There are several factors increasing pressure on water resources such as demographic, economic, social, and climatic changes, in addition to the growing demand for energy, food, and water. Water-related hazards, such as floods and droughts, are affecting millions of people’s lives and will become more frequent, and the need for early warning systems is growing and is being addressed by UN Early Warnings for All initiative. Water is the 6th of the 17 Sustainable Development Goals (SDGs) and impacts on 15 other SDGs. There is a growing demand for water by different sectors.

Responding to the above water challenges and related hazards demands hydrological data that is findable, accessible, interoperable, and reusable, sufficient, and useful. Unfortunately, in most countries and regions, management of water resources is mostly addressed without adequate consideration of the inter-sectoral and transboundary implications of planned developments or decisions on different sectors. This is due to lack or inadequate management and exchange of reliable data among various sectors. It is essential that the management and sharing of hydrological data are performed effectively to maximize the benefits of data collection and optimize data reuse, and thus get a return on investment.

Data exchange is still a challenge in hydrology from both the technological and policy perspective. The technology challenges include sparse measuring networks and lack of automatic data transmission, inadequate data quality control systems, heterogeneous and incompatible standards and protocols for data and metadata storage and exchange, and the inability to openly publish and maintain data and metadata in a publicly interoperable way. The policy challenges are often related to restrictive national legislation and financial consideration on data sharing. The WMO Unified Data Policy adopted in 2021 and the Earth System approach will help to address some of the issues, while the relevant integrated and interoperable data management and access tools, will support the technical aspects.

WMO programmes promote exchange of Earth System data. WHOS (WMO Hydrological Observing System) is the hydrological part of the WIS providing data sharing solutions. It is a system of systems supporting interoperable hydrological data exchange using open standards and web services, and harmonizing the data to meet specific user needs.

The goal of WHOS is to make hydrological data accessible through the use of open standards and free open-source tools for the harmonization of data, metadata, protocols, and vocabularies. Due to the diversity in the use of hydrological data and heterogeneous data sources, their effective exchange requires the implementation of interoperability enablers and data exchange mechanisms such as WHOS Discovery and Access Broker (DAB) technology, and development of hydrological terminologiesand Metadata Data Profiles.

The WHOS has been implemented in La Plata Basin, Arctic Region, Dominican Republic, UK, and SAVA River Basin. Those regions benefit from a platform that enables interoperable data sharing among different stakeholders and water resources management. With new countries connecting to WHOS each year, there will be a notable improvement in global, regional and national implementation of Early Warning systems and other projects.

How to cite: Korhonen, J., Otieno, W., and Berod, D.: Hydrological Data Sharing is a key for Sustainable Development and building Early Warning Systems, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12991, https://doi.org/10.5194/egusphere-egu23-12991, 2023.

The Tibetan Plateau is known as the water tower of Asia, supplying water to almost 2 billion people. As a result of the unique high-elevation terrain and atmospheric circulation, this region is severely affected by floods each year. Due to global warming in recent years, the Tibetan Plateau is experiencing more extreme precipitation events, and flood disasters are more likely to occur. However, compared with other regions in China, the Tibetan Plateau is still in its early stage when it comes to flood risk assessment and prediction because of the complex topographic conditions and a lack of gauging stations. At the same time, the unclear flood occurrence mechanism and the various flood types under monsoons and upper-level westerly winds in this region lead to strong uncertainty in the storm flood simulation.

To provide support for regional-scale hydrological simulation and improve the flood risk assessment information, we produce a hydro-geomorphic unit hydrograph dataset that characterizes the rainfall and runoff response relationship in 11069 catchments across the Tibetan Plateau. More specifically, the main geomorphological features of 11069 catchments are extracted first. Then, the WFIUHs are derived from DEM and other remote sensing data combined with the empirical physical formula. Finally, the performance of the WFIUHs in hydrological simulation is assessed in several gauging catchments in this region.

How to cite: guo, Y., zheng, H., yang, Y., and sang, Y.: Hydro-geomorphic dataset of catchments across the Tibetan Plateau, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12003, https://doi.org/10.5194/egusphere-egu23-12003, 2023.

Among the Essential Climate Variables (ECVs) defined by the Global Climate Observing System (GCOS), groundwater is one of the terrestrial ECVs in the field of hydrology. As the world’s largest distributed freshwater storage, groundwater is a key resource for mankind, industrial, and agricultural demands, and for ecosystems. Very recently, in its Implementation Plan of 2022, GCOS defined terrestrial water storage (TWS) as a new hydrological ECV. The state variable TWS quantifies the net effect of climatic, hydrological and anthropogenic change on the continental water cycle and is essential for closing the terrestrial water balance.

In spite of their importance, there is no data service or product yet on the ECVs groundwater and TWS in Copernicus, the European Union’s Earth observation program. The EU-funded project G3P (Global Gravity-based Groundwater Product) recently developed a satellite-based global-scale data set of groundwater storage anomalies (GWSA) for the period 2002-2020, with monthly resolution and on a 0.5-degree global grid. We present this data service developed as a prototype for later implementation into the EU Copernicus Climate Change Service. G3P is a global data set of groundwater storage variations as a cross-cutting extension of the existing Copernicus portfolio. G3P capitalizes from the unique capability of the satellite gravimetry mission GRACE (Gravity Recovery and Climate Experiment, 2002-2017) and its successor mission GRACE-FO (GRACE-Follow-On, since 2018) being the only remote sensing techniques to monitor subsurface mass variations, and from other satellite-based water storage products to provide a data set of groundwater storage change for large areas with global coverage. G3P is obtained by using a mass balance approach, i.e., by subtracting satellite-based water storage compartments such as snow water equivalent, root-zone soil moisture, glacier mass, and surface water storage from GRACE/GRACE-FO monthly TWS anomalies. The resulting TWS and groundwater data sets are currently made available via the GravIS portal and within GGMN, the Global Groundwater Monitoring Network of IGRAC, the International Groundwater Resources Assessment Centre.

The GravIS (‘Gravity Information Service’, gravis.gfz-potsdam.de) portal is operated by the German Research Centre for Geosciences (GFZ), together with the Technische Universität Dresden and the Alfred-Wegener-Institute (AWI). It facilitates the dissemination of user-friendly products of mass variations in the Earth system, based on GRACE/GRACE-FO. In addition to TWS and GWSA data, GravIS provides ocean bottom pressure (OBP) variations from which global mean barystatic sea-level rise can be estimated, as well as mass changes of the Greenland and Antarctic ice sheets. All these data sets can be interactively displayed at the portal and are freely available for download, either provided as gridded products or as regional averages.

This study has received funding from the European Union’s Horizon 2020 research and innovation programme for G3P (Global Gravity-based Groundwater Product) under grant agreement nº 870353.

How to cite: Dahle, C., Güntner, A., Sharifi, E., Haas, J., Dorigo, W., Jäggi, A., Ruz Vargas, C., and Dobslaw, H. and the G3P team: A data service for global groundwater and terrestrial water storage variations based on satellite gravimetry, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15510, https://doi.org/10.5194/egusphere-egu23-15510, 2023.

The Physical Oceanography Distributed Active Archive Center (PO.DAAC https://podaac.jpl.nasa.gov/) is NASA’s data center for the Surface Water and Ocean Topography (SWOT) mission (https://podaac.jpl.nasa.gov/SWOT?sections=data), which has recently launched in December 2022. PO.DAAC also archives physical oceanography data, which includes winds, salinity, sea surface temperature, gravity, ocean circulation, and a growing number of terrestrial hydrology data. The SWOT mission provides a comprehensive view of Earth's freshwater bodies from space and allows scientists to determine changing volumes of fresh water across the globe. SWOT hydrology data (of rivers, lakes, and reservoirs) is expected to be made publicly available in the latter part of 2023 (exact timeframe TBD). PO.DAAC has been preparing its data archive to deliver various tools and services to the hydrologic community in support of streamlined data access and use. In anticipation for SWOT, PO.DAAC has gathered requirements from the hydrology community over the last several years. In this presentation we will cover the various information systems developed to meet the hydrology community needs. PO.DAAC has also been working on migrating all of its data to the cloud. Users now have the ability to explore SWOT hydrology data directly in the Earthdata Cloud and also interface with the data using Application Programming interfaces (API). Hydrology domain specific data search and discovery methods (such as search by pre-defined hydrologic units) have also been implemented. PO.DAAC has been focused on exposing its SWOT hydrology data through programming interfaces such that scripting tools to GIS software can easily interface with the SWOT data. PO.DAAC has also been developing new functionalities to support analysis of large data, and new, innovative science and applications. Those functionalities and services will be discussed, along with what datasets users can find on the cloud, which will remain free and open to discover and access. 

How to cite: Vannan, S., Taglialatela, C., Nickles, C., Tarpinian, N., Greguska, F., McDonald, V., Armstrong, E., Gangl, M., and McNelis, J.: PO.DAAC SWOT Hydrology Data Tools and Services, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16890, https://doi.org/10.5194/egusphere-egu23-16890, 2023.

The Global Runoff Data Centre (GRDC) operates under the auspices of the World Meteorological Organization (WMO) at the German Federal Institute of Hydrology (BfG). It serves an important function for the scientific community as an archive for global runoff data. In 2022, the GRDC was referenced as a data source in over 100 peer-reviewed publications. 
Awareness of the need for reproducibility in hydrologic science has grown considerably in recent years. Thus, data archives also have the responsibility to improve their infrastructure to meet these requirements. Essential measures include making data and programs available in public repositories, containerization of computational environments and the provision of application programming interfaces (APIs).
To achieve these goals, the GRDC uses web portals for data provision, develops APIs for script-based data access, and provides program libraries in R or Python, e.g. for data analysis, as open source on repositories such as Github. We show the implementation status of these measures as well as positive effects that have resulted from the implementation, but also highlight obstacles and challenges in achieving a fully open and unrestricted data world.

How to cite: Recknagel, T., Färber, C., Plessow, H., and Looser, U.: The Global Runoff Data Centre: A building block in the chain of reproducible hydrology, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15454, https://doi.org/10.5194/egusphere-egu23-15454, 2023.

Microwave links from cellular communication networks have been proposed as an opportunistic source of precipitation data more than two decades ago. The first scientific studies demonstrating the potential of this ground-based remote sensing technique, in particular for areas around the world were dedicated rainfall observation networks are sparse, were published some 15 years ago. Since then, a small but dedicated community of scientists and engineers working at universities, national meteorological services, consulting companies, mobile network operators and telecommunication equipment manufacturers has been making significant progress in turning this promise into a reality. In the meantime, numerous papers and reports have been published, conference presentations have been given and courses have been delivered. However, real-time access to high-resolution rainfall information from commercial microwave link networks over large continental areas is still a dream. How far have we come after 20 years of research and development? What does the future have in stall for the hydrological and meteorological communities? What should be done to turn this dream into a reality? This presentation will attempt to provide some preliminary answers to these questions.

How to cite: Uijlenhoet, R.: Opportunistic sensing of precipitation using commercial microwave links: opportunities and challenges, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15358, https://doi.org/10.5194/egusphere-egu23-15358, 2023.

The increasing number and quality of numerical groundwater models worldwide represent a great source of knowledge for local, regional, and international scientists as well as water managers and decision makers. This development is facilitated by recent advancements in computational tools and access to open software. At the same time, scientific journals stress the importance of sharing model codes and data upon publishing, setting a new publishing standard. Altogether, these developments in the groundwater modelling field create a richer and more dynamic environment, fostering model reproducibility. Such an environment calls for a global, integrated, and standardized database of groundwater models to help members of the groundwater modelling community to search, deposit, and analyse groundwater model information. Unfortunately, despite attempts in the past, such a database is not yet constructed and made available to the public. This is why multiple universities and institutes from different countries came together to create the Groundwater Model Portal (GroMoPo), where groundwater model information can be collected and shared easily. The process of building GroMoPo started by collecting information about individual groundwater models via an online form where various information was compiled by researchers from the institutes involved in the project. Apart from simple information such as names of model developers, year of model development, and country of origin, we also collected information on model implementation (e.g. software used, time and area covered, calibration and validation data availability). The collected data is stored at the Consortium of Universities for the Advancement of Hydrologic Science, Inc. (CUAHSI) HydroShare environment. The collected data are freely accessible via a web portal, which allows the user to query and visualize groundwater model information and to contribute new models. This web portal also allows new users to submit groundwater model information and explore previously collected data. Furthermore, we plan to keep GroMoPo updated in the future as an ongoing service, with CUAHSI’s help, for the hydrological community. We collected information from more than 500 groundwater models in our first phase. This number might appear large, but we estimate that it captures only a few percent of published peer-reviewed articles that include a groundwater model. Therefore, we wish to invite the groundwater modelling community to contribute to and use GroMoPo, expanding our group even further to ensure that more data is collected and shared in the future. With such community involvement, we hope to facilitate meta-analysis and comparative studies, enable broader sensitivity and uncertainty analysis, avoid duplication or replication in groundwater modelling efforts, increase the visibility of existing models and associated publications, and create a teaching tool for aspiring groundwater modelers.

How to cite: Zamrsky, D., Zipper, S., Reinecke, R., Befus, K., Kretschmer, D., Ruzzante, S., Compare, K., Jordan, K., Bierkens, M., and Gleeson, T.: Groundwater Model Portal (GroMoPo) – collecting and sharing groundwater model information in a standardized open-access database, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12340, https://doi.org/10.5194/egusphere-egu23-12340, 2023.

Water is the basis for life and ultimately the reason why our society could develop the way it did, and thus, water security is an indirect core component in all 17 UN sustainable development goals. However, scientific water data and information are rarely accessible in an easy and understandable way for managers and policy makers. Moreover, hydrological sciences are fragmented with less tradition of sharing results, data and tools between scientists than in many other disciplines. Numerous efforts from development projects have launched prototypes and demonstrators of web-based applications to overcome these issues, but without long-term maintenance most of them disappear at project end. Here we will present experience from developing, maintaining and using three non-commercial operational services to facilitate actions in water security and promote scientific engagement with stakeholders.

https://hypeweb.smhi.se/ provides readily available modelled hydrological data for continent or global scale at sub-catchment resolution of some 100 km² (Arheimer et al., 2020), along with open source code with documentation and data compilation/visualization/training tools. The visitor can explore data for the past, present or future, download the numerical model, or order data subscriptions. SMHI has a long tradition of operational water predictions and also estimate status of water quality, design values for infrastructure, and the impact of climate change on water resources. The website is linked to an annual open (free) training course in HYPE modelling for various societal needs.

https://climateinformation.org/ offers access to three different tools to explore climate-change impact on water resources: 1) instant summary reports of climate change for any site on the globe, 2) easy access to many pre-calculated climate indicators, 3) a software package to calculate indicators by inserting local observations. The main purpose of this new service is to provide scientific data to argue for climate mitigation and adaptation investments in vulnerable countries (Photiadou et al., 2021). Pre-calculated water variables are based on a state-of-the-art production chain with global model ensembles from CMIP, Cordex, a global catchment model (WWH) and a rigorous quality assurance protocol.

https://dwg.smhi.se/dwg/ (prototype for a Digital Water Globe– address will change in February) is a brand-new platform to search and find (based on key-words) where on Earth there are: scientific results available from research projects (case-studies), monitoring programs (data repositories), publications (in HSJ, PIAHS) and researchers (personal profiles). The aim is to stimulate and facilitate engagement, interactions and dialogues among scientists and between scientists and stakeholders. The Digital Water Globe offers co-creation and re-examines the role of scientific outreach; it is a scientific community effort completely dependent on content from the users to explore networking and science communication in action.

The presentation will focus on obtained feedback, opportunities and challenges in running operational services with aim to share scientific data with a wide range of users.

References:

Arheimer et al., 2020: Global catchment modelling using World-Wide HYPE (WWH), open data and stepwise parameter estimation, HESS 24, 535–559, https://doi.org/10.5194/hess-24-535-2020   

Photiadou et al. 2021. Designing a climate service for planning climate actions in vulnerable countries. Atmosphere 12:121. https://doi.org/10.3390/atmos12010121 

How to cite: Gyllensvärd, F., Arheimer, B., Andersson, J., Berg, P., Gatti, M., and Schutzer, S. and the IAHS Task force: Maintaining operational services to share scientific knowledge and water data for a better world, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16216, https://doi.org/10.5194/egusphere-egu23-16216, 2023.