https://polipapers.upv.es/index.php/raet/issue/feed Revista de Teledetección 2024-01-30T12:25:20+01:00 Pere Serra Ruiz Pere.Serra@uab.cat Open Journal Systems <p class="default" style="text-align: justify; text-justify: inter-ideograph; margin: 0cm 0cm 6.0pt 0cm;"><em>Spanish Journal of Remote Sensing / Revista de Teledetección (RAET)</em> is a biannual scientific journal that publishes original research papers related to a wide range of methods and applications in remote sensing. The official publication languages are both, Spanish and English. The journal is open access and there are no charges for publication..</p> https://polipapers.upv.es/index.php/raet/article/view/20147 Estimation of sediment volumes due to rainfall erosion using RUSLE model in basins of the province of Manabí, Ecuador 2023-10-18T14:05:39+02:00 Gema Casanova-Ruiz gemykas_1990@hotmail.com Daniel Delgado daniel.delgado@utm.edu.ec Ramona Panchana ramona.panchana@utm.edu.ec <p>Sediment production due to rainfall erosion is a topic of great interest because its lack of knowledge can represent serious dangers for nearby communities and infrastructures. Several methods have been developed inrecent years to quantify sediments, but their complexity, precision, and accuracy vary depending on the approach used. However, many of these models require the use of extensive precipitation time series, but in Ecuador, the meteorological stations present a worrying lack of data and their spatial distribution is not homogeneous, which generates an incorrect rainfall estimation in the analyzed territory. To solve this problem, it is possible to implement methodologies that use satellite raster information. The objective of the present investigation was to estimate the volumes of sediments in the hydrographic basins of the province of Manabí, through the implementation of the RUSLE model and an empirical procedure that requires the use of the apparent density of the soil in its three main textures (sand, clay and silt). The methodology considered the delimitation of the analyzed basins, the evaluation of satellite raster data to determine the six parameters of the RUSLE model between 2001 and 2020, and the estimation of apparent density through an innovative method. The delimitation of the basins was obtained through regional sources; the satellite information was obtained from official web sources; the typical values of the apparent density were obtained from sources at global scale; and the validation of the apparent density data was carried out by means of on-site sampling. The results allowed identifying soil erosion rates that vary between 0.10 ton ha<sup>-1</sup> and 3252.22 ton ha<sup>-1</sup>, which generated an estimate of sediments between 0.06 m<sup>3</sup> year<sup>-1</sup> and 692.43 m<sup>3</sup> year<sup>-1</sup> at the pixel level. The average apparent density was 1.49 ton m<sup>-3</sup>, which demonstrates a high sand content in the basins of Manabí. The data validation revealed an excellent compatibility between the proposed methodology and the conventional on-site analysis, which is reflected in an average difference of less than 3%. The information obtained will allow the competent government entities to establish mitigation programs to deal with the loss of soil due to rainfall erosion and to control the sediments production.</p> 2024-01-30T00:00:00+01:00 Copyright (c) 2024 Gema Casanova-Ruiz, Daniel Delgado, Ramona Panchana https://polipapers.upv.es/index.php/raet/article/view/20142 Erosion, sedimentation and lateral migration of the Amazon River between the confluence of the Marañón-Ucayali rivers and the town of Indiana - Loreto, Peruvian Amazon 2023-12-18T13:54:20+01:00 José Sanjurjo-Vílchez jsanjurjo@iiap.org.pe León Bendayán-Acosta ojsadmin@upvnet.upv.es <p>Fluvial dynamics are characterized by various phenomena that occur along the course of a river, among these processes of erosion, sedimentation, and lateral movement that affect the lives of riversiders settled on the banks of rivers in tropical regions. In this study we evaluated the indices of erosion, sedimentation and lateral migration of the main channel in three sectors of the middle basin of the Amazon River in the Peruvian Amazon. The results show great vulnerability to erosion and lateral migration in the "Samaria" sector and in part of the "Iquitos" sector. The “Muyuy” sector on the left bank presents a scenario of probable avulsion or incursion of the Amazon River on the Itaya River. The analyzed processes have been interpreted and illustrated through the use of procedures and techniques provided by Remote Sensing and Geographic Information Systems.</p> 2024-01-30T00:00:00+01:00 Copyright (c) 2024 José Antonio https://polipapers.upv.es/index.php/raet/article/view/20272 Identification of areas with high aboveground biomass and high species richness of the native forest at northeastern Uruguay 2023-12-12T16:18:32+01:00 Carla E. Ocaño-Silveira carlaocano@gmail.com José René Valdez-Lazalde valdez@colpos.mx Rodrigo Duno-de Stefano roduno@cicy.mx Jose Luis Hernández-Stefanoni jl_stefanoni@cicy.mx <p>The native forests of Uruguay provide important ecosystem services. Despite this, there are few maps with the spatial distribution of vegetation attributes in the country. The objective of this study was to obtain maps with the spatial distribution of aboveground biomass and species richness that show areas with high concentrations of both variables, essential for climate change mitigation and biodiversity conservation. The study area includes the Gondwanan Sedimentary Basin ecoregion. Generalized Linear Models were used to estimate aboveground biomass and tree species richness, where the response variables were calculated using field data from the National Forest Inventory. Whereas, the predictor variables were obtained with spectral and texture information derived from Sentinel-2, and ALOS PALSAR; as well as environmental, topography and climate data. The biomass estimation model presented an explained deviance (D2) of 0,25, while in the species richness model, the D2 was 0,19. To evaluate both models, cross-validations were carried out, obtaining an R2 of 0.25 for aboveground biomass and 0,19 for species richness, with a relative mean square error of 45,8 % and 32,5 % respectively. The bivariate map with the joint distribution of species richness and aboveground biomass shows that there is a positive correlation between both variables in 63,8 % of the native forest area of the ecoregion. The results of this work could be used for the maintenance of carbon stocks and for the conservation of biodiversity.</p> 2024-01-30T00:00:00+01:00 Copyright (c) 2024 Carla E. Ocaño-Silveira, José René Valdez-Lazalde, Rodrigo Duno-de Stefano, Jose Luis Hernández-Stefanoni https://polipapers.upv.es/index.php/raet/article/view/20047 Analysis of climatic and anthropogenic forcing in the reduction of water in the Copiapó river basin, Chile (28° S) using satellite products 2023-11-16T12:27:12+01:00 Abel González abgonzalez@udec.cl Cristian Mattar cmattar@uchile.cl Héctor H. Sepúlveda andres@dgeo.udec.cl <p>A water shortage has been affecting Chile in recent years. Due to the negative effects that water deficit can generate on the environment and the population, an improved understanding of the influence of climatic and anthropogenic factor on water depletion is needed, especially in arid regions such as northern Chile. The main objective of this study is to assess the implications of climatic and anthropogenic variables on the water deficit of the Copiapó River basin, Atacama region, Chile. The study period spans from 2001/02 to 2021/22 seasons. MODIS satellite products (MOD10a2 and MOD16a2) and Landsat images were used for this analysis. Water extraction information obtained from the Chilean National Water Agency (DGA) was also included for this study. The analyzed variables include actual evapotranspiration (ETr), Snow Water Equivalent (SWE), and water use for mining and agriculture. Changes in Snow Water Equivalent (SWE) in the Andes were analyzed as climatic variables, while changes in irrigation and water extraction for mining were used as anthropogenic variables. The amount of water lost by the basin through actual evapotranspiration (ETr) was estimated to quantify changes in water reduction.<br />The results show a significant reduction (p&lt;0.05) of water at a rate of 0.7 Mton/year. Through correlation analysis, an important relationship was found between this reduction and the consumption of the mining sector (-0.52), suggesting that the anthropogenic forcing influences the water deficit more than the climate. Enhanced monitoring of water extraction will contribute to a more accurate identification of its effects on water availability.</p> 2024-01-30T00:00:00+01:00 Copyright (c) 2024 Abel Gonzalez, Cristian Mattar, Héctor H. Sepúlveda https://polipapers.upv.es/index.php/raet/article/view/20158 Improving the evapotranspiration estimation by coupling soil moisture and atmospheric variables in the relative evapotranspiration parameterization 2023-11-20T12:21:13+01:00 Elisabet Walker ewalker@fich.unl.edu.ar Virginia Venturini vventurini@fich.unl.edu.ar <p>Accurate monthly evapotranspiration (ET) estimation is essential for many forest, climate, and hydrological applications, as well as for some agricultural uses. In this study, the relationship between ET and relative evapotranspiration (F) using land surface, and atmospheric variables was assessed with 17 FLUXNET sites data in savanna, cropland, and forest land covers, distributed all over the world. A sigmoid (Fs) and a logarithmic (Fl) F expression were included in Walker et al.’s (2019a,b) equations to evaluate their impact on the accuracy of ET estimations. The new parameterizations of ET outperformed the original expression, showing root mean square errors lower than 24% of the mean observed ET. The results presented here suggest that atmospheric parameters, coupled with land explanatory variables included in F estimates, produce more precise ET estimations. In addition, Soil Moisture Active Passive (SMAP) products were used to obtain global maps of ET and compared with Global Landsurface Evaporation Amsterdam Methodology (GLEAM) and Terra Moderate Resolution Imaging Spectroradiometer (MODIS) MOD16 products, displaying the flexibility of these new parametrizations with different sources of data.</p> 2024-01-30T00:00:00+01:00 Copyright (c) 2024 Elisabet Walker, Virginia Venturini https://polipapers.upv.es/index.php/raet/article/view/20481 LiDAR-photogrammetry coverage, bathymetry and infrastructures survey to support flood risk analysis in the Genil River sub-basin 2023-12-04T12:15:22+01:00 J. J. Vales-Bravo juanj.vales@juntadeandalucia.es E. M. Méndez-Caballero elena.mendez.caballero@juntadeandalucia.es R. Prieto-Molina raquel.prieto@juntadeandalucia.es L. Granado-Ruíz laura.granado@juntadeandalucia.es I. Pino-Serrato isabel.pino.serrato@juntadeandalucia.es E. Sañudo-Costoya e.sanudo@udc.es G. García-Alén Lores g.glores@udc.es A. M. Pello-Rodríguez anam.pello@juntadeandalucia.es A. Zabala-Ordóñez alvaro.zabala@juntadeandalucia.es E. Ortega-Díaz elena.ortega@juntadeandalucia.es <p align="justify"><span style="color: #000000;"><span lang="es-ES-u-co-trad">Floods are the natural disasters that affect the most people in the Atlantic Area. In this sense, the AA-Floods project is developed with the objective of developing and highlighting new tools, plans and regulations that improve the management and response to floods. </span></span><span style="color: #000000;"><span lang="es-ES-u-co-trad">The importance of quality altimetric information for the evaluation of flood danger is based on the fact that it requires knowledge, as detailed and precise as possible, of the relief and the heights of the elements located above the ground. To this end, the acquisition of LIDAR coverage with a density of 21 points/m² and photogrammetric coverage has been carried out to obtain Orthophotographs of 0.10 m for the generation of altimetric products with great positional accuracy and high precision in the study areas of the Genil River basin. Likewise, the bathymetric survey of the Genil River bed has been carried out and the final Topobathymetric Model has been obtained. Furthermore, for the adequate development of hydraulic modeling and determination of flood zones, it is necessary to take into consideration all those structural elements close to the channel that affect flood risk. To achieve this, a combination of geomatic techniques has been used: Classic Topography, GNSS, Lasergrammetry (LST) and Drone Photogrammetry. Analysis of flood </span></span><span style="color: #000000;"><span style="font-size: medium;"><span lang="es-ES-u-co-trad">areas</span></span></span><span style="color: #000000;"><span lang="es-ES-u-co-trad"> has been carried out with these improved information sources, contrasting them with analysis of information sources used by the National Mapping System of flood </span></span><span style="color: #000000;"><span style="font-size: medium;"><span lang="es-ES-u-co-trad">areas</span></span></span><span style="color: #000000;"><span lang="es-ES-u-co-trad">. The flood sheet results for the different return periods have been contrasted with the 2010 flood sheets mapped by direct observation using Satellite Radar (SAR) technology.</span></span></p> 2024-01-30T00:00:00+01:00 Copyright (c) 2024 J. J. Vales-Bravo, E. M. Méndez-Caballero, R. Prieto-Molina, L. Granado-Ruíz, I. Pino-Serrato, E. Sañudo-Costoya, G. García-Alén Lores, A. M. Pello-Rodríguez, A. Zabala-Ordóñez, E. Ortega-Díaz