Askoa Ibisate

Universidad del País Vasco / Euskal Herriko Unibertsitatea | UPV/EHU · Departamento de Geografía, Prehistoria y Arqueología

Small hydropower plants (SHP) affect river flow and sediment transport and thus impact river morphology. Eight hydropower schemes were studied along the meandering middle and lower reaches of Aragón River (Spain) to assess their effects on channel morphology and sediment dynamics from 1927 to 2010. GIS tools were used to measure changes in fluvial...

In the last five decades, mountain and lowland rivers of the Iberian Peninsula have undergone noticeable hydrological and geomorphological change, in response to an overall reduction of discharge, floods and sediment supply. The causes are humaninduced land use change, the building of reservoirs and gradual climate change. In lowland river floodpla...

Dam removal has been demonstrated to be one of the most frequent and effective fluvial restoration actions but at most dam removals, especially of small dams, there has been little geomorphological monitoring. The results of the geomorphological monitoring implemented in two dams in the rivers Urumea and Leitzaran (northern Spain) are presented. Th...

Is geomorphology at the forefront of river management? The aims of this article are to explore potential answers to this question in terms of role, barriers, motivation and prospects for river management in the Anthropocene Era. We justify and execute our analysis, first through the growing interest in applied geomorphology and its role to improve...

El río Ritort es un afluente del río Ter con diversos obstáculos transversales que dificultan la continuidad longitudinal de la fauna, el caudal y el sedimento. En este artículo se presentan los resultados del seguimiento geomorfológico de la evolución del río Ritort tras la demolición de un azud de 8 m de altura realizada a finales de 2020. Se lle...

El vaciado del embalse de Enobieta constituye un proyecto de restauración fluvial, que ha sido objeto de numerosos estudios de diversa índole para evaluar la capacidad de recuperación de los distintos ecosistemas asociados al espacio recuperado. El sistema fluvial restaurado, responde, de una manera inmediata y eficiente, a las nuevas condiciones h...

This book gives positive examples how humans and rivers have been, and are still in some places, living in harmony. It analyses how this knowledge can be transferred into modern river management schemes and thereby it attempts to mitigate the deplorable trend of the decline of biological and cultural heritages and diversities in and along rivers. A...

Se ha analizado la evolución y relación entre los usos del suelo, el cauce activo y las actuaciones realizadas en el último medio siglo en las cuencas de los ríos Oiartzun y Oria. Se constata una importante reducción de la superficie del cauce activo, con estrechamiento e incremento de la vegetación, coincidiendo en el tiempo con un aumento de la s...

El estudio de la dinámica de los cauces efímeros mediterráneos (CEM) resulta de gran interés, al tratarse de sistemas geomorfológicos expuestos a importantes fluctuaciones recientes en los factores extrínsecos e intrínsecos que los gobiernan. Para obtener una aproximación a su modelo dinámico y comprender su adaptación a diferentes perturbaciones,...

A preliminary version of a global automatic burned-area (BA) algorithm at medium spatial resolution was developed in Google Earth Engine (GEE), based on Landsat or Sentinel-2 reflectance images. The algorithm involves two main steps: initial burned candidates are identified by analyzing spectral changes around MODIS hotspots, and those candidates a...

El río Enobieta recupera su dinámica natural y reorganiza su cauce y riberas tras el vaciado del embalse que ocupaba el valle de Artikutza, uno de los entornos naturales más notables de Euskadi y Navarra por el estado de conservación de sus bosques y por la gran biodiversidad que acoge. La no utilización, desde hace años, de dicho embalse para el u...

The hydromorphological diagnosis and assessment of rivers is a necessary procedure aimed to improve the ecological status of rivers af- fected by notable human impacts. The hydrogeomorphological index IHG was designed 15 years ago for that purpose. Its most updated version and its modality for ephemeral courses (IHG-E) are presented. All applicatio...

In his comment on our recent article “Promoting fluvial geomorphology to ‘live with rivers’ in the Anthropocene Era” (García et al., 2021), Dave Rosgen (2021) suggests that we make three erroneous claims about him and his technical protocol Natural Channel Design (NCD). In this reply, we contextualize and address his comments, analysing the repeate...

The floods of 2015 and 2018 in the Middle Ebro River have led to a rethinking and updating of the forecasting and management systems. The improvements in the flow measurement systems applied in this type of extreme phenomena have led to questioning the values that were recorded in the past, officially changing the maximum flow rates of some histori...

Ephemeral rivers hydromorphological processes are intermittent and many times of fast response. Therefore they remain still quite unknown. The geomorphological mapping of river forms and geomorphological units is a useful tool to recognize the evolution, changes and the response of river adjustments of hydrological events. A diachronic geomorpholo...

Bedload sediment transport was monitored from 2016 to 2020 in the Leitzaran River, in a reach affected by the removal of 7-meters high dam (Oioki dam). The removal was accomplished in two phases, the 3 first meters were removed in September 2018 and the second phase (September 2019) involved the removal of the remaining 4 meters. The study area was...

Los trabajos de hidromorfología fluvial en España se han desarrollado en el presente siglo y han sido abordados en su mayor parte desde la Geografía Física. Esta ciencia aporta una visión integradora de todos los factores, elementos y procesos en la dinámica fluvial, resultando muy útil en el diagnóstico del estado de los ríos y en la propuesta de...

The floods of 2015 and 2018 in the Middle Ebro River have led to a rethinking and updating of the forecasting and management systems. The improvements in the flow measurement systems applied in this type of extreme phenomena have led to questioning the values that were recorded in the past, officially changing the maximum flow rates of some histori...

Los cursos de agua efímeros del ámbito mediterráneo plantean muchas dificultades para que puedan ser objeto de programas de restauración. Los problemas derivan de la gravedad de los impactos geomorfológicos que sufren, de su funcionamiento repentino y esporádico-de ocurrencia a veces impredecible-, de su escasísima consideración en el marco de la g...

Se estudia el transporte de carga de fondo (caudal sólido) mediante el seguimiento en un tramo del río Leitzaran afectado por la presa de Oioki. Se rastrearon 600 partículas de sedimentos utilizando técnicas RFID (radio-frequency identification) en 3 puntos diferentes: tramo control (fuera de los efectos de la presa), tramo aguas arriba y tramo agu...

A set of dimensionless morphological ratios are commonly used as a basis for studies of stream stability and natural channel restoration. Often, such ratios have been obtained from morphometric measurements made in the field and developed into a template for a given geomorphic reference site. The main objective of the present study is to analyze th...

A set of dimensionless morphological ratios are commonly used as a basis for studies of stream stability and natural channel restoration. Often, such ratios have been obtained from morphometric measurements made in the field and developed into a template for a given geomorphic reference site. In this study, high resolution aerial photographs from 2...

Lithological and aridity conditions in the central area of the Ebro Basin favour the abundance of intermittent and ephemeral rivers. These rivers suffer important environmental problems but lack specific scientific studies, and in most cases they are not even considered water bodies in their management. A methodological proposal is launched combini...

Este libro es fruto de las jornadas organizadas por el CIREF y Wetlands International en colaboración con la Agencia Vasca del Agua URA, COBE, AIL, Diputación Foral de Gipuzkoa, Gobierno Vasco y Ayuntamiento de Donostia-San Sebastian en septiembre de 2017 en Urdaibai. El libro ha sido publicado por el Servicio Central de Publicaciones del Gobierno...

La cartografía en general, y la cartografía digital en particular, es una de las herramientas principales en cualquier estudio relacionado con el territorio, cualquiera que sea el elemento del territorio a analizar. La cartografía topográfica, la cartografía temática, la ortofotografía, los modelos digitales nos permiten conocer desde la distancia...

Complete 3D models of five alluvial reaches affected by the removal of Inturia dam (Leitzaran River) have been obtained through laser scanner techniques. Removal was accomplished in four phases, 3 m per year, and completed in January 2016. Data registration started before the removal started in 2013 and every year after. Therefore erosion and sedim...

The use of topographic instruments for massive data capture, like laser scanner, automatic photogrammetry or drones, is very frequent in the geometric documentation of different realities like heritage, industry or geomorphology. However, the apparent simplicity in the handling of such devices and the high speed of the measurement hides the true wo...

River dynamics, global change and human pressure in Ebro basin, channel and delta. The river Ebro and its tributaries has undergone very remarkable changes since 1950. They have suffered marked process of simplification and stabilization, both in the main river and in its main Pyrenean and Iberian tributaries. They show important changes in the cha...

The ecological condition and functionality of the Ebro basin’s rivers have suffered a notable deterioration in the last decades, because of the global change and anthropic pressures. Opposite to this problem, the initiatives of restoration are still scanty, local and very dispersed in the territory. Ebro basin does not stand out at present for rive...

River classification is one of the recommendations of the European Water Framework Directive 2000/60/EC, which establishes that classifications should be carried out according to different variables hierarchically organized from a smaller to a larger scale. We suggest incorporating into the Directive’s hierarchical system a geoecological unit (lith...

River restoration in Ebro basin, a synthesis. The ecological condition and functionality of the Ebro basin’s rivers have suffered a notable deterioration in the last decades, because of the global change and anthropic pressures. Opposite to this problem, the initiatives of restoration are still scanty, local and very dispersed in the territory. Ebr...

Resumen Se trata de la fase inicial de un proyecto que busca la puesta en valor de los ríos en gravas, muy amenazados y en claro proceso de desaparición, siendo al mismo tiempo de alto valor patrimonial. Se presenta el censo y la propuesta preliminar de tipologías de los ríos de gravas en el Pirineo central aragonés. A partir de fotointerpretación...

The methodology and results of two dam removals in two different rivers is presented and compared. One removed all-at-once and the second one in a four-stage removal process. Methodology included topographical measurements of the channel, TLS measurements of river bed and bars and sediment grain size and transport. Morphological channel adjustments...

The application of hydrogeomorphology as a tool for river management and decision making on reference condition definition for river restoration is presented. Water Framework Directive (2000/60/CE) requires the identification of reference conditions and attainable target images, to achieve the good ecological status, taking into account the direct...

RIVER DYNAMICS, GLOBAL CHANGE AND HUMAN PRESSURE IN EBRO BASIN, CHANNEL AND DELTA. The river Ebro and its tributaries has undergone very remarkable changes since 1950. They have suffered marked process of simplification and stabilization, both in the main river and in its main Pyrenean and Iberian tributaries. They show important changes in the cha...

River restoration in Ebro basin, a synthesis. The ecological condition and functionality of the Ebro basin's rivers have suffered a notable deterioration in the last decades, because of the global change and anthropic pressures. Opposite to this problem, the initiatives of restoration are still scanty, local and very dispersed in the territory. Ebr...

The development and application of a methodology for the identification of the morphological reference condition and target image for the morphological restoration in the Oiartzun and Oria basins (Gipuzkoa) is presented. The methodology started with the identification of the geomorphological homogeneous river reaches. Two reach-making processes wer...

The monitoring of the morphological changes of a sand bar in the beach Karraspio (Lekeitio, Biscay) is presented. The annual coastal dynamics and the sand deposition were affected by several coastal storms given in 2011 that broke the Lazunarri dike in several parts. The dike were constructed in the 19th century to protect the sea port from the Lea...

The development and application of a methodology for the identification of the morphological reference condition and target image for river restoration is presented. The methodology started with the identification of the geomorphological homogeneous river reaches. Two reach-making processes were developed; one based on crossed variables by GIS tool...

The monitoring of the morphological changes of a sand bar in the beach Karraspio (Lekeitio, Biscay) is presented. The annual coastal dynamics and the sand deposition were affected by several coastal storms given in 2011 that broke the Lazunarri dike in several parts. The dike were constructed in the 19th century to protect the sea port from the Lea...

RESUMEN: La restauración fluvial es un dominio científico-técnico de reciente y creciente desarrollo. En España y en todos los países es muy destacable la aportación de los geógrafos a la restauración fluvial, especialmente desde el ámbito de la hidrología y la geomorfología fluvial. En este trabajo de síntesis se exponen las principales líneas tem...

Resumen Se presenta la metodología diseñada para el seguimiento geomorfológico del derribo de las presas de Mendaraz (río Urumea) e Inturia (río Leitzaran) en Gipuzkoa, así como los resultados obtenidos. Se han realizado secciones transversales, perfiles longitudinales, abundantes mediciones de procesos sobre testigos, mediciones con escáner láser...

Resumen Con el objetivo de la colaboración en la evaluación periódica del estado de las masas de agua de la categoría ríos en España, se está generando un protocolo de caracterización y valoración de la hidromorfología, que incluye hidrología, conectividad acuíferos-ríos, transporte de sedimentos y morfología fluvial, conectividad longitudinal y fr...

Resumen Se presenta el desarrollo y la aplicación de una metodología para la identificación de la condición de referencia e imagen objetivo alcanzable para la restauración de la morfología fluvial en las cuencas de Oiartzun y Oria en Gipuzkoa. El principio metodológico lo constituye una tipificación, que identifica tramos homogéneos geomorfológicam...

Global change, understood not only as an alteration of climate but also as the anthropic influence on river basins, is affecting control factors of fluvial morphology. Land-use has long changed in the Ebro basin, and so have water flows and sediment yield. In the last decades the construction of reservoirs for irrigation, urban uses, or hydroelectr...

1.Fluvial territory: concept and usefulness 2. Delimitation and cartography 3. Solutions for application difficulties 4. References and more information

A methodology for dam removal monitoring and the results of two case studies is presented: Mendaraz dam (Urumea River) and Inturia dam (Leitzaran River), both located in Gipuzkoa. This monitoring is conducted by river survey cross-sections, measurements of processes and granulometrical analysis. Fast sediment erosion and sedimentation together with...

Landscape shows the natural and cultural heritage of some lands. The assessment of this capacity is the first step for its consideration as the case study of Salinas de Añana and its Salt Valley (Basque Country, Spain). Paleogeographical, geotectonical and morphological factors have drawn a physiographic support: the diapir and, a natural resource,...

A methodology for dam removal monitoring and the results of two case studies is presented: Mendaraz dam (Urumea River) and Inturia dam (Leitzaran River), both located in Gipuzkoa. This monitoring is conducted by river survey cross-sections, measurements of processes and granulometrical analysis. Fast sediment erosion and sedimentation together with...

Dam removal has been demonstrated as one of the most frequent and effective fluvial restoration actions. The results of the geomorphological monitoring implemented in two dams in Urumea and Leitzaran Rivers (northern Spain) are presented. The first one was removed completely whereas the second one is being removed in 4 different phases. Changes in...

The geomorphological monitoring made for one year after the dam removal of Mendaraz (Gipuzkoa) has consisted of river channel cross-sections, longitudinal profiles, lateral and vertical dynamics of river banks measurements from fix points and 200 marked trees, sediment grain size, mobility and transport assessment and river bed morphologies. River...

Arga and Aragón Rivers have registered at their confluence an important fluvial dynamics until the middle of 20th century. However the impacts given in both basins have intensively reduced it and have affected the fluvial planform and sediment yield. A grain size characterization of the sediments on all the sediment bars has been done in order to s...