Global Digital Elevation Models (DEMs) are widely used in many developing countries to help mapping soil-scapes, and users rely on metadata on vertical accuracy (VA) given by product developers. VA is important in modelling topographic attributes useful for mapping and predicting soil-scapes. This paper summarizes a comparative analysis of vertical accuracy of eight freely available DEMs derived from EO datasets in a low-relief landscape of Argentina (Entre Rios province), where the main objective is to map complex soil cover patterns. These are: MERIT-DEM; SRTMGL1 v3; ASTGTM v3; AW3D30 v3.1; Copernicus GLO-30; NASA DEM HGT v1; SRTMGL1up-sampling; Argentina's MDE-Ar v2. Results show the Copernicus GLO-30 dataset was consistent with its nominal quality specifications, whereas the ASTGTM v3 from NASA/Jaxa ranked last. While these results are restricted to the geography of this study area, they reaffirm the need to assess DEM's quality independently of that provided by the product developers.

Digital terrain models (DTM) allow deriving topographic attributes that help predict soil properties within a landscape. A variety of DTMs, digital elevation models (DEMs), and digital surface models (DSM) derived from Earth Observation (EO) data are freely accessible via Internet for download and use: MERIT-DEM, SRTM v3 (SRTM Plus), GDEM v3 (ASTGTM), AW3D30 v3, Copernicus GLO-30, NASADEM HGT v1, SRTMGL1 up-sampled (ASF DAAC) and MDE-Ar v2. However, information on their accuracy to represent terrain surfaces (particularly topographic attributes) can vary according to regions and geographies, which can impact soil cartography accuracy at sub-regional and catchment levels. This research evaluates the accuracy of the models mentioned above for estimating topographic attributes relevant to the cartography of soil vertic properties in the northern part of the Entre Ríos province, Argentina. To this end, east-west and north-south transects were used to collect 126 evenly distributed ground control points. The root mean squared error (RMSE) and symmetric mean absolute percentage error (sMAPE) served as the basis for comparing the performance of the terrain models. The sMAPE provides a percentage (or relative) error, facilitating a comparison of the accuracy with which each elevation value is predicted (in addition to the average error expressed by the RMSE value).The results show that out of the 8 models compared, the Copernicus GLO-30 offers the highest accuracy (RMSE=1.36; sMAPE=1.5%) for representing terrain surface features in the province of Entre Rios, whereas the highest RMSE (7.79) and sMAPE (11.2%) corresponded to the ASTGTM v3. The paper describes a simplified approach for extracting a digital terrain model (DTM) from the digital elevation information provided in the Copernicus GLO-30. Grid-spline interpolation and multilevel b-spline interpolation (from SAGA open GIS software) were applied to remove natural and built features. The output DTM was used to calculate plan and profile curvature index, multi-scale topographic position index (TPI), multiresolution index of valley bottom flatness (MrVBF), terrain ruggedness index (TRI), and topographic wetness index (TWI) that are important in modelling relationships between geomorphology, vertic soils, and surface hydrology in landscapes characterized by catenary sequences of Mollisols-Alfisols-Vertisols. A higher TRI was associated to increased local relief heterogeneity. Higher values of the MrVBF relate to broad flat valley bottoms and more extensive alluvial zones often confined between the slightly rolling and undulating plains, and peneplain landscapes. Lastly, the TWI was used to map potential areas for surface water accumulation that field verifications showed as corresponding with the location of vertic soils.Integrating DTM-derived topographic attributes with other ancillary data enabled mapping the spatial distribution of soil vertic properties over the study area and associating their occurrence to specific landscape zones (ie. close to drainage networks). The approach and findings are relevant for showing where and how the landscapes of the Entre Rios province are affected by a combined impact of human activities (intensive agriculture) and a hydrographic network that boosts the processes of soil erosion and contaminant transport.

Most of the territorial studies require maps of the state and dynamics of ecosystems. Land cover mapping has been subject of numerous global (Land Cover, Globe cover) and continental initiatives, but not for regional or local scales in areas associated with the Predelta National Park. The objectives of this contribution was to develop a methodology for mapping land cover and change for the PNPredelta using spatial (Landsat TM data) and terrain data. As result, was obtained a map of land cover changes (forest, shrub, herbaceus, bare soil/infrastructure class) for the study area between 1987 and 1998. The overall confidence was higher than 80% in class assignment. The “change classes” had the lowest confidence. Information relevant to land management was generated.

Most of the territorial studies require maps of the state and dynamics of ecosystems. Land cover mapping has been subject of numerous global (Land Cover, Globe cover) and continental initiatives, but not for regional or local scales in areas associated with the Predelta National Park. The objectives of this contribution was to develop a methodology for mapping land cover and change for the PNPre-delta using spatial (Landsat TM data) and terrain data. As result, was obtained a map of land cover changes (forest, shrub, herbaceus, bare soil/infrastructure class) for the study area between 1987 and 1998. The overall confidence was higher than 80% in class assignment. The "change classes" had the lowest confidence. Information relevant to land management was generated.

Fire occurrences at the of Parana River Coastal Complex during the 2004-2008 period were studied through hotspot data analysis. Spatial information from different remote sensors (MODIS, ERS, Goes, NOAA) and sources (CONAE, ESA, INPE) was evaluated. The MODIS Aqua sensor (downloaded and processed by CONAE), showed a high hotspot detection performance. For this sensor, an algorithm was developed that allows the interpretation of hotspot data as fire, applying previous knowledge of the fire behavior in the study area. Maps, tables and figures were elaborated. Descriptive statistics, normality (Shapiro Willks) and variance tests (Kruskal Wallis) were carried out. No statistically significant differences (SSD) were founded between hotspots and fire occurrence to different months and seasons. SSD were found between 2004, 2006 and 2008 on the one hand, and 2005 and 2007 on the other. Taking into account these results, fires at the Parana River Coastal Complex are, in general, of short duration and small extent, with a seasonal pattern of occurrence (in spring-summer), and vary from year to year. Exceptional periods (2008) can be identified by the changes of these parameters. This information is presented as a suitable tool for the study and management of fire in the study area.

Resumen es: Se ha estudiado las ocurrencias de incendio en el Complejo del Rio Parana costeras durante el periodo 2004-2008 se estudiaron mediante analisis de datos ...

Este trabajo presenta el Proyecto trianual actualmente en ejecucion en la Facultad de Ciencia y Tecnologia de UADER-Universidad Autonoma de Entre Rios. Eneste proyecto se desarrolla un sistema operacional para el monitoreo de cambios interanuales en la cobertura vegetal del bosque nativo del centronorte de Entre Rios utilizando imagenes digitales obtenidas en el espectro optico por satelites orbitales. Para ello se adaptan tecnicas digitales de procesamiento de imagenes para la deteccion de cambios en la vegetacion en los ambientes sub-humedos del norte provincial. La metodologia posibilitara el monitoreo operacional a partir de imagenes satelitales de diferentes sensores. Las tecnicas articuladas por esta metodologia permiten la deteccion de cambios entre imagenes de sensores espectralmente compatibles, con o sin calibracion atmosferica. Estas ademas son resistentes a la confusion producida por la dinamica compleja de la cobertura vegetal del area y capaces de incorporar las nuevas tecnologias satelitales actualmente en desarrollo. Los resultados y metodologias desarrolladas en el marco del proyecto permitiran establecer para el futuro un sistema operacional de monitoreo de la cobertura de bosques en la region permitiendo a la Provincia contar con herramientas para monitoreo del cumplimiento de la Ley de Presupuestos Minimos de Proteccion Ambiental de los Bosques Nativos de la Ley Nacional de Bosques 26331.