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The process of shoreline change is inherently complex and reliable predictions of shoreline position remain a key challenge in coastal research. Predicting shoreline evolution could potentially benefit from Deep Learning (DL), which is a recently developed and widely successful data-driven methodology. However, so far its implementation for shoreline time series data has been limited. The aim of this contribution is to investigate the potential of DL algorithms to predict interannual shoreline position derived from camera system observations at a New Zealand study site. We investigate the application of Convolutional Neural Networks (CNNs) and hybrid CNN - Long Short-Term Memory networks. We compare our results with two established models, a shoreline equilibrium model, and a model that addresses time scales in shoreline drivers. Using a systematic search and different measures of fitness we found DL models that outperformed the reference models when simulating the variability and distribution of the observations. Overall, these results indicate that DL models have potential to improve accuracy and reliability over current models.

Tide-surge interaction (TSI) is a critical factor in assessing flooding in shallow coastal systems, particularly in estuaries and harbours. Non-linear interactions between tides and surges can occur due to the water depth and bed friction. Global investigations have been conducted to examine TSI, but its occurrence and impact on water levels in Aotearoa New Zealand (NZ) have not been extensively studied. Water level observations from 36 tide gauges across the diverse coast of NZ were analysed to determine the occurrence and location of TSI. Statistical analysis and numerical modelling were conducted on data from both inside and outside estuaries, focusing on one estuary (Manukau Harbour) to determine the impact of TSI and estuarine morphology on the co-occurrence rate of extreme events. TSI was found to occur at most sites in NZ and primarily affects the timing of the largest surges relative to high tide. There were no regional patterns associated with the tide, non-tidal residual, or skew-surge regimes. The strongest TSI occurred in inner estuarine locations and was correlated with the intertidal area. The magnitude of the TSI varied depending on the method used, ranging from -16 cm to +27 cm. Co-occurrence rates of extreme water levels outside and inside the same estuary varied from 20% to 84%, with TSI modulating the rate by affecting tidal amplification. The results highlight the importance of investing in a more extensive tide gauge network to provide longer observations in highly populated estuarine coastlines. The incorporation of TSI in flooding hazard projections would benefit from more accurate and detailed observations, particularly in estuaries with high morphological complexity. TSI occurs in most sites along the coast of NZ and has a significant impact on water levels in inner estuarine locations. TSI modulates the co-occurrence rate of extreme water levels in estuaries of NZ by affecting tidal amplification. Therefore, further investment in the tide gauge network is needed to provide more accurate observations to incorporate TSI in flooding hazard projections.

La ricerca sui criteri seguiti nella scelta dei componenti del Sacro Collegio è stato da sempre uno degli aspetti più salienti della storia del Papato, poiché nel corso dei secoli i parametri di giudizio si sono diversificati. Se da una parte si è mantenuto costante il principio di attribuire la porpora a coronamento di un particolare cursus honorum ecclesiastico, dall’altra la scelta dei singoli candidati è cambiata di pari passo alla volontà del Pontefice regnante, le cui decisioni sono state influenzate da una serie di fattori, tra i quali bisogna menzionare l’azione del Segretario di Stato e la pressione della diplomazia internazionale. In questo contesto vanno interpretate anche le nomine decretate sotto Pio XI, il cui pontificato fu costellato dalla convocazione di 17 Concistori, dalla creazione di 76 cardinali e, persino, dalla rinuncia alla porpora di un cardinale francese.

Les cardinaux sont connus du grand public comme des figures prestigieuses des Églises et des sociétés locales. Ils suscitent aussi l’intérêt des médias internationaux par leur rôle, majeur mais toujours mystérieux, dans l’élection du pape. Pourtant, la nature de leur charge et la réalité de leurs fonctions demeurent largement dans l’ombre. Les membres du Sacré Collège composent une élite qui ne ressemble à aucune autre : aristocratique au sens du choix des « meilleurs », et cependant non héréditaire, à fort ancrage local mais aussi très internationalisée, placée à partir des Lumières et de la Révolution face au défi de s’adapter à la modernité. Cet ouvrage est centré sur les aspects spécifiquement romains de l’activité multiforme des « porporati ». Ceux-ci sont saisis à la fois en tant que corps constitué, sede plena (consistoire) et sede vacante (conclave), qu’individuellement, comme responsables de dicastères de la Curie, acteurs majeurs de la diplomatie vaticane, mais aussi protecteurs de congrégations religieuses, dignitaires de la Cour pontificale et détenteurs d’un « titre » cardinalice symbolisant leur ancrage dans la Ville. Les vingt-cinq contributions réunies dans ce volume, accompagnées d’une bibliographie et de plusieurs index, sont le fruit d’un programme de recherches interdisciplinaires qui a rassemblé une équipe internationale d’historiens et d’historiens du droit, et qui a été conduit par l’École française de Rome, l’Institut catholique de Paris et l’Université Paris-Sud.

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Summary Sediment‐stabilizing and ‐destabilizing organisms, i.e. microphytobenthos (biofilms) and macrozoobenthos (bioturbators), affect the erodibility of muddy sediments, potentially altering large‐scale estuarine morphology. Using a novel eco‐morphodynamic model of an idealized estuary, we investigate eco‐engineering effects of microphytobenthos and two macrozoobenthic bioturbators. Local mud erodibility is based on species pattern predicted through hydrodynamics, soil mud content, competition and grazing. Mud resuspension and export is enhanced under bioturbation and prevented under biostabilization through respective exposure and protection of the supra‐ and intertidal. Bioturbation decreases mud thickness and bed elevations, which increases net mud fluxes. Microphytobenthos reduces erosion, leading to a local mud increase of intertidal sediments. In multi‐species scenarios, an effective mud‐prone bioturbator strongly alters morphology, exceeding that of a more abundant sand‐prone moderate species, showing that morphological change depends on species traits as opposed to abundance. Altering their habitat, the effective mud‐prone bioturbator facilitates expansion of the sand‐prone moderate bioturbator. Grazing and species competition favor species distributions of dominant bioturbators. Consequently, eco‐engineering affects habitat conditions while species interactions determine species dominance. Our results show that eco‐engineering species determine the mud content of the estuary, which suggests large effects on the morphology of estuaries with aggravating habitat degradation., Sediment‐stabilizing and ‐destabilizing organisms alter large‐scale estuarine morphology in a novel eco‐morphodynamic model of an idealized estuary. Mud resuspension and export are enhanced under bioturbation and prevented under biostabilization through respective exposure and protection of the supra‐ and intertidal. This leads to reduced mud content and widening of the estuary under bioturbation and muddy confined morphologies under biostabilization. In multi‐species scenarios, eco‐engineering affects habitat conditions which reorganizes species distribution, while species interactions determine species dominance.

The role of three-dimensionality (3D) in modulating both flow and sediment transport remains poorly understood. 3D bed elevation measurements are difficult to obtain due to irregular dune shapes and submergence. Using photogrammetric tools for topographic reconstruction has become popular in surface studies, yet water refraction makes through-water image capturing of submerged dunes still challenging. We show that through-water images and Structure from Motion (SfM) tools can produce accurate Digital Elevation Models (DEMs) of a measured dune field, with a high level of detail. It is a low-cost and non-intrusive alternative for submerged bed elevation measurements. We provide a detailed SfM workflow, introduce and discuss the use of camera coordinates and underwater ground control points, and processing steps needed to obtain high accuracy DEMs. Our method results in DEMs with mm resolution in controlled laboratory conditions. New data for 23 dune field DEMs from 6 experiments were obtained and are presented. The dune field DEM time series provide insights on dune interaction processes. In our experiments, merging and defect creation were most common. Merging decreases the number of bedforms, and defect creation is responsible for more bedforms. Dunes continue to interact and jostle after achieving equilibrium. Simple crests are much more frequently observed than irregular, sinuous or double crests. Two-dimensional (2D) crest shapes were observed, although crest shapes were generally of 3D nature. Observed dune migration rates are not steady and vary in time and space. Bedform splitting speeds up dune migration, whilst neighbouring dunes tend to accelerate or decelerate. We identify a cascade of processes and show that 3D DEMs at high frequency are required to resolve observed rapid deformations and interaction of dunes. The identified dune interaction processes are inherent to sediment flux (variability), whereas the temporal component of the underlying sediment transport processes is still not well understood in relation to average transport.

Double sandbar systems often characterize the surf zone of wave-dominated beaches and display a variety of poorly explained spatial configurations. Here, we explore the morphodynamic stability of double-barred beaches using a model based on linear stability analysis. Surf zone hydrodynamics are described by coupling depth and wave-averaged conservation of mass and momentum with the wave energy and phase equations, including roller dynamics. A simplified sediment transport formulation relates flow to seabed changes. Under normal wave incidence, an alongshore uniform coast with a cross-shore profile characterized by the presence of two sandbars can be unstable, thereby resulting in the development of crescentic and/or rip channel patterns. Our study demonstrates that sandbar coupling can be either in phase (highs and lows of both sandbars are at the same alongshore position) or out of phase (highs and lows of one sandbar correspond to lows and highs of the other sandbar). In line with observations, results of simulations show a large variability in the possible emerging bottom patterns. Our analysis indicates that modes of which the amplitude of the inner sandbar perturbation is larger than that of the outer sandbar are dominant for large height–depth differences between the two sandbar crests and small offshore wave heights. Patterns related to the outer sandbar dominate for small values of the difference in sandbar depth. For intermediate differences between the two sandbar depths, patterns on both longshore bars appear to be fully coupled (similar growth rates and strongly correlated pattern shapes). For relatively large waves and large depth over the outer sandbar, patterns can also develop close to the shoreline and/or inner surf zone together with patterns in the inner or outer sandbar.

It has been asserted by Vousdoukas et al., that climate change, in particular global sea-level rise (SLR), poses a threat to the existence of sandy beaches. The authors used global data bases of sandy beaches, bathymetry, wave conditions and SLR to drive a simple model based on the ‘Bruun Rule’ to quantitatively evaluate shoreline retreat. To this modelled retreat, they add a background ambient trend in shoreline dynamics and the modelled response of an extreme storm, that together contribute c. 20% of the shoreline retreat. When retreat was more than 100 m by 2100, they declared those beaches extinct. This is an incorrect and potentially damaging finding that must be repudiated along with the associated implications.

Timely monitoring and modeling of landuse change is vital to manage land resources effectively and to rectify defective land use policies, especially in rapidly urbanizing areas. Our research is applied to an annual land use dataset in order to simulate urban expansion in a fast developing area, through a hybrid model coupling Artificial Neural Networks (ANNs), cellular automata (CA), and Markov Chain (MC). The ANNs were optimized to create the urban suitability index (USI) map that was then integrated with CA-MC to spatially allocate urban expansion cells. Two ANNs, multiple-layer perceptron (MLP) and long short-term memory network (LSTM), were implemented comparatively. Since LSTM is able to take into account more temporal information, it outperformed MLP in modelling urban expansion process over a short temporal interval. The results, validated using kappa and fuzzy kappa simulation, indicate that the integration of ANNs with CA-MC can capture the possible nonlinear relationship between urban expansion and its drivers, hence it can accurately simulate and predict urban expansion in the study area.

Timely monitoring and modeling of landuse change is vital to manage land resources effectively and to rectify defective land use policies, especially in rapidly urbanizing areas. Our research is applied to an annual land use dataset in order to simulate urban expansion in a fast developing area, through a hybrid model coupling Artificial Neural Networks (ANNs), cellular automata (CA), and Markov Chain (MC). The ANNs were optimized to create the urban suitability index (USI) map that was then integrated with CA-MC to spatially allocate urban expansion cells. Two ANNs, multiple-layer perceptron (MLP) and long short-term memory network (LSTM), were implemented comparatively. Since LSTM is able to take into account more temporal information, it outperformed MLP in modelling urban expansion process over a short temporal interval. The results, validated using kappa and fuzzy kappa simulation, indicate that the integration of ANNs with CA-MC can capture the possible nonlinear relationship between urban expansion and its drivers, hence it can accurately simulate and predict urban expansion in the study area.

Simple stability relationships are practically useful to provide a rapid assessment of coastal and estuarine landforms in response to human interventions and long‐term climate change. In this contribution, we review a variety of simple stability relationships which are based on the analysis of tidal asymmetry (shortened to “TA”). Most of the existing TA‐based stability relationships are derived using the one‐dimensional tidal flow equations assuming a certain regular shape of the tidal channel cross‐sections. To facilitate analytical solutions, specific assumptions inevitably need to be made e.g. by linearising the friction term and dropping some negligible terms in the tidal flow equations. We find that three major types of TA‐based stability relationships have been proposed between three non‐dimensional channel geometric ratios (represented by the ratio of channel widths, ratio of wet surface areas and ratio of storage volumes) and the tide‐related parameter a/h (i.e. the ratio between tidal amplitude and mean water depth). Based on established geometric relations, we use these non‐dimensional ratios to re‐state the existing relationships so that they are directly comparable. Available datasets are further extended to examine theutility of these TA‐based relationships. Although a certain agreement is shown for these relationships, we also observe a large scatter of data points which are collected in different types of landscape, hydrodynamic and sedimentologic settings over the world. We discuss in detail the potential reasons for this large scatter and subsequently elaborate on the limited applicability of the various TA‐based stability relationships for practical use. We highlight the need to delve further into what constitutes equilibrium and what is needed to develop more robust measures to determine the morphological state of these systems.

Simple stability relationships are practically useful to provide a rapid assessment of coastal and estuarine landforms in response to human interventions and long‐term climate change. In this contribution, we review a variety of simple stability relationships which are based on the analysis of tidal asymmetry (shortened to “TA”). Most of the existing TA‐based stability relationships are derived using the one‐dimensional tidal flow equations assuming a certain regular shape of the tidal channel cross‐sections. To facilitate analytical solutions, specific assumptions inevitably need to be made e.g. by linearising the friction term and dropping some negligible terms in the tidal flow equations. We find that three major types of TA‐based stability relationships have been proposed between three non‐dimensional channel geometric ratios (represented by the ratio of channel widths, ratio of wet surface areas and ratio of storage volumes) and the tide‐related parameter a/h (i.e. the ratio between tidal amplitude and mean water depth). Based on established geometric relations, we use these non‐dimensional ratios to re‐state the existing relationships so that they are directly comparable. Available datasets are further extended to examine theutility of these TA‐based relationships. Although a certain agreement is shown for these relationships, we also observe a large scatter of data points which are collected in different types of landscape, hydrodynamic and sedimentologic settings over the world. We discuss in detail the potential reasons for this large scatter and subsequently elaborate on the limited applicability of the various TA‐based stability relationships for practical use. We highlight the need to delve further into what constitutes equilibrium and what is needed to develop more robust measures to determine the morphological state of these systems.

Infragravity (hereafter IG) waves are surface ocean waves with frequencies below those of wind-generated “short waves” (typically below 0.04 Hz). Here we focus on the most common type of IG waves, those induced by the presence of groups in incident short waves. Three related mechanisms explain their generation: (1) the development, shoaling and release of waves bound to the short-wave group envelopes (2) the modulation by these envelopes of the location where short waves break, and (3) the merging of bores (breaking wave front, resembling to a hydraulic jump) inside the surfzone. When reaching shallow water (O(1–10 m)), IG waves can transfer part of their energy back to higher frequencies, a process which is highly dependent on beach slope. On gently sloping beaches, IG waves can dissipate a substantial amount of energy through depth-limited breaking. When the bottom is very rough, such as in coral reef environments, a substantial amount of energy can be dissipated through bottom friction. IG wave energy that is not dissipated is reflected seaward, predominantly for the lowest IG frequencies and on steep bottom slopes. This reflection of the lowest IG frequencies can result in the development of standing (also known as stationary) waves. Reflected IG waves can be refractively trapped so that quasi-periodic along-shore patterns, also referred to as edge waves, can develop. IG waves have a large range of implications in the hydro-sedimentary dynamics of coastal zones. For example, they can modulate current velocities in rip channels and strongly influence cross-shore and longshore mixing. On sandy beaches, IG waves can strongly impact the water table and associated groundwater flows. On gently sloping beaches and especially under storm conditions, IG waves can dominate cross-shore sediment transport, generally promoting offshore transport inside the surfzone. Under storm conditions, IG waves can also induce overwash and eventually promote dune erosion and barrier breaching. In tidal inlets, IG waves can propagate into the back-barrier lagoon during the flood phase and induce large modulations of currents and sediment transport. Their effect appears to be smaller during the ebb phase, due to blocking by countercurrents, particularly in shallow systems. On coral and rocky reefs, IG waves can dominate over short-waves and control the hydro-sedimentary dynamics over the reef flat and in the lagoon. In harbors and semi-enclosed basins, free IG waves can be amplified by resonance and induce large seiches (resonant oscillations). Lastly, free IG waves that are generated in the nearshore can cross oceans and they can also explain the development of the Earth's “hum” (background free oscillations of the solid earth).

We integrate published data sets of field and laboratory experiments of wave ripples and use genetic programming, a machine learning paradigm, in an attempt to develop a universal equilibrium predictor for ripple wavelength, height, and steepness. We train our genetic programming algorithm with data selected using a maximum dissimilarity selection routine. Thanks to this selection algorithm we use less data to train the genetic programming software, allowing more data to be used as testing (i.e. to compare our predictor vs. common prediction schemes). Our resulting predictor is smooth and physically meaningful, different from other machine learning derived results. Furthermore our predictor incorporates wave orbital ripples that were previously excluded from empirical prediction schemes, notably ripples in coarse sediment and long wavelength, low height ripples (‘hummocks’). This new predictor shows ripple length to be a weakly nonlinear function of both bottom orbital excursion and grain size. Ripple height and steepness are both nonlinear functions of grain size and predicted ripple length (i.e. bottom orbital excursion and grain size). We test this new prediction scheme against common (and recent) predictors and the new predictors yield a lower normalized root mean squared error using the testing data. This study further demonstrates the applicability of machine learning techniques to successfully develop well performing predictors if data sets are large in size, extensive in scope, multidimensional, and nonlinear. © 2017. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/

The storm erosion hazard on coasts is usually expressed as an erosion volume and/or associated episodic coastline retreat. The accurate assessment of present-day and future storm erosion volumes is a key task for coastal zone managers, planners and engineers. There are four main approaches that can be used to assess storm erosion volumes for coastal management/planning purposes. These approaches include: extrapolated wave exceedance characteristics (EWEC) approach, synthetic design storm (SDS) approach; Corbella and Stretch (CS) approach; and the joint probability method (JPM) approach. The EWEC and SDS approaches can only return a single deterministic estimate of storm erosion volume associated with a design storm wave height. However, in situations where a hazard assessment study is hindered by budgetary, computational or modelling skill constraints, these approaches may still be used to support coastal management/planning strategies if the user is acutely aware of the caveats associated with thus calculated storm erosion volume estimates.

The development and evolution of crescentic patterns in double-barred systems is explored using a morphodynamic stability model. The description of the surf zone hydrodynamics is based on depth and wave averaged conditions while sediment transport is calculated using a total load formula. The linear stability analysis predicts that an initially rectilinear coast, subject to infinitesimal perturbations and under normal wave incidence, is unstable and can result in the development of crescentic shapes that can be coupled either in-phase (highs and lows of both sandbars are at the same alongshore position) or out-of-phase (highs and lows of one sandbar correspond to lows and highs of the other sandbar). Results of numerical simulations are sensitive to some of the parameterizations used in the description of hydrodynamics. Changes in the breaker index can have an effect not only on the spacing and growth rate of the pattern but also on the type of pattern that develops. An increase in the breaker index leads to a faster growth of the pattern but also to a smaller alongshore spacing. The role of parameterizations in lateral mixing and roughness length appear to be limited.

The possibility that the periodic features observed in the nearshore region are the result of self-organisational processes is investigated in this work. The behaviour of two numerical models, based on different techniques, has been analysed in order to describe the formation of periodic features in the surf and swash zone respectively. The appearance of periodic patterns in the nearshore region has been traditionally linked to the presence of standing edge waves with the topographic changes passively driven by the flow patterns. A more recent approach indicates the possibility that periodic patterns appear because of feedback processes between beach morphology and flow. In the first model, the coupling between topographic irregularities and wave driven mean water motion in the surf zone is examined. This coupling occurs due to the fact that the topographic perturbations produce excess gradients in the wave radiation stress that cause a steady circulation. To investigate this mechanism, the linearised stability problem in the case of an originally plane sloping beach and normal wave incidence is solved. It is shown that the basic topography can be unstable with respect to two different modes: a giant cusp pattern with shore attached transverse bars that extend across the whole surf zone and a crescentic pattern with alternate shoals and pools at both sides of the breaking line showing a mirroring effect. For the swash zone, the formation of beach cusps has been investigated. The several theories proposed in the past have been analysed and all the field and laboratory measurements available in the literature collected in order to test such theories. It is suggested that, with the available measurements it is not possible to distinguish between the standing edge wave model and the self-organisation approach. A numerical model based on self-organisation has been here developed and tested in order to understand the processes occurring during beach cusp formation and development, to evaluate the sensitivity towards the parameters used and to look at how the model might relate to field observations. Results obtained confirm the validity of the self-organisation approach and its capacity to predict beach cusp spacing with values in fair agreement with the available field measurements and with most of the input parameters primarily affecting the rate of the process rather than the final spacing. However, changes in the random seed and runs for large numbers of swash cycles reveal a dynamical system with significant unpredictable behaviour. A qualitative comparison between the model results and field measurements collected by Masselink et al. (1997) during beach cusp formation and development has also been performed on the basis of a non-linear fractal technique. Results indicate beach locations and time-scales where non-linearities are more important and self-organisation can play a fundamental role.

Tidal networks are characterized by an intricate hierarchy of channels and shoals, acting as one of the most striking morphological features in coastal and estuarine environments. Located at the land-sea boundaries, they are shaped by feedbacks between a variety of processes operating over a wide range of temporal and spatial scales. The aim of this thesis is to investigate the effects of the major processes and their associated feedbacks on the long-term morphodynamics of tidal networks. Through a comparative study of physical and numerical modeling of tidal networks, this research indicates that fast- and small-scale models can reproduce the long-term morphological evolution of tidal networks. Quantitative comparisons in terms of a variety of different geometric measures are conducted and suggest that numerical modeling is a useful tool to unravel the mechanisms underlying the morphodynamic behaviors of tidal networks. This research also constructs a comprehensive framework to study the river-influenced tidal network system and explores the physics governing the distribution of different types of sediment on intertidal flats. RESUMEN: Los canales mareales son elementos característicos de los ambientes estuarinos. Estos canales se forman por el predominio de las corrientes de marea sobre el oleaje y los aportes fluviales. Los canales mareales consisten en un intrincado sistema que se caracterizada por la presencia de canales que se van ramificando y por la presencia de bajos mareales que albergan una flora y fauna de gran valor ecológico. El objetivo general de esta investigación es obtener los conocimientos fundamentales de la morfodinámica a largo plazo de los canales mareales, enfocándose principalmente en los procesos y reacciones que dan forma a estos paisajes. Este estudio verifica que los modelos de pequeña escala acelerados pueden reproducir la evolución morfológica a largo plazo de las redes mareales de una manera correcta. Los resultados obtenidos indican concordancia entre las características geométricas de los canales mareales obtenidos numéricamente y los obtenidos de manera experimental. Además, este estudio aborda el efecto del caudal fluvial en la evolución morfológica de los canales mareales, y explora la dinámica de la clasificación de los sedimentos cohesivos y no cohesivos en los bajos mareales.

RESUMEN: El objetivo general es avanzar en el conocimiento del funcionamiento de los sistemas estuarinos y mejorar nuestra capacidad de gestionarlos de una manera sostenible. Es por ello que en el capítulo 1 se desarrolla una metodología para ayudar a los gestores en la toma de decisiones y priorizar las acciones de restauración basándose en los efectos morfodinámicos que cada acción puede ocasionar en el estuario. Uno de los elementos morfodinámicos estudiados son los canales mareales, que desempeñan un papel clave en la hidrodinámica del sistema y por lo tanto en el intercambio de sustancias que entran y salen del estuario. Es por ello que cobra gran relevancia la forma en el que el volumen de agua se distribuye por el sistema, es decir la distribución de la red de drenaje. En los capítulos 2 y 3 se estudia la evolución y organización de esta red de canales (red de drenaje), tratando de determinar la existencia de posibles relaciones de escala en diversas características de la red de drenaje del estuario. Estas características de escala se muestran como una medida estadística representativa de las propiedades geométricas del sistema que no dependan de los detalles específicos del sistema. Una vez explorada la caracterización estadística de la estructura de una red de drenaje en un sistema mareal, en el capítulo 4 se realiza un ejercicio teórico que tiene como objetivo analizar como esa estructura se ve afectada por diferentes acciones de restauración. ABSTRACT: The general objective of the thesis is to advance in the understanding of the behavior if estuarine systems and improve our capabilities to manage them in a sustainable way. It is for this reason that in chapter 1 a new methodology has been developed in order to help managers and decision makers to prioritize the restoration actions based on the morphodynamics effect that each action may induce in the recovery of the estuary. One of the morphodynamic elements studied are the tidal channels, which play a key role in the hydrodynamic of the system and therefore the exchange of substances into and out of the estuary. Therefore becomes very relevant how the volume of water through the system is distributed, ie the distribution of drainage network. For this reason in Chapters 2 and 3 the evolution and organization of channel network (drainage network) has been studied, trying to determine the existence of scaling relationships in several features that can characterize the drainage network in the estuary. These scale relationships will be shown to be a representative statistical measure of estuarine geometric properties that do not depend on the specific details of the estuary. Having explored that statistical characterization of a tidal system drainage network, in chapter 4 a theoretical analysis has been performed which aims to analyzed how this statistical structure is affected by the different restoration actions.