{"title":"Geomorfología y sedimentología del sistema de cárcavas en el borde costero al suroeste del Castillo de Araya, Estado Sucre, Venezuela","authors":"Franklin Antonio Nuñez Ravelo","doi":"10.14350/rig.53428","DOIUrl":"10.14350/rig.53428","url":null,"abstract":"<div><p>The study area is located in the south-west coast of Araya in Sucre State, between 10° 33’30” N, 10°33’59” N y 64°15’32” W, 64°15’36” W, which it is affected by erosion processes impacting the population center that sits there. Hence the research is to analyze the geomorphological processes developed, based on a model no-experimental and design field, in descriptive and explanatory levels, operationalized in three phases: a) field, to collect 21 samples of surface sediment (0-20 cm) distributed in 12 samples in the first badlands and 9 samples in the second and lift the morphometry of these landforms erosion; (b) image analysis, three stages such as the <em>development of thematic maps</em> from the Topographical maps of Cumana, Geological Araya Peninsula and The Cadastral Charter covered: Punta Caracare; <em>followed by drawing sketches of gullies</em>, from the data collected in the <span></span>field, refer to height, length and width of the land. Corresponding to the last two variables data were corrected by the equation suggested by Wolf and Ghilani (2008), for data collected on slopes using measuring tape; and finally <em>drawing the sketch of the apical cliff line drawn</em> from the interpretation of the captured images of Google Earth for the years 2003, 2006, 2009 and 2011, based on the proposal of Soriano (2009) and (c) laboratory, to analyze the comportamientode physical properties such as: hygroscopic water content, determined by gravimetric method, based on the arguments presented by Rivera, et al. (2006) and Toledo (2009); size distribution of the particles (Method Bouyoucos) following the protocol reported by Lara (1985); Percentage of dispersion and soil (double hydrometer method) based on the specifications referred by porters and Alva (1999). As for the chemical-mineralogical properties, it was determined from 10 samples analysis of total rocks and clay mineralogy, for both analyzes samples were prepared, processed and analyzed in the laboratory Diffraction x-ray (<span>xrd</span>), assigned to the Departmental Management Exploration <span>pdvsa-intevep</span>. Being used for analysis brand <span>pan</span>alytical diffractometer X’Pert model equipped with a curved crystal monochromator graphite (Cu Ka radiation) and operated by the X-Pert Data collector <span>ltu</span> <span>pw</span>3240 / 92 (version 2.2b) software, applying a range scanning of 5 ° θ 45 ° θ. For all rock and 0 2 ° to 35 ° θ clay minerals for less than 2 microns (<2μ) fraction. As to biochemical properties, the organic carbon were analyzed on the floor (COs) using in method Wlakley and Black, reported by Arrieche and Pacheco (sf) and Toledo (2008), and content of organic matter (<span>mo</span>) by the conventional factor Vammelen, referred to by Navarro (2007) and Toledo (2008) and checked against the proposal by <span>palmaven</span> (1992) qualitative scale In general, you have to cliff erosion affected by the retrograde type badlands, It consi","PeriodicalId":39866,"journal":{"name":"Investigaciones Geograficas","volume":"2017 92","pages":"Pages 3-20"},"PeriodicalIF":0.0,"publicationDate":"2017-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.14350/rig.53428","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129073278","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}
J.A. Paz Tenorio , R. González Herrera , M. Gómez Ramírez , J.A. Velasco Herrera
{"title":"Metodología para elaborar mapas de susceptibilidad a procesos de remoción en masa, análisis del caso ladera sur de Tuxtla Gutiérrez, Chiapas","authors":"J.A. Paz Tenorio , R. González Herrera , M. Gómez Ramírez , J.A. Velasco Herrera","doi":"10.14350/rig.52822","DOIUrl":"10.14350/rig.52822","url":null,"abstract":"<div><p>The city of Tuxtla Gutiérrez, Chiapas, has historically presented processes landslides in the southern part of the valley, specifically in deposits of slope whose genesis is determined from La Mesa karst of Copoya, geological forms subjected to intense fracturing processes dissolution and erosion, giving as a result the breaking into large blocks. These are distributed in the margins of La Mesa being altered and destroyed by mechanical and chemical weathering, which generated smaller particles that rest on siltstones, shale and sandstones. This condition determines that the slopes are unstable by nature.</p><p>A 1000 x 1000 m grid was constructed, corresponding to the canvass of the Mercator Transverse Universal Coordinate System (UTM) of the topographic map scale 1:50 000 (<span>INEGI, 1984</span>;emsp <span>Instituto, 2004</span>, <span>Lugo-Hubp, 1988</span>). In each cell a centroid was generated to apply the interpolation process and draw isolines. For numerical variables such as drainage density and unevenness, defined ranges (number of equal intervals) were used by ArcMap software (version 9.3). For the non-quantitative variables such as geology, edaphology and soil use and vegetation, the same AHP method was used, obtaining numerical values for the cartographic representation.</p><p>In all three cases, the normalized values and a Consistency Index (CI) and Consistency Ratio (CR) (the latter according to the dimension of the matrix) were obtained, below 10%, so that the weights are correct.</p><p>In order to obtain information on the changes in the use of the ground, images of Google Earth of 2006, 2008 and 2010 were revised. Subsequently, a very high resolution orthophoto was added (pixel of 0.2 m), obtained for cadastral purposes by Town Hall of Tuxtla Gutierrez between the end of 2012 and the beginning of 2013.</p><p>Finally, five layers of information are defined, one for each variable, and the final result overlaps with the events recorded in the last nine years (2006 to date), which shows that the areas classified as Very High Threat are the more susceptible to the occurrence of these events. It is to be expected that in time, the incidence of this type of phenomena is manifested in the levels of High and Very High Threat.</p><p>Applying the Analytic Hierarchy Process (AHP) developed by <span>Saaty (1988)</span>, which consists of matrix analysis and involves value judgments. In this way the matrix of preference over the selected criteria was generated, obtaining the weighting of the five chosen variables. It was important the knowledge of the study area, the documentation and local studies generated to date, where the criteria of the specialists are taken up.</p><p>The process was done in an Excel spreadsheet (2007 version), applying the corresponding formulas. Because only five variables and the size of the area (250 km2) were handled, no specialized software was required.</p><p>With the data obtained a table was created in","PeriodicalId":39866,"journal":{"name":"Investigaciones Geograficas","volume":"2017 92","pages":"Pages 128-143"},"PeriodicalIF":0.0,"publicationDate":"2017-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.14350/rig.52822","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126462687","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}
Marcos Salas Pascual , Emilio Fernández Negrín , Gregorio Quintana Vega , Marcelino J. del Arco Aguilar
{"title":"Efecto de la inclinación y pedregosidad sobre el reparto del agua de lluvia, su cuantificación y aplicación al estudio de la vegetación en zonas áridas","authors":"Marcos Salas Pascual , Emilio Fernández Negrín , Gregorio Quintana Vega , Marcelino J. del Arco Aguilar","doi":"10.14350/rig.55204","DOIUrl":"10.14350/rig.55204","url":null,"abstract":"<div><p><span></span>For the correct distribution of vegetation in an area, it is essential to manage accurate information on the variables that condition information. Most likely, the parameter that determines further the type of vegetation that can grow in one place is the amount of water available to plants. In this sense, and leaving aside the formations linked to watercourses, lakes, etc., the main source of this resource is the rain. Thus, the study of the distribution of vegetation in any territory is closely related to the analysis of rainfall it receives. To know the amount of rainwater that receives a zone always uses data provided by meteorological stations located in the same. The data collected by these stations are applied to a hypothetical, uniform and flat surface. This information is accurate enough when the scale at which it works is small (1: 100,000, 1: 50,000), but when it requires greater detail, especially in arid areas where the vegetation structure is open and the soil directly receives much of the rainfall, soil conditions exist that determine the distribution of rainwater and therefore access to this resource plants. Two of these variables, perhaps the most important are the inclination and the presence of rocky outcrops or stoniness on the floor.</p><p>In short, our job is to propose different mathematical models that allow to know the actual amount of water available to plants, we call A. This value is obtained from rainfall data (<strong>P</strong>), relating to the sloping terrain and the percentage of it occupied by rocks (<strong>af</strong>). The relationship between precipitation and tilt gives us a value we call the real precipitation (<strong>P’</strong>), which is lower the greater the inclination, since the amount of rainfall should be distributed over a larger area. The amount of rocky outcrop increases runoff, accumulating water in the earthy areas between the rocks, so a higher percentage of stoniness in soil involves an accumulation of water in the surrounding soil. Thus a model that allows both better explain the distribution of vegetation in arid areas and on large scales (: 25.000 or higher 1) is provided.</p><p>To test the model and test its usefulness, it has made a study of it in different localities in arid areas of the island of Gran Canaria, one of the Canary Islands. On this island 14 towns located in arid environments, with precipitation always less than 200 mm/m<sup>2</sup> were chosen. Among these locations, with similar climatic conditions, there is a very important plant diversity. Most are occupied by a crasicaule very open scrub dominated by Euphorbia balsamífera, called <em>tabaibal de tabaiba dulce,</em> typical of the most barren areas of the Canary Islands, and considered the potential of its arid and hyper-arid vegetation areas. But other situations are occupied by a lush vegetation: the cardonal, almost totally enclosed high scrub, dominated by <em>Euphorbia canariensis</em>, the <","PeriodicalId":39866,"journal":{"name":"Investigaciones Geograficas","volume":"2017 92","pages":"Pages 51-63"},"PeriodicalIF":0.0,"publicationDate":"2017-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.14350/rig.55204","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134549664","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":"","authors":"Gerónimo Barrera de la Torre","doi":"10.14350/rig.59439","DOIUrl":"https://doi.org/10.14350/rig.59439","url":null,"abstract":"","PeriodicalId":39866,"journal":{"name":"Investigaciones Geograficas","volume":"2017 92","pages":"Pages 163-165"},"PeriodicalIF":0.0,"publicationDate":"2017-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.14350/rig.59439","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136612024","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":"Trabajo de campo en el territorio de San Juan Lachao, Oaxaca. Un acercamiento desde las “otras” geografías al paisaje chatino","authors":"Gerónimo Barrera de la Torre","doi":"10.14350/rig.57877","DOIUrl":"https://doi.org/10.14350/rig.57877","url":null,"abstract":"","PeriodicalId":39866,"journal":{"name":"Investigaciones Geograficas","volume":"2016 91","pages":"Pages 176-181"},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.14350/rig.57877","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91778245","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":"2016 91","pages":"Pages 208-209"},"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}