Ecogeomorfologia i drons com a eines de gestió dinàmica postincendi. El cas de la comarca del Pariatge, Mallorca

Ecogeomorphology and drones as dynamic tools for post-fire management. The experience in the Pariatge County, Mallorca Wildfires are one of the most significant driving factors in desertification processes. Furthermore, insular territories such Mallorca are more affected by human impacts due to their intrinsic socioecological fragility. The increase of burned surface area since 2011 in Balearic Islands involves a challenge in which forest management and research through interdisciplinary and technological advances should be joined. Ecogeomorphology is an emergent discipline which allows investigating the role of geomorphic processes in the vegetation recovery. Additionally, the introduction of unmanned aerial vehicles as remotesensing tools offers new and exciting opportunities for monitoring environmental processes. This paper pretends to elucidate the potential of ecogeomorphology and drones to implement more effective and dynamic post-fire management integrating both the resilience capacity of ecosystems with sediment connectivity for landscape restoration.Els incendis forestals són considerats un dels factors causals més importants en els processos de desertificació. Els territoris insulars com Mallorca són particularment sensibles als impactes antròpics, per la seva major fragilitat socioecològica. L?increment de superfície cremada a Mallorca d?ençà el 2011 esperoneja a vincular gestió forestal i recerca amb interdisciplinarietat i avenços tecnològics. L?ecogeomorfologia permet investigar el paper dels processos geomorfològics en la recuperació de la vegetació. Endemés, la introducció dels vehicles aeris no tripulats com a instruments de teledetecció presenta noves oportunitats en el monitoratge de processos ambientals. Aquest article pretén dilucidar el potencial de l?ecogeomorfologia i els drons per aplicar una gestió postincendi més efectiva i dinàmica, integrant la capacitat de resiliència dels ecosistemes amb la connectivitat dels sediments per restaurar el paisatge.Ecogeomorfología y drones como instrumentos de gestión dinámica post-incendio. El caso de la comarca del Pariatge, Mallorca Los incendios forestales son uno de los factores causales más importantes en los procesos de desertificación. Los territorios insulares como Mallorca son particularmente sensibles a los impactos antrópicos, a causa de su mayor fragilidad socioecológica. El incremento de superficie quemada en Mallorca desde el año 2011 incita vincular gestión forestal e investigación a través de interdisciplinariedad y avances tecnológicos. La ecogeomorfología permite investigar el papel de los procesos geomorfológicos en la recuperación de la vegetación. Además, la introducción de vehículos aéreos no tripulados como instrumentos de teledetección presenta nuevas oportunidades en la monitorización de procesos ambientales. Este artículo pretende dilucidar el potencial de la ecogeomorfología y de los drones para aplicar una gestión post-incendio más efectiva y dinámica, integrando la capacidad de resiliencia de los ecosistemas con la conectividad de los sedimentos para restaurar el paisaje

Sediment fingerprinting and hydro-sedimentary monitoring as tools for catchment management in Mediterranean environments

[eng] Soil erosion is a natural process that encompasses weathering, transport and deposition of soil particles. These processes are essential in terrestrial geochemical cycles. However, the on- and off-site erosion effects are considered to be one of the most important causes of terrestrial and aquatic ecosystems degradation. The characteristics of the Mediterranean region are marked by complex relationships between natural, human, biotic and abiotic variables. In addition, an irregular rainfall distribution, strong seasonality and the physiographic landscape characteristics promote divergent responses in erosion rates and sediment yields. In this context, the Mediterranean basin has the highest sediment yields in all of Europe. In addition, it is emerging as a hot spot point in Global Change dynamics, especially with reference to climate and land use change, which could generate an increase in erosive and sediment transport processes. At the catchment scale, sediment transfer occurs in hill slopes, between hill slopes and channels or within channels. Information on the nature and relative contribution of sediment sources is a key aspect with regard to designing and implementing erosion control strategies in catchments. The main objective of this thesis is to identify erosion and sediment transport processes in two Mediterranean catchments affected by different global change processes at different spatio-temporal scales, improving current techniques for sediment origin determination (i.e., reducing uncertainties, time and cost) so it can better implemented in catchment management plans. For this purpose, the hydro-sedimentary dynamics and the origin of the sediments has been investigated on the island of Mallorca (Spain), in two small catchments; the Sa Font de la Vila catchment -4.8 km2, affected by wildfires - and the Es Fangar catchment (3.4 km2), affected by land use changes. The combination of sediment fingerprinting and hydro-sedimentary monitoring made it possible to assess its hydro-sedimentary dynamics during the study period. In Sa Font de la Vila, results showed a gradual decrease in contribution from burned sources over time, while in Es Fangar the contributions from crops dominated throughout the study period, without substantial changes. Sediment yields were 6.3 t km2 yr-1 and 4.5 t km2 yr-1 for Sa Font de la Vila and Es Fangar respectively, low results in comparison with other Mediterranean catchments. This was mainly attributed to the calcareous lithology, land uses (in Es Fangar catchment), vegetation recovery (in Sa Font de la Vila catchment) and agricultural terraces. The use of soil colour parameters as tracers was successfully evaluated in the two catchments, confirming its suitability as a fast and inexpensive tracer, even in fire-affected catchments. Furthermore, the strong correlations between the measurements made with a spectro-radiometer and a scanner make colour even more accessible for its implementation in catchment management plans. The experiment on tracer conservatism confirmed that in-channel changes suffered by all the analysed tracers (coefficient of variation x̄ 8.1 ± 8.8%) were generally lower than their spatial variability within the catchment (coefficient of variation x̄ 16.3 ± 18.5%). Furthermore, the colour parameters were the least variable tracers (i.e. the most conservative). with a coefficient of variation of 2.6 ± 2.2%. Finally, it was not possible to identify the activation patterns of different sediment sources combining hydro-sedimentary monitoring and sediment fingerprinting. This was probably caused by Es Fangar's catchment stability in terms of the origin of the suspended sediment. Es Fangar catchment sediment source stability is attributed to lithological characteristics, land uses and the presence of agricultural terraces in the study area. However, events of higher magnitude could exceed the sedimentary (dis)connectivity thresholds of the rest of the sources, promoting a sediment cascade effect. The results presented in this thesis are relevant and represent an advance in the optimization of the sediment fingerprinting technique. Despite some limitations that need to be further investigated, hydro-sedimentary monitoring and sediment fingerprinting used in combination was shown to be very useful for integrated catchment management plans in Mediterranean environments.[spa] La erosión es un proceso natural que comprende la meteorización, transporte y depósito de partículas del suelo. Estos procesos son esenciales dentro de los ciclos geoquímicos terrestres. Sin embargo, los efectos in situ y ex situ de la erosión se consideran una de las causas más importantes de la degradación de la calidad en ecosistemas terrestres y acuáticos. Las características de la región mediterránea están marcadas por relaciones complejas entre variables naturales, humanas, bióticas y abióticas. Además, una distribución irregular de las lluvias, una marcada estacionalidad y las características fisiográficas del paisaje promueven respuestas divergentes en las tasas de erosión y producción de sedimentos. En este contexto, la cuenca Mediterránea presenta los rendimientos de sedimento más altos de toda Europa. Además, se perfila como un punto crítico de la dinámica del Cambio Global, especialmente en lo que respecta al Cambio Climático y de uso del suelo, lo que podría generar un aumento de los procesos erosivos y de transporte de sedimento. A escala de cuenca de drenaje, la transferencia de sedimentos ocurre en laderas, entre laderas y canales o dentro de canales. La información sobre la naturaleza y contribución relativa de las fuentes de sedimento es un aspecto clave para diseñar e implementar estrategias de control de la erosión en cuencas de drenaje. El objetivo principal de esta tesis es identificar procesos de erosión y transporte de sedimentos en dos cuencas mediterráneas afectadas por diferentes procesos de cambio global a diferentes escalas espacio-temporales, mejorando las técnicas actuales para la determinación del origen de los sedimentos (es decir, reducir incertidumbres, tiempo y costo) para su mejor implementación en planes de gestión de cuencas de drenaje. Para ello, se investigó la dinámica hidro-sedimentaria y el origen de los sedimentos en dos pequeñas cuencas de drenaje de la isla de Mallorca (España); Sa Font de la Vila -4,8 km2, afectada por incendios forestales - y Es Fangar (3,4 km2), afectada por cambios de usos del suelo. La combinación de la técnica sediment fingerprinting y monitoreo hidro-sedimentario continuo permitió evaluar su dinámica hidro-sedimentaria durante el período de estudio. En Sa Font de la Vila, los resultados mostraron una disminución paulatina de las aportaciones de fuentes quemadas a lo largo del tiempo, mientras que en Es Fangar las aportaciones de las zonas de cultivos dominaron durante todo el período de estudio sin cambios sustanciales. Los rendimientos de sedimentos fueron 6,3 t km2 a-1 y 4,5 t km2 a-1 para Sa Font de la Vila y Es Fangar respectivamente, bajos en comparación con otras cuencas mediterráneas. Esto se atribuyó principalmente a la litología calcárea de las cuencas, los usos del suelo (en Es Fangar), la recuperación de la vegetación (en Sa Font de la Vila) y la presencia de terrazas agrícolas. El uso de parámetros de color como trazadores se evaluó con éxito en las dos cuencas, lo que confirma su idoneidad para su uso como un trazador rápido y económico, incluso en cuencas afectadas por incendios. Además, las fuertes correlaciones entre las medidas tomadas con un espectro-radiómetro y un escáner, hacen del color un trazador muy accesible para su implementación en planes gestión. El experimento sobre conservación de las propiedades de los trazadores mostró variaciones bajas en la mayoría de los trazadores analizados (coeficiente de variación x̄ 8,1 ± 8,8%). Estas fueron generalmente menores que su propia variabilidad espacial dentro de la cuenca (coeficiente de variación x̄ 16,3 ± 18,5%). Además, los parámetros de color fueron los trazadores menos variables (i.e. más conservadores) con un coeficiente de variación de 2,6 ± 2,2%. Finalmente, no fue posible identificar los patrones de activación de diferentes fuentes de sedimentos combinando el monitoreo hidro-sedimentario y sediment fingerprinting. Esto fue causado principalmente por la estabilidad de la cuenca de Es Fangar en términos de origen de sedimentos en suspensión. La estabilidad de las fuentes de sedimentos se atribuyó a las características litológicas, usos del suelo y la presencia de terrazas agrícolas en el área de estudio. Sin embargo, eventos de mayor magnitud podrían superar los umbrales de (des)conectividad sedimentaria del resto de fuentes consideradas y activarlas. Los resultados que presenta esta tesis son relevantes y suponen un avance en la optimización de la técnica sediment fingerprinting. Pese a algunas limitaciones que se han de seguir investigando, se demostró que la combinación de monitoreo hidro-sedimentario y sediment fingerprinting es de gran utilidad para los planes de gestión integrada de cuencas de drenaje Mediterráneas.[cat] L'erosió és un procés natural que comprèn la meteorització, transport i dipòsit de partícules sòl. Aquests processos són essencials dins dels cicles geoquímics terrestres. No obstant això, els efectes in situ i ex situ de l'erosió es consideren una de les causes més importants de la degradació de la qualitat en ecosistemes terrestres i aquàtics. Les característiques de la regió mediterrània estan marcades per relacions complexes entre variables naturals, humanes, biòtiques i abiòtiques. A més, una distribució irregular de les pluges, una marcada estacionalitat i les característiques fisiogràfiques del paisatge promouen respostes divergents en les taxes d'erosió i la producció de sediments. En aquest context, la conca Mediterrània presenta els rendiments de sediment més alts de tot Europa. A més, es perfila com un punt crític de la dinàmica del Canvi Global, especialment pel que fa a el Canvi Climàtic i usos del sòl, la qual cosa podria generar un augment dels processos erosius i de transport de sediment. A escala de conca de drenatge, la transferència de sediments es dona en vessants, entre vessants i canals o dins els canals. La informació sobre la naturalesa i contribució relativa de les fonts de sediment és un aspecte clau per dissenyar i implementar estratègies de control de l'erosió en conques de drenatge. L'objectiu principal d'aquesta tesi és identificar processos d'erosió i transport de sediments en dues conques mediterrànies afectades per diferents processos de Canvi Global a diferents escales espai-temporals, millorant les tècniques actuals per a la determinació de l'origen dels sediments (és a dir, reduir incerteses, temps i cost) per a la seva millor implementació en plans de gestió de conques de drenatge. Per a això, es va investigar la dinàmica hidro-sedimentària i l'origen dels sediments en dos petites conques de drenatge de l’illa de Mallorca (Espanya); Sa Font de la Vila -4,8 km2, afectada per incendis forestals - i Es Fangar (3,4 km2), afectada per canvis d'usos del sòl. La combinació de la tècnica sediment fingerprinting i monitoratge hidro-sedimentari va permetre avaluar la seva dinàmica hidro-sedimentària durant el període d'estudi. A Sa Font de la Vila, els resultats van mostrar una disminució gradual de les aportacions de fonts cremades al llarg del temps, mentre que a Es Fangar les aportacions de fonts de cultius van dominar durant tot el període d'estudi sense canvis substancials. Els rendiments de sediments van ser 6,3 t km2 a-1 i 4,5 t km2 a-1 per a Sa Font de la Vila i Es Fangar respectivament, baixos en comparació amb altres conques mediterrànies. Això es va atribuir principalment a la litologia calcària de les conques hidrogràfiques, els usos de terra (a Es Fangar), la recuperació de la vegetació (a Sa Font de la Vila) i la presència de terrasses agrícoles. L'ús de paràmetres de color com a traçadors es va avaluar amb èxit en les dues conques, la qual cosa confirma la seva idoneïtat per al seu ús com un traçador ràpid i econòmic, fins i tot en conques afectades per incendis. A més, les fortes correlacions entre les mesures preses amb un espectre-radiòmetre i un escàner, fan del color un traçador molt accessible per a la seva implementació en plans gestió. L'experiment sobre conservació de les propietats dels traçadors, va mostrar variacions baixes en la majoria dels traçadors analitzats (coeficient de variació x̄ 8,1 ± 8,8%). Aquestes van ser generalment menors que la seva pròpia variabilitat espacial dins de la conca (coeficient de variació x̄ 16,3 ± 18,5%). A més, els paràmetres de color van ser els traçadors menys variables (i.e. més conservadors) amb un coeficient de variació de 2,6 ± 2,2%. Finalment, no va ser possible identificar els patrons d'activació de diferents fonts de sediments combinant el monitoratge hidro-sedimentari i sediment fingerprinting. Això va ser causa principalment a l'estabilitat de la conca d'Es Fangar en termes d'origen de sediments en suspensió. L'estabilitat de les fonts de sediments s'atribueix a les característiques litològiques, usos de sòl i la presència de terrasses agrícoles en l'àrea d'estudi. No obstant això, esdeveniments de major magnitud podrien superar els llindars de (des)connectivitat sedimentària de la resta de fonts considerades i activar-les. Els resultats que presenta aquesta tesi són rellevants i suposen un avanç en l'optimització de la tècnica sediment fingerprinting. Malgrat algunes limitacions que s'han de seguir investigant, es va demostrar que la combinació de monitorització hidro-sedimentari i sediment fingerprinting és de gran utilitat per als plans de gestió integrada de conques de drenatge Mediterrànies

Post-Fire hidrological and sediment delivery dynamics of two Mediterranean nested catchments

A continuous monitoring network of nested catchments was set - up as soon as possible after the largest wildfire that affected Mallorca, which occurred in July 2013. The Sa Font de la Vila catchment is a Mediterranean afforested catchment of 4.8 km 2 , which is located in the western part of the island. Altitude s range between the 71 to 515 m with an average gradient slope of 38%. The lithology is mainly composed by Keuper clays and loams in the bottom valleys with gentle gradient slopes ca. <10%. Meanwhile, Raethian dolomites and Lias limestones predominate in t he upper parts of the catchment. The intensive agricultural use in the past is witnessed by the widespread occurrence of traditional soil conservation structures (i.e., terraces and valley bottom terraces), occupying 65% of the area. It was affected by 2 l arge wildfires in the last 20 years, i.e. in 1994 and 2013 affecting 44% and 71% of the area, respectively. The Sa Murtera is a headwater sub - catchment of 1.2 km 2 representative of lithology, land uses and fire affection. Altitudes range between the 185 to 515 m with an average gradient slope of 36%. In October 2013, the outlet of both the Sa Font de la Vila and Sa Murtera was instrumented with a gauging station, which recorded water level, average turbidity, electric conductivity and temperature at 15 minu te intervals (average values based on 1 minute readings). Within the study area, also precipitation, air temperature and soil moisture content were measured also continuously with a meteorological station and a humidity probe. The results indicate a very low sediment yield in the two post - fire hydrological years, showing important differences between the two nested catchments, although monitoring problems during the first year (2013 - 14) caused that results were only available from the Sa Font de la Vila. In this station, total runoff and sediment yield were 5 mm and 23 t km - 2 respectively, with a total sediment load of 111 t, although 99% was exported in the first event after the wildfire when 50 mm were accumulated in only 15 minutes. During the second post - fire year (October 2014 - July 2015) in Sa Font de la Vila the tota l runoff was higher with 23 mm. However, the sediment yield was lower – 0.5 t km - 2 – showing a significant decrease. At Sa Murtera, the 31 m m of runoff and 3.3 t km - 2 of sediment yield showed greater results, indicating that most of the sediment yield from t he upstream parts of the catchment must have been deposited before reaching the outlet of the Sa Font de la Vila. Despite the fire effects on erosion and delivery processes, sediment is therefore progressively trapped along the main channel during its tran sport due to the downstream gradient reduction

Rainfall-runoff relationship at different time scales in a mid-mountainous Mediterranean catchment

(1) Mediterranean Ecogeomorphological and Hydrological Connectivity Research Team (http://medhycon.uib.cat), Department of Geography, University of the Balearic Islands, Carretera de Valldemossa Km 7.5 07122, Palma, Spain, (2) Institute of Agro-Environmental and Water Economy Research –INAGEA, University of the Balearic Islands, (3) Institute of Earth and Environmental Science, University of Potsdam, Karl-Liebknecht-Straße 24/25, 14476 Potsdam-Golm, Germany, (4) Institute of Environmental Assessment and Water Research (IDAEA), Spanish Research Council (CSIC), Jordi Girona 18, 08034 Barcelona, Spain Mediterranean catchments are characterized by high inter-intra annual precipitation variability and summer drought. The hydrological regime is characterized by ephemeral behaviour due to the direct rainfall-runoff relationship. Furthermore, extreme precipitations can generate an amount of rainfall higher than 200 mm in 24 hours with short response time. These events occurred normally under wet soil moisture conditions. The Mediterranean catchment morphology is a favourable factor for flash floods: short catchments with a high gradient slope. Others factor that condition the hydrological regime are the presence of limestone lithology and the impact of human activities on fluvial systems as geomorphological changes in channels and flood plains. The aim of this study is analyse the hydrological response of five hydrological years (2012-17) in an agricultural headwater catchment (i.e. < 4 km2) at different time scales. Rainfall-runoff relationship was carried out at annual and seasonal scale through the flow duration computation, the variability index, 30/70 ratio, quick flow response ratio and base flow index. The rainfall-runoff relationship at event scale was carried out through a Pearson correlation matrix using different variables extracted from the hyetograph and hydrograph. These variables were placed into two groups: a) antecedent conditions and b) event conditions. The correlation results determined the involved factors in the hydrological response. At annual scale total flow was present for 42.8% of the time and quick flow was 1.4%. The Variability index value (0.64) was higher than catchments with high dynamics storage (Vi < 0.5). At season scale, winter with 90.6%, showed the highest discharge presence. This highest discharge percentage duration generated a sustained water storage (Vi: 0.55) and increased the soil moisture from autumn getting favourable conditions for runoff generation. Because of that, winter had the highest quick flow duration (3.1%) and also the 30/70 denotes an increase of the flow variability. Autumn and spring had lower percentage of discharge duration than winter, 53% and 41% respectively. Autumn is the season after the dry season when starts again the wet period getting favourable conditions for runoff generation. Spring denotes the importance of the accumulated precipitation contribution of the wet seasons, also indicated for the highest seasonal BFI (0.7). Summer presented flow and quick flow the 0.93% and 0.21% of time respectively. At event scale, peak discharge, mean discharge, runoff and quick flow showed significant correlations (p<0.01) with the total precipitation and correlated with antecedent precipitation of one and three days (p<0.05). Baseflow variables correlated with antecedent precipitation until 15 days before flood date. Peak discharge was the unique hydrological variable that correlated with maximum rainfall intensity 30’. That indicated that a shorter period of rainfall intensity (15min) is not enough to generate a response. So, for peak discharge a combination of two mechanisms is needed to generate runoff: a) surface runoff occur when rainfall intensity exceeds infiltration capacity and b) surface runoff is produced by precipitation over the area where water table is at the surface.Peer reviewe

Runoff and soil moisture as driving factors in suspended sediment transport of a small mid-mountain Mediterranean catchment

Soil moisture conditions play a key role in runoff and sediment load dynamics in river catchments of contrasting ecosystems. However, the highly marked seasonality of Mediterranean climate affects hydrological processes and sediment transport strongly, as evapotranspiration determines a succession of wet, transition and dry periods throughout a hydrological year. This study examines results of soil moisture, water and sediment fluxes during five hydrological years in a representative small mid-mountain Mediterranean catchment. It aims to assess the sediment load contribution and its variability at different temporal scales. Precipitation, runoff and suspended sediment load were calculated at annual, seasonal and event scales to assess inter- and intra-annual variability. A database with 45 events was used to identify the main controlling factors over sediment load thought bivariate relationships and an analysis of soil moisture-discharge and discharge-suspended sediment concentration hysteresis. At the annual scale, lithology, land use and soil conservation structures characteristic of the catchment caused low values of sediment yield, although inter-annual rates varied by up to three orders of magnitude (0.08 to 11.86 t km−2 y−1). Seasonal analysis of accumulated sediment load showed that 80% was generated during the autumn and winter seasons. At the event scale, streamflow and soil moisture were the controlling factors for the largest sediment load contributions. The highest frequency of clockwise discharge-suspended sediment concentration hysteresis revealed that most of the sediment was generated from nearby sources, although the largest sediment loads were contributed under wet antecedent conditions, as depicted by the soil moisture-discharge hysteresis assessment.This research was supported by project CGL2017-88200-R “Functional hydrological and sediment connectivity at Mediterranean catchments: global change scenarios –MEDhyCON2”, funded by the Spanish Ministry of Science, Innovation and Universities, the Spanish Agency of Research (AEI) and the European Regional Development Fund (ERDF). The contribution of Jérôme Latron was supported by the research project PCIN-2017-061/AEI, also funded by the Spanish Government. Josep Fortesa has a contract funded by the Ministry of Innovation, Research and Tourism of the Autonomous Government of the Balearic Islands [FPI/2048/2017]. Julián García-Comendador is in receipt of a pre-doctoral contract [FPU15/05239] funded by the Spanish Ministry of Education, Culture and Sports. Jaume Company is in receipt of a Young Qualified Program funded by the Employment Service of the Balearic Islands and European Social Fund (SJ-QSP 48/19). Some of the meteorological data were provided by the Spanish Meteorological Agency (AEMET).Peer reviewe

Changes in Soil Quality and Hydrological Connectivity Caused by the Abandonment of Terraces in a Mediterranean Burned Catchment

Wildfires and agricultural activities are relevant factors affecting soil quality, hydrological cycle and sedimentary dynamics. Land abandonment leads to afforestation, which increases fire risk and land degradation. However, no studies have yet evaluated the effect of combining the two factors, which occur frequently in Mediterranean ecosystems. This study assessed the changes in soil quality caused by the abandonment of terraces in two microcatchments (&lt;2.5 ha) affected distinctly by wildfires (once and twice burned) and in an unburned control microcatchment by analyzing soil quality parameters, biochemical indices and spatial patterns of hydrological and sediment connectivity. Soil samples were collected in thirty-six plots (25 m2) representing terraced and non-terraced areas within these microcatchments. Unburned non-terraced plots had higher organic matter content and higher microbiological and enzymatic activities than other plots. Plots in abandoned terraces had lower soil quality indices, regardless of the fire effect. Land abandonment induced changes in the spatial patterns of hydrological connectivity, leading to concentrated runoff, enhanced erosion and soil degradation. Fire also negatively affected soil quality in both terraced and non-terraced plots. However, microbiological communities had different positive post-fire recovery strategies (growth and activity), depending on the previous soil conditions and land uses, which is indicative of the resilience of Mediterranean soil ecosystems

Combining sediment fingerprinting and hydro-sedimentary monitoring to assess suspended sediment provenance in a mid-mountainous Mediterranean catchment

[eng] Soil erosion and sediment transport are controlled by complex factors promoting variable responses in catchment's erosion rates and sediment yields. To mitigate eventual negative effects derived from altered fluxes, integrated catchment management plans should assess the sediment cascade from upstream erosive processes, sediment mobilization through hillslopes and within the channel, up to downstream sediment yields. This study links hydro-sedimentary dynamics with sediment fingerprinting source ascription in a mid-mountainous Mediterranean catchment during five hydrological years (2013-2018). Soil colour parameters and fallout radionuclides were used as tracers to predict dominant suspended sediment sources using (i) a Bayesian mixing model (MixSIAR) and (ii) an End Member Mixing Analysis (EMMA). MixSIAR suggested that crops were the dominant source in most of the collected samples. EMMA showed similar results, clustering all except one sediment samples close to the crop and channel bank signatures. In addition, a quantitative hysteresis index was calculated and floods were clustered in function of their hydro-sedimentary characteristics. Despite different patterns were associated to each of the four identified clusters (e.g. different sediment loads and maximum suspended sediment concentrations), correlation between sediment origin and hydro-sedimentary variables was not significant due to the little seasonal variation in source type ascription

Multiple Temporal Scales Assessment in the Hydrological Response of Small Mediterranean-Climate Catchments

27 Pags.- 10 Figs.- 7 Tabls. © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).Mediterranean-climate catchments are characterized by significant spatial and temporal hydrological variability caused by the interaction of natural as well human-induced abiotic and biotic factors. This study investigates the non-linearity of rainfall-runoff relationship at multiple temporal scales in representative small Mediterranean-climate catchments (i.e., <10 km2) to achieve a better understanding of their hydrological response. The rainfall-runoff relationship was evaluated in 43 catchments at annual and event—203 events in 12 of these 43 catchments—scales. A linear rainfall-runoff relationship was observed at an annual scale, with a higher scatter in pervious (R2: 0.47) than impervious catchments (R2: 0.82). Larger scattering was observed at the event scale, although pervious lithology and agricultural land use promoted significant rainfall-runoff linear relations in winter and spring. These relationships were particularly analysed during five hydrological years in the Es Fangar catchment (3.35 km2; Mallorca, Spain) as a temporal downscaling to assess the intra-annual variability, elucidating whether antecedent wetness conditions played a significant role in runoff generation. The assessment of rainfall-runoff relationships under contrasted lithology, land use and seasonality is a useful approach to improve the hydrological modelling of global change scenarios in small catchments where the linearity and non-linearity of the hydrological response—at multiple temporal scales—can inherently co-exist in Mediterranean-climate catchments.This work was supported by the research project CGL2017-88200-R “Functional hydrological and sediment connectivity at Mediterranean catchments: global change scenarios –MEDhyCON2” funded by the Spanish Ministry of Science, Innovation and Universities, the Spanish Agency of Research (AEI) and the European Regional Development Funds (ERDF). The contribution of Jérôme Latron was supported by the research project PCIN-2017-061/AEI also funded by the Spanish Government. Josep Fortesa has a contract funded by the Ministry of Innovation, Research and Tourism of the Autonomous Government of the Balearic Islands (FPI/2048/2017). Julián García-Comendador is in receipt of a pre-doctoral contract (FPU15/05239) funded by the Spanish Ministry of Education, Culture and Sport. Miquel Tomàs-Burguera acknowledges the support from the project CGL2017-83866-C3-3-R financed by the European Regional Development Funds (ERDF) and the Spanish Ministry of Science, Innovation and Universities. Jaume Company is in receipt of Young Qualified Program fund by Employment Service of the Balearic Islands and European Social Fund (SJ-QSP 48/19). Aleix Calsamiglia acknowledges the support from the Spanish Ministry of Science, Innovation and Universities through a pre-doctoral contract (BES-2013-062887).Peer reviewe

Comparison of stage/discharge rating curves derived from different recording systems: Consequences for streamflow data and water management in a Mediterranean island

Obtaining representative hydrometric values is essential for characterizing extreme events, hydrological dynamics and detecting possible changes on the long-term hydrology. Reliability of streamflow data requires a temporal continuity and a maintenance of the gauging stations, which data are affected by epistemic and random sources of error. An assessment of discharge meterings' and stage-discharge rating curves' uncertainties were carried out by comparing the accuracy of the measuring instruments of two different hydrometric networks (i.e., one analogical and one digital) established in the same river location at the Mediterranean island of Mallorca. Furthermore, the effects of such uncertainties were assessed on the hydrological dynamics, considering the significant global change impacts beset this island. Evaluation was developed at four representative gauging stations of the hydrographic network with analogic (≈40 years) and digital (≈10 years) data series. The study revealed that the largest source of uncertainty in the analogical (28 to 274%) and in the digital (17–37%) networks were the stage-discharge rating curves. Their impact on the water resources was also evaluated at the event and annual scales, resulting in an average difference of water yields of 183% and 142% respectively. Such improvement on the comprehension of hydrometric networks uncertainties will dramatically benefit the interpretation of the long-term streamflow by providing better insights into the hydrologic and flood hazard planning, management and modelling. © 2019This work was supported by a research contract funded in 2014 by the Directorate-General of Water Resources (Department of Environment, Agriculture, and Fishery of the Balearic Autonomous Government) and the research project CGL2012-32446 “Assessing hydrological and sediment connectivity in contrasting Mediterranean catchments. Impacts of Global Change-MEDhyCON” funded by the Ministry of Economy and Competitiveness of the Spanish Government. The contribution of Jérôme Latron was supported by the research project PCIN-2017-061/AEI also funded by the Ministry of Economy and Competitiveness of the Spanish Government. Josep Fortesa has a contract funded by Ministry of Innovation, Research and Tourism of the Autonomous Government of the Balearic Islands (FPI/2048/2017). He also acknowledges the support from “la Caixa” Foundation through a mobility grant for young researchers at the Universitat de les Illes Balears with announcement reference number 3111. Julián García-Comendador is in receipt of a pre-doctoral contract (FPU15/05239) funded by the Spanish Ministry of Education and Culture. Aleix Calsamiglia acknowledges the support from the Spanish Ministry of Economy and Competitiveness through a pre-doctoral contract (BES-2013-062887). José Andrés López-Tarazón is in receipt of a Vicenç Mut postdoctoral fellowship (CAIB PD/038/2016) funded by the Vice-presidency and Ministry of Innovation, Research and Tourism of the Autonomous Government of the Balearic Islands. Meteorological data were facilitated by the Spanish Meteorological Agency (AEMET). Authors thank the three anonymous reviewers and the Guest Editor, Prof. Axel Bronstert, for their constructive comments and suggestions that significantly improved the final version of the paper.Peer reviewe

Ecogeomorfología y drones como instrumentos de gestión dinámica post-incendio. El caso de la comarca del Pariatge, Mallorca

Els incendis forestals s&oacute;n considerats un dels factors causals m&eacute;s importants en els processos de desertificaci&oacute;. Els territoris insulars com Mallorca s&oacute;n particularment sensibles als impactes antr&ograve;pics, per la seva major fragilitat socioecol&ograve;gica. L&rsquo;increment de superf&iacute;cie cremada a Mallorca d&rsquo;en&ccedil;&agrave; el 2011 esperoneja a vincular gesti&oacute; forestal i recerca amb interdisciplinarietat i aven&ccedil;os tecnol&ograve;gics. L&rsquo;ecogeomorfologia permet investigar el paper dels processos geomorfol&ograve;gics en la recuperaci&oacute; de la vegetaci&oacute;. Endem&eacute;s, la introducci&oacute; dels vehicles aeris no tripulats com a instruments de teledetecci&oacute; presenta noves oportunitats en el monitoratge de processos ambientals. Aquest article pret&eacute;n dilucidar el potencial de l&rsquo;ecogeomorfologia i els drons per aplicar una gesti&oacute; postincendi m&eacute;s efectiva i din&agrave;mica, integrant la capacitat de resili&egrave;ncia dels ecosistemes amb la connectivitat dels sediments per restaurar el paisatge.Paraules clau: gesti&oacute; postincendi, connectivitat dels sediments, ecofisiologia vegetal, UAV, ecosistemes mediterranis.Ecogeomorphology and drones as dynamic tools for post-fire management. The experience in the Pariatge County, Mallorca Wildfires are one of the most significant driving factors in desertification processes. Furthermore, insular territories such Mallorca are more affected by human impacts due to their intrinsic socioecological fragility. The increase of burned surface area since 2011in Balearic Islands involves a challenge in which forest management and research through interdisciplinary and technological advances should be joined. Ecogeomorphology is an emergent discipline which allows investigating the role of geomorphic processes in the vegetation recovery. Additionally, the introduction of unmanned aerial vehicles as remotesensing tools offers new and exciting opportunities for monitoring environmental processes. This paper pretends to elucidate the potential of ecogeomorphology and drones to implement more effective and dynamic post-fire management integrating both the resilience capacity of ecosystems with sediment connectivity for landscape restoration.Keywords: post-fire management, sediment connectivity, vegetal ecophysiology, UAVs, Mediterranean ecosystems.Los incendios forestales son uno de los factores causales m&aacute;s importantes en los procesos de desertificaci&oacute;n. Los territorios insulares como Mallorca son particularmente sensibles a los impactos antr&oacute;picos, a causa de su mayor fragilidad socioecol&oacute;gica. El incremento de superficie quemada en Mallorca desde el a&ntilde;o 2011 incita vincular gesti&oacute;n forestal e investigaci&oacute;n a trav&eacute;s de interdisciplinariedad y avances tecnol&oacute;gicos. La ecogeomorfolog&iacute;a permite investigar el papel de los procesos geomorfol&oacute;gicos en la recuperaci&oacute;n de lavegetaci&oacute;n. Adem&aacute;s, la introducci&oacute;n de veh&iacute;culos a&eacute;reos no tripulados como instrumentos de teledetecci&oacute;n presenta nuevas oportunidades en la monitorizaci&oacute;n de procesos ambientales. Este art&iacute;culo pretende dilucidar el potencial de la ecogeomorfolog&iacute;a y de los drones para aplicar una gesti&oacute;n post-incendio m&aacute;s efectiva y din&aacute;mica, integrando la capacidad de resiliencia de los ecosistemas con la conectividad de los sedimentos para restaurar el paisaje.Palabras clave: gesti&oacute;n post-incendio, conectividad de sedimentos, ecofisiolog&iacute;avegetal, UAVs, ecosistemas mediterr&aacute;neos