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
Finding hidden patterns in the data using principal components analysis
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. Original data have been transformed to make the time series more
About the logo
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. The equaliser is surrounded by a
Hydrology basics, episode 1: streamflow, precipitation and evapotranspiration
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. For
El NiñOz
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. These are known as El Niño episodes. Sometimes the
Sonification techniques: sequencing
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”
Exploring the hydrologic regime of 195 rivers in Australia
Plotting hydrologic regimes Most hydrologic studies start by determining the average quantity of water in rivers and how it is distributed throughout the year. Let’s consider the Australian reference dataset provided by the Bureau of Meteorology, with daily runoff data
Sonification techniques: mapping data to pitch and volume
Mapping data to visual or auditory properties A common visualization technique is to use the color or size of symbols to represent data. The bubble map below shows an example. This figure visualizes the main flood events of 2019 as
A short introduction to sonification
What is data sonification? Sonification refers to the transformation of data into sound, using some algorithmic process. Here are three examples worth a thousand words. These videos illustrate three common sonification techniques we will explore in future posts of this