bluuebunny/crossref_metadata_2025 huggingface dataset:
How does the seasonal forecast quality of hydrological extremes vary in space and time?
Authors: Du Yiheng , Pechlivanidis Ilias , Clemenzi Ilaria
Published: September 2022

The scientific advancement in hydrological modeling along with the progress in numerical weather forecasting has allowed the generation of useful hydro-climate services providing skillful simulations and reliable forecasts. To meet the needs from the climate-dependent socio-economic sectors, such as energy production and public water supply, there is a need to quantify the predictability of hydrological extremes. In this study, seasonal hydrological reforecasts were generated across about 35,400 basins in Europe using the E-HYPE hydrological model for the period 1993-2015. The service setup uses seasonal predictions of daily mean precipitation and temperature from the fifth-generation seasonal forecasting system of the European Centre for Medium-Range Weather Forecasts (ECMWF SEAS5). Hydrological forecast predictability was analyzed with respect to the simulated streamflow climatology. The assessment was conducted on both high and low streamflow and therefore the Brier Skill Score (BSS) was used for 10th, 90th and 95th weekly percentiles for different initializations and lead times. Results show that overall hydrological extremes over Europe are well predicted in terms of BSS, with spatial and temporal variability depending on the initialization month and lead time. The results contribute to identifying different geographical areas and times where the seasonal hydrological forecasts provide an added-value on the long-term predictability of, and hence preparedness to, flooding and droughts, which consequently benefit regional and even national decision-making in various socio-economic sectors.
Water Accounting of the Ogun River in the Tropical Environment of South-West Nigeria 
Authors: Odunuga Shakirudeen , Olufiade Iyanuoluwa , Adegun Olubunmi
Published: September 2022

The study examines the water resources potential of Ogun River Basin in Southwestern Nigeria using the rapid water accounting plus (WA+). This was achieved by using data from the Water Productivity (WaPOR) version 2.0 Level 1 with 250m resolution open access database of the Food and Agricultural Organization (FAO). Python and Jupyter notebook programming were used to download data from WaPOR database as well as for the implementation of the Water Pixel model. QGIS and ArcGIS were used to carry out raster calculation and mapping of water indices. Ground based rainfall data from Nigeria Meteorological Agency (NiMET) for three stations (Ikeja, Abeokuta and Ibadan) were used for rainfall validation while Ogun River discharge data at Abeokuta provided the hydrological flow data for the computation of the water balance. The results showed that the WaPOR 2.0 level 1 precipitation data showed close agreement with the in situ observations by the NiMET at the Ikeja, Abeokuta, and Ibadan stations with the coefficient of correlation values varying from 0.618 to 0.687. The basin was a net water generator as precipitation (16471 mm/year) was higher than total evapotranspiration (13888 mm/year), which implies that as a whole, the basin generates surplus water (150.85 mm/year) for the 2018 hydrological year. The exploitable water resources are 12.7 km3/year, while the renewable water resources are higher (14.14 km3/year), which is due to an increase of the basin storage by 1.4 km3/year. The gross inflow is 29.2 km3/year and the total outflow and consumed water is 27.8 km3/year, which resulted in 1.4 km3/year stored as total water storage change (Balance). Also, the average available water was depicted to be 12.1 km3/year, out of which approximately 2.9% was managed. The Managed Water, which is Incremental ET of Managed Water use, was on average 0.1 km3 /year. The study recommends provision of medium sized dams across the basin for proper harvest of the surplus water to increase urban water supply, reduce proliferation of boreholes and control flooding.
Developing a real-time ecological forecast for the Northern Murray-Darling Basin 
Authors: Savage Callum , Liu Moyang , Croke Barry , Lerat Julien , Jakeman Anthony
Published: September 2022

The last 20 years have seen the Murray-Darling basin under increased environmental stress due to land clearing, flow alteration, increased water allocations, and the growing impacts of climate change. Policy measures have been established to address this problem (e.g. The Water Act, The Basin Plan). However, the management of environmental water allocations remains a challenging task that requires estimates of current and future water availability, as well as an understanding of how environmental water releases will impact ecosystem health. Currently available environmental modelling is not well suited to support these day-to-day management decisions as the focus is predominantly on long-term environmental outcomes. There is a need for real-time predictive ecological models that operate at a shorter forecast horizon to directly meet the needs of environmental managers. This project aims to develop the science which would underpin a real-time ecological forecast for the Northern Murray-Darling Basin. 

Our aim is to develop a real-time ecological forecasting service in the Northern Murray-Darling Basin built on top of existing hydrological services such as the Australian Water Outlook (https://awo.bom.gov.au/) operated by the Bureau of Meteorology. The new service will output estimated ecological health indices with fully specified uncertainties. The Northern Basin includes significant environmental assets and is an important part of overall basin management, yet has received relatively little attention from the scientific community. Based on modelling work undertaken by the ANU and CSIRO, the project will focus on vegetation in the Narran Lakes, a site of high ecological and cultural value, which has been the focus of previous comparable research.

This research will also link to a study of the impact of water quality on small, rural communities in the region. These communities have a substantial Indigenous population and have a low socioeconomic status. Community water concerns include access to potable water as well as water suitable for washing, cooking and bathing. The aim is to develop integrated water quality-health models to project future water quality conditions (with confidence intervals) for selected locations. Improved flow and ecological forecasting developed in the project will be an important contribution to this research.
Snowfall gauge under-catch correction: a key parameter for snow-hydrological simulations
Authors: Ruelland Denis
Published: September 2022

Modelling snow and glacier melt runoff processes is essential for local water supply, hydropower management and flood forecasting. However, melt runoff modelling in mountainous regions faces two challenges: scarcity of meteorological data and uncertainty in parameter calibration due to limited understanding of the complex hydrological processes. Numerous free parameters have been introduced in most of the snow-accounting routines (SAR) used in operational hydrology in order to compensate for errors in the input data, adapt to local snow processes or deal with scale effects between different snow data.  This talk investigates the degree of liberty required in a SAR to simulate local snow dynamics, distributed snow cover areas and flows at the catchment outlet. To address this issue, a SAR on top of the GR4J model was tested on a dataset covering 17 mountainous catchments (45 to 3580 km²) in the French Alps and Pyrenees. Model calibration and control were based on streamflow series, fractional snow-covered areas (FSC) computed from MODIS snow products and at least one chronicle of local measures of snow water equivalent (SWE) acquired in each catchment over the period 2004−2016. The SAR was applied according to elevation bands of 100 meters and various parametrisation: from ten free parameters (precipitation orographic correction, temperature lapse rate, seasonal variation of the temperature lapse rate, snowfall gauge under-catch correction, thermal inertia of the snow pack, melt degree day factor, variable melt factor, ice degree day factor, 2-parameter hysteresis between SWE and FSC) to only one free parameter (snowfall gauge under-catch correction). Results shows that the one-free-parameter SAR is as efficient as more free structures to simulate both distributed and local snow dynamics as well as runoff. Interestingly, using a SAR without any free parameters by fixing the snowfall gauge under-catch correction to a value of 150% leads only to a deterioration of local SWE dynamics. These findings suggest that it is possible, and even advisable, to limit the number of free parameters in temperature-index models in order to reduce problems of over-parameterisation and equifinality.
Multi-criteria evaluation of the AquaCrop model in a Mediterranean rainfall context 
Authors: Dhouib Mariem , Zitouna-Chebbi Rim , Mekki Insaf , Prévot Laurent , Molénat Jérôme , Jacob Frédéric
Published: September 2022

The spatial organization of crops at the landscape scale is a promising solution to be explored within Mediterranean hilly agrosystems, for agroecological transition and adaptation to climate change. In this perspective, it is necessary to ensure the capacity of crop models to simulate a range of agro-hydrological processes within these agrosystems. The objective of this study is to perform a multi-criteria assessment of the FAO AquaCrop model to simulate crop functioning for a diversity of plant and soil combinations, by considering several hydro-climatic years. This multi-criteria assessment includes canopy cover (CC), dry above-ground biomass (biomass), soil water content (SWC), actual evapotranspiration (ETa) and runoff (non-infiltrated rain). The study area is the small rainfed watershed of Kamech located within the Lebna regional watershed, Cap Bon Peninsula, North-eastern Tunisia. The data, collected in the framework of the OMERE Observatory, are derived from ten measurement campaigns between 2001 and 2013 that focus on (1) predominant soils (Cambisols, Luvisols, Vertisols), and (2) representative crops of the region (wheat and barley as grain cereals, oats as fodder and faba bean as legume). Except ETa, which simulations are quite poor (R2 of 0.3, RMSE of 0.9 mm/d and NRMSE of 44%), AquaCrop correctly simulates the water transfer within the soil-plant continuum along with crop growth, for the ten aforementioned campaigns. First, CC is correctly simulated (R2 of 0.6, RMSE of 3% and NRMSE of 9%), as is runoff (R2 of 0.5 and RMSE of 0.7) mm. Second, SWC is well simulated (R2 of 0.88, RMSE of 8.34 mm and NRMSE of 2.34%), as is above-ground dry matter (R2 of 0.83, RMSE of 0.17 ton/ha and NRMSE of 5.9%). These results indicate that AquaCrop is relevant for characterizing the water use efficiency under the influence of intra-plot runoff.
Climate Risk Analysis for Water Resources in Dryland Area of West Bengal
Authors: Bera Dr. Kartic , E. Newcomer Dr. Michelle , Banik Prof. Pabitra
Published: September 2022

Drylands are characterized by their limited water supply, low and highly variable rainfall, and recurrent drought. Almost 40% of land in the world is considered drylands, which are the most sensitive areas to climate change and human activities. Representative Concentration Pathways (RCPs) projections data show an increase of drylands by 50% near the end of this century. With the expansion of drylands, and the increasing population in West Bengal (85° 40'E-88° 15'E longitudes and 21° 45'N-24° 45'N latitude), this puts pressure on water managers to accurately plan, prepare, and implement new measures for increasing water sustainability and sources of water. Future climate projections will require finding alternative and reusable water sources for present and future use. The goal of this study is to design a methodology to evaluate current existing groundwater resources, and to identify future potential zone for artificial groundwater recharge activities to improve groundwater storage during rain events. We also evaluate locations for rainwater harvesting, the state-of-the science of wastewater reuse and alternative crop rotations to minimize water use while maximizing production and benefits to farmers. Our work is applicable to other dryland areas around the world experiencing accelerated warming and desertification. 
Modelling long-term effects of climate change and anthropogenic activities on water resources of the Moselle River basin.  
Authors: Lemaitre-Basset Thibault , Thirel Guillaume , Oudin Ludovic
Published: September 2022

Climate warming and evolution water demand for anthropogenic activities are two related ongoing changes that may increase existing pressure on water resources. Adaptation strategies are usually thought on the basis of hydrological projections. These projections, however, rarely incorporate changes in water and land management, issues that are then addressed by the adaptation plans within a sequential process. The objective of this study is to develop a modelling framework that incorporates water and land management evolution within a spatially distributed hydrological model in order to produce projections that are more realistic on the water resources shortages. We applied this methodology on the Moselle River (North-East France) basin using climate projections derived from various representative concentration pathway scenarios (RCPs), general circulation models (GCM), and regional climate models (RCM) in a multi-scenario multi-model approach. Hydrological projections are computed from a conceptual hydrological model, and a recent R package (airGRiwrm) was used to account for anthropogenic water withdrawals. Through contrasting scenarios of water use evolution built in partnership with the water stakeholders, we are able to explore different evolutions of water demand for each type of use present in the Moselle basin (withdrawals for domestic and industrial uses, energy production, and waterway navigation). These scenarios allow us to feed the hydrological model with different water withdrawals, in addition to the climate scenarios. The results of this multi-scenario and multi-model impact study on the water resources will be used to evaluate the water management sustainability and the adaptation levers.
Parameterizing the spatial structure of torrential rain for flood impact assessments
Authors: Peleg Nadav , Leitão João P. , Paschalis Athanasios , Fatichi Simone , Molnar Peter , Burlando Paolo
Published: September 2022

In response to climate change, torrential rains undergo changes in their magnitude and temporal properties. In many places, it is predicted that these extreme short-duration rainfalls will intensify, become more frequent, and shorten in duration. In climate change impact studies, the spatial aspect of torrential rain is often overlooked, despite many case studies demonstrating its importance. The main reason why changes in rainfall structure are ignored is the lack of information derived from convection-permitting models. They are capable of simulating the rainfall at the fine spatial and temporal scales required to accurately represent torrential rainfall under various warming scenarios, although they are very computationally demanding. Recent studies have shown a relationship between rainfall spatial structure and air temperature but the relationship is not universal and varies by location. In some places, increasing temperature is associated with an increase in rainfall heterogeneity and a decrease in storm area, while in other locations it is associated with rainfall intensification and an increase in storm area. For flood impact assessments, we propose a parameterization method to change the spatial structure of extreme short-duration rainfall. The method is applicable to either simulated data derived from convection-permitting models or observed data obtained from remote sensing devices (such as weather radar) and can be adapted to a variety of global warming scenarios. We will illustrate how the method can be applied to alter the spatial profile of a design storm and demonstrate its implications for assessing changes to flood statistics.
Estimating point rainfall statistics from gridded large scale rainfall data
Authors: Salas Aguilar Silvia , Leblois Etienne , Creutin Jean-Dominique , Gonzalez Sosa Enrique
Published: September 2022

Many stochastic rainfall generators rely on the structure of rainfall considered a spatio-temporal point process. Ordinary practice is to infer these parameters from data observed on a group of rain gauges over some reference time. However, gridded estimates of rainfall (out of meteorological radar, satellites, or meteorological models) give a distinct perspective on the same precipitation, albeit with scaling issues and biases, and a question is how to value this information even if we target the urban scale. This contribution is about how the scaling issue can be handled in a geostatistical perspective, deriving a point variability model consistent with the variability observed at grid scale. Available local raingauge data, even in moderate amount, can be used to checked the suggested methodology. Expected uses are in data merging, downscaling climate scenarios, and establishing local rainfall models, also in local data-poor contextes.

 

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How does the relationship between soil moisture and runoff evolve with increasing urbanization?
Authors: Saadi Mohamed , Oudin Ludovic , Ribstein Pierre
Published: September 2022

Urbanization changes the rainfall-runoff relationship mainly by increasing catchment imperviousness. This increase questions the importance of antecedent soil moisture in runoff generation in urbanized catchments, which are composed of a mix of rural and urban surfaces. Using a large sample of 70,227 events in 852 United States catchments, we quantified the relative importance of total impervious area (TIA) and antecedent soil moisture (ASM) in determining the runoff ratio (RR) at the event scale. To this end, we grouped the events into 30 classes of TIA and 30 classes of ASM, and we applied linear regression models to analyze the evolution of RR depending on TIA or ASM. The key findings are as follows: (1) Compared to event characteristics (precipitation amount and intensity), ASM showed a stronger ability in predicting the event-scale RR. (2) Even in catchments with high TIA, ASM still played an important role in runoff generation. (3) The impact of urbanization on the relationship between RR and ASM was relatively gradual, but became significant as TIA exceeded 5%. These empirical results are beneficial for advancing the process-based representation of the rainfall–runoff relationship at the scale of an urbanized catchment. They are potentially useful to revise the widely applied methods in practical urban hydrology by elucidating the interplay of ASM and TIA in influencing the catchment response.
Riparian zone assessment as a tool for planning nature-based solutions
Authors: Jakubínský Jiří , Cudlín Pavel , Pechanec Vilém , Machová Kateřina , Cudlín Ondřej , Štěrbová Lenka , Purkyt Jan , Prokopová Marcela
Published: September 2022

Riparian habitats represent an important ecosystem providing a number of functions and services that are important to humans - such as promoting biodiversity, reducing erosion risk, or transporting pollutants from the surrounding landscape into waterways. At the same time, unfortunately, it is an environment that has very often come under considerable pressure as a result of agricultural cultivation of the landscape or the development of industrial and human settlement activities. Thus, a large number of riparian ecosystems have disappeared or deteriorated. The assessment of the overall ecological status of riparian habitats is therefore an important source of information for the needs of water management and landscape planning in the riparian landscape, the aim of which should be to maintain the good status or improve the currently unsatisfactory status of these habitats. In the Czech Republic, there is not yet a comprehensive assessment procedure that takes into account not only the important sub-variables that influence the current status (e.g. the morphological condition of the watercourse or the predominant land use categories in the surrounding area), but also the potential reference status. For this reason, a tool (Riparian Habitat Quality Index) was developed by the author's team to assess the ecological status of riparian habitats. The created web platform "RipaSoft" allows streamlining the whole assessment process. Our contribution describes the assessment procedures and selected results of applying the methodology to several case study sites (small stream watersheds). The results can significantly contribute to the identification of sites suitable for the implementation of nature-based solutions aimed at mitigating vulnerability to hydrological risks (not only the risk of droughts and flash floods, but also the pollution of surface waters due to the transport of fertilizers and other pollutants from the surrounding landscape).
Use of a multi-tracer approach for the hydrogeochemical characterization of fractured crystalline aquifers in semi-arid region
Authors: Kreis Marjorie , Taupin Jean Denis , Patris Nicolas , Lachassagne Patrick , Vergnaud-Ayraud Virginie , Burte Julien , Leduc Christian , Martins Eduardo
Published: September 2022

In crystalline aquifers, groundwater resources are generally scarce and may be subject to salinization, notably in semi-arid areas. In semi-arid Northeastern Brazil (NEB), the processes at the origin of the high and heterogeneous salinity observed in the crystalline basement are still controversial. This field study demonstrates how the use of stable and radioactive isotopes and dissolved gases, combined with hydrodynamic and hydrochemical methods, are powerful tools to understand the hydrogeological functioning and the salinization processes of fractured aquifers in such a region.

The study area is located in the state of Ceará (NEB). Monthly and hourly piezometric data were collected respectively from March 2018 to December 2019 over a network of 56 boreholes, and from November 2016 to December 2019 in four of these boreholes. Chemical sampling (major ions and/or minor and trace elements) was carried out in 27 boreholes in December 2017, in 38 in June 2018 and 20 in June 2019. Stable (18O, 2H) and radioactive (14C, 3H) isotopes, as well as CFC and SF6 concentrations were also measured on a total of 137, 10 and 10 samples, respectively.

The strong heterogeneity of the crystalline aquifer was highlighted by Electrical Conductivity (EC) ranging between 1000 and 15000 μS/cm and contrasted temporal variations of EC or piezometric levels. Stable isotope data showed that groundwater recharge occurs through both direct and indirect infiltration of evaporated surface (45-65% on average for the latter). Multi-tracer dating confirms that groundwater is relatively recent (from decades to hundreds of years, with a large contribution of post-1950 water) and that circulation processes are fast. The chemical study suggests that the groundwater, originally bicarbonated, becomes progressively enriched in chloride and sodium, due to the strong evapotranspiration in the quite endorheic context. The NaCl salinity is interpreted as originating from rainfall. However, water and chloride budgets modeling shows that the highest salinities can only be explained by direct withdrawal of groundwater by the vegetation roots of the native bush, with an evapotranspiration rate equivalent to the annual recharge.
Low flows and irrigation in Mono River basin at Athiéme outlet (West -Africa).
Authors: Noumon Coffi Justin , Kodja Domiho Japhet , Amoussou Ernest , Sintondji Luc Olliver , Agbossou Euloge Kossi
Published: September 2022

Low flows and irrigation in Mono River basin at Athiéme outlet (West -Africa)

1Coffi Justin Noumon, 2Domiho Japhet Kodja, 2Ernest Amoussou, 1Luc O. Sintondji,1 Euloge K. Agbossou.

1Laboratoire d’Hydraulique et de Maîtrise de l’Eau (LHME), Institut National de l’Eau, Université d’Abomey Calavi 01 BP 526 Cotonou (Bénin).

2Laboratoire Pierre Pagney Climat Eau Ecosystèmes et Développement (LACEEDE), Institut de Géographie et Aménagement du Territoire et de l’Environnement, Université d’Abomey Calavi 01 BP 526 Cotonou (Bénin).

Auteur correspondant: 1Coffi Justin NOUMON (justinoum2001@yahoo.fr)

Abstract

The basic goal of this survey is the assessment of water resources of Mono River at Athiémé outlet in low flow period where it availability for agriculture uses is problematic. Therefore, daily data (precipitations, ETP, flows) from 1971 to 2016 are collected. It allows to simulate low discharge with GR4J model. Field survey permits the characterization of agriculture uses and the assessment of water requirement for irrigation. Low flows of Mono River at Athiémé outlet simulation with GR4J showed a good performance of the model to simulate low discharges before the construction of Nangbéto dam in 1988. Criteria values of Nash-Sutcliffe before dam establishment are 69% (calibration) and 71% (validation). The performance of the model is less for the period after the dam establishment: The change in the hydrological regime of the river due to water jets from Nangbéto dam can explain this low performance. Water requirement for irrigated areas estimation has given 42 587 596 m3 in 2020 and 73 007 308 m3 in 2030 mainly for the constraint period production which came from february to may. The comparison of water availability/water requirement shows that the water needs are closely covered monthly but a fine decade period analysis revealed some deficit decades. These results involve a great attention and consequent investments for deep knowledge of the resource in order to plan it sustainable management.

Key words: Mono basin, Low flow, GR4J, Irrigation.
Socioeconomic vulnerability of a Mediterranean coastal lagoon : case of Ghar El Melah, Tunisia
Authors: Hzami Abderraouf , Mahé Gil , Amrouni Oula , Missaoui Hechmi
Published: September 2022

The coastal lagoon system is undergoing pronounced shoreline retreats and floods as a consequence of the ongoing sea level rise resulting from global warming. The aim of this study is to assess shoreline changes, land use occupation and to evaluate socioeconomic vulnerability in the urbanized coastal lagoon in Ghar El Melah, Tunisia in central Mediterranean. Methods are based on the diachronic shoreline changes monitoring from satellite scene, aerial photograph, topographic, and bathymetric maps during the period 1882, 1936, 1974 and 2021. Shoreline movement is acquired according to the statistical Digital Shoreline Analysis System (DSAS) from 1882 to 2021 data sets. Land use classification was established from supervised algorithm using multiple satellites scenes of Landsat 5 (1985) and Landsat 8 (2021). The Socioeconomic Vulnerability Index (SVI) is calculated from five socioeconomic parameters: (1) population density, (2) land use, (3) coastal fishing (4) road network and (5) settlement. Our results reveal alarming erosion of the sandy barrier with a maximum value of Net Shoreline Movement (NSM) − 1580 m (± 6 m) between 1882 to 2021. Temporal classification of the Ghar El Melah landscape from 1985 to 2021 revealed the extended urban class over the lagoon internal ridge from 5.4% to 14 % respectively. Whereas the vegetation crops are decreasing by 10%. The statistical coastal (SVI) map reveals that 87% of the lagoon area are characterized by high to very high vulnerability (class 5). These high coastal vulnerabilities risk is primarily induced by the extensive land occupation since the last few decades.
Site identification and discharge measurements through Mobile Crowdsensing in the Mar Menor region
Authors: Peña-Haro Salvador , Cecilia José M. , Blanco-Gómez Pablo , Prandi Catia , Senent-Aparicio Javier
Published: September 2022

Hydrological models need continuous streamflow data for calibration, however these data are not always available due to the lack of monitoring stations or properly functioning ones. Mobile Crowdsensing (MCS) can help alleviate this problem. MCS relies on data collection from mobile sensing devices, it is inexpensive and its spatial coverage can be outstanding. Moreover, it can be an effective way of increasing local and citizen awareness of socio-environmental issues.

 

Herein, we introduce the MCS strategy developed in SMARTLAGOON, a H2020 project (grant agreement No. 10101786). The main study area of the project is the Mar Menor in Spain, which is the largest hypersaline coastal lagoon in Europe, it is under many pressures which are compromising the ecosystem stability. A SWAT model will be built which needs streamflow data for calibration. It is expected that DischargeApp (http://photrack.ch/dischargeapp.html) can provide some of the lacking information. DischargeApp is a user-friendly smart-phone application which provide fast and accurate volumetric flow measurements in rivers and canals. For this, citizens are invited to use their mobile devices to voluntarily monitor stream flow.

 

Fisrt, users located potential sites through the watershed and uploaded the calculated pixel displacement to the cloud using the DischargeApp. A selection of final sites was done based on the flow velocity (pixel displacement) and the cross section. Finally, those sites were fully setup for participatory discharge measurements. Additionally, the DischargeApp is connected to a cloud data-based which can be accessed via a web platform, any user can see the data recorded making the data transparent to everyone.

 

We also propose the use of social sensing to leverage user-contributed data from social media. This mode of MCS considers participants as “social sensors”, i.e., agents that provide information about their environment through social-media. We use sensingTools.com, a framework for the development of applications based on social sensing. The main objective of using this strategy is threefold; to obtain videos of affected areas in the Mar Menor for discharge measurements, to locate sites of interest to subsequently in situ infrastructures and to identify potential users who can collaborate in citizen science activities.
Assessment of the effectiveness of natural flood management in medium scale lowland catchments
Authors: Badjana Heou Maleki , Verhoef Anne , Cloke Hannah L , Julich Stefan , Camargos Carla , McGuire Patrick , Clark Joanna M
Published: September 2022

Over the last decades, there has been much interest in natural flood management (NFM). However, there is still a lack of evidence on the effectiveness of NFM in general and particularly land and soil management based NFM in medium to large scale catchments. This study investigates the effects of soil and land management based NFM in the lowland Pang and Blackwater catchments in the UK. It uses the Soil and Water Assessment Tool (SWAT) to model the effects of broadscale land use and crop rotation scenarios on peak flows in selected catchments, while considering uncertainties. The broadscale land use scenarios consisted of the conversion of the catchments’ land to broadleaf woodland and cropland, respectively, except for water and urban areas. The results indicate that the NFM effects vary across the catchments and depend on landscapes characteristics. In addition, the blanket conversion to broadleaf woodland or cropland has a larger effect on small peak flows than on large floods such as those of January 9 and February 6, 2014. Afforestation leads to a reduction of 10 to 16% of the modelled 2014 winter flood events. In contrast, implementing crop rotation scenarios increases the peak flows, with the increase depending on the crops used and tillage practice. These findings suggest that via bespoke woodland planting and farming practices, combined with other measures that can reduce the amount of flow reaching the river channel or delay the timing of the peak flow (eg. leaky barriers), flood risks can be minimized. The results of this study provide information that can benefit future decision making on flood risk reduction in suitable catchments.
How to be reflexive about an Agent Based Model of social and hydrological system?
Authors: Bonté Bruno , Collard Anne-Laure , Idda Salem
Published: September 2022

The added value of using computer modeling to study the relationship between water and society is not always shared between modelers and other disciplines in the humanities such as qualitative sociology. Although both can share the same research object, the methods of interpretation, the field approaches or the posture with local actors can sometimes be too different to really work together. In this communication, we propose to revisit the interdisciplinary dialogue between a modeler of socio-hydrological dynamics and a sociologist in order to overcome their misunderstandings. We thus develop a reflexive approach about the contribution of their disciplines to produce knowledge and contribute to water management issues facing society.

Our case study is an agent-based model of a social and hydrological system developed for a thesis in geography (by Idda Salem) to understand the dynamics of the oasis traditional agriculture in front of social and environmental changes that occurred in the modern Algerian state. The model gives an integrated and systemic vision of all elements mentioned in the issue studied, included a spatial representation of the aquifer dynamics, an implementation of institutional rules of water uses and associated social and physical external drivers. The model constitutes a support for dialogue and negotiation between our two disciplines. What emerges from this dialogue is the sharing of a common ontology that goes beyond the methods, tools and vocabulary of each. This translates into the identification of a common research object (hybrid water: social and physical), similar research questions (what contributions do agent-based models make to the understanding of the relationship between water and society?) and the meaning given to research (producing alternative narratives to dominant discourses).

In concrete terms, we will clarify the role of each party in the dialogue: the modeler's interest in taking a fresh look at the construction of the model he has produced and its assumptions, the sociologist's interest in questioning the modeling activity. Moreover, we will identify the stages of formalization of this dialogue (drawing, writing, oral communication in a seminar organized by ethnologists).
The impact of assimilating Earth Observation and in-situ data on seasonal hydrological predictions
Authors: Musuuza Jude Lubega , Crochemore Louise , Pechlivanidis Ilias G.
Published: September 2022

Earth Observations (EO) have become popular in hydrology because they provide valuable information in locations where direct measurements are either unavailable or prohibitively expensive to make. Recent scientific advances have enabled the assimilation of EO’s into hydrological models to improve the estimation of initial states and fluxes which can further lead to improved forecasting of different hydrometeorological variables. When assimilated, the data exert additional controls on the quality of the forecasts; it is hence important to apportion the effects according to model forcings and the assimilated data. Here, we investigate the hydrological response and seasonal predictions over the snow-melt driven Umeälven catchment in northern Sweden. The HYPE hydrological model is driven by two meteorological forcings: (i) a down-scaled GCM product based on the bias-adjusted ECMWF SEAS5 seasonal forecasts, and (ii) historical meteorological data based on the Ensemble Streamflow Prediction (ESP) technique. Six datasets are assimilated comprising of four EO products (fractional snow cover, snow water equivalent, and the actual and potential evapotranspiration) and two in-situ measurements (discharge and reservoir inflow). We finally assess the impacts of the meteorological forcing data and the assimilated data on the quality of streamflow and reservoir inflow seasonal forecasting skill for the period 2001-2015. The results show that all assimilations generally improve the skill but the improvements vary depending on the season and assimilated variable. The lead times until when the data assimilations influence the forecast quality are also different for different datasets and seasons; as an example, the impact from assimilating snow water equivalent persists for more than 20 weeks during the spring. We finally show that the assimilated datasets exert more control on the forecasting skill than the meteorological forcing data, highlighting the importance of initial hydrological conditions for this snow-dominated river system.
Uncertainty propagation in derived flood frequency analysis driving a rainfall-runoff model with stochastically generated climate input data
Authors: Thiele Luisa-Bianca , Pidoto Ross , Haberlandt Uwe
Published: September 2022

For derived flood frequency analysis (DFFA), weather generators are usually linked to rainfall-runoff models. This approach is accompanied by uncertainties from different sources that need to be quantified. In order to find the main sources of uncertainty, possible relations among them and their contribution to the total uncertainty, this study examines in more detail the uncertainties resulting from rainfall-runoff-modelling using stochastically generated input climate data. The conceptual rainfall-runoff model HBV-IWW is driven by stochastically generated climate input data, namely rainfall, temperature and potential evaporation, on an hourly time step for 140 meso- and macroscale (30km² - 1500km²) catchments in Germany. Monte Carlo simulations are carried out varying (a) climate data, (b) model parameters, and (c) climate data and model parameters so as to analyse the uncertainty propagation which might also be linked with catchment conditions.
Grounding sociohydrology through a justice lens  
Authors: Zwarteveen Margreet , Rusca Maria , Linton James , Haeffner Melissa , Lave Rebecca , Mukherjee Jenia , Ndiritu John , Pacheco Vega Raul
Published: September 2022

This paper considers the theoretical and empirical potential of a focus on water justice to ground sociohydrology scholarship. The field of sociohydrology recognises the role of humans in altering – deliberately or not – hydrological flows and seeks to account for the feedbacks and interactions between human and water systems. This scholarship, however, tends to reduce the role of humans and societies to social variables and indicators and is anchored in the ontological separation of nature-society, with nature as the 'anchor' of truth claims. The preference is for larger datasets, and for knowers as positioned outside of (and as independent from) what they study. These approaches are less suited for unravelling the social processes generative of so-called global water challenges, while they also are difficult to translate into actionable insights and tools that are useful to those making actual water decisions (water managers, policy makers, and civil society actors). In our paper, we discuss possible ways of ‘grounding’ sociohydrology in order to better capture sociohistorical contexts, recognize power relations and embrace multiple ways of knowing water. Conceptually, we examine how critical water studies – focusing on water equity and justice - can provide ways of ‘grounding’ sociohydrological understandings of water-society relations. We specifically consider how Haraway’s (1988) notion of situated knowledges in helping do this methodologically and conceptually. Empirically, we draw on our own research expertise to argue that grounded, empirical case studies can significantly add to theorisations of socionatural change, providing critical insights into processes of societal inclusion and exclusion, and the production of social difference through water – insights that can provide a good basis for imagining and helping develop just transformations to water sustainability. 
Climate change attribution in the river runoff using model-based approach
Authors: Kalugin Andrey , Lupakov Sergey
Published: September 2022

The main goal of this study is to obtain new results of a physical assessment of the modern hydrological consequences of the natural and anthropogenic components of climate change based on the synthesis of detailed process-based models of river runoff formation using the ECOMAG software and an ensemble of the Earth system models (ESMs) within the large river basins of Eastern Siberia. This approach allows calculating the river flow using the ESMs-based data over the observation period under two scenarios: (1) taking into account the anthropogenic impact of increasing greenhouse gas emissions and (2) taking into account only internal fluctuations of the climate system and natural external forcing.

In the first stage, the long-term annual and seasonal runoff of the Lena and Selenga rivers over the period of instrumental observations was evaluated using the ESMs-based data as boundary conditions in spatially distributed hydrological models. The ensemble of 4 ESMs (GFDL-ESM2M, HadGEM2-ES, IPSL-CM5A-LR, MIROC5) satisfactorily reproduces annual and seasonal values of both air temperature and precipitation and river runoff calculated using hydrological models over the observation period. The PBIAS in the calculation of annual runoff was 4% and 5% for the Lena and Selenga rivers, respectively.

In the second stage, the attribution of natural and anthropogenic climate-driven runoff change over the historical period was evaluated by runoff formation models and ESMs, including before streamflow measurements on the Lena and Selenga rivers. According to the results of numerical experiments, it was found that the anthropogenic component of climate change in the dynamics of the Lena runoff is weak, i.e. during the observation period the Lena River flow statistically significantly increases, but it occurs mainly due to natural climate variability. The changes in the Selenga runoff are intensely influenced by the anthropogenic component of climate change. This has been particularly noted since the 1970s, when in the case of natural climatic conditions the flow would have increased, but taking into account anthropogenic greenhouse gas emissions, it has decreased especially since the mid-1980s due to a decrease in summer precipitation, which caused the last low-water period of 1996-2017 in the Selenga basin.
Assessment of Climate Change Impact and Comparison of Downscaling Approaches: A Case Study in a Semi-arid River Basin
Authors: Woyessa Yali
Published: September 2022

Rapid population increase, industrialization and pollution are putting a strain on available and diminishing freshwater resources. Recent climate projections suggest a drop of up to 10% in precipitation in most of Southern Africa by 2050. The main aim of this paper is to model the impact of climate change on water resources in a semi-arid river basin in South Africa using two downscaling approaches: statistical downscaling (SDE) and dynamic downscaling (CORDEX) approaches. Both SDE and CORDEX data were derived from the GCM simulations of the Coupled Model Inter-comparison Project Phase-5 (CMIP5) and across two greenhouse gas emission scenarios known as Representative Concentration Pathways (RCP) 4.5 and 8.5 with a spatial resolution 25 km × 25 km for SDE and 50 km x 50 km for CORDEX. Six GCM models were used for SDE set of data and eight for CORDEX data. SWAT hydrological model was run using these data for a period of 2020 to 2050.

For SDE data, comparison of measured data with simulated historical data showed strong correlation (R2 ≥ 0.9), which is indicative of the reliability of projected future climate. Varied results were obtained depending on the type of climate model used, but generally, the trends were similar in most cases. However, the multimodel average showed a possible decrease in precipitation (by 14%), a decrease in water yield (by 15%) and an increase in potential evapotranspiration (by 10%). For CORDEX data, the result showed similar strong correlation (R2 ≥ 0.9). The multimodel average showed a possible decrease in precipitation (up to -3%), a decrease in water yield (up to -13%) and an increase in potential evapotranspiration (ET) (up to +22%). The latter is indicative of possible drought spells between rainy events. The SDE approach showed much more pronounced decrease of precipitation and water yield compared to the CORDEX approach. This difference could be attributed to the difference in spatial resolution of the two downscaling approaches. However, it is expected that the results of this study could assist in policy formulation to mitigate the negative impact of climate change in the region.
Multiscale analysis of soil moisture variability for a typical semi-arid Mediterranean ecosystem
Authors: Corona Roberto , Montaldo Nicola , Katul Gabriel G.
Published: September 2022

Soil moisture content influences the partitioning of net radiation into latent and sensible heat fluxes that, in turn, affect the dynamics of the atmospheric boundary layer depth and concomitant generation of precipitation. The interactive effect between soil moisture and precipitation has been found to be stronger in areas where soil moisture temporal variability is enhanced such as in arid and semiarid regions, and in transitional regions between dry and wet climate. For this reason, variability in soil moisture at multiple time scales continues to draw attention in climate science and hydrology. In this work, the soil moisture variability at multiple scales for a typical Mediterranean ecosystem, has been quantified using the spectrum of soil moisture.

The case study is the Orroli site in Sardinia (Italy), a typical semi-arid Mediterranean ecosystem which is an experimental site for the ALTOS European project of the PRIMA MED program.

The spectrum of root-zone soil moisture content for this Mediterranean ecosystem is analyzed using 14-years of half-hourly measurements. A distinguishing hydro-climatic feature in such ecosystems is that sources (mainly rainfall) and sinks (mainly evapotranspiration) of soil moisture are roughly out of phase with each other. For over 4 decades of time scales and 7 decades of energy, the canonical shape of the measured soil moisture spectrum is shown to be approximately Lorentzian determined by the soil moisture variance and its memory but with two exceptions: the occurrences of a peak at diurnal-to daily time scales and weaker peak at near annual time scales. Model calculations and spectral analysis demonstrate that diurnal and seasonal variations in hydroclimate forcing responsible for variability in evapotranspiration had minor impact on the normalized shape of the soil moisture spectrum. However, their impact was captured by adjustments in the temporal variance. These findings indicate that precipitation and not evapotranspiration variability dominates the multi-scaling properties of soil moisture variability consistent with prior climate model simulations.

 