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. The one from the River Urumea, originally 3.5 m high and impounding 500 m of river course, was removed instantaneously whereas that in the River Leitzaran, 12.5 m high, and impounding 1500 m of river course, is in its second phase of a four‐stage removal process. Changes in channel morphology, sediment size and mobility and river bed morphologies were assessed. The monitoring included several different techniques: topographical measurements of the channel, terrestrial laser scanner measurements of river bed and bars, sediment grain size and transport; all of them repeated in four (May, August, November 2011 and May 2012) and five (July and September 2013, April and August 2014 and June 2015) fieldwork campaigns in the River Urumea and River Leitzaran, respectively. Geomorphic responses of both dam removals are presented, and compared. Morphological channel adjustments occurred mainly shortly after dam removals, but with differences among the one removed instantaneously, that was immediate, whereas that conducted by stages took longer. Degradational processes were observed upstream of both dams (up to 1.2 m and 4 m in the River Urumea and River Leitzaran, respectively), but also aggradational processes (pool filling), upstream of Inturia Dam (2.85 m at least). Less evident aggradational processes were observed downstream of the dams (up to 0.37 m and 0.50 m in the River Urumea and River Leitzaran, respectively). Flood events, especially a 100 year flood registered during the monitoring period of Mendaraz Dam removal, reactivated geomorphological processes as incision and bank erosion, whereas longitudinal profile recovery, grain‐size sorting and upstream erosion took longer. Copyright © 2016 John Wiley & Sons, Ltd.

ResumenLos estudios hidrológicos y geomorfológicos se han incrementado en los últimos años indicando su importancia para entender el funcionamiento de los sistemas fluviales. En esta investigación se evaluó la calidad hidrogeomorfológica del río Utcubamba, ubicado en la cuenca del Amazonas, mediante la aplicación del Índice Hidrogeomorfológico (IHG) dividiéndolo en ocho sectores fluviales. Los resultados mostraron que el río Utcubamba está afectado por notables impactos antropogénicos que alteran las condiciones hidrogeomorfológicas, con un creciente deterioro de las mismas desde su nacimiento a su desembocadura. La calidad de las riberas es la más afectada en toda la cuenca, principalmente en el curso bajo debido a las explotaciones agropecuarias de carácter extensivo dominantes en este tramo. Por otra parte, el IHG presentó una adaptabilidad total a las condiciones del área de estudio, en un ámbito geográfico diferente y alejado de la Península Ibérica. Palabras clave: Hidrología, IHG, índice, valoración, calidad, ríos, Utcubamba. AbstractHydrological and geomorphological studies have increased in recent years indicating their importance to understand the functioning of river systems. In this research, the hydrogeomorphological quality of the Utcubamba River, located in the Amazon basin, was evaluated. By applying the Hydrogeomorphological Index (IHG) along its main watercourse the basin was divided into eight river sections. The results showed that the Utcubamba River is affected by significant anthropogenic impacts which modify the hydrogeomorphological conditions, with an increasing damage of them from its river source to his mouth. The quality of the riverbanks is most affected along the entire basin, mainly in the lower course due to extensive agriculture and livestock farms that are dominant in this part. Moreover, the IHG showed a complete adaptability to the conditions of the study area, in a different geographical area and far from the Iberian Peninsula.

The IHG index for hydromorphological quality assessment of rivers and streams: updated versionAn updated version of the IHG index is presented. The index is based on three appraisal parameters: 1) the functional quality of the fluvial system, including a) flow regime naturalness, b) sediment supply and mobility, and c) floodplain functionality; 2) the channel quality, including a) channel morphology and planform naturalness, b) riverbed continuity and naturalness of the longitudinal and vertical processes, and c) riverbank naturalness and lateral mobility; and 3) the riparian corridor quality, including a) longitudinal continuity, b) riparian corridor width, and c) structure, naturalness and cross-sectional connectivity.

<p>Ephemeral streams are an important reality in the Mediterranean area, constituting more than 50% of the channel network in the eastern region of the Iberian Peninsula. The northernmost cases are located in the semi-arid areas of the Ebro basin. Among the 592 cases registered (under the CCAMICEM project) in the Ebro basin, the Rambla de Cariñena stands out for its representativeness and dimensions.</p><p>With a basin area of 330 km<sup>2</sup>, it drains the northern piedmont of Sierra de Algairén (Iberian Mountain Range). It is a temporary river in its headwaters and upper course (Frasno River), which becomes ephemeral (Rambla) in its middle and lower courses, where it forms a large gravel bed river morphology, until it disappears without flowing into any river. In the past, there are references, as well as geomorphological evidence, that it had surface flow, but intensive vineyard agriculture and the global change recorded in the last 50 years have transformed it in ephemeral.</p><p>Recent years have showed relevant flash-floods, such as in the springs of 2008, 2015 and 2018. Its geomorphological dynamics is very interesting, with a highly sinuous meander, formation and destruction of gravel bars in each flood, and some incipient signs of incision. The Rambla de Cariñena constitutes a remarkable case for analyzing climate and global change in this type of fluvial course, as it has been worked on in the CCAMICEM project.</p><p>In this project, different characterization, assessment and monitoring works have been carried out in recent years, applying river survey techniques such as field reconnaissance, analysis and geomorphological mapping using drone flights, and radioelectric tomography to observe the depth of the alluvium. The evolutionary dynamics of the Rambla de Cariñena has also been explained through a multi-temporal analysis using aerial images and LiDAR PNOA data with a density of 0.5-4 points/m² to model the current channel. And the IHG hydrogeomorphological index has been applied to observe its impacts and assess its ecological status.</p><p>All this work has result in a database which is a base to follow the evolution of these streams in the future, as well as a pilot research for these river typologies in the Ebro basin and the identification of symptoms linked to climate change.</p><p>Key words: river survey techniques, flash flood, channel dynamics, IHG index, Rambla de Cariñena</p>