands, and to a lesser extent, fir and mountain cloud forests. Soil types include mainly Regosol, Leptosol, Cambisol, Luvisol, Andosol, Umbrisol, and Phaeozem in slopes of 15%-30% covering units of rhyolitic tuff, andesite-basalt, andesite, lahar-pyroclastic rock, granite-granite diorite, and limestone. These areas are located mainly in Sierra de Cacoma-Manantl, Sierra Verde, Sierra de Quila, Sierra de Tapalpa, and the Nevado de Colima volcanic complex. For its part, discharge areas are found mainly in the coastal plains of Jalisco and Colima, associated with Calcisol, Arenosol, Fluvisol, Planosol, Gleysol, Solonchak, and Vertisol soils, and with with halophytic-hydrophytic grassland, bulrush, and mangrove vegetation. These are located in inland-lake areas in San Marcos, Sayula, and Zapotlán. Other discharge areas are the plains and intermontane valleys of Union de Tula and Autlán-El Grullo, as well as the bottom of V-valleys in certain areas of the basin. These can act as natural hydraulic boundaries of flow systems, limiting the amount of groundwater in each zone. The lateral alternation of recharge and discharge areas implies that the water recharged in a particular region may flow to a number of discharge areas, i.e., the water discharged in a given region may come from different regions. The above has important implications in the estimation of the availability estimated from the water balance, since groundwater may flow to more than one discharge area within the same “administrative” aquifer. This type of studies are a first approach providing innovative evidence to the systemic study of groundwater, i.e., the recharge-discharge areas. Their application positively supplements the results of the water balance used in the official evaluation of groundwater availability in Mexico. 

The elaboration of updated land-use maps in irrigated agriculture regions is essential for the monitoring of production as well as for the application of hydrological or other models. Due to cost and time constraints, remote sensing and Geographic Information Systems are valuable tools for this purpose. This study evaluated the applicability of an index that combines satellite imagery for mapping land uses, focusing on irrigated agriculture lands in the Huaquechula sub-basin, state of Puebla, Mexico. The study area is characterized by a complex array of irrigated crops with broad spatial variations and succession of crops throughout the year, making it difficult to delimit irrigated agricultural land. Addressing this complexity requires the application of methodologies to identify the presence/ absence of irrigated crops throughout the year. As an alternative to the delimitation of land uses, we used Landsat 8 images for three dates: 23 January 2017, 19 August 2017, and 23 November 2017. For each image, we obtained the Normalized Difference Vegetation Index (NDVI) with the program ERDAS Imagine 2014; the indices for the three dates were combined to make a Red-Green-Blue NDVI image (RGB-NDVI). The spectral signatures for land uses and vegetation identified with the Google Earth program were obtained for this image. A total of 250 random points were located with ArcGis 10.4 and the Hawth's Analysis Tools extension to check the correspondence between of land uses in the map and real uses; 155 selected points were located in natural vegetation; 32, in irrigated agriculture; 52, in agriculture; 11, in urban use; and 1, in a water body. The map obtained from satellite images was compared with the Inegi Map on Land Use and Vegetation, Series VI, considered to be the most up-to-date official map in Mexico. Maps were evaluated using confusion, omission and commission matrices, and overall user and producer reliability indices. The values obtained for confusion matrices indicate that the map produced from satellite images was better at delimiting land uses compared to the Inegi Map of Vegetation and Land Use, Series VI. For the irrigated agricultural land use, the primary delimitation objective, the map produced was 81.82% reliable for the user (probability of selecting a random point in one category that really belongs to that category) for irrigated land, versus 78.57% for the Series VI map. The produced map also yielded a higher reliability for the producer, relative to the reference map (84.38% vs. 61.11%, respectively), as well as less omission errors (18.18% versus 21.43%) and commission errors (15.63% versus 38.89%). We concluded that the map generated from Landsat 8 images using the RGB-NDVI index, provided a higher reliability than the map of Land Use and Vegetation, Series VI. For regions with high spatial and temporal complexity of crops, such as the study area, the procedure involving the RGB-NDVI index is an expeditious low-cost alternative for the continuous updating of land-use maps. The map obtained here is useful for monitoring changes in land use, and as an input for hydrological models, such as the Soil and Water Assessment Tool (SWAT), to estimate the effects of agricultural practices on surface streams.

Current and future studies on precipitation are essential for designing space-planning policies, being particularly relevant in semi-arid regions. The south of the Pampas region is an agricultural area where rainfed crops occupy the largest area. This area, located in a transition zone between temperate and semi-arid climates, is characterized by the occurrence of the most severe and lasting extreme events of the whole region. Therefore, knowledge of their current and future seasonal and annual rainfall regimes, along with their spatial-temporal changes, is essential to ensure the economic and environmental sustainability of this area. In this context, this study analyzed rainfall variability in six periods defined as recent past (1977-1997), present (1998-2018), near future (2019-2039), and distant future (2079-2099). The latter two were identified considering two greenhouse gas (GHG) concentration scenarios. We worked with on-site data from six weather stations and those from the Community Climate System Model version 4 (CCSM4) climate model.In a first instance, the period 1960-2010 was analyzed to evaluate whether both data sources were statistically equivalent. To this end, mean values and standard deviations were calculated, followed by Fisher and Kolmogorov-Smirnov tests. After demonstrating that the datasets were statistically homogeneous, the annual, seasonal, and spatial patterns of each weather station were compared for the periods previously defined. We analyzed the mean values, homogeneity, trends, and spatial behavior. The trend was evaluated using the Mann-Kendall test, and the time series were analyzed with an empirical probability study. In addition, the spatial-temporal variation was explored applying the Kriging interpolation method.The study area showed significant changes between the periods considered. These included changes in mean values. For example, the north showed four periods with different precipitation levels, while only three were observed in the south. In all cases, we found a highly significant statistical significance (Fisher's statistic < 0.001), considering an α of 5 %.For its part, the analysis of trends showed an increase of annual precipitation in the distant future in the north. At Coronel Suárez (north), for example, annual precipitation figures were 864 and 1093 mm for the present and the distant future, respectively. However, the south of the study area showed a @ 50 mm decrease, but with an increase in the frequency of rainy years. This was evident, for example, in the Hilario Ascasobi station, showing a decreasing trend with annual precipitation figures ranging from 520 mm in the past to 442 mm in the distant future (GHG concentration of 4.5).The region showed a marked seasonality in future precipitation estimates. The highest amounts occur during summer and spring, being intermediate in autumn and lowest in winter. This same pattern was observed across most of the study area, except for Hilario Ascasobi (located to the south), where summer was the season with the lowest precipitation levels in the past and present. However, the seasonal pattern in the near and distant future was similar to the pattern in the rest of the study area. Autumn was the only season when precipitation increased in the south of the study area (@ 30 mm).The importance of assessing past, present, and future changes in precipitation lies in their direct relationship with productive activities in the study area. The inter-annual and seasonal variability of precipitation given the different growth stages of rainfed crops, while exposing the population to flood and drought risks, thus affecting their access to the resource. Therefore, these results will set the grounds for public and private decision-making social stakeholders to have a useful tool for sustainable land-use management.

From 2010 to 2016, Rebecca Solnit published three atlases of three different cities: San Francisco, New Orleans and New York. Apart from being interesting examples of the possibilities of the relations of Cartography, Literary Studies, and other disciplines, these books state an apparent paradox linked to the decision of making maps from the belief that it is an impossible task because it is infinite, unfathomable, and unstoppable. This article shows how these atlases are iconotexts that solve this contradiction considering that a place is a texture that depends of the words, the images, the affects, the memories, the perceptions associated to it, in other words, that it is a product both of human relations and symbolic representations. The article also shows some of the strategies used in these collections to account for this texture, for instance, the use of a rhetoric similar to that of metaphors, related to their intermedial character and the presence of different materials, such as, literary, cartographic, photographic and pictorial; the bifurcation of perspectives from several authors; or the advantage of anachronic, complex and hypothetical narratives to produce public histories. Solnit’s atlases appropriate Cartography, aesthetically and politically, and make evident that it is a creative, constructive, and restorative practice.First, the article explains notions such as space, place, texture of the place, iconotextuality, and intermediality, central to understanding these atlases. Then, it analyzes each one of them generally, from a selection of their maps and emphasizing their common features. Regarding the atlas of San Francisco, the essay underlines the advantage of being a collection of maps created by the collaboration of people coming from several fields, such as, Cartography, Literature, Photography, Botanic, and History. The notion of “anachronic public history” is presented to explain the temporal leaps of the different sections and the capacity of saving from oblivion certain life histories with what is called a “restorative epistemology”. Regarding the atlas of New Orleans, the fluidity of the city is emphasized along with the importance that cultural memory had to rescue it from hurricane Katrina. Special attention is payed to the materiality of the atlases as books. Solnit prefers maps on paper to the virtual materiality of the digital maps. The approach to the atlas of New York is done from its fragmental character and the importance that the conservation of languages has acquired there. It also underlines how fiction is able to present reality in clever and understandable ways, through a map that pictures New York as one of the Caribbean isles.The comparisons made throughout the essay show how Solnit’s atlases do not try to account for the totality of the places, their truth, but for the multiplicity of perspectives, times, topics and materials that conform their texture and complexity.

Earth Observation Satellites have been acquiring images across the entire world for decades. However, a technological lag has prevented analyzing the vast amount of satellite data currently available. Until recently, most studies focused on relatively small regions and short periods of time, but the potential of this imagery allows addressing issues at global scale and spanning long periods of time. Google Earth Engine is an innovative tool that facilitates geospatial analyses using cloud processing and data archives. It thus provides an interesting alternative to solve the technological lag, and hence be able to analyze the large files of satellite data currently available.