Back to search

JPIWATER-Water challenges for a changing world

Model-based global assessment of hydrological pressure

Alternative title: Modell-basert global vurdering av kritisk påvirkning på vannressurser

Awarded: NOK 4.0 mill.

Project Number:


Application Type:

Project Period:

2019 - 2022


The United Nations Intergovernmental Panel on Climate Change has stated that the impacts of meteorological and hydrological extremes pose a threat to society. Despite advances in climate research and strategies for adapting to climate change, the use of this information is limited for various reasons. Concepts from scientific theory are not adapted to the needs of decision makers; uncertainty in climate projections; difference in geographical scale in climate data and the needs of decision makers; inability to describe natural variability in today's climate; and adaptation to a changing climate are just some of several factors that decision makers must address for assessment of meteorological and hydrological impacts that pose challenges for agriculture, business, transport and settlement. To overcome some of these challenges, a conceptual framework for so-called decision support indicators has been developed with emphasis on magnitude, probability, spatial extent and duration of extreme hydroclimatic events in cooperation with local stakeholders and international partners. Decision support indicators are designed to simplify communication of climate change impacts on important societal functions to local decision makers. Three categories of decision support indicators have been defined, according to the level information they provide and relative ease with which they can be quantified: Classical hydroclimatic indicators based on statistics; Event-based indicators that express a predicted event relative to a well-known historical event; and Impact based indicators that quantify the socio-economic impacts of events. An interdisciplinary environment among the partners (hydrology, meteorology, climate science, bioeconomy) ensures a good balance between research and operational applications. Hydrological models and the global hydrological service World Wide Hype ( have been adapted to watercourses in Vestland County in Norway and the Xinjiang region in China. The spatial extent of the models are watersheds discretized into grid cells of 1 km2; the temporal scales are one day to several decades. In Vestland County, hydrological processes and their effect on floods, droughts and hydropower production have been studied. Results indicate an increase in the magnitude of rainfall generated floods, especially by the end of the century, and a reduction in the magnitude of snowmelt generated floods. The mean day of flood occurrence will shift to an earlier date for inland areas, while floods tend to occur later in the year in coastal regions. Event-based decision support indicators show that specific historical flood events will have a higher probability of occurrence in the future. In general, increases in floods magnitudes are expected, but the changes vary between coastal and inland regions and whether floods are caused by rainfall or snowmelt events in the present climate, and are therefore depending on changes in the climatic and hydrological regime of each catchment. There will be a general reduction in low flow levels in summer and an increase in winter, and a pronounced increase of drought duration and deficit volume in summer. There will only be a small to moderate reduction in annual potential hydropower production caused by droughts, in spite of more severe summer drought events, due to a compensating effect of increased runoff in winter. Event-based indicators show that conditions comparable to the most severe historical drought events will become common by the end of the century. In the Xinjiang region in China, climate change is a determining factor of water supply, agriculture and social and economic development. This region has around 20,000 glaciers which are the main source of water resources. Since the 1950s, the area of these glaciers has been reduced by 20-30%, which has led to reduced river flow and drought in the lower parts of several watercourses. There is therefore a strong need to evaluate the impacts of climate change on glaciers and available water resources. Projections of changes in glaciers and runoff until the end of century have been determined using climate scenarios and hydrological models. Results indicate a strong decrease in glacier covered area and runoff. The local economy in the Xinjiang region has two important production sectors, agriculture and industry, each with a water productivity equal to the ratio between economic production and water consumption. Hydrological model results and data on production in agriculture and industry make it possible to determine the water consumption available in the future and thus how the local economy is affected under different scenarios for climate change and production in agriculture and industry. Although local farmers adapt gradually to higher prices and agricultural products with low water demand, the conflict between water demand and water supply in this area will most likely intensify.

Et system av hydrologiske modeller som spenner over skala i tid fra døgn til dekader og i rom fra én til flere tusen kvadratkilometer er utviklet, med formål å beregne virkningene av klimaendringer på ekstreme hydrologiske hendelser som har betydning for viktige samfunnsfunksjoner som samferdsel, bosetning, landbruk, industri, energiproduksjon og vannforsyning. En global hydrologisk tjeneste er kombinert med lokale hydrologiske modeller for å evaluere effekten av endringer i langtidsmidler og variabilitet i meteorologiske prosesser på isbreer, snøforhold, fordampning, grunnvann og vannføring i vassdrag. Evaluering av klimaendringers virkning på viktige samfunnsfunksjoner i to regioner, Vestland fylke i Norge og Xinjiang-regionen i Kina, er oppsummert ved hjelp av beslutningsstøtteindikatorer som er utviklet i samarbeid med internasjonale partnere og lokale beslutningstakere fra offentlig forvaltning og næringsliv. Kommunikasjon med sluttbrukere utføres med tre type beslutningsstøtteindikatorer. Klassiske hydroklimatiske indikatorer for flere skalaer i tid og rom; Hendelsesbaserte beslutningsstøtteindikatorer basert på informasjon om endring fra velkjente historiske hendelser; Sosioøkonomiske beslutningsstøtteindikatorer for virkning på viktige samfunnsfunksjoner.

The objective of GlobalHydroPressure is to provide global model-based support for assessing and quantifying the fundamental hydrological pressure in basins worldwide. A consistent and reliable estimation of this pressure is a prerequisite for assessment of vulnerability and resilience to the total, multiple environmental pressure, including both natural and human-driven components. As hydrological pressure is closely associated with extreme events (natural hazards) on different scales in space and time, a multi-scale perspective will be adopted. A key feature of the project is the development of hydrological Decision Support Indicators (DSIs), innovative indicators pertinent to the main hydrological pressures tailored for decision support with different time horizons. The project will develop existing hydrological models on global and local scales into innovative tools for supporting the decisions of end users. Local cases span different climatic, areal and topographic characteristics so that hydrological models may be adapted to different characteristics and may then be used to support local vulnerability, resilience and risk assessment in ungauged regions of difficult access, as well as contribute with input to practical tools for adaptation and decision support. The applications covered in the cases include e.g. water resources management, hydropower production, flood risk assessment and agricultural production. An important aspect of GlobalHydroPressure is the multi-scale perspective, as different hydro-meteorological hazards operate on widely different scales in time and space. Examples of extremes include flash floods, with scales down to hours and single km2s, and droughts, with scales up to multi-years and continents. A second important aspect is the close involvement of stakeholders and the intention to have a bottom-up approach, where modelling and assessment are driven by stakeholder needs in continuous collaboration.

Funding scheme:

JPIWATER-Water challenges for a changing world