R. Corona , L. Galicia , J.L. Palacio-Prieto , Matias Bürgi , Anna Hersperger
The tropical dry forest is an ecosystem that is undergoing rapid changes. Although global driving forces behind these changes have been addressed at a local scale, spatio-temporal dynamics are still largely unknown. The main objective of this study was to identify the causes governing the dynamics of changes in land use and land cover in the tropical dry forest in two municipalities in Southern México. Satellite imagery and air photographs were used in a gis context to produce maps of land use and land cover for 1985, 1995 and 2006. A number of statistical methods (Markov chains, general lineal models and regression tree analysis) were applied to identify the proximate and the underlying causes of deforestation, agriculture being the most important one. When agriculture is mainly for self consumption, topographic factors determine its location. Increasing job opportunities in the tourism sector has resulted in the abandonment of agricultural land; consequently, the forest has recovered. Different studies have examined the dynamics of local deforestation and its driving forces in México; however, this study considered both spatial and temporal elements in order to identify the most important underlying driving forces of deforestation and its dynamics at local scale, and also compared two neighboring municipalities.
{"title":"Local deforestation patterns and driving forces in a tropical dry forest in two municipalities of southern Oaxaca, Mexico (1985-2006))","authors":"R. Corona , L. Galicia , J.L. Palacio-Prieto , Matias Bürgi , Anna Hersperger","doi":"10.14350/rig.50918","DOIUrl":"https://doi.org/10.14350/rig.50918","url":null,"abstract":"<div><p>The tropical dry forest is an ecosystem that is undergoing rapid changes. Although global driving forces behind these changes have been addressed at a local scale, spatio-temporal dynamics are still largely unknown. The main objective of this study was to identify the causes governing the dynamics of changes in land use and land cover in the tropical dry forest in two municipalities in Southern México. Satellite imagery and air photographs were used in a <span>gis</span> context to produce maps of land use and land cover for 1985, 1995 and 2006. A number of statistical methods (Markov chains, general lineal models and regression tree analysis) were applied to identify the proximate and the underlying causes of deforestation, agriculture being the most important one. When agriculture is mainly for self consumption, topographic factors determine its location. Increasing job opportunities in the tourism sector has resulted in the abandonment of agricultural land; consequently, the forest has recovered. Different studies have examined the dynamics of local deforestation and its driving forces in México; however, this study considered both spatial and temporal elements in order to identify the most important underlying driving forces of deforestation and its dynamics at local scale, and also compared two neighboring municipalities.<span></span></p></div>","PeriodicalId":39866,"journal":{"name":"Investigaciones Geograficas","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.14350/rig.50918","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91684003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Exposición fotográfica: “La fotografía aérea de la Fundación ICA”, Instituto de Geografía, Universidad Nacional Autónoma de México, Ciudad Universitaria, Cd. Mx., agosto-noviembre 2016","authors":"Héctor Mendoza Vargas","doi":"10.14350/rig.57887","DOIUrl":"10.14350/rig.57887","url":null,"abstract":"","PeriodicalId":39866,"journal":{"name":"Investigaciones Geograficas","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.14350/rig.57887","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130332314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The environmental characteristics of the upper Lerma river basin and the accessibility to the Balsas midelevation basin from its southern margins facilitated the settlement of different human groups since the early history of Mesoamerica. The mountain passes of Atlatlahuca were one of the most strategic ancient routes that communicated these basins, since no steep slopes had to be walked to descend or climb up over 700 meters, from the pre-Hispanic village of Atlatlahuca to the valley of Tenancingo. So far, the relevance of these mountain passes has not been recognized by the studies focused on the territorial evolution of the upper Lerma basin and neighboring regions.
The fifteenth and sixteenth centuries were the time when the strategic quality of these mountain passes reached its peak, first under the rule of the Matlatzinca federation, and later by the Aztecs and their allies. Historical approaches to the territorial evolution of the upper Lerma basin have focused on the lacustrine area that used to cover the lowlands; in our view, this approach is insufficient to explain the territorial evolution of this basin. An approach beyond watersheds or contemporary administrative limits, encompassing broader temporal and spatial scales, has revealed the strategic character of these mountain passes. Understanding these territorial priorities also requires to acknowledge the changes in landscape of the main historical settlements that controlled the access to these mountain passes: Tenango and Atlatlahuca. Our goal is not to outline a definitive version of this territorial structure; instead, we want to set the grounds for a discussion from a geographical viewpoint ranging several historic stages.
Our explanation is based on the principles of contemporary Cultural Geography and their application to areas of Mesoamerican tradition, and was derived from a continuous temporal analysis encompassing the Mesoamerican Post-Classic period and most of the 16th century. The cultural approach in geography aims to understand the thoughts and priorities of local inhabitants within their territorial context in different historical stages. In our case, the territorial structure we aim to explain involves physical changes in landscape, as well as changes in land use or in the way the environment is perceived according to different cultural practices.
In physical and biological terms, our case of study is located in the transition zone between Nearctic and Neotropical regions in southern-central Mexico. The mountain passes of Atlatlahuca descend from around 2 700 m a.s.l. to approximately 2 000 m in the valley of Tenancingo within less than 15 kilometers. The physical characteristics that assured a broad range of supplies and the control of vast territories. In our cultural reconstruction, besides physical and biological conditions, it is also necessary to understand the concept of altepetl: a nahuatl word that literally means “wa
{"title":"Los puertos de montaña de Atlatlahuca: un espacio estratégico en el siglo XVI","authors":"Gustavo Garza Merodio , Federico Fernández Christlieb","doi":"10.14350/rig.53179","DOIUrl":"10.14350/rig.53179","url":null,"abstract":"<div><p>The environmental characteristics of the upper Lerma river basin and the accessibility to the Balsas midelevation basin from its southern margins facilitated the settlement of different human groups since the early history of Mesoamerica. The mountain passes of Atlatlahuca were one of the most strategic ancient routes that communicated these basins, since no steep slopes had to be walked to descend or climb up over 700 meters, from the pre-Hispanic village of Atlatlahuca to the valley of Tenancingo. So far, the relevance of these mountain passes has not been recognized by the studies focused on the territorial evolution of the upper Lerma basin and neighboring regions.</p><p>The fifteenth and sixteenth centuries were the time when the strategic quality of these mountain passes reached its peak, first under the rule of the Matlatzinca federation, and later by the Aztecs and their allies. Historical approaches to the territorial evolution of the upper Lerma basin have focused on the lacustrine area that used to cover<span></span> the lowlands; in our view, this approach is insufficient to explain the territorial evolution of this basin. An approach beyond watersheds or contemporary administrative limits, encompassing broader temporal and spatial scales, has revealed the strategic character of these mountain passes. Understanding these territorial priorities also requires to acknowledge the changes in landscape of the main historical settlements that controlled the access to these mountain passes: Tenango and Atlatlahuca. Our goal is not to outline a definitive version of this territorial structure; instead, we want to set the grounds for a discussion from a geographical viewpoint ranging several historic stages.</p><p>Our explanation is based on the principles of contemporary Cultural Geography and their application to areas of Mesoamerican tradition, and was derived from a continuous temporal analysis encompassing the Mesoamerican Post-Classic period and most of the 16th century. The cultural approach in geography aims to understand the thoughts and priorities of local inhabitants within their territorial context in different historical stages. In our case, the territorial structure we aim to explain involves physical changes in landscape, as well as changes in land use or in the way the environment is perceived according to different cultural practices.</p><p>In physical and biological terms, our case of study is located in the transition zone between Nearctic and Neotropical regions in southern-central Mexico. The mountain passes of Atlatlahuca descend from around 2 700 m a.s.l. to approximately 2 000 m in the valley of Tenancingo within less than 15 kilometers. The physical characteristics that assured a broad range of supplies and the control of vast territories. In our cultural reconstruction, besides physical and biological conditions, it is also necessary to understand the concept of altepetl: a nahuatl word that literally means “wa","PeriodicalId":39866,"journal":{"name":"Investigaciones Geograficas","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.14350/rig.53179","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125807709","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Luis Alberto Salinas Arreortua, Ana Melisa Pardo Montaño
{"title":"Ciclo de conferencias “Vivienda y migración. Una mirada desde la geografía crítica”, Instituto de Geografía, Universidad Nacional Autónoma de México, Ciudad Universitaria, Cd. Mx., 22 y 26 de septiembre de 2016","authors":"Luis Alberto Salinas Arreortua, Ana Melisa Pardo Montaño","doi":"10.14350/rig.57886","DOIUrl":"10.14350/rig.57886","url":null,"abstract":"","PeriodicalId":39866,"journal":{"name":"Investigaciones Geograficas","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.14350/rig.57886","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128898003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Marco Antonio Pablo Pablo , José Ramón Hernández Santana
Environmental conservation depends largely on the appropriate management and rational use of natural resources. The assessment of natural landscapes and their suitability for human occupation is key to ensure optimal resource use. The criteria for establishing land-use potentials vary according to the type of activity concerned. For example, in determining the most suitable areas for growing grapes in Cuyo, Argentina, Valpreda (2005) focused on topography, soil quality and water availability, whereas in their study on the oil-producing region of northern Chiapas, Mexico, Bollo et al. (2010) applied markedly different criteria. Soil components and their variability were key to the multi-purpose study of Ovalles and Núñez (1994), while morphometric criteria have been used by Bocco et al. (2010) on farming; for cattle raising, Travieso-Bello et al. (2013) added soil quality and moisture, similar to Rodríguez-Gallego, et al. (2012). In the state of Oaxaca, scientific studies on the feasibility of human activity in different natural landscapes are yet to be undertaken. This study assesses the natural landscapes and resources of the Río Grande drainage basin aimed at establishing optimal locations for agriculture, livestock farming, forestry, wildlife conservation and their combinations. Following the FAO studies (1976, 1993), geomorphological and morphoclimatic systems have been considered as landscape units for analysis. The methodology was adapted from the following studies: The Revised Universal Soil Loss Equation (Ouyang, 2002); an estimate of soil pH based on Landsat imagery (López-Granados et al., 2005); a calculation of potential livestock carrying capacity (lcc) (Semarnat, 2003; Vergara and Ortiz-Espinoza, 2010); and a land use and vegetation cover analysis for forestry suitability and the potential distribution of two cat species (Lynx rufus and Panthera onca) (Chávez y Ceballos, 2006; Medellín-Legorreta and Bárcenas, 2009; Semarnat 2010; Semarnat-Conanp, 2010). Our analysis shows that 15.6% of the total area (152 km2) has optimal conditions for agriculture; 12.5% (122 km2) for livestock farming; 6.5% (64 km2) for conservational agricultural activities; 11% (108 km2) for conservational livestock production; 11.7% (114 km2) for conservational forestry activities; and 167 km2 (17.1%) for conservation alone. Finally, 25.6% of the territory (250 km2) is suitable (but not optimal) for agriculture, conservational livestock activities and conservation. This methodology based on physical-geographical landscapes allows to identify vocational land-use patterns across the Río Grande drainage basin as a means to optimize the management of the various economic activities. The identification and evaluation of productive and conse
环境保护在很大程度上取决于对自然资源的适当管理和合理利用。自然景观的评价及其对人类活动的适宜性是确保资源优化利用的关键。确定土地利用潜力的标准因有关活动的类型而异。例如，Valpreda(2005)在确定阿根廷Cuyo最适合种植葡萄的地区时，侧重于地形、土壤质量和水分供应，而Bollo等人(2010)在对墨西哥恰帕斯北部产油区的研究中采用了明显不同的标准。土壤成分及其变异是Ovalles和Núñez(1994)多用途研究的关键，而Bocco等人(2010)在农业方面使用了形态计量学标准;对于养牛，Travieso-Bello等人(2013)添加了土壤质量和水分，类似于Rodríguez-Gallego等人(2012)。在瓦哈卡州，关于人类活动在不同自然景观中的可行性的科学研究尚未开展。本研究评估了Río大流域的自然景观和资源，旨在建立农业、畜牧业、林业、野生动物保护及其组合的最佳位置。根据粮农组织的研究(1976年、1993年)，地貌和形态气候系统已被视为分析的景观单位。该方法改编自以下研究:修订的通用土壤流失方程(欧阳，2002);根据陆地卫星图像估算土壤pH值(López-Granados等人，2005年);牲畜潜在承载能力(lcc)的计算(Semarnat, 2003年;Vergara and ortizs - espinoza, 2010);对两种猫科动物(猞猁和美洲豹)的森林适宜性和潜在分布进行了土地利用和植被覆盖分析(Chávez y Ceballos, 2006;Medellín-Legorreta和Bárcenas, 2009;Semarnat 2010;Semarnat-Conanp, 2010)。分析表明，该区15.6%的面积(152 km2)具有最佳农业发展条件;12.5%(122平方公里)用于畜牧业;6.5%(64平方公里)用于保护性农业活动;11%(108平方公里)用于保护性畜牧业生产;11.7%(114平方公里)用于保护性林业活动;仅保护区面积167平方公里(17.1%)。最后，25.6%的领土(250平方公里)适合(但不是最佳的)农业，保护性畜牧业活动和保护。这种基于自然地理景观的方法可以识别整个Río大流域的职业土地利用模式，作为优化各种经济活动管理的一种手段。确定和评价河流流域各种地貌和形态气候系统的生产和保护潜力是由两个基本的地理原则支配的:用整体方法对自然和地理限制进行空间分析，以及将自然资源绘制成地图，作为领土分析和制定最佳管理战略的投入。这两个原则都允许在自然倾向和最佳土地利用的放大镜下建立部门规划。同样的工作也可以进行，以使其他瓦哈坎地区以及其他区域和国家项目受益。
{"title":"Evaluación de la aptitud natural de los paisajes físico-geográficos en la cuenca del río Grande, Oaxaca, México","authors":"Marco Antonio Pablo Pablo , José Ramón Hernández Santana","doi":"10.14350/rig.49203","DOIUrl":"https://doi.org/10.14350/rig.49203","url":null,"abstract":"<div><p>Environmental conservation depends largely on the appropriate management and rational use of natural resources. The assessment of natural landscapes and their suitability for human occupation is key to ensure optimal resource use. The criteria for establishing land-use potentials vary according to the type of activity concerned. For example, in determining the most suitable areas for growing grapes in Cuyo, Argentina, Valpreda (2005) focused on topography, soil quality and water availability, whereas in their study on the oil-producing region of northern Chiapas, Mexico, Bollo <em>et al.</em> (2010) applied markedly different criteria. Soil components and their variability were key to the multi-purpose study of Ovalles and Núñez (1994), while morphometric criteria have been used by Bocco <em>et al.</em> (2010) on farming; for cattle raising, Travieso-Bello <em>et al.</em> (2013) added soil quality and moisture, similar to Rodríguez-Gallego, <em>et al.</em> (2012). In the state of Oaxaca, scientific studies on the feasibility of human activity in different natural landscapes are yet to be undertaken. This study assesses the natural landscapes and resources of the Río Grande drainage basin aimed at establishing optimal locations for agriculture, livestock farming, forestry, wildlife conservation and their combinations. Following the FAO studies (1976, 1993), geomorphological and morphoclimatic systems have been considered as landscape units for analysis. The methodology was adapted from the following studies: The Revised Universal Soil Loss Equation (Ouyang, 2002); an estimate of soil pH based on Landsat imagery (López-Granados <em>et al.,</em> 2005); a calculation of potential livestock carrying capacity (<span>lcc</span>) (Semarnat, 2003; Vergara and Ortiz-Espinoza, 2010); and a land use and vegetation cover analysis for forestry suitability and the potential distribution of two cat species (<em>Lynx rufus</em> and <em>Panthera onca</em>) (Chávez y Ceballos, 2006; Medellín-Legorreta and Bárcenas, 2009; Semarnat 2010; Semarnat-Conanp, 2010). Our analysis shows that 15.6% of the total area (152<!--> <!-->km<sup>2</sup>) has optimal conditions for agriculture; 12.5% (122<!--> <!-->km<sup>2</sup>) for livestock farming; 6.5% (64<!--> <!-->km<sup>2</sup>) for conservational agricultural activities; 11% (108<!--> <!-->km<sup>2</sup>) for conservational livestock production; 11.7% (114<!--> <!-->km<sup>2</sup>) for conservational forestry activities; and 167<!--> <!-->km<sup>2</sup> (17.1%) for conservation alone. Finally, 25.6% of the territory (250<!--> <!-->km<sup>2</sup>) is suitable (but not optimal) for agriculture, conservational livestock activities and conservation. This methodology based on physical-geographical landscapes allows to identify vocational land-use patterns across the Río Grande drainage basin as a means to optimize the management of the various economic activities. The identification and evaluation of productive and conse","PeriodicalId":39866,"journal":{"name":"Investigaciones Geograficas","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.14350/rig.49203","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90016931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The aim of this paper is to ascertain the territorial dimension of the fishing economy in Guaymas, Mexico. The geographical studies addressing this economic activity in Mexico and published in the last decades are scarce. For this reason, this research work is particularly important, as it outlines the fishery activities in one of the most active sea-ports of northwest Mexico, from a territorial perspective. The first part of this article explains why and how Economic Geography addresses fishery activities and which methodology we pursued to carry out this investigation, based on studies carried out by geographers, particularly in France and Argentina. Then the paper describes the natural conditions prevailing in the Gulf of California (also known as Sea of Cortez), a large inlet of the eastern Pacific Ocean that is rich in marine resources and where most of the main national fisheries are located. Guaymas is one of the most important sea ports located along the Gulf of California for its long fishing history and the variety of fishing species captured. This port, located in the southern coast of the state of Sonora, is a mediumsized city with a little over 100 thousand inhabitants; a considerable proportion of the local labor force works in the fishery sector and associated industries. Today, the fishery sector in Guaymas is characterized by a large number of artisan fishermen, a prominent fleet preciand the regular practise of illegal catching. This port is the seat of large enterprises, such as Ocean Garden, involved in the industrialization of catches (basically fish oil and fish meal) and their further commercialization within and outside Mexico. Two commercially important species have played a key role in the evolution and outline of the current territorial structure of fisheries in Guaymas. One is shrimp, with a fishery that recorded a boom during 1970-1990, bringing along a number of benefits for local fishermen in Sonora. This fishery declined in subsequent years, mostly due to the overexploitation of shrimp banks and the incorporation of private capital investors to the local shrimp economy; the downward trend of this fishery in Guaymas is still evident. For its part, sardine, particularly Monterey sardine, is the other important species in the economy in this sea port. It is captured to meet the demand for oil and fish meal. Since the 1960s, Guaymas has become Mexico's sardine port, as this species is at the core of the territorial structure of fisheries in this city. A significant volume of sardine biomass has been captured in the last 50 years in Guaymas, resulting in the overexploitation of the resource which, along with water pollution, has led to the collapse of sardine populations. Nonetheless, stakeholders and authorities involved this fishery have obtained the international certification of local sardine catches. There are several enterprises located in Guaymas dedicated to the industrial processing of sard
{"title":"Estructura territorial de la actividad pesquera en Guaymas, Sonora","authors":"Gonzalo Yurkievich , Álvaro Sánchez Crispín","doi":"10.14350/rig.49937","DOIUrl":"10.14350/rig.49937","url":null,"abstract":"<div><p>The aim of this paper is to ascertain the territorial dimension of the fishing economy in Guaymas, Mexico. The geographical studies addressing this economic activity in Mexico and published in the last decades are scarce. For this reason, this research work is particularly important, as it outlines the fishery activities in one of the most active sea-ports of northwest Mexico, from a territorial perspective. The first part of this article explains why and how Economic Geography addresses fishery activities and which methodology we pursued to carry out this investigation, based on studies carried out by geographers, particularly in France and Argentina. Then the paper describes the natural conditions prevailing in the Gulf of California (also known as Sea of Cortez), a large inlet of the eastern Pacific Ocean that is rich in marine resources and where most of the main national fisheries are located.<span></span> Guaymas is one of the most important sea ports located along the Gulf of California for its long fishing history and the variety of fishing species captured. This port, located in the southern coast of the state of Sonora, is a mediumsized city with a little over 100 thousand inhabitants; a considerable proportion of the local labor force works in the fishery sector and associated industries. Today, the fishery sector in Guaymas is characterized by a large number of artisan fishermen, a prominent fleet preciand the regular practise of illegal catching. This port is the seat of large enterprises, such as Ocean Garden, involved in the industrialization of catches (basically fish oil and fish meal) and their further commercialization within and outside Mexico. Two commercially important species have played a key role in the evolution and outline of the current territorial structure of fisheries in Guaymas. One is shrimp, with a fishery that recorded a boom during 1970-1990, bringing along a number of benefits for local fishermen in Sonora. This fishery declined in subsequent years, mostly due to the overexploitation of shrimp banks and the incorporation of private capital investors to the local shrimp economy; the downward trend of this fishery in Guaymas is still evident. For its part, sardine, particularly Monterey sardine, is the other important species in the economy in this sea port. It is captured to meet the demand for oil and fish meal. Since the 1960s, Guaymas has become Mexico's sardine port, as this species is at the core of the territorial structure of fisheries in this city. A significant volume of sardine biomass has been captured in the last 50 years in Guaymas, resulting in the overexploitation of the resource which, along with water pollution, has led to the collapse of sardine populations. Nonetheless, stakeholders and authorities involved this fishery have obtained the international certification of local sardine catches. There are several enterprises located in Guaymas dedicated to the industrial processing of sard","PeriodicalId":39866,"journal":{"name":"Investigaciones Geograficas","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.14350/rig.49937","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124905604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alexis Ordaz Hernández , José Ramón Hernández Santana , Elmidio Estévez Cruz , Carlos Díaz Guanche , Ana Patricia Méndez Linares
Due to their geological nature, beaches are susceptible to changes over a relatively short period of time. Composed mainly of recently formed rocks, the scarcely consolidated structure of the substrate makes beaches vulnerable to the action of waves, tides, currents, wind, changes in sea level and human activity. Beach dynamics is marked by different degrees of fragility. In tropical regions, especially in the Caribbean, extreme hydro-meteorological phenomena such as hurricanes and cold fronts associated with extra-tropical storms significantly accelerate the erosion and accretion processes along the coast. The geographical location of the Cuban archipelago, at the margins of the Tropic of Cancer (its northernmost latitude is 27°17’ N), makes it susceptible to the combined action of hurricanes (between June and November) and cold fronts (between November and March). This very fact makes the study of coastal morphodynamic changes a subject of the utmost importance in sustainable-development projects and environmental planning, including the preservation of coastal natural resources. In Cuba, several authors have reported a coastal retreat of 1 to 3 m per year in western beaches, as well as an average loss of sand of about 50 000 m3 per year in the famous Varadero beach. The latter case is mainly due to the extraction of sand from the underwater platform between 1968 and 1978 for construction purposes. This paper addresses the morphodynamic processes taking place at Bailén beach, on the southwestern Cuban coast, as observed during a 10-year period, from 2003 to 2013. Transversal topographic measurements were taken at the beachfront and coastline at 15 observation stations along 2 140 m of beach in 2007, 2010 and 2013. These measurements were then compared to the data available for 2003. Estimated volumes of accreted and eroded sand for the period 2003-2007 indicate remarkable changes in beach morphology and evidence the vulnerability of coastal systems to extreme events, such as those unleashed by hurricane Ivan in 2004. The most important morphological changes observed included an increase of 0.20 to 0.50 m in dune height in some cases, and a decrease in others in the order of 0.15 to 0.40 m. Finally, granulometric tests were conducted to establish the spatial and temporal variations in the diameter of sand grains. To the north side of the beach, the maximum recession rate was 2.0 m per year, and sand grains were larger. Both measurements are indicative of the impact of buildings constructed at the front side of dunes and the beach berm on beach morphology. In the southern sector, on the other hand, the maximum accretion reached 8.0 m per year, whereas the average value was 2.3 m per year. During the 10 years of analysis, beach recovery has been characterized by a low resilience to the impact of hurricanes and other meteorological events. There is a clear spatial correlation between the inadequate location of buildings less than
由于其地质性质，海滩在相对较短的时间内容易发生变化。主要由新近形成的岩石组成，基材的结构几乎没有固结，这使得海滩容易受到波浪、潮汐、海流、风、海平面变化和人类活动的影响。海滩动态的特点是不同程度的脆弱性。在热带地区，特别是加勒比地区，与热带外风暴有关的飓风和冷锋等极端水文气象现象显著加速了沿海的侵蚀和增积过程。古巴群岛的地理位置位于北回归线的边缘(其最北纬为27°17′N)，使其容易受到飓风(6月至11月)和冷锋(11月至3月)的共同作用。这一事实使得对沿海形态动力学变化的研究成为可持续发展项目和环境规划(包括保护沿海自然资源)中最重要的课题。在古巴，几位作者报告说，西部海滩每年后退1至3米，著名的巴拉德罗海滩每年平均损失约5万立方米的沙子。后一种情况主要是由于1968年至1978年期间为建设目的从水下平台提取沙子。本文讨论了2003年至2013年10年期间在古巴西南海岸的bail海滩上观察到的形态动力学过程。分别于2007年、2010年和2013年在海滨和海岸线2 140 m的15个观测站进行了横向地形测量。然后将这些测量结果与2003年的可用数据进行比较。据估计，2003-2007年期间的泥沙淤积量和侵蚀量表明了海滩形态的显著变化，并证明了海岸系统对极端事件的脆弱性，例如2004年“伊万”飓风引发的那些事件。观察到的最重要的形态变化是，有的沙丘高度增加了0.20 ~ 0.50 m，有的沙丘高度减少了0.15 ~ 0.40 m。最后，通过粒度试验确定了沙粒直径的时空变化规律。海滩北侧最大退缩速率为2.0 m /年，沙粒较大。这两项测量都表明了在沙丘正面建造的建筑物和海滩护堤对海滩形态的影响。南段最大增积量为8.0 m /年，平均为2.3 m /年。在10年的分析中，海滩恢复的特点是对飓风和其他气象事件影响的复原力较低。在距离海岸不到30米的沙丘和护堤上，海滩动态最强烈的地方，建筑物的位置不适当，与强烈侵蚀过程的发展之间存在明显的空间相关性，如在bail n海滩北部所观察到的那样。初始海岸线位置的缓慢恢复转化为沉积物平均直径的稳步增加。当水文气象事件发生时，这些海滩的低恢复能力变得更加明显。为了使通过重新安置当地沙子的海滩恢复项目取得成功，必须密切监测海滩，记录沉积物动态以及风和水对横向剖面的影响。此外，为了确保这种自然资源的有效再生，必须确定每线性米海滩的平均沙子体积。最后，拆除位于护堤和沙丘正面的旧建筑，并禁止在这些地点进行进一步的建设，应有助于恢复该海滩的形态动力平衡，提高旅游服务质量。
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Juan Carlos Núñez Gómez , Rodimiro Ramos Reyes , Everardo Barba Macías , Alejandro Espinoza Tenorio , Lilia María Gama Campillo
Sea level rise is one of the most serious events that will impact low-lying lands, as is the case of most of Tabasco State. Historically, the State of Tabasco has been repeatedly impacted by extreme floods, the most recent one occurring in 2007. However, recent studies have shown that coastal erosion is the effect that most directly has impacted the Tabasco's coastline, as this has even modified soil strata; this is also related to extreme hydrometeorological events associated with environmental changes and changes in the salinity gradient off the coast. In such a situation, future changes in the coastline are almost certain. Tabasco's coastline has been recognized as one of the most vulnerable zones in the country since Mexico's first national communication to the unfccc in 1997. Therefore, it is important to evaluate the vulnerability of this zone. The purpose of this study was to estimate the vulnerability of the Tabasco's coastline by applying the coastal vulnerability index method (ivm) using a geographic information system (gis). This method has been successfully applied in several different places around the world including Canada, the United State, Spain and Indonesia. This model is suitable for the local conditions of Tabasco coast, as the input variables it requires (including waves, tides, sea level, coastal slope, erosion rates and geomorphology) are available for the study area, thus allowing the possibility of estimating the coast's vulnerability based on local data. Results from map algebra operations showed that the zones of very high or high vulnerability encompass a six-kilometer stretch around the Sánchez Magallanes community, near the del Carmen lagoon in the municipality of H. Cárdenas, Tabasco. This is due to the high-waves regime and other conditions associated to the coastal dune geomorphology as well as the unconsolidated fine sediments prevailing therein. Other high vulnerability zones are found just in front of the major lagoon system in the State of Tabasco, the Carmen-Pajonal-Machona and Mecoacan lagoons; being the last one the most vulnerable of all. It is worth pointing out that this zone is located within the influence zone of the Dos Bocas port where an intense anthropogenic activity occurs. It is also important to point out that this study is one of the first approaches to the estimation of coastal vulnerability in Mexico. The implementation and application of this model of coastal vulnerability evaluation are significant given the spatial scale of the study and that this is the first time that these variables have been collected for the state of Tabasco. Our results might inform decision-making processes on the proper management of the Tabasco coastline, thus benefiting the local communities.
{"title":"Índice de vulnerabilidad costera del litoral tabasqueño, México","authors":"Juan Carlos Núñez Gómez , Rodimiro Ramos Reyes , Everardo Barba Macías , Alejandro Espinoza Tenorio , Lilia María Gama Campillo","doi":"10.14350/rig.50172","DOIUrl":"https://doi.org/10.14350/rig.50172","url":null,"abstract":"<div><p>Sea level rise is one of the most serious events that will impact low-lying lands, as is the case of most of Tabasco State. Historically, the State of Tabasco has been repeatedly impacted by extreme floods, the most recent one occurring in 2007. However, recent studies have shown that coastal erosion is the effect that most directly has impacted the Tabasco's coastline, as this has even modified soil strata; this is also related to extreme<span></span> hydrometeorological events associated with environmental changes and changes in the salinity gradient off the coast. In such a situation, future changes in the coastline are almost certain. Tabasco's coastline has been recognized as one of the most vulnerable zones in the country since Mexico's first national communication to the <span>unfccc</span> in 1997. Therefore, it is important to evaluate the vulnerability of this zone. The purpose of this study was to estimate the vulnerability of the Tabasco's coastline by applying the coastal vulnerability index method (<span>ivm</span>) using a geographic information system (<span>gis</span>). This method has been successfully applied in several different places around the world including Canada, the United State, Spain and Indonesia. This model is suitable for the local conditions of Tabasco coast, as the input variables it requires (including waves, tides, sea level, coastal slope, erosion rates and geomorphology) are available for the study area, thus allowing the possibility of estimating the coast's vulnerability based on local data. Results from map algebra operations showed that the zones of very high or high vulnerability encompass a six-kilometer stretch around the Sánchez Magallanes community, near the del Carmen lagoon in the municipality of H. Cárdenas, Tabasco. This is due to the high-waves regime and other conditions associated to the coastal dune geomorphology as well as the unconsolidated fine sediments prevailing therein. Other high vulnerability zones are found just in front of the major lagoon system in the State of Tabasco, the Carmen-Pajonal-Machona and Mecoacan lagoons; being the last one the most vulnerable of all. It is worth pointing out that this zone is located within the influence zone of the Dos Bocas port where an intense anthropogenic activity occurs. It is also important to point out that this study is one of the first approaches to the estimation of coastal vulnerability in Mexico. The implementation and application of this model of coastal vulnerability evaluation are significant given the spatial scale of the study and that this is the first time that these variables have been collected for the state of Tabasco. Our results might inform decision-making processes on the proper management of the Tabasco coastline, thus benefiting the local communities.</p></div>","PeriodicalId":39866,"journal":{"name":"Investigaciones Geograficas","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.14350/rig.50172","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91684002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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