Be Kind, Rewind!
Flood risk assessment relies on hydrometric stations (sometimes called streamgages) that monitor river discharge, i.e. the amount of water flowing in rivers every hour or day.
Flood risk assessment relies on hydrometric stations (sometimes called streamgages) that monitor river discharge, i.e. the amount of water flowing in rivers every hour or day.
Observed data are essential to understand, quantify and predict the risk posed by extreme climatic events. In the case of floods or heavy precipitation, such data take the form of long series measured at stream gauging or weather stations.
The seasonality of flows in a river is an important part of its identity. Many studies start by displaying a chart similar to the one below to identify high-flow and low-flow seasons at a glance.
“This was a 100-year event”. This type of sentence is often heard in the news after a flood or a storm hits somewhere, as it does a good job at carrying the rarity of what happened.
Avant de s’écouler dans la rivière, l’eau suit un long périple au sein de la surface de collecte des eaux appelée bassin versant (en rouge ci-dessous).
Some time ago we’ve been lucky enough to receive the postcard below from the Mc Murdo Dry Valleys, in Antarctica (thank you so much Kaelin!
In a previous post, we illustrated a widely used method called principal component analysis (PCA). This method can be used as an exploratory tool to summarise a dataset made of hundreds or thousands of time series into just a few ‘summary’ time series called principal components.
In hydrology, it is frequent to analyse long time series coming from many sites. The figure below shows monthly streamflows at 207 sites in France for the period 1969-2014.
The globXblog logo is a colourful doughnut that mimics an equaliser, referring to the sonification and visualisation part of the blog. In its core, a stormy icon represents the hydrological part of the blog.
How does water end up flowing in rivers? As schematized below, it is the result of processes that have taken place in the river basin, also known as a catchment and delineated by a red line in the figure.
The Pacific Ocean sometimes catches a fever in its Eastern tropical part (off the coasts between Central America and Peru): for extended periods of time, its surface waters are abnormally warm.
Sounds triggered by events The map below shows the main flood events of 2019, their duration and the size of the flood-affected area (for further discussion of this dataset, see the post Sonification techniques: mapping data to pitch and volume).