How writing an article can come out of the blue (KGE on log-transformed flows: a bad idea?)

How writing an article can come out of the blue (KGE on log-transformed flows: a bad idea?)

Contributed by Léonard Santos (Irstea, France). It is common to read articles in which the Kling and Gupta Efficiency (KGE, Gupta et al., 2009) or its modified version (KGE’, Kling et al., 2012) are used as a metric to evaluate the quality of streamflow simulations. They are often seen as a solution to substitute the Nash and Sutcliffe Efficiency (NSE, Nash and Sutcliffe, 1970). However, are these two criterion totally comparable? Can the KGE be used exactly in the same…

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Fictitious Forcings have Macondo in Trouble: A Hackathon Story

Fictitious Forcings have Macondo in Trouble: A Hackathon Story

Contributed by Georgy Ayzel.  Meteorological ensemble forecasts form the core of every system for hydrological ensemble prediction. There are multiple data sources where our meteorological ensembles could come from: historical observations, numerical weather prediction and climate models, or stochastic weather generators. Different sources serve different ways we want to communicate and deliver the information of possible runoff responses to various meteorological conditions. However, there is a source that is typically ignored in the modern landscape of ensemble runoff prediction –…

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Summer 2018 in Europe: did the EFAS seasonal outlook predict low river flows?

Summer 2018 in Europe: did the EFAS seasonal outlook predict low river flows?

— this post is jointly published on the blogs of HEPEX and the European Drought Centre — Contributed by Louise Arnal (ECMWF and University of Reading), Shaun Harrigan (ECMWF) & David Lavers (ECMWF). Summer 2018 in Europe was remarkable from a hydroclimate perspective, with large regions experiencing persistent dry conditions, very little to no rainfall for extended periods, a series of heatwaves with record-breaking temperatures and numerous wildfires (in the UK, Sweden, Greece, Spain, Portugal, Latvia and Germany, among others)….

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GloFAS-Seasonal: Global Scale Seasonal River Flow Forecasts

GloFAS-Seasonal: Global Scale Seasonal River Flow Forecasts

Contributed by Rebecca Emerton. My PhD research looks into how we can provide earlier indications of flood hazard at the global scale. One way of doing this is through seasonal forecasts of high (or low) river flow. Seasonal forecasts are designed to provide an early indication that a given variable, in this case river flow, will differ from normal in the coming weeks or months. While many operational centres produce seasonal forecasts of meteorological variables, operational seasonal forecasts of hydrological…

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We need better topography data for better flood inundation simulation

We need better topography data for better flood inundation simulation

Contributed by Dai Yamazaki. In recent years, technical barriers for executing flood inundation simulation are getting lower and lower, thanks to increasing computational power and increasing availability of satellite observation data. Flood inundation models are now being used for flood risk assessment and monitoring, such as making a flood hazard map at any location in the world and forecasting flood hazard in a real-time manner. The physics equations used in flood inundation models are relatively simple, compared to those of…

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