bluuebunny/crossref_metadata_2025 huggingface dataset:
System level water use efficiency of rural water supply systems in rural Colombia: a top - down analysis
Authors: Callejas Moncaleano Diana Carolina , Rietveld Luuk , Pande Saket
Published: September 2022

In developing countries, such as Colombia, the majority of the rural water supply systems (RWSS) emerge from the water needs of the community, in order to transit from manual water collection to piped systems. The communities usually construct their water supply system and assume the responsibility of the system. How big these system grow and how well these are maintained are key to how well these systems serve its communities. This paper explores whether the scale of a system, i.e. the size of the system and the number of water users, is an emergent property of the human-water system and that the maintenance of a RWSS depends on this emergent property. Key questions addressed here are: what factors control the scale of a system and how these factors affect the maintenance of the system.

Eight RWS systems located in the rural area of two municipalities, Restrepo and the rural area of Cali in the Valle del Cauca province in Colombia, are investigated to compare and contrast the systems and associated factors such as location, occupation and income distributions of the communities. Nearly 900 households representing the population are surveyed. Even though the RWSS are located in the same region, water use efficiencies (indicator of system maintenance) are different from one system to another.

Rarely, the distance from the RWSS to urban areas is considered to analyse how well a system is maintained. The results highlight that the locations of the systems, dominant occupation and income levels, as a result,  of the communities play an important role because it determines the surplus that communities are able to muster to maintain as well as grow the systems. The surplus is less in remote areas compared to those close to the peri-urban areas while the maintenance costs are similar. As a result, factors are identified that affect the scale and water use efficiency of the studied RWSS in the Valle del Cauca province in Colombia.
Water scarcity conflicts: Supporting dialogue and negotiation
Authors: Ferchichi Intissar , Zairi Abdelaziz , Marlet Serge
Published: September 2022

Abstract

Conflict over water resources emerges from complex interactions among biophysical, social, and economic processes operating at multiple scales. The concomitant use of surface and groundwater managed for multiple uses is a classic coping strategy to manage the water scarcity yet a relevant example of such conflict. Managing these resources is thus a dynamic decision-making process involving actors with different perceptions of the situation, who adapt different strategies to satisfy their objectives and interests. This paper presents the results of an effort to address these conflicts through reinforcing the adaptive capacity of different actors to cope with water scarcity in a multi-scale irrigation system. The study site focuses on the irrigated area of Zaouiet Jedidi in Northeast Tunisia. This region is characterized by an intensive irrigated agriculture, mostly through an excessive pumping of groundwater resources. Individual strategies to face the water scarcity are dominating leading to a rapid deterioration of the groundwater resources. Irrigation through individual and informal wells is an example of such strategies. As the demand for agricultural and urban water has concurrently continued to develop, the groundwater has continued to drop. Despite the State’s efforts to increase the water supply to the region through the transfer of surface water from the dams of northwestern Tunisia, the overexploitation of groundwater resources exceeded 200%. A participatory process was implemented to initiate a process of interaction and coordination between the different stakeholders involved in the management of the irrigated area. We analyzed to what extent and by what mechanisms, a participatory problem-solving process can facilitate the emergence of collection action to face the water scarcity.

 

 
Tailoring large-scale hydrological models for national planning of climate actions in vulnerable countries
Authors: Arheimer Berit , Gyllensvärd Frida , Capell René , Andersson Jafet
Published: September 2022

Many countries vulnerable to climate change do not yet have national modelling systems in place to guide adaptation measures. Especially low- and middle-income countries are at the mercy of global or large-scale estimates of climate change impacts, which might not be relevant to the spatial scale of societal challenges or to engineering methods based on observations.

Climate services are launched with scientific data, which can be misunderstood and misused if not communicated in a pedagogic way. For instance, the results from climate models represents an average for a calculation unit and neglects the spatial variability within that unit. In-situ observations from monitoring stations represents a point value and may thus be very different from areal estimates. Moreover, observations are relatively few leaving large areas ungauged. Sometimes, the area of interest falls in between grids or is very small compared to the grid or catchment and the average values may then not be representative or useful.

Moreover, the results from climate models represents a statistical period of 30 years, but not the chronological happening of events or weather conditions. Time-series from climate models are thus not representing specific dates and should not be compared to observed time-series but only to statistical estimates, such as indicators. 

In this presentation we showcase (1) state-of the art methods to produce climate indicators for weather and water data over large domains, and (2) some ways to tailor climate and water data for local applications and practical use.

We will demonstrate the global climate service climateinformation.org, in which climate and water indicators result from an extensive production chain, merging data from various sources with different resolution in time and space.

For water indicators, climateinformation.org uses results from a global integrated-catchment model, the world-wide HYPE. To tailor data, it is recommended to use a more detailed national/local model or set-up the HYPE model using national/local data. SMHI share the open source HYPE-model code and here we will explain how to apply climate indicators to calculate climate-change effects on water resources using a local/national model. Showcases are given for St Lucia, DR Congo, Cape Verde, and Cambodia.
Survey on relationship between hydrogeological risk awareness/preparedness and multiple sociodemographic factors: case study in a flood-prone area, Nagano, Japan
Authors: Nakamura Shinichiro , Takano Tsuyoshi , Terakawa Koki , Nakai Fuko , Otsuyama Kensuke , Oki Taikan
Published: September 2022

Flood is a typical phenomenon that involves the human-water interactions. In socio-hydrology, which deals with the coevolution of water and society, the development of socio-hydrological models to represent the human-flood interaction has been progressing rapidly. The proposed model describes the interaction between floods, residential density, awareness, preparedness, and flood losses, and uses empirical data to estimate the parameters of the model (Di Baldassarre et. al., 2015). The data on flood awareness and preparedness are the most important for correctly estimating the parameters and modeling the system dynamics (Barendrecht et. al., 2019). It is assumed that flood awareness and preparedness vary from region to region depending on the sociodemographic characteristics and socio-hydrological context in the region. Therefore, comparative analysis of those parameters among different regions is absolutely necessary to properly understand and represent the socio-hydrological phenomena.

In this study, we conducted a questionnaire survey on flood awareness/preparedness, memory, and sociodemographic factors in Nagano City, a typical flood-prone area in Japan, which was also affected by the Typhoon Hagibis in 2019 (number of subjects: 1,000). And we clarified how these factors are related to sociodemographic characteristics, disaster experience, risk perception, and land attachment. Finally, we compare the several results of the survey with those conducted in the northeastern part of the Italian Alps, which was affected by mudslides in 2000 and 2002 (Scolobig et.al., 2012), and discuss the characteristics of human-water interaction in Japan.

 

References:

Barendrecht, M. H., Viglione, A., Kreibich, H., Merz, B., Vorogushyn, S., & Blöschl, G. (2019). The value of empirical data for estimating the parameters of a sociohydrological flood risk model. Water Resour. Res., 55, 1312– 1336.

Di Baldassarre, G., Viglione, A., Carr, G., Kuil, L., Yan, K., Brandimarte, L., and Blöschl, G. (2015), Debates—Perspectives on socio-hydrology: Capturing feedbacks between physical and social processes, Water Resour. Res., 51, 4770– 4781.

Scolobig, A., De Marchi, B., and Borga, M., 2012. The missing link between flood risk awareness and preparedness: findings from case studies in an Alpine Region. Natural Hazards, 63 (2), 499–520.
Hydrochory in agricultural landscapes
Authors: Faucher Martin , Bailly Jean-Stéphane , Vinatier Fabrice
Published: September 2022

Maintaining biodiversity of spontaneous species in agricultural landscapes is a major challenge regarding the bundle of ecosystem services provided by them, such as preservation of water and soil resources. It is possible to increase landscape’s resilience to climate change through their renaturalization with agroecological measures, especially maintenance practices of vegetation cover in agroecological infrastructures. 

In the Mediterranean environment, those infrastructures such as ditches, plot borders or even inter-rows of perennial crops concentrate both biodiversity and flow of matter (water, pollutants, particles), making these landscape elements particularly susceptible to intense rainfall events that contribute to exchange of biodiversity across landscapes. Managing vegetation of these elements is a significant lever for biodiversity maintenance considering impacts of plants on flows of matters, such as water and seeds. Promoting exchanges requires knowledge of the relative importance of the main types of plant dispersal i.e. hydrochory, anemochory and zoochory that affects seed exchange between landscape elements, by making the hypothesis that the hydrochoric dispersion, i.e. by water, is particularly important in the Mediterranean environment. 

To establish the potential of hydrochory to rehabilitate Mediterranean vineyard environments, we proposed a conceptual model of seed exchanges at landscape scale incorporating the levers available to stakeholders (vegetation maintenance in inter-rows, drainage ditches and plot borders), as well as climatic variables and the specific characteristics of each seed present. We will present the first results of seed dispersal experiments after a rainy event on a vineyard plot, as well as manipulations to determine the seed bank, allow us to make a first estimate of seed transport and the rehabilitation potential of Mediterranean vineyard environments. At the end of the experiments, the knowledge obtained will be integrated into a spatially explicit model based on the source-sink principle to simulate the dispersion of seeds by water, this model being considered as a virtual laboratory to co-construct landscape arrangements with stakeholders for maintaining biodiversity.
Changes in groundwater spring yield patterns in Czechia
Authors: Ledvinka Ondrej , Lamacova Anna , Vlnas Radek
Published: September 2022

Springs are crucial for maintaining surface-water resources and healthy ecosystems and provide a valuable source of information about groundwater. Monthly, seasonal and annual trends in spring yield of 138 springs in Czechia over the period 1971–2020 were evaluated. Furthermore, field significant trends in spring yields in 18 hydrogeological regions were identified. Monotonic deterministic trends were detected by the trend-free pre-whitening modification of the Mann–Kendall test using mean monthly values. Most of the series (70%) did not exhibit any long-term trends in annual data. However, considering statistically significant changes, the decrease prevailed over the increase. A reduction in the yield was observed at 28% of the springs, while an increase only at 2% of them. In the seasonal cycle, the yield decreased mostly in summer (32% of springs), in other seasons the yield decreased at 23–28% of the springs. Most often, the yield decreased in May (42% of springs), June (38%), and July (36%), least often in March (14%) and February (18%). Monthly long-term yield increases were observed only at a maximum of 5% of the springs in any of the months. In past years, a spring maximum shift from April to March or even to February was observed (compared to the 1981–2010 period). However, the increase in March and February spring yield expected due to this shift, probably caused by the air temperature rise and earlier snowmelt, has not been detected yet. Annual time series at 7 of 18 hydrogeological regions exhibited a significant decreasing trend (p < 0.05). No increasing trend was detected in any of the regions when analyzing annual data. The decrease prevailed in crystalline bedrock hydrogeological regions (4 of the 7 regions). However, a significant spring yield decrease in the region of the North Bohemian Cretaceous Basin (area between the Jizera and the Lower Elbe) is worth noting since this area represents a protected area of natural water accumulation. Similar to individual site trends, the most field significant trends occurred in summer (11 of 18 regions) and the least in winter (5 of 18 regions).
Reconstruction of the evolution of the hydro-sedimentary signal to the sea from the study from the study of the sedimentary archive: Case of the Cheliff wadi, Algeria.
Authors: Hadour Ali , Mahe Gil , Meddi Mohamed
Published: September 2022

This work focuses on the contribution of the documentation of the fluvial sedimentary archive in the study of the contribution of rainfall and large dams in the decline of sedimentary inputs of the Cheliff Wadi at the outlet. Therefore, three sediment cores, taken in the lower Cheliff valley, were studied through the paleohydrological approach. Such an examination aims, on the one hand, to establish a chronology of depositional accumulation and, on the other hand, to evaluate the ability of the information incorporated in the sedimentary archive to transcribe the evolution of the hydrosedimentary signal and the fluctuations of the controlling factors.

The results reveal: a strong variation in the granulometric distribution of the deposits and a progressive decline in the progressive decline in the rate of sediment accumulation. Thus, the upper part of the core is mainly made of particles belonging to the fine granulometric class that have accumulated with fine that accumulated with an average rate of about 1.31 cm / year. Contrary to the deposits composed of a succession of coarse and fine sedimentary layers, and showing a rhythm of accumulation much more superior, whose value is evaluated to 16 cm/year. However, the fluctuations observed in the granulometric composition and the accumulation rate of the deposits correlated strongly with the evolution of the rainfall signal and/or the multiplication of the number of large dams. Indeed, relatively coarse deposits and a higher accumulation rate correspond to the wet period before 1980.  Then, the decrease in rainfall was accompanied by a longer accumulation rate and deposits composed mainly of fine particles. In addition, the recently built dams, bringing the outlet of the watershed closer and closer, have a drastic effect on the deposition process.

Key words: Sedimentary archive, paleohydrological approach, Cheliff, rainfall, granulometric profile.
Uncertainty propagation in the modelling chain of the impact of climate change on a specific site on French subsurface drainage
Authors: Jeantet Alexis , Tournebize Julien , Martin Philippe , Thirel Guillaume
Published: September 2022

Subsurface drainage is a hydraulic technique currently used on agricultural soils showing strong waterlogging issues. This technique is applied on near 10% of French arable soils. Consequently, assessing its future in a context of climate change is relevant since subsurface drainage may have a major influence on the environment, specifically on agricultural water pollution. Here, the purpose is to analyse the evolution of hydrological indicators of subsurface drainage under climate change by 2100, on the La Jaillière plot being representative of French drainage in the Great West region. We define seventeen hydrological indicators to best describe the main aspects of subsurface drainage: drained water balance, temporality of the drainage season, flood events… These indicators are simulated by modelling subsurface drained discharge on the projected future using three hydrological subsurface drainage models: DRAINMOD, MACRO and SIDRA-RU. These three models are fed by twelve climate projections CPs provided by the EURO-CORDEX project, being selected by Météo-France to ensure the representativeness of future conditions in France. We consider three climatic scenarios RCPs (Representative Concentration Pathways): the RCP 2.6 (optimistic), the RCP 4.5 (intermediate) and the RCP 8.5 (pessimistic). The propagation of uncertainties on the hydrological indicators from the modelling chain is assessed by variance decomposition using the QUALYPSO method, from the various potential sources of uncertainties (hydrological models, CPs and RCPs).  Preliminary results obtained with the SIDRA-RU model alone showed that subsurface drainage will be exposed to more extreme events such as more intense flood events over shorter periods by 2100. Depending on RCPs, the sustainability of the current network may no longer be ensured.
A semi-distributed eco-hydrological model for the estimation of the effect of the climate change on a Mediterranean forest
Authors: Sirigu Serena , Corona Roberto , Montaldo Nicola , Airi Marcello , Mallocci Maurizio
Published: September 2022

Over the past century, climate change altered precipitation and temperature regimes worldwide.  Recently, Montaldo and Sarigu (2017) showed that Sardinia runoff decreased over the 1975-2010 period, with mean annual values 40% lower than the 1922-1974 period.

These trends may have dramatic consequences on basin water resources, impacting forest sustainability. Forests are frequently exposed to periods characterized by a reduced water availability and increasing temperature that influence the evapotranspiration process (ET),and may increase tree mortality and change tree spatial distribution and density.

The Marganai forest, located in the South-West of Sardinia (Italy), is a Long-Term Ecosystem Research (LTER) Italian site and a European Site of Community Importance (Natura 2000) managed by the Sardinian forest authority (FORESTAS). Trees are mainly Quercus Ilex and historical data are available from 1924, with rain from 16 stations, and runoff one the at the Fluminimaggiore basin section (area of 83 km2). A persistent decrease trend of winter precipitation (Mann-Kendall t of -0.14) impacted runoff (t of -0.26). A distributed hydrological model at basin scale has been developed, which computed runoff, ET and predicted grass and tree leaf area index (LAI). The model has been successfully calibrated for runoff and ET estimation for the 1925–2020 period, confirming a dangerous trend in soil moisture and water availability for the trees.

The hydrologic water balance of the basin were also investigated under future IPCC climate change scenarios. From the General Circulation Models of Flato et al. (2013), we selected the HadGEM2-AO that simulates reasonable approximation of observed past seasonal precipitation and air temperature changes in Sardinia. Using the distributed eco-hydrologic model and future climate scenario we predicted both hydrologic water balance terms (soil moisture, runoff, ET).

The future scenario predicted a reduction of annual precipitation, an increase of rain intensity and extreme events, and an increase of temperature and VPD.

The model predicted a significant decrease of tree LAI (t of -0.79) and runoff (t of -0.11), mainly due to VPD increase. Future scenario predicting further dry will require new strategies in both forestal and water resources planning and management. 
What can we learn from flume experiments about the transport of polyamide microplastics in streams?
Authors: Schneidewind Uwe , Nel Holly , Drummond Jennifer , Kukkola Anna , Lynch Iseult , Sambrook-Smith Greg , Krause Stefan
Published: September 2022

Microplastics have been found to be an emerging contaminant of concern in many ecosystems worldwide. While microplastics have been around for many decades, only recently have studies started to improve understanding of their transport and fate in riverine environments, toxicity to aquatic organisms and distribution throughout riverine food chains. Microplastics of various size, shapes and polymer types have been identified in water and sediment samples in streams and rivers on a global scale with the potential to accumulate in river sediments for extended periods of time. As this accumulation often occurs and increases downstream from where microplastics enter a stream, they can well be considered legacy pollutants.

While earlier studies assumed that microplastics deposit on the streambed mostly by gravitational settling, recent research indicates that turbulent flow processes near the sediment-water interface and groundwater-surface water interactions can greatly influence particle deposition patterns and retention times. In order to directly assess the deposition, accumulation and resuspension of polyamide (PA) particles in a more controlled setting we conducted experiments in mesocosms (recirculating flumes with dimensions of 200 x 42 x 15 cm).

Flumes were filled with either gravel (10-20 mm) or mixed sediment (ranging from silt to fine gravel) and freshwater and were spiked with PA fibres (500 μm length, 14 μm diameter), pre-crushed fragments (size ranges: 150-250 μm and 400-600 μm, pre-stained with Nile Red) or both. Sampling over 24 hours at three locations in each flume allowed us to study the deposition behaviour and we found that due to turbulent flow especially fibres remained in the water column much longer than would be the case for gravitational settling. Deposition rates and retention times of deposited particles were estimated by fitting flume data to a mobile-immobile model that provide insight into the differential transport between polymer types, sizes, and sediment grain size distribution. Subsequent resuspension experiments with variable flow velocities achieved by using one or several pumps per flume indicated significant differences in resuspension with respect to polymer shape and sediment type in the flume. Results will help us better understand and predict microplastic fate in streams and improve current models.  
Using socio-hydrogeology to identify pollutant fluxes toward groundwater within a highly anthropized coastal hydrosystem
Authors: Crayol Eléa , Huneau Frédéric , Garel Emilie , Re Viviana , Mattei Alexandra , Santoni Sébastien , Pasqualini Vanina
Published: September 2022

Coastal Mediterranean lagoons are usually groundwater dependent systems, however their hydrogeological functioning is poorly investigated, damaging their management. Socio-hydrogeology allows, in a transdisciplinary way to clarify the relationships linking human and groundwater. Those interactions within the watershed can generate processes leading to pollutant fluxes with impact on surface water, groundwater and lagoon water quality. This approach integrates both social and economic components into hydrogeological investigations.

The Biguglia lagoon watershed (Northern Corsica) has been chosen as a pilot site. Indeed, significant nitrate content, emerging compounds, and pesticides have already been observed, but their origin still needs to be specified, both in terms of source and dispersion modalities.

The aim of this study is to : (1) assess the link between groundwater quality and the anthropogenic pressures on the watershed, (2) understand water users’ and the stakeholders‘  perception and knowledge of the watershed and the local territory, (3) identify the origin of pollution detected in the lagoon’s water.

For this purpose, a field campaign was led in spring 2021 combining classical hydrogeological investigations with structured interviews. The latter involved the administration to 32 water users and 16 local stakeholders to determine the land use evolution since 1950’s to present and aiming at identifying past and present uses of the water resource over the watershed. At the same time, hydrogeological investigations have been carried out including chemical, geochemical and isotopic (2H/18O) sampling at 53 points, of which 21 samples were also analysed for pesticides.

Pesticide’s analysis shows that the site is affected by agricultural pollution. Neonicotinoid insecticides imidacloprid and acetamiprid are extensively used worldwide, threatening ecosystems and human health, they have been found on the sampling points with concentrations between 28.8ng/l to 36.4 ng/l and 6.3ng/l to 123 ng/l. Also benzotriazole, one of the most commonly found compound in groundwater is present with concentrations between 30.7ng/l to 233 ng/l.

The purpose of this work is to offer a new functional diagram of the Biguglia hydrosystem, including the space-time continuum of anthropogenic modifications within the watershed. This new knowledge will help local stakeholders to maintain the good status of water bodies on the watershed. 
Impact of future climate change and anthropization on the discharges of the So'o watershed (South Cameroon)
Authors: Ebodé Valentin Brice , Mahé Gil , Braun Jean-jacques , Dzana Jean-guy , Ndam Ngoupayou Jules Remy , Nka Nnomo Bernadette
Published: September 2022

The purpose of this article is to get an idea of ​​the evolution of the flows of the So’o basin in the relatively near future (2022-2060), but also in the distant future (2061-2100). In this perspective, the Cellular Automata (CA) -Markov was used to predict the evolution of the future land use of the basin, and the outputs of three regional climate models/RCMs (RCA4, RACMO22T and CCCma) were used to predict future climate change. Distribution mapping was retained as a method of correcting the precipitation and temperature biases of the outputs of the climate models used. The SWAT (Soil and Water Assessment Tool) model was used to simulate the future flows of the So’o. The results obtained show that a change in precipitation in accordance with the forecasts of the CCCma and RACMO22T models will be the cause of a decrease in the runoff, except under the RCP8.5 scenario during the second period (2061-2100), where we will note an increase compared to the historical period of approximately + 4%. This decrease will mainly affect the months of autumn, and the decades 2020, 2040 and 2070 will be the most affected. Concerning the RCA4 model, the results obtained show that a change in precipitation following its forecasts will cause an increase in runoff of more than 50%, regardless of the period and the scenario taken into account. In general, this increase will be greatest during the dry seasons (winter and summer), and the decades at the end of the century (2080s to 2100s) will be the wettest. An increase in discharges was noted in certain cases despite a decrease in rainfall, in particular in the case of flows simulated for the first period (2022-2060) from the outputs of the CCCma model. This seems to be a consequence of the increase in impervious areas, insofar as the runoff also increases during this period according to the model. The results of this study could be used to strengthen the management of future water resources in the basin and the entire region.

Keywords: So’o, RCMs, Climate Change, Anthropization, SWAT
The importance of retention times in Natural Flood Management interventions
Authors: Beven Keith , Follett Elizabeth , Hankin Barry , Mindham David , Page Trevor , Chappell Nick
Published: September 2022

The Nature-based Solution for reducing flood peaks known as Natural Flood Management is an increasingly popular policy option for flood mitigation in the UK and other parts of the world.   It involves a variety of different types of management intervention, including both in-stream and off-line storage elements.   These are often implemented on the basis of convenience in the choice of both sites and materials without any consideration of the importance of unimpeded flow during normal events, and the need for cumulatively large volumes of storage during extremely high flows that could flood downstream communities.   Yet past work (e.g. Metcalfe et al. HESS 2018) has suggested that there may be a rather subtle effect of retention times on peak flows.   If storage elements fill too quickly the effect on downstream hydrograph peaks during events that flood properties will be small.   Equally, if storage elements fill and then drain too slowly, their effectiveness during multi-peaked extreme events will be much reduced. Given the cost of adding sufficient storm-effective storage to a catchment is high, it is important that the interventions are constructed to work for those design events that affect flood risk in the downstream community.   This paper describes a simple tool for evaluating the retention times of in-stream structures of different types that can be used to make natural flood management more effective.

 
Delft Measures Rain – sharing experiences from two rainfall measurement campaigns by citizens
Authors: Uijlenhoet Remko , ten Veldhuis Marie-Claire , de Vries Sandra , Bogert Marit , Timori Illias , Chen Karen , van Beek Rafaël
Published: September 2022

Rainfall varies strongly in space and time. Capturing this variability is essential for hydrology and water management, particularly in rapidly responding urban areas. Traditional dedicated rain gauge networks are often too sparse for hydrological applications. This is especially the case in cities, where gauges often cannot be installed according to official requirements. This is where citizen science can come to the rescue.

Many citizens have an interest in their living environment, notably in the amount of rain falling in their city, neighbourhood, street or backyard. We took advantage of this intrinsic motivation by inviting inhabitants of the Dutch city of Delft to participate in rainfall measurement campaigns for two years in a row. Both in 2020 and in 2021 some 100 citizens installed simple funnel type rain gauges we provided to them in their backyards or on the roofs of their houses. This allowed them to take daily measurements from late summer to early fall (August – October).

After initial quality control, rainfall was found to vary strongly across the city. Readings by citizens were found to match well with official measurements of a KNMI station. This indicated that observed spatial variations could be attributed to real rainfall variability rather than to instrumental artefacts. The nearest automatic gauge from KNMI is operated 10 kilometres south of Delft. The general tendency of the daily accumulations measured by the citizens matched well with that from the KNMI gauge. However, for some days, appreciable differences were found. These could be attributed to spatial rainfall variability, as detected by the KNMI weather radars.

During the 2021 campaign, we also provided 10 citizens with automatic tipping bucket gauges. Rainfall accumulations from the tipping buckets were found to be in close correspondence with those from the funnel gauges. Although automatic gauges are more expensive than simple manual gauges, they can provide rainfall information at higher temporal resolutions. That is why we hope to be able to deploy more automatic gauges next year. This would allow us to study spatial rainfall variability across a range of temporal scales. Systematic comparisons with radar measurements are another objective for next year.
On the role of water resources management to transform water, energy, food and ecosystem (WEFE) systems in transboundary river basins
Authors: Uhlenbrook Stefan , Ringler Claudia , Lautze Jonathan , McCartney Matthew , Hafeez Mohsin
Published: September 2022

The program NEXUS Gains addresses key challenges of transforming water, energy, food and ecosystem (WEFE) systems in transboundary bread-basket basins in East and Southern Africa (Blue Nile and Limpopo basins), Central (Aral Sea basin) and South Asia (Ganges and Indus basin) in a changing world. The program particularly explores water resource management options to understand WEFE system interdependencies, trade-offs and synergies and develop more sustainable development pathways for all members society.

The presentation will discuss alternative interventions to increase water productivity different sectors (irrigation, forestry, industries) across scales ranging from farm to watershed to river basin scales. Therefore, particular attention will be given to integrated water storage management in human built and natural infrastructure in South Asia and East Africa. The implications for hydrological process and water resources dynamics and wider environmental, social and economic systems are analyzed and related policy implications are discussed considering also climate change.
The Systemic Timeline Multistep methodology: a framework for analyzing interdependencies between knowledge and action in socio-hydrological observatories
Authors: Daudin Kevin , Colin François , Weber Christiane
Published: September 2022

This communication intends to promote an ex-post methodology to systematically document coupled trajectories between environmental sciences and planning. While specific institutional arrangements facilitate collaborative practices in long-term socio-environmental observatories, the collaboration mechanisms are still poorly documented and some framework developments are needed for capitalization studies. To fill this gap, we propose an approach to trace, illustrate and evaluate interactive activities between researchers and managers. We proposed the Systemic Timeline Multistep (STM) methodology on the basis of a typical case-study, the coastal Thau catchment (south of France), where societal challenges emerged from water-related issues.

First we propose a conceptual framework of the collaborative process: the system under study is composed of bundles of research and development projects, which forms a given sociotechnical configuration that fulfill specific functions. The trajectory is marked by the succession of relatively stable periods, globally oriented by transitions. Second, we implement this framework on past environmental projects through a diachronic and dialectic approach: the objective is to characterize regimes (driving mechanisms of interactive arrangements) and identify transitions in the trajectory (triggers and impacts of regime shift). The multi-step methodology is divided in: define spatial and temporal system boundaries, list and contextualize all projects, represent the dynamics of projects and events, and analyze the overall pathway (relate projects’ role to context variables).

The implementation of the methodology on the Thau case study helps rapidly visualize research activities and their interactions with water management and broader governance and societal events through time. Both research and practice communities were bridged in the frame of specific governance instruments dedicated to lagoon water quality, which ‘sanitary crises’ required interventions across public policies and sustained interactions with knowledge production. It points out the role of technical infrastructures (monitoring and modelling of water fluxes) on water quality and related-activities, and it highlights the importance of boundary works for integrated planning (coastal zone, land and water). Finally, the STM methodology supports the characterization of interdependencies between water fluxes characterization, water management and water uses. Exploring the impacts of information system on collaborative mechanisms may provide place-based reflexive insights on governance approaches in long-term research platforms.
Water availability and expansion of agricultural activity in southwestern Tocantins - Brazil: identification of scenarios and weaknesses
Authors: Oliveira Roberta , Luz Rodolfo Alves , Vergara Fernan
Published: September 2022

The environmental problems in the Middle Araguaia region, southwest of Tocantins, are resulted of an occupation pattern  oriented by the economic development established in the 1960s, and that persists to current days. This research analyzed the evolution of land use and occupation over 34 years (from 1985 to 2019). It was determined the transformation rates occurred and the environmental fragility, as well as thesuitable lands for agricultural production. It was evaluated the physical and environmental aspects associated with the land use dynamics, which aided in the modeling future scenarios of occupation scenarios environmental fragility and hydrological and climatic suitability for agricultural production. Considering the maintained of the current occupation patterns guided by the expansion of the crop to pasture areas, deforestation and the increase of irrigated areas, the region will lose its environmental support capacity and will reach a situation of extreme water deficit, causing negative impacts in the agricultural productivity. In view of this scenario, the methodology used in this study is quite adequate to support public policies and actions of planning and monitoring, which are essential to that help in the process of regional development in the region.
Hydrologic model calibration using MODIS-ET data: The impact on predictions at gauged and ungauged locations
Authors: Jeyalakshmi Saranya , Bolisetti Tirupati , Balachandar Ram
Published: September 2022

Increasing availability of satellite remote sensing data triggered the use of hydrologically relevant satellite-based fluxes and variables towards improved modelling. Importance of innovative and satellite data sources for a better understanding of hydrologic processes has been highlighted in the IAHS scientific assembly’s 23 unsolved problems in hydrology. In this context, the present study investigates the use of satellite ET dataset form MODIS in the physically based semi-distributed model Soil and Water Assessment Tool (SWAT). The study area is Nith river watershed, located in Southern Ontario, Canada. We compare the potential of MODIS ET in improving the performance of SWAT at gauged and ungauged locations of Nith River watershed. Streamflow calibrated SWAT model is used as a benchmark model. The benchmark model results are compared with the MODIS ET only calibrated model results to understand the importance of satellite data in hydrologic model calibration. It is found that the calibration of SWAT model only using MODIS ET data resulted better or similar results to that of streamflow-based calibration. The results show that SWAT model improvement is highly dependent on the input data quality such as the precipitation data and land use data used in the initial model set up. The SWAT model calibrated using MODIS ET improved the soil moisture accounting and crop yield estimation. From our results we conclude that the satellite datasets can be a potential solution to parameter estimation in ungauged basins across the world.
Pros and cons of various efficiency criteria for evaluating hydrological models
Authors: Onyutha Charles
Published: September 2022

Hydrological models are commonly applied to investigate impacts of climate change and variability on hydrology. Confidence in hydrological predictions is linked to the model’s performance in reproducing observed variable under consideration. Judgment of a model’s quality is challenged by the differences which exist among the various efficiency criteria. Some of the efficiency criteria commonly applied for assessment of hydrological models include Nash-Sutcliffe Efficiency, coefficient of determination and Kling and Gupta Efficiency. However, a plethora of recently introduced "goodness-of-fit" metrics exists including, for instance, the revised R-squared and Liu efficiency. Studies on comparative analysis of the various efficiency criteria applied to hydrological modeling considering both the old and recently introduced "goodness-of-fit" metrics are lacking. In this study, several efficiency criteria are compared with respect to the computation difficulty, and speed of computation while considering various sample sizes. The pros and cons of the various (both old and new) efficiency criteria are given. The results of this study show the need for modelers to gain insights into the impact of each "goodness-of-fit" metric on model performance assessment before making hydrological predictions for planning predictive adaptations to the impacts of climate change or variability on hydrology.
The challenge of integrating local communities to evaluate the WEFE Nexus: the example of the Senegal River
Authors: Bruckmann Laurent , Tilmant Amaury , Sarr Khady Yama , Barry Ibrahima , Gueye Fama , Mbaye Massaer , Sambou Clément
Published: September 2022

Managing the WEFE nexus is a prerequisite towards the sustainable management of water and connected resources at the river basin scale. The challenge is even more important in transboundary river basins such as the Senegal River where the four riparian countries (Guinea, Mali, Mauritania, Senegal) share a common vision: to transform the river into a food-energy-transportation hub in West Africa. This vision requires the construction of hydroelectric power plants, modern irrigation systems and river transport infrastructure, and often requires constant river flows. Several dams already exist and several more are planned in the coming decades. These developments directly threaten the livelihoods of riverine communities that depend on the river banks, mainly for flood-recession agriculture and fishing.

Evaluating the WEFE nexus and its objectives usually involves indicators describing how well the sectoral objectives are met in terms of food production, energy production or percentage of the population with access to safe drinking water and sanitation services. These indicators are often aggregated at the river basin level, which masks local realities: the water needs, water management practices water management practices and inequalities in access to water at communities or households’ level.

The objective of this communication is to present a portfolio of regional and community-level indicators to analyze the WEFE nexus across different spatial and temporal scales. The construction of this portfolio is a two-stage process. Firstly, the definition of relevant indicators is carried out on the basis of consultation with a variety of participants involved in water management in the Senegal River (researchers and experts, institutional stakeholders, civil society actors, local communities). Secondly, local data describing the state of the local indicators of the nexus at the local level are collected from field surveys. We will also show how these indicators can enrich the analysis of basin-wide hydroeconomic models by assessing multi-scale trade-offs, as well as the distributional impacts of nexus interventions. This work is part of the H2020 GoNexus project, which aims at improving the governance of the WEFE nexus in transboundry river basins.
Is there any trend in groundwater level in South India? Case study from Telangana State, India.
Authors: Selles Adrien , Paswan Abhilash , Ferrant Sylvain , Dewandel Benoit , Maréchal Jean-Christophe
Published: September 2022

Worldwide groundwater is under an increasing pressure, mainly for agricultural water uses. Among that, India is the first groundwater user. Indian agriculture has exceeded the total available groundwater resources, which in turn have put a serious concern on food security as well as aquifer health.  Therefore, trend indicator is commonly used in analysis of groundwater level time series, showing clear drop of water level in North west of India. Nevertheless, the trend analysis in South India does not appear obvious. This work intends to raise awareness about the strength but also the weakness of time series trend analysis of groundwater level. This work uses the Telangana state in south India as a case study. Indeed, the Central Groundwater Board, used one of the most dense piezometer system in the world to estimate the ratio of groundwater extraction to aquifer recharge. The state average is 65 % (Excluding Hyderabad, the main city, where it is 340 %). Over the last 20 years, the state groundwater level shows a gentle declining trend of 0.8 m per year. However, this trend hides local and temporal disparities that cannot be neglected.

Mann–Kendall and Sen’s slope tests were accomplished on monthly groundwater level data from 2007 to 2020 over more than 1000 monitoring borewells to investigate the annual and seasonal groundwater-level trends. The trend information was mapped at Telangana state scale (110 000 km2) and estimated for different periods depending on climate conditions (very rainy year or at the opposite in drought condition). These results allow us to identify the impact of irrigation practices changes considering the hydrogeological setting and the resilient behaviour of users.  Indeed, the spatial distribution and time period chosen can have a tremendous impact on the conclusion of trend analysis in South India. 

On a first hand, this work proposes to highlight the main misunderstanding that trend analysis could bring in this kind of groundwater system, and on another hand, to show the enhancement of knowledge that this technic allows. The trend analysis need to be adapted to the local context to raise alert and help the decision makers to improve groundwater management.