La Albufera de Son Bou

Abstract not availabl

Los barrancos del Migjorn de Menorca

Abstract not availabl

Características sedimentológicas y morfológicas de los espacios costeros de transición situados al sur de la desembocadura del Xúquer

La interpretación de los resultados obtenidos del análisis sedimentológico de las muestras de los sondeos manuales realizados al sur de la desembocadura del río Xúquer, así como el estudio de la topografía de detalle analizada tras la elaboración de un modelo digital de elevaciones (MDE), han permitido reconocer con mayor claridad los ambientes sedimentarios de este sector. Se trata de una costa que secularmente ha sido progradante como demuestra la existencia de una doble restinga y dunas de hasta 6 m de altura. Las zonas húmedas que quedan delimitadas por estas dos restingas muestran una serie de vaguadas, algunas de las cuales canalizan las aguas de crecidas fluviales o conectan antiguas difluencias en la desembocadura del Xúquer. La acción antrópica, mediante las obras de encauzamiento del río, ha cambiado por completo la tendencia acumulativa y ha convertido este sector en un buen ejemplo de costa recesiva

Torrents, barrancs i canalons, la xarxa de drenatge del Migjorn

Abstract not availabl

Caracterització morfomètrica del Migjorn de Menorca

Abstract not availabl

Els avenços de la Cartografia: cap a la tercera dimensió

Advances in cartography: towards the third dimensionThe last fifteen years have witnessed an authentic revolution in the field of cartography, and specially in the three dimensional characterization of territory. The change is founded, undoubtedly, in improvements in the field of geographical positioning —global positioning systems— in that of the massive catchment ofgeographical data —with the development of aero-transported sensors that are increasingly more exact and powerful, like satellites and radars— and in their management —with the development of geographical information systems (GIS) and digital elevation models (DEM)—. From our perspective, four things have fundamentally changed: the way in which information is gathered, the degree of accuracy, the size of the geographical space reached and the popularization and diffusion of cartograph

Quantifying slumness with remote sensing data

The presence of slums in a city is an indicator of poverty and its proper delimitation is a matter of interest for researchers and policy makers. Socio-economic data from surveys and censuses are the primary source of information to identify and quantify slumness within a city or a town. One problem of using survey data for quantifying slumness is that this type of data is usually collected every ten years and is an expensive and time consuming process. Based on the premise that the physical appearance of an urban settlement is a reflection of the society that created it and on the assumption that people living in urban areas with similar physical housing conditions will have similar social and demographic characteristics (Jain, 2008; Taubenb¨ock et al., 2009b); this paper uses data from Medellin City, Colombia, to estimate slum index using solely remote sensing data from an orthorectified, pan-sharpened, natural color Quickbird scene. For Medellin city, the percentage of clay roofs cover and the mean swimming pool density at the analytical region level can explain up to 59% of the variability in the slum index. Structure and texture measures are useful to characterize the differences in the homogeneity of the spatial pattern of the urban layout and they improve the explanatory power of the statistical models when taken into account. When no other information is used, they can explain up to 30% of the variability of the slum index. The results of this research are encouraging and many researchers, urban planners and policy makers could benefit from this rapid and low cost approach to characterize the intra-urban variations of slumness in cities with sparse data or no data at all

Análisis de la evolución de la línea de costa entre Alcossebre y Oropesa a partir de la fotografía aérea (1956-2015)

[ES] El artículo presenta un análisis de la evolución de la línea de costa entre Alcossebre y Orpesa, a partir de fotografías aéreas y ortofotografías, entre 1956 y 2015. La digitialización de 12 líneas de costa ha permitido calcular los cambios netos y máximos, así como la tasa de cambio entre los diferentes años. Los resultados muestran una costa recesiva, con una gran variabilidad espacio-temporal. Conviven sectores con crecimiento sostenido provocado por la acción antrópica (deriva arriba de los espigones y regeneraciones de playa) o causas naturales (prominencias costeras), con otros claramente erosivos (deriva abajo de espigones). Además, el análisis de las isobatas del estrán sumergido, ha permitido explicar cómo la configuración de este espacio puede incrementar o frenar la erosión. Los temporales son los responsables de los grandes cambios, mientras que el déficit hidrosedimentario de los ríos a lo largo del siglo XX, subyace como causa última del comportamiento erosivo del área de estudio, tendencia que ya se manifestaba antes de la aparición de la acción antrópica. Así, la fotografía aérea, a pesar de su baja resolución temporal, compensa este déficit con la amplitud de sus series, lo que permite conocer el comportamiento de la línea de costa en un momento en el que la presión antrópica sobre este espacio era baja.[EN] This article presents an analysis of the coastline evolution between Alcossebre and Orpesa, based on aerial photographs and orthophotographs between 1956 and 2015. Twelve digitalized shoreline positions have allowed the calculation of net and maximum changes, as well as the rate of change between the different years. The results show a recessive coast, with a large spatial and temporal variability. Sectors with sustained accumulation, caused mainly by anthropic action (updrift sediment retention by groins and artificial nourishment of beaches) or natural causes (prominences) coexist with other clearly erosive (sediment deficit groins downdrift). In addition, the analysis of the isobaths of the submerged beach, has allowed to explain how the configuration of this space can increase or reduce the erosion. The big coastal storms are the main cause of the major changes, while the rivers hydrosedimentary deficit, generated along the twentieth century, underlies as the primary cause of the erosive behavior of the whole sector, which already were detected before the beginning of the main anthropic actions. Despite its low temporal resolution, the comparison of enough long series of aerial photography has allowed us to detect and quantify the coastline main changes when anthropogenic pressure was scarce.El presente trabajo forma parte de los proyectos de investigación CGL2013-44917-R, RESETOCOAST (CGL2015-69906-R) y EPHIMED (CGL2017-86839-C3-1-R) del Programa Estatal de Investigación, Desarrollo e Innovación Orientada a los Retos de la Sociedad, del Ministerio de Economía, Industria y Competitividad y están cofinanciados con fondos FEDER. Los autores agradecen las sugerencias de dos revisores anónimos que han mejorado notablemente el presente trabajo.Pardo Pascual, JE.; Roca-Moya, R.; Segura-Beltrán, F. (2019). Análisis de la evolución de la línea de costa entre Alcossebre y Orpesa a partir de fotografía aérea (1956-2015). Cuadernos de Geografía de la Universitat de València. 102:39-72. https://doi.org/10.7203/CGUV.102.14511S397210

Satellite derived shorelines at an Eexposed meso-tidal beach

Shoreline position data offer extremely valuable information for understanding coastal dynamism and beach changes. This research applies SHOREX system for defining the shoreline position from free mid-resolution Landsat-8 (L8) and Sentinel-2 (S2) satellite imagery. This system allows an automatic definition of Satellite Derived Shorelines (SDS) over large regions and periods. Accuracy and utility of the resulting SDS have been previously assessed with positive results at low energy, microtidal, Mediterranean beaches. This work assesses SDS extracted using SHOREX at a mesotidal and moderate to highly (during storms) energetic environment, namely at Faro Beach, a barrier beach located in Ria Formosa (Algarve, South Portugal). Accuracy was defined for 14 SDS derived from S2 and 10 from L8 by measuring the differences in position with respect to the shoreline inferred from profiles obtained on close dates (or simultaneously) to imagery acquisition. For non-simultaneous datasets, the water level was estimated for the time of the satellite images acquisition using oceanographic data and run-up formulations. The measured and estimated shoreline positions were then compared with the extracted SDS. The overall accuracy is good, with errors about 5 m RMSE, supporting the application of the used methodology to define shoreline dynamics and evolution at challenging environments, as mesotidal exposed and dynamic beaches.Spanish Ministry of Economy and Competitiveness [CGL2015-69906-R]; Spanish Ministry of Education, Culture and Sports [FPU15/04501]info:eu-repo/semantics/submittedVersio

Analysis of the morphological changes of the beaches along the segment València - Cullera (E Spain) from satellite-derived shorelines

Beaches are spaces of paramount importance for coastal societies currently threatened by coastal erosion. Their preservation requires accurate quantification of their changes in order to understand their behavior and to propose efficient solutions. Landsat 8 and Sentinel 2 mid-resolution satellites offer free-of-charge images with great potential for coastal monitoring. From them, it is possible to automatically extract the shoreline position as a quantitative indicator of the beach morphology over large territories and with high temporal frequency. Beach changes take place at different spatial and temporal scales, typically responding to coastal storms and human interventions on the coast. The collection of large packages of satellite-derived shorelines (SDS) at the coastal sector València-Cullera (W Mediterranean) covering the period 2013-2020 makes it possible to characterize the state of its beaches and their width changes over space and time. Results reveal a widespread erosional trend, most likely caused by a shortage of sediment in the coastal system. Thus, the majority of the beaches are not capable of restoring their previous conditions after storm-driven retreats. The information provided by the SDS also shows the ineffectiveness of the nourishment actions, at least in the way they have been carried out, and the urgent need for a strategy to address the erosion problem