The Global Runoff Data Centre (GRDC) Report on selected GRDC activities during the inter-sessional period 2008-2012 Ulrich Looser Koblenz 09/2012 1
1. Introduction This report summarises some of the activities of the Global Runoff Data Centre (GRDC) during the inter-sessional period 2008-2012. It will give a brief account on the following: 1. Activities and current results related to the Open Geospatial Consortium Hydrology Domain Working Group 2. Data policy and data sharing 3. Future recommendations for the data management at the GRDC 4. Data acquisition activities and GRDC database status 2. Activities and results related to the Open Geospatial Consortium (OGC) 2.1. Background The Commission for Hydrology (CHy) of the WMO has a mandate for the publication of international water data standards. The hydrology domain has a large and diverse community of organisations providing and consuming data. CHy has the challenge of developing a model that will support the needs of this community. The Open Geospatial Consortium (OGC) is the primary international organisation for developing open standards concerning exchange of data with geospatial context. A number of OGC members had a particular interest in hydrology and standards for describing and sharing hydrological information. The original proposal for a hydrology domain specific working group came about when different teams discovered they were working on similar problems and that an international approach to the problem space would potentially have greater benefits than each team continuing alone. These groups further realised that technology standards developed and maintained by the OGC, provide an excellent basis upon which to develop protocols for the hydrology domain. Since this time discussions including CHy have led to the proposal to jointly convene a Hydrology Domain Working Group (HDWG), hosted by OGC and co-chaired by representatives nominated by CHy. This will provide an open forum for work on water data, metadata, and web services interoperability leading to the development of standards that CHy can endorse. The WMO/OGC HDWG was officially established during 2009, involving hydrological and government agencies, software providers, universities and research organisations from around the world. The HDWG has three co-chairs: Ilya Zaslavsky (San Diego Supercomputer Center) elected by the HDWG David Lemon (CSIRO) nominated by the President of the CHy Ulrich Looser (GRDC) nominated by the President of the CHy. Furthermore a Memorandum of Understanding was signed between WMO and OGC in November 2009 to strengthen the work of joint WMO/OGC working groups. 2.2. Current status of the HDWG The HDWG has conducted several Interoperability Experiments (IE) as part of its efforts to develop and test standardised data exchange and interoperability. These IEs were supporting the development 3
of WaterML 2.0 and testing its use with various OGC service standards such as Sensor Observation Service (SOS), Web Feature Service (WFS), Web Mapping Service (WMS) and Catalogue Service for the Web (CSW). Both Groundwater and Surface Water IEs were conducted to test the contrasting requirements. Surface water datasets typically containing a large number of observations at a small number of locations opposed by groundwater observations were normally a small number of observations are taken at many locations. A further focus of the HDWG is the development of a hydrology domain feature model and vocabularies, which are essential for interoperability in the hydrology domain. 2.3. First achievements of the HDWG The first achievement of this international cooperative effort of members of the HDWG involving hydrological and government agencies, software providers, universities and research organizations from Australia, the USA, Canada, Germany, the Netherlands and other countries, is the release of WaterML 2.0. WaterML 2.0 is a new XML-based OGC open source international standard for encoding and exchanging data describing the state and location of water resources, both above and below the ground surface. WaterML 2.0 supports encoding of hydrological and hydrogeological observation data in exchange scenarios such as: exchange of data for operational monitoring and forecasting programs; supporting operation of infrastructure (e.g. dams, supply systems); exchange of observational and forecast data for surface water and groundwater; release of data for public dissemination; enhancing disaster management through data exchange; and exchange in support of national reporting. Furthermore a Hydrologic Feature Model has been developed by the GRDC and members of the HDWG and the model has been released as a discussion paper on the OGC website and has also been released on the CHy pre-session Forum for information and discussion amongst WMO members. Adoption of the Hydrologic Feature Model as a standard and endorsement to promote its implementation, testing and use is sought through the CHy. 3. Data policy and data sharing 3.1. GRDC data policy The provision of discharge data by the GRDC is governed by the GRDC data policy, which is based on WMO Resolution 25 (Cg-XIII-1999). Data are not freely available from the GRDC website. The GRDC provides a station catalogue for information so that data users can identify suitable stations for their planned studies. Data users have to apply for the data in writing and they have to agree to the following conditions by signing a user declaration: Data may only be used for science, research or teaching Data may not be used for commercial purposes Data may not be redistributed to third parties Ownership of the data remains with the original data provider Neither the GRDC nor the data providers can be held liable for the correctness of the data Data sources must be acknowledged Research results should be provided to the GRDC This approach is widely accepted by the data users and many data providers trust that the GRDC is following its data policy and are therefore prepared to provide data to the GRDC for redistribution to 4
science and research. The GRDC is achieving its objectives in protecting the data that have been entrusted to the GRDC by WMO member states and the GRDC has at this stage no intention to change its data policy. 3.2. EU and EEA data requests The GRDC has been approached by the European Union and by the European Environmental Agency (EEA) to provide them with original data collected from European countries for purposes such as environmental reporting and policy development. These requests have been declined by the GRDC, because the GRDC has not been mandated by the data providers to supply the data for these specific purposes. During the RA VI Hydrology Forum held in Koblenz, Germany in May 2012 this topic was discussed, because a joint letter from the EU (DG Environment), the EEA and the European Joint Research Center (JRC) was received with the request to engage in a process for effective, efficient and constructive data sharing. This request is now being discussed at the WMO and a reply has been send by the WMO Secretary- General requesting the EU institutions to specify their data needs. Based on this information amicable solutions will be considered. 3.3. River discharge data for GEO/GEOSS Within the framework of the EU funded FP7 project GEOWOW, the BfG/GRDC is involved in a study to make river discharge information available to the GEOSS Common Infrastructure (GCI). Initially only statistical information derived from the original discharge time-series data will be provided for selected stations capturing part of the freshwater flux to the world oceans. The GRDC is now engaging in a negotiation process with a number of countries to obtain permission to provide original time-series data to the GCI for unrestricted use according to the GEO data sharing principles. The original mean daily discharge time-series data will then be made available in a standardised data exchange format. The following countries have already given their permission or are about to give the permission to make the original time-series data for a selected number of stations available: USA, Canada, Island, Norway, Finland, Great Britain, France, Germany, Australia, and New Zealand. The negotiation process has also been expanded to further countries. 4. Future developments for the data management at the GRDC The involvement of the BfG/GRDC in the FP7 GEOWOW project serves amongst others the purpose to assess possibilities at the GRDC to implement web services technologies for their future operations. These services will allow for more efficient and time saving methods for data provisioning and data acquisition. Operationalisation of data updates could be implemented with certain providers. Suitable technologies are being developed by the GEOWOW project partners. Substantial adjustments to the existing operational software will be required to integrate the provisions of the GRDC data policy into an IT based workflow. The inclusion of additional stations and data-updates via web services will also require considerable changes. At the same time backward compatibility needs to be maintained to allow for data provisioning and inclusion with current practices, as web services many not be implemented immediately by all Hydrological Services. 5
5. Data acquisition activities and GRDC database status 5.1. Overall GRDC database status Over the last number of years the database could be further expanded. In May 2012 the GRDC database held world-wide discharge data for 8,428 stations in 158 countries featuring more than 330,000 station-years of monthly and daily values with an average time-series length of 41 years. Fig. 1: GRDC main database status and growth from 2001(solid) until 2011(shaded) Since November 2008 more than 1100 new stations have been added to the GRDC database and the discharge data for 4,200 stations could be updated, some of them repeatedly. Together with a number of data providers the institutionalisation of data acquisition was further advanced. This will simplify data acquisition in the years ahead. 6
Fig. 2: Global Coverage of GRDC Stations indicated by time series end The expanding GRDC dataset with more stations and updated time-series for a number of countries results in a bigger demand of this dataset by science and research. This is reflected by the increased data requests. Fig. 3: GRDC data provision and support since 1993 7
5.2. Watershed boundaries of GRDC Stations The widespread use of GIS in hydrology and environmental sciences, led to an increasing demand for basin polygons and the GRDC was repeatedly asked for the provision of watershed boundaries for the gauging stations represented in the Global Runoff Database. The HydroSHEDS drainage network (Lehner et al., 2008) offers the unique opportunity to generate watershed boundaries for GRDC gauging stations using a proofed dataset and applying a consistent methodology. The GRDC is happy to have engaged Bernhard Lehner from McGill University Montreal, Canada, who is one of the developers of HydroSHEDS, for the creation of the watershed boundaries for more than 7000 GRDC stations. The Watershed Boundaries of GRDC Stations are provided as ESRI Shapefiles under the conditions of the GRDC Data Policy, which states the non-commercial use of the data and the overall citation of GRDC as the source. The methodology used to determine the watershed boundaries is published as Report 41 in the GRDC Report Series. 5.3. Global Terrestrial Network for River Discharge (GTN-R) More than 60 countries have been approached by the WMO in mid 2011 with the request to actively support the GTN-R by providing the relevant station metadata and river discharge time-series data to the GRDC. Currently negotiations are ongoing with approximately 20 countries concerning station selection and the provisioning of station metadata and time-series data. With a number of countries regular data provisioning could be established. Some countries even agreed to make the GTN-R data freely available so that they can also be shared with the GEOSS data portal. Fig. 3: GRDC stations initially selected for the Global Terrestrial Network for River Discharge (GTN-R) 5.4. Climate sensitive stations 878 GRDC stations from 27 countries identified by the countries as stations representing climate sensitive river basins having minimal disturbance ( pristine basins ) are currently stored in the GRDC database. 8
Fig. 4 & Table 1: Distribution of Climate Sensitive Stations reported to the GRDC and overlap in Climate sensitive Stations and GRDC Stations (Status 19 September 2012) Country No. Of Stations in GRDC database Proposed Climate Sensitive Stations Overlap Clim. Sens. & GRDC Stations Australia 304 31 22 Azerbaijan 4 14 1 Belarus 5 10 0 Brazil 478 238 230 Canada 1116 229 152 China 39 15 15 Cyprus 14 4 0 Czech Republic 13 6 1 Ecuador 19 6 1 Finland 36 12 0 Georgia 8 8 1 Kenya 5 60 1 Kyrgyzstan 28 7 Unknown Lithuania 12 7 0 Mauritius 6 2 0 Morocco 25 12 1 Pakistan 27 6 1 Romania 19 23 4 Samoa No Data 2 0 Slovakia 23 20 2 Sweden 42 8 8 Switzerland 25 8 0 Tajikistan 24 23 12 Ukraine 24 3 0 United Kingdom 239 20 16 United States of America 1007 1703 409 Uzbekistan 12 6 1 Total 3554 2483 878 9
An additional 170 stations have been obtained from 6 European countries. The data will be released in the GRDC database, once final permission to provide the data under GRDC data policy has been negotiated. GRDC data requests for climate sensitive stations has in several countries triggered the process to either examine their stations again or even determine a network of stations that comply with the climate sensitive station criteria and that could serve as a national reference network. 5.5. UNESCO FRIEND-Water Programme The GRDC continues to host the European Water Archive (EWA), the river discharge database of the UNESCO EURO-FRIEND-Water community. Currently the EWA contains data for more than 3800 stations from 28 European countries. Requests for EWA data updates are done together with GRDC data requests. At the same time permission is requested to host the updated EWA stations also in the GRDC database. This approach paves the way for future data provision under the GRDC data policy. The cooperation with the International Hydrological Programme (IHP) of UNESCO could be extended and now the GRDC is providing the metadata for the EWA stations on a regular basis to UNESCO for the inclusion into a UNESCO IHP web portal where ultimately monitoring stations from all UNESCO FRIEND Programmes could be explored. At the 6th UNESCO World FRIEND Conference in Morocco, October 2010, it was agreed that the GRDC will be hosting the Flow Database of the UNESCO Southern Africa FRIEND Programme. The GRDC has included the 850 stations of this database into its own data structures and since May 2012 the data from these stations are provided under the GRDC data policy. Updates for a large number of stations have already been received and now the GRDC is also hosting data from an additional country, namely Angola. The GRDC has offered the UNESCO Hindu Kush Himalayan FRIEND Project to also host its data. Negotiations are currently underway. 6. Conclusion The support from the international hydrological community in terms of data provision and cooperation on joint projects and the guidance by the GRDC Steering Committee, which met in 2009 and 2011, enables the GRDC to look back on a successful inter-sessional period from 2008 to 2012. 10