bluuebunny/crossref_metadata_2025 huggingface dataset:
Detection and prediction of illicit drilling by combination of drought indices and NDVI: case of the Nadhour-Saouaf aquifer (Northeast Tunisia)
Authors: Gargouri Emna , Slama Fairouz , Khmiri Khaoula , Dakhlaoui Hammouda , Chakroun Hedia
Published: September 2022

In Tunisia, illicit drilling exists since the 1980s in both southern and central Tunisia. Since 2011, with the weakening of the administration control, farmers and landowners have been drilling in a frantic manner in the various aquifers throughout the country. According to DGRE (Direction Générale des Ressources en Eau), aquifers are in advanced overexploitation, more accentuated in case of drought. It would therefore be relevant to monitor, detect and forecast this phenomenon by combining drought (SPEI and SGI) and remote sensing (NDVI) indices.

The objective of this work is the monitoring, detection and prediction of illicit drilling by the cross-checking and exploitation of hydroclimatic and vegetation indices, derived from remote sensing for Nadhour-Saouaf aquifer. SPEI makes it possible to consider precipitation and evapotranspiration on different time scales which facilitates the analysis of drought impact on water resource demands. The same is true for SGI, which makes it possible to analyse the water table level. As for NDVI calculated on time series, it allows monitoring the state of crops and their development over time.

These different indices have been used in different contexts to detect anomalies that would be interpreted as illicit drilling, since the detection of significant plant cover in drought conditions could indicate the existence of such drilling. We first computed SPEI and SGI from time series of rainfall (series of more than 30 years derived from DGRE Zaghouan database), temperatures and piezometric levels. The analysis allowed to (1) describe, summarizing, and evaluating the data and (2) Fill gaps. Then, we extracted NDVI time series from LANDSAT data. Finally, the multidimensional exploratory analysis of the three indices combined (SPEI, SGI, NDVI) revealed relationships between them.

A robust indicator is currently being constructed to detect the probable existence of illicit drilling. The variation of this indicator will make it possible to detect the over-exploitation of aquifers caused by these drillings, based on DGRE data. This analysis, moreover, considered the social typology of farmers in the study area and was supported by interviews with farmers. This index makes it possible to analyse the socio-spatial and temporal evolution of the study area.
Fluvial sediment transport degradation after dam construction in North Africa.
Authors: El Aoula Rajae , Mhammdi Nadia , Dezileau Laurent , Mahe Gil , Kolker Alexander
Published: September 2022

Recent reductions of sediment transport are observed in Bouregreg River and estuary close to the city of Rabat in Morocco. The cause of this evolution in sediment transport which may be due to human activities (dam, pollution), climate variability and natural events has been investigated from a paleo-hydrological approach. Sedimentological and geochemical analyses of slackwater flood deposits are used to assess the impact of a dam installed in 1974 and the climate change on the evolution of sediment transport during about 60 years. Higher accumulation rate of about 3,64 cm/year is observed between 1950 and 1978, whereas it was much lower about 0,41 cm/year between 1990 and 2017. This strong decrease in sediment rate appears much more due to the impact of dam construction rather than to climate change, however climate change in an increasing concern for the future.
Long-term climatological SM2RAIN datasets for rainfall spatiotemporal analysis 
Authors: Mosaffa Hamidreza , Filippucci Paolo , Massari Christian , Ciabatta Luca , Brocca Luca
Published: September 2022

A long-term rainfall dataset with high spatial and temporal resolution is an indispensable resource for climatological studies. This information is crucial for water resource management. Among available rainfall products, SM2RAIN datasets estimate rainfall from satellite soil moisture observation through the so-called “bottom-up” approach. Previous research has indicated the high performance of rainfall estimation of SM2RAIN products over different parts of the globe. SM2RAIN-CCI and SM2RAIN-ASCAT are two rainfall products that estimate rainfall at 0.25° and 0.1° spatial and daily temporal resolution for the period of 1998-2015 and 2007-2020 on a global scale, respectively. The goal of this study is to design the long-term climatological datasets with 0.25° spatial and monthly temporal resolution for the period from 1998 to 2020 by merging these two SM2RAIN products for spatiotemporal investigation of rainfall over the United States of America as a case study. Moreover, the spatiotemporal analysis results of the resulting product are compared with other rainfall products based on ground observations and reanalysis, such as the Global Precipitation Climatology Project (GPCP) and ERA5. The results show a good agreement of the developed SM2RAIN-based monthly rainfall dataset with respect to GPCP and ERA5 and pave the way to build a global scale dataset based on satellite soil moisture data through SM2RAIN.
Estimating Land Use Changes due to Levee Improvement: A Case Study of the Kiso River Basin in Japan from the 1890s to 2000s
Authors: Nakai Fuko , Matsukawa Ryo , Nakamura Shinichiro
Published: September 2022

The development of modern flood control infrastructures has reduced the human and economic damage caused by floods. Nevertheless, the reduced frequency of floods may increase the number of people in the floodplain because of low awareness of disasters, thus increasing the exposure of society (Di Baldassarre et al., 2013). To examine this human-water interaction, in this study, we empirically analyzed how flood control infrastructures (i.e., levees) have affected land use in the floodplain. We considered the Kiso River basin in Japan as the research domain, where the population has significantly increased over 100 years. The traditional flood control culture that involves living with discontinuous levees known as "Kasumi levees" and "Wajyu levees" (ring levees) has rapidly replaced modern flood control technologies. We attempted to understand the impact of levee improvement when dealing with various complex factors that influence land use. Land use in hazardous areas can be affected not only by levees but also other infrastructures and industries that are located in the area; this can bias the estimation of the impact on land use "with" and "without" levees. We employed the propensity score method (PSM) to control these variables that influence the impact estimation. PSM is a quasi-experimental method that generates an artificial control group (area "without" levees) by matching each treated area (area "with" levees) with a non-treated area having similar characteristics. We also employed the difference-in-differences method for the time-series change detection of the data controlled by the PSM. We generated the data from maps of the Kiso River basin from the 1890s to the 2000s. These maps are provided by the Geospatial Information Authority of Japan. They are of uniform quality and depict the entire land area of Japan. We traced not only levees and land use but also the location of schools, industries, and infrastructures in the Kiso River basin as GIS data and developed them as panel data. Finally, we identified the affected area by installing modern flood control facilities such as levees and when the impact emerged.
Impacts of climate change and forestation on the hydrology of a tropical catchment in Indonesia
Authors: Marhaento Hero , Booij Martijn J. , Rahardjo Noorhadi
Published: September 2022

The aim of this study is to assess the impacts of climate change and forestation on the hydrology of a tropical catchment in Java, Indonesia. The study area is an exemplary case in Indonesia where a forestation programme has been implemented at the catchment scale. The hydrological effects of this forestation programme, in combination with climate change effects, have not been assessed. The individual and combined effects of climate change and forestation on the hydrology are assessed by employing a calibrated Soil and Water Assessment Tool (SWAT) model. Different water balance components are considered including streamflow, surface runoff, lateral flow, base flow and evapotranspiration. The results show that the forest area has increased from 2.7 to 12.8% of the catchment area from 2006 to 2019. In the same period the mean annual and seasonal temperature, rainfall and streamflow have increased as well. The SWAT simulations show that the effects of forestation on the annual and seasonal water balance components were relatively small, while the effects of climate change on these components were more pronounced. The combined effects of climate change and forestation show the dominant influence of climate change and both opposite effects of climate change and forestation on water balance components (e.g. for streamflow) and similar effects (e.g. for evapotranspiration). The outcomes of this study indicate that the forestation programme has small impacts on water balance components in the study catchment on an annual scale compared to the impacts of climate change. However, seasonally, forestation has resulted in a decrease in streamflow and surface runoff during the wet season which may reduce the flood risk. At the same time, the effects of forestation on severe drought events in the dry season should be carefully monitored. In conclusion, this study showed the relative importance of climate change and forestation impacts on water balance components and the potential of forestation programmes to flatten extreme events on a seasonal scale.
Does Groundwater Dynamics Impact Heat Waves Simulations and Projections? Explicit Groundwater Representation in a State-of-the-art Regional Climate Model Ensemble over Europe
Authors: Furusho-Percot Carina , Poshyvailo-Strube Liubov , Hartick Carl , Goergen Klaus , Kollet Stefan
Published: September 2022

Recent record-breaking heat wave events around the world raised awareness and concerns that these extremes are more likely to happen due to global warming. Previous studies showed that coupling a 3D groundwater representation to the land surface of regional climate models impacts near-surface air temperatures (Keune et al., 2016; Barlage et al., 2021). However, the effect of groundwater dynamics on long-term simulations and climate projections remains to be explored. In order to advance our physical understanding, in climate time scale simulations, we applied the Terrestrial Systems Modelling Platform (TSMP, Shrestha et al., 2014), which closes the terrestrial water cycle and includes a 3D variably saturated groundwater flow representation. First, we evaluated the TSMP heat waves climatology forced by ERA-Interim (Furusho-Percot et al., 2019) in the context of a representative EURO-CORDEX Regional Climate Model ensemble, and an observational reference data (E-OBS). In our evaluation, TSMP shows consistently improved statistics with respect to observations in comparison to the RCM ensemble. Then, we used TSMP with 3D groundwater to downscale a CMIP5 Global Climate Model (MPI-ESM-LR, r1i1p1 experiment by the Max-Planck Institute) simulation over Europe and compared to RCM similar EURO-CORDEX downscaling experiments for the periods of 1976-2005 and 2006-2099 using the RCP2.6 and RCP8.5 scenarios. With the fully coupled TSMP simulations, we are able to address the following questions: How are future heat waves going to evolve in Europe under near-natural conditions? How does the evolution differ from the projections of climate models that do not consider groundwater dynamics explicitly? Future work will additionally consider groundwater use scenarios to identify the role of groundwater for drought and heat wave mitigation.
When the exception becomes the rule: learning how to govern water scarcity in the French Grand Est Region. Analysis of the regulatory work of State services.
Authors: Fernandez Sara , Barbier Rémi , Antoine Charles , Liziard Sophie
Published: September 2022

This communication analyzes how the administration of the Grand-Est region in France seizes an existing drought management instrument, the administrative decrees limiting or suspending water use, to deal with a situation considered as unprecedented, where the lack of water goes from a status of cyclical crisis to that of a structural problem. The administration grasps and also transforms this device to stimulate new ways of dealing with the material environment, to draw boundaries and spaces for action or inaction. This work is based on a quantitative and qualitative analysis. We gathered all the "drought decrees" issued between 2010 and 2020 in the départements that belong to the Grand-Est Region in order to build a typology. We also conducted a dozen semi-structured interviews in several regional and departmental State services.

We analyze the administrative acculturation to drought and the processes associated with it. They concern (i) socio-technical infrastructures (measurement networks, drought committees), (ii) organization and professionalization, as well as (iii) negotiation and coordination of public officers' fields of competence. In particular, we mobilize the "framing - overflowing" dialectic (Callon, 1999) to account for the permanent tension between, on the one hand, the desire to frame management protocols and measures regionally and, on the other hand, the overflows, adjustments, and adaptations imposed by the singularities of biophysical phenomena (Granjou, 2016) and the socio-territorial dynamics at play as well. The analysis of the social life of drought decrees then highlights the different functions that the local services of the State assign to them. The decrees aim to acculturate users to this new reality and to allow the administration to test the extent and limits of its power of intervention. The case of the droughts in the Grand Est illustrates the processes of construction of a new administrative competence over a territory.

Bibliography:

Callon M. 1999. «La sociologie peut-elle enrichir l’analyse économique des externalités? Essai sur la notion de cadrage-débordement », In Foray D., Mairesse J. (Dir.), Innovations et performances. Approches interdisciplinaires, Paris : EHESS, 399-431.

Granjou C. 2016. Sociologie des changements environnementaux. Futurs de la nature. Londres, Grande Bretagne: ISTE. 189 p.
Global and local sensitivity analysis of heat transport in fractured rock using a modified LH-OAT method
Authors: Wu Xiao-long , Kueper Bernard , Novakowski Kent
Published: September 2022

Thermal conductive heating is an in-situ groundwater remediation technique that can be implemented in weathered or fractured rock. However, the characterization and identification of heat transfer in fractured rock is challenging because of complex hydrogeological and thermodynamic processes, particularly for irregular heat source configurations. As an effective practice, sensitivity analysis has been widely used to screen, rank, and quantify the influential factors in complex systems. In this study, a three-dimensional numerical model was applied to investigate, using global and local sensitivity analyses, the significance of six input factors that influence the heating of fractured rock. The factors include the radius and energy delivery strength of the heat source (which were used to study the scale effect and heating processes), the fracture aperture, fracture spacing, groundwater velocity, and the thermal conductivity of the rock matrix. A discrete Latin Hypercube-One at A Time (LH-OAT) approach is proposed and utilized as an experimental design and data analysis method for the discrete input factors that apply to this study. We also used Machine Learning techniques to enhance the robustness of simulation results with a significant reduction of computational cost. The results show that at all locations within the heating area, the radius of the source and energy delivery strength are the most influential input factors. The scale effect associated with the radius of the heat source is significant for the rock matrix temperature. The groundwater flow related factors jointly determine the temperature variation in the upstream areas. The contribution of the thermal conductivity of the rock matrix to heat dissipation is nearly isotropic in the heating area. A nonlinear trending of sensitivity indices is observed for all factors in the input space. Based on these results, the discrete LH-OAT approach has been demonstrated to efficiently identify influential factors within a discrete input value space. The use of a two-way OAT perturbation approach is suggested to avoid potential errors caused by the one-way perturbation method for parameter ranking.
Crowdsourcing, Remote sensing and hydrogeomorphic modelling for supporting Data Assimilation for near real time flood forecasting in data scarce regions
Authors: Annis Antonio , Nardi Fernando
Published: September 2022

The increasing availability of remotely sensed and social media crowdsourcing is bringing new distributed georeferenced data and opportunities for better monitoring and managing natural disasters. On the other hand, hydrogeomorphic models demonstrated their ability to parsimoniously delineate floodplain domains and assess river basin hydrologic forcing. In this contribution we present and test a Data Assimilation (DA) framework for real time flood forecasting supported by hydrogeomorphic floodplain terrain processing. The presented novel DA framework seeks to optimize the computational domain of a 2D hydraulic model, improving rapid flood detection using satellite images, and filtering geotagged crowdsourced data for flood monitoring. Different cases studies are presented where both traditional and innovative measurements are adopted, jointly and separately, for analyzing in comparative terms the performance of flood forecasting models with specific focus on the computational efficiency the ability to cope with data scarcity in ungauged river basins.
Nature-based solutions for urban water management
Authors: Liu Junguo
Published: September 2022

The traditional means of urban water management relied heavily on engineering measures, or the use of “gray” infrastructure. Recently, there has been a call to integrate green infrastructure. This study conducts a systematic survey to characterize various nature-based solutions (NBS) adopted in different regions of the world and to elaborate on the benefits and limitations. It highlights the role of NBS in urban flood risk management under ongoing climate change and rapid urbanization. It shows that NBS could effectively mitigate urban flooding caused by high-frequency precipitation events, with additional economic, ecological, and social benefits. However, NBS are less effective at helping cope with pluvial flooding caused by extreme precipitation events over a short period of time, while gray infrastructures also have limitations as a mitigation measure against extreme pluvial flooding. It is thus recommended that integrating green and gray infrastructure is critical for urban water management, in particular with deep uncertainty in future.
Uncertainty quantification in climate change impacts on hydrology using ANOVA
Authors: Pogakula Tejith , Bolisetti Tirupati
Published: September 2022

The climate model projections obtained from the Regional Climate Models (RCMs) and their forcing through the hydrological models are known to include multi-source uncertainties. Using the subsequent modelling data for their intended purposes, such as watershed studies, flood mitigation, and climate change adaptation policies while containing unsupervised uncertainties of such nature, will prove detrimentally misjudged and potentially do more harm than good. The uncertainty propagation takes place at each stage along the modelling process and depends on the choice of climate model projections, Representative Concentration Pathways (RCPs), bias correction methods (BCs),  hydrological models, and hydrological parameters among other contributors.

 

The aim of this paper is to quantify the overall uncertainty in climate change impacts using Analysis of Variance (ANOVA) to decompose or disaggregate it into components and assess relative contribution of each of the components. The approach is demonstrated through a case study in Little River Experimental Watershed (LREW watershed) under two different emission scenarios (RCP 4.5 and RCP 8.5), five sets of RCM and driving GCM combinations, two bias correction methods by utilizing the Soil & Water Assessment Tool (SWAT) hydrological model. The results will indicate breakdown of the total uncertainty (T) into the respective uncertainties caused by the climate models (C), emission scenario (R), bias correction method (B) and unlike most of the uncertainty decomposition studies, further uncertainty breakdown due to the interactions between various components are also presented. The findings from this study will be useful to the modelers involved with flood mitigation or policy management by enhancing their understanding about the nature of streamflow projections and effectively aid in better decisions concerned with adapting to a changing climate subjected to uncertainties.
Panta Rhei: A Decadal Review of Cause-effect Pathways from Global Case Studies
Authors: Castro Cynthia V. , Penny Gopal , Gunda Thushara , Polo Maria Jose , Montanari Alberto
Published: September 2022

The forthcoming Panta Rhei book will include a chapter that focuses on socio-hydrology case studies. Although phenomena and interactions between social and hydrological systems have been observed in many of these cases, an understanding of drivers and feedbacks has, thus far, lacked clear scientific explanation. This chapter addresses this issue by integrating key insights from over two-dozen case studies from around the world, representing authors and study locations from six continents and 26 countries. Many of the cases contain cross-cutting themes that build upon existing socio-hydrological research, including the relationship between extreme hydrological events and societal adaptation, drought propagation, water security, and eco-environmental phenomena. Some of the cases represent a distinct departure from previous research in socio-hydrology, for example, by exploring technological innovations (e.g., sustainable infrastructure) and climate prediction (e.g., snow conditions in alpine regions). Collectively, these case studies demonstrate the wide applicability of socio-hydrology to understand coupled human-water systems while simultaneously identifying unresolved questions that demand additional future research.
Rainfall and drought: Changes in the synoptic distribution over semi-arid Tunisia
Authors: Feki Haifa , Cudennec Christophe
Published: September 2022

Tunisia is a coastal region of the Mediterranean Sea in North Africa with an area of ​​164,150 km2. The physical geography of the region is very heterogeneous with mountains to the north and the Sahara to the south. It is located in the transition zone between the humid Mediterranean climate and the arid Saharan climate. Precipitation is characterized by a large North-South spatial distribution varying between 1400 mm/year in the North to less than 40 mm/year to the South.

Thanks to the consolidation of a quality, long-term, synoptic database over the whole country, the average monthly rainfall was mapped by comparing the beginning and the end of the 20th century to look for a possible change in the spatial distribution of rain across Tunisia. We found a slight change in the spatial distribution of rainfall by comparing average monthly rainfall in the early to late twentieth century. A slight change in the direction of the rainfall gradient is perceptible during transition seasons with a speed of change in spatial structure that is more important at the end of the twentieth century for the fall season. This change may intensify as a result of the impacts of climate change and subsequently have an effect on socio-economic aspects. On the other hand, the phenomenon of meteorological drought continues to migrate towards the North and it appears that the stations with significant tendencies towards the increase of drought are located mainly in the regions of North / North-West of the country.
Relevance of Water Accounting Plus in the MENA region: A pragmatic analysis in light of the region’s challenges to sustainable water management
Authors: Amdar Nafn , Mul Marloes , Uhlenbrook Stefan , Rutten Martine , Al-Bakri Jawad , Jewitt Graham
Published: September 2022

Water is the most vital resource on Earth, sustaining all life forms, and it is also the most threatened by climate change and anthropogenic activities. This situation is even more urgent in water-scarce regions like the Middle East and North Africa (MENA) due to water scarcity and increasing demands. Managing these water resources sustainability requires accurate information on water availability and utilization.

Water Accounting is the systematic acquisition, analysis, and communication of information relating to water stocks and fluxes in natural, disturbed, or heavily engineered environments (FAO, 2016). It helps decision-makers understand problems in river basins, identify their drivers, quantify water availability, form proper decisions, and monitor their results over time. Water Accounting Plus (WA+) utilizes open-access spatial data for the analyses, allowing visualizing spatial and temporal trends and patterns. While analyses tools are being refined and made accessible for all, it has not been fully adopted in the MENA, and its implementation is limited to one-off studies.

This paper explores the type of information used/ needed by decision-makers to address the most pertinent water problems in the MENA region through a focused literature review. This was contrasted by the information provided by WA+. Because water problems are context-specific, a more detailed analysis was done for Jordan using semi-structured interviews with key stakeholders.

The results show that the most used information for the assessments in the region is precipitation, river discharge, surface and groundwater stocks at a monthly time scale. However, other aspects such as actual water consumption and losses are essential but not readily available and are therefore estimated using many assumptions. The WA+ framework, by utilizing spatial and temporal RS-based information, can support a systematic quantification of water consumption and losses and helps fill such information gaps. However, supporting decision-making requires more, from assessing the impact of climate change to informing proper water management decisions. Therefore, it is critical to underpin WA+ with scientifically sound hydrological models that can simulate future water fluxes and stocks and test different management interventions using scenario analysis.
Open Science in hydrology – 100 years of precursors and actual tectonics from the IAHS perspective
Authors: Cudennec Christophe
Published: September 2022

IAHS has developed over the last 100 years with a key role for the discipline, the community and society. IAHS and committed individuals have defended values, implemented mechanisms, facilitated partnerships and catalysed outcomes which were precursors of the now-called Open Science paradigme. Actual developments within IAHS (including agenda-setting, synthesis, editorial and curating initiatives), across cooperations with sister associations and other learned societies (water-related, interfacing geosciences within IUGG, generic or systemic aspects within ISC), and across tangible partnerships with UN agencies and programmes (UNESCO IHP, WMO, and the wider UN Water dynamics) are strong contributions to the ongoing tectonic of Open Science in the field of hydrology. A panoramic view of these historical roots and actual developments shall allow to identify strengths, weaknesses and paths for IAHS and the hydrological community to contribute to the paradigme shift that is required, as called by the multilateral UNESCO recommendation on Open Science (2021), and knowing the increasing societal need for reinforced hydrological knowledge and methods in the frame of Agenda 2030 and beyond.
Compound hydrometeorological risks on the Spanish Mediterranean coast in face of climate, environmental and social change
Authors: Llasat María Carmen , Jiménez José Antonio
Published: September 2022

The effect of compound events, during which different climatic hazards such as surges, waves, heavy rainfalls, and flood episodes simultaneously or consecutively occur, may amplify the impacts from those same events occurring separately. Despite of this, their combined action is seldomly considered when assessing the impact of extreme events, with most of studies considering both types of hazards as they were univariate. This is also extendable to the development of risk management and adaptation strategies, where the different groups of hazards and their main influence zone are addressed separately. The differential treatment of these types of events allows us to analyze the possible impact of climate change in each of its parts. In Spain, the hydrometeorological disasters suffered in recent years, such as the Gloria and Filomena storms, the serious flash floods produced in Alcanar, or the current floods produced by the Ebro River and its tributaries, are in line with the effects of the climate change. Greater intensification is observed in some of the drivers. At the same time, there is a decrease in the tolerance limits, which entails a possible increase in risk. This is a notable problem on the Spanish Mediterranean coast, where exposure is increasing, both due to the increase in population and the assets exposed. The improvement of early warning systems has led to a decrease in vulnerability, but the uncertainty in the objective forecast that responds to the “when-where-how much” of a compound hydrometeorological event may be increasing.

In this framework the present contribution deals with the strategy to cope with these hydrometeorological compound events in the NE of Spain to characterize their remarkability by assessing their impact in terms of induced damages and required risk management measures; to identify the contribution of climatic and societal drivers to the impact for each type of events; and to assess the future coastal risk from compound events under climate change. This contribution has been developed into the Spanish project C3RiskMed (PID2020-113638RB-C21 and C22).
Analysis of structural lineaments in the fissural aquifers of the Forquilha and Vista Alegre catchments using remote sensing
Authors: Linhares Samiramisthaís , Alves Rafaela , Kreis Marjorie , Rocha Renan , Estácio Alyson , Bezerra Jorgiane , Martins Eduardo , Barbosa Natanael
Published: September 2022

The Brazilian semi-arid region presents fragility in terms of surface and groundwater resources due to the irregularity in precipitation regimes and the high evaporation rates. In this context, the communities and the stakeholders are conditioned to seek strategies to cope with droughts, and groundwater emerges as  an alternative supply. This demand requires detailed studies to understand fissural aquifers, given the circulation and storage of water in these aquifers is subject to the presence of structural discontinuities, in particular, influencing the variation of hydrodynamic characteristics and the salinity of wells. The area object of this study corresponds to the Forquilha and Vista Alegre Catchments, in the Ceará State, Northeast Brazil. The present research performed the identification and automatic extraction of the structural lineaments through remote sensing. PALSAR MDE images with 12.5 m spatial resolution and technical data from wells drilled in the region were used. This method promoted the identification of areas of interest for groundwater prospecting. The basins present intermittent drainages and low hydrogeological vocation. Lineaments with preferential NE-SW striking and WNW-ESE striking, in a secondary way, were identified, mainly associated with the drainages of the region. In Vista Alegre the relationship between flow rates and lineaments show a direct affinity. The wells reveal higher flow rates in the western region of the basin, where there is a zone of greater intersection of lineaments, moderate salinity and low variation of the static level in the rainy season. Preliminary results indicate poor interaction between surface and groundwater dynamics. At Forquilha, the relationship between structural features and the most productive wells occurs between structural intersections and drainage. Salinity and static level variation present direct interference in the rainy season, which is reflected in the reduction of the electrical conductivity. In this case, the interaction between the structures and the drainages is more coherent with respect to the lineaments, drainage direction and local relief. Therefore, knowing the structural context of a basin is a necessary increment for a more efficient and planned exploitation of groundwater resources, especially in semi-arid regions that are highly vulnerable to climate change.
Adapting an Event-based, Distributed and Conceptual Model to the Hydrological Response of Small Catchments in the Island of Tahiti
Authors: Tanguy Garance , Sichoix Lydie , Bouvier Christophe
Published: September 2022

The tropical volcanic Island of Tahiti is prone to heavy rainfalls and flash floods which can generate very severe damages. Hydrological response here appears highly variable from one catchment to the other, in terms of runoff production as well as peak flow amplitude. There is a strong need for an operational method able to estimate well the design flood metrics on any Tahitian catchment, taking into account the variability of their response. This study deals with five small catchments (surface range between 0.6 and 1.4 km²). It aims at adjusting the equations of the production function of the Soil Conservation Service – Lag and Route (SCS-LR) model in order to improve its flexibility until it is able to reproduce the hydrological responses. In practice for each catchment, a few dozens to a hundred of rainfall-runoff events were extracted from available records and then event cumulated rainfall and runoff were calculated and plotted to characterize the asymptotic behavior. The theoretical equation of the SCS production function was successively adjusted for the five catchments. Original SCS equations well fitted rainfall-runoff events for one particular catchment (linear determination coefficient R² of 0.85) while weak fits were obtained for the other catchments. We applied modified equations of SCS inspired by Mishra and Singh (with introduction of parameter M in SCS equations) and better regressions with R² ranging between 0.52 and 0.87 were estimated. However when using this modified model, compensation of cumulated rainfall by the optimization of the initial condition parameter S decreased values of correlation coefficient. Further exploitation of asymptotic behaviors must be undertaken to modify and render SCS equations more adapted to Tahitian hydrological variability.
Characteristics of debris-covered snow-covered gorge during the snowmelt period in the Northern Japan Alps
Authors: Mouri Goro , Chalov Sergey
Published: September 2022

We introduce the result of field observation associated with debris-covered snow-covered gorge in the Japanese Alps incorporating the effects of high mountain climate and extreme environment. The Japanese Alps strata that form the slopes and piedmonts of the extreme mountainous environments are highly erodible, which determines the specific features on the shrinkage of snow-covered gorges. In this study, we report the characteristics of debris-covered snowy gorges during the beginning of the snowmelt period in the extreme mountainous environment region of the Japanese Alps. We measured the temperature profiles and daily variations in typical nutrient parameters at debris-covered gorge and bare-ice glacier in the Kekachi valley in the northern Japan Alps of north-central region in Japan, to assess the characteristics association with the effect of debris-covered snowy gorge. The Kekachi valley is a typical snowy gorge region in Japan and also in the world that is located on the northern Japan Alps and lies over the Holocene sediment of the median tectonic line on Honshu Island, Japan. The debris covered snowy gorge remains almost throughout the year. This study indicated that the effect of debris coverage on the shrinkage of snow-covered gorges results in how the gorges respond to high mountain climate and environment of the Japanese Alps. We also compared debris-covered snowy area and bare ice area. Our results indicated that the highest ground surface temperature within 10 cm varied from 8 °C to 15 °C, having diurnal cycle for the crucial baseline factor associated with the existence of debris-covered snow-covered gores. Although, the growing meltwater discharge and surface lowering indicates that such snowy gorges are currently shrinking, their fronts remain remarkably stable, as also been observed in other regions.
Application of theoretical principles of citizen science in the estimation of water levels in small basins through images from photo traps. The pilot case study of Montecalvello in Viterbo Province (Central Italy)
Authors: Spasiano Andrea , Grimaldi Salvatore , Nardi Fernando , Noto Simone , Braccini Alessio Maria
Published: September 2022

In this contribution main concepts, tools and methods that distinguish citizen science are discussed in order to build a theoretical framework applicable to empirical cases study. The term citizen science refers to a set of methodological approaches for the engagement of volunteered participants in scientific research activities mainly related to environmental monitoring and assessment and spatial planning. The distinctive character of citizen science is transdisciplinarity. This concept indicates the integration of different scientific backgrounds and methods for science-driven solution-oriented applications to solve a specific problem that requires support and engagement of a wide range of potential non expert users and actors.
The theoretical insights deriving from the review are tested at an empirical level on a pilot case study for estimating water levels in small basins, where the use of traditional monitoring tools is a real challenge due to the unstable morphological conditions of the riverbeds and the difficult-to-access environments of ephemeral and intermittent streams. In order to overcome such practical limitations, recently a technique based on image analysis was introduced, based on a white pole and its pictures taken by a phototrap (i.e. named stage-cam sensor). To calibrate such tool, the contribution of non-expert volunteers is fundamental. Indeed, they are recruited to perform a visual analysis of a continuous series of images to create a set of observations to use as benchmark for the image-analysis algorithm calibration. The study is based on the pilot case of the secondary basin of Montecalvello, located in the municipality of Graffignano (Viterbo Province), about 100 km north of Rome. The volunteers have been recruited by the student community of the University of Tuscia. Preliminary results presented here show the significant opportunities as well as the challenges of citizen engagement for water monitoring in remote areas. The presented transdisciplinary framework is also discussed, as linked to the presented preliminary results, underlying the multiple benefits of general public volunteering in similar research projects, paving the way for increased awareness, science literacy, engagement and distributed participation for environmental sustainability and safety.
RIM2D – fast 2D hydraulic modelling for operational flood and flood impact forecast
Authors: Apel Heiko , Vorogushyn Sergiy , Merz Bruno
Published: September 2022

The disastrous floods of July 2021 in Germany has shown, that abstract forecasts of river discharge or water levels at selected gauges do not provide sufficient information for timely and location specific warning of the population and targeted disaster management actions. The forecasts as well as the available flood hazard maps did neither allow for detailed information, which areas will actually be affected, nor could any information about the severity of the flooding derived. In order to provide better informed flood forecasts, RIM2D was developed. It solves the inertial formulation of the shallow water equations on a regular grid, and is highly parallelized on Graphical Processors (GPUs). Moreover, the modelling concept is parsimonious and allows for fast model setup. We will show that hydraulic simulations driven by the available gauge forecasts would have been feasible with sufficient lead time to provide spatially explicit forecasts of inundation depths and flow velocities. Moreover, we also show that impact forecast derived from the simulations would in terms of hazard maps indicating human instability in water and building failure hazard can be additionally derived for the operational forecasts. We argue that using these hydraulic and impact forecasts would have had an substantial impact on the flood alertness of the population and responsible authorities, enabling a better early warning and disaster management, which eventually saves lifes in such extreme flash flood conditions.
Evaluation of precipitation in the winter season in higher altitudes of the Bohemian Forest under changing environmental conditions
Authors: Tesař Miroslav , Šípek Václav , Procházka Jan
Published: September 2022

Precipitation during the winter season represents a very significant proportion of the yearly precipitation total in higher mountainous areas in the Czech Republic. This region generally has lower fluctuations in precipitation during the year than in the lowlands. In addition to the altitude, this is mainly due to the oceanic character of precipitation, especially in Bohemia, where there is an increase in precipitation before and during winter.  

The main objectives of the present contribution are to (i) describe the snow cover characteristics (snow depth and snow water equivalent) concerning the mid-latitude forested catchment; (ii) use the snow cover evaluation in the Bohemian Forest as an indicator of climatic and related changes; and (iii) introduce new techniques for a monitoring both snow depth and snow water equivalent.

The influence of the forest canopy (Picea Abies and Fagus Sylvatica) and altitude (ranging from 835 m a.s.l. to 1118 m a.s.l.) has been investigated for the time period from 2002 to 2021. Preliminary results proved that forest cover has a significant influence on the snow cover accumulation, reducing SWE by 50 % on average, compared to open sites. The elevation gradient concerning SWE ranged from 30 to 40 mm and from 5 to 20 mm per 100 m in open and forested sites, respectively. Its magnitude was found to be temporarily variable and positively related to the total seasonal snowfall amount.

The hydrological effects related to changes in the snowmelt regime were studied in a small forested basin Liz (0,99 km2, 835 – 1074 m a.s.l.). The attention was paid to the streamflow generation during spring snowmelt, which is a dominant hydrological event in many seasonally snow-covered regions. The changes in snow cover amount and its variability at two mountainous stations in the Bohemian Forest (Churanov 1118 m n. m., 1962 - 2021 and Breznik 1137 m n. m., 1987 - 2021) were used as indicators of going along climate transition in the area. It was proved that the streamflow originating from the snowmelt starts earlier compare to the end of the 20th century.
Hydrological records of the Rhône River at Beaucaire from 1816 to 2020: accounting for uncertainty in the discharge estimation and flood frequency analysis
Authors: Lucas Mathieu , Lang Michel , Bard Antoine , Renard Benjamin , Le Coz Jérôme , Darienzo Matteo , Pierrefeu Gilles
Published: September 2022

As floods and droughts strongly influenced the navigability of the river and the commercial activity of the region, the Rhône at Beaucaire has always been monitored by the locals. Consequently, one of the French first permanent hydrological gauging stations was installed at Beaucaire at the beginning of the 19th century. The Lower Rhône valley has remained a vulnerable area in terms of flood risk. A recent archival work (Pichard et al., 2017) allowed to build a continuous daily stage time series from 1816 to 2020. The goal of this work is to establish the corresponding series of discharge, considering the main sources of uncertainty, and to improve the statistical knowledge of the flood occurrence and variability in the Lower Rhône valley. The conversion from stage series to discharge series is not straightforward, especially for the ancient times for many reasons such as ungauged periods, rating shifts and morphogenic floods, metrological or climatic changes. First, the periods with stable stage/discharge relationships were determined by applying the segmentation procedure of Darienzo et al. (2021) to the available gaugings since 1845. This recursive segmentation procedure accounts for both gaugings and rating curve uncertainties, through a Bayesian framework. Then, the uncertain rating curves of each period have been estimated using the BaRatin SPD model (Mansanarez et al., 2019), allowing to include prior hydraulic knowledge and to transfer information across periods. After checking the homogeneity of this exceptionally long discharge series, a flood frequency analysis has been conducted in a Bayesian framework. Some assumptions have been tested to improve the estimation of the parameters of the GeV distribution, such as a regional estimation of the scale parameter, or the introduction of climatic covariates for a time-varying analysis. A key objective of this work was to account for uncertainties at all steps steps of the approach, from the stage measurements and the gaugings to the flood quantiles estimation.