Archive for the ‘Water’ Category:

Earth is known as the blue planet, because it’s covered with quite a bit of water. But do you know where all that water on Earth is located? This interactive visualization will show the various amounts of water in its many forms on Earth: Oceans, Lakes, Rivers, Ice, Groundwater, etc….

If you hover over a part of the circular, sunburst graph, it will show you the amount of water that is in each of the various forms shown. If the label for that form is bolded, you can click on it and see further subdivisions beyond that broad category. For example, if you click on Oceans, it will show you how the water in the oceans is distributed among the five main oceans on Earth. As you move towards more focused views on the graph, you can click on the center of the circle to move back out to larger categories and see the big picture again.

As you can see, most of the water on Earth is found in a salty form, and most of that is in the oceans. It can be hard to click through to see freshwater lakes and rivers, as you have to be very precise to expand the “Surface Water” wedge, when you are looking at all “Freshwater”.

Even smaller, on that same visualization, is the “Living things” wedge is basically invisible. You can further explore the details of the living things category by clicking on the button that appears on the freshwater graph.

Checking the Group Rivers and Lakes checkbox will group rivers by continent and lakes by major groups.

It is interesting to see how much water there is on Earth (about 1.4 billion cubic kilometers of water), but how little of it is non-salty, liquid freshwater at the surface (about 100,000 cubic kilometers, though that is still quite a lot) but it only makes up about 0.008% of all water on Earth. That means for every 10,000 gallons of water on Earth, only one of those gallons is freshwater in a lake or river that we can easily access.

It is also believed that there is more water deep in the Earth’s interior (i.e. the mantle) than on the surface or near-subsurface, but estimates of that are highly uncertain and are not included in this graph.

If you click out past Earth’s water to look at water in the solar system, the estimates shown in this visualization are only including liquid water and do not include estimates of ice (which I haven’t been able to find estimates of). The amount of water in living things is estimated assuming that the ratio of organic carbon to liquid water is more or less the same across all different types of living things (i.e. viruses, bacteria, fungi, plants, animals, etc.). This isn’t a great assumption but the estimates, which come from estimates of the dry carbon weight of these organisms, vary across many orders of magnitude so being off in liquid water weight/volume by a factor of two or so isn’t a huge problem.

Tools and Data Sources
The sunburst chart is made using the open source, javascript Plot.ly graphing library. Data on water distributions is primarily from Wikipedia – Distribution of Water – List of Rivers by Discharge – List of Lakes – Weight of Living Biomass – Extra-terrestrial water estimates

How much water is in California’s reservoirs?

Check out my new Colorado river reservoirs visualization.

I also added the ability to select specific reservoirs to display on the graph and share a custom URL which will point those selected reservoirs (click on “list” button on top right of dashboard).

If you are reading this, it’s probably the winter rainy season in California again, and time to check on the status of the water in the California reservoirs. I previously made a “bar graph” showing the overall level of water in the major California reservoirs. This dashboard provides a bit more detail on the state of each of the reservoirs while also showing an aggregate total. It updates hourly using data from the California Department of Water Resources (DWR) website, giving an up-to-date picture of California reservoir levels.

This is a marimekko (or mekko) graph which may take some time to understand if you aren’t used to seeing them. Each “row” represents one reservoir, with bars showing how much of the reservoir is filled (blue) and unfilled (brown). The height of the “row” indicates how much water the reservoir could hold. Shasta is the reservoir with the largest capacity and so it is the tallest row. The proportion of blue to brown will show how full it is, while the red line shows the historical level that reservoir is typically at for this date of the water year. The blue line indicates the reservoir’s water level one year ago today. There are many very small reservoirs (relative to Shasta) so the bars will be very thin to the point where they are barely a sliver or may not even show up.

Instructions:
If you are on a computer, you can hover your cursor over a reservoir and the dashboard at the top will provide information about that individual reservoir. If you are on a mobile device you can tap the reservoir to get that same info. It’s not possible to see or really interact with the tiniest slivers. The main goal of this visualization is to provide a quick overview of the status of the main reservoirs in the state and how they compare to historical levels.

You can sort the mekko graph by size – largest at the top to smallest at the bottom – or by reservoir location, from north to south.

If you click on the “list” button in the top right of the dashboard, it will show a list of the reservoirs (in order of size from largest to smallest) and you can check which ones you would like to display. You can also share a custom URL by clicking the “Save URL” button which will put the custom URL into the URL bar of your browser which you can then copy and share. You can also use it to monitor only the reservoirs you are most interested in.

Units are in kaf, thousands of acre feet. 1 kaf is the amount of water that would cover 1 acre in one thousand feet of water (or 1000 acres in water in 1 foot of water). It is also the amount of water in a cube that is 352 feet per side (about the length of a football field). Shasta is very large and could hold about 3.5 cubic kilometers of water at full (but not flood) capacity.

Data and Tools
The data on water storage comes from the California Department of Water Resources’ (DWR) Data Exchange Center. Python is used to extract the data from this page hourly and wrangle the data in to a clean format. Visualization was done in javascript and specifically the D3.js visualization library. It was my first time using D3 and it took me a long time to get up to speed. It takes a fair amount of work to make graphs compared to other more plug-and-play libraries but its very customizable, which is a plus. It was the only tool that I could find that would allow me to make a vertical marimekko graph.

Update: I added a date slider to let you scrub through dates as well as the ability to pause the animation.

In my California water levels visualization, I presented a “bar graph” showing the amount of water currently in California’s reservoirs.  However, I thought it’d be interesting to see how this has changed over the course of the last few months, since the state has gotten alot of rain and snow recently.  

This visualizations “animates” the graph for recent history (going back to October 1, 2015) showing how the recent rains (or lack thereof) has been caused the levels of the reservoirs in California to rise (and fall).  

The historical average represents a daily average reservoir level. It changes for each day of the water year to represent seasonality of precipitation and runoff.

Click the “animate” button below the figure and you can use the slider to change the speed of animation as it cycles through the days. I added a Date slider which lets you scrub through all the dates and animate from different points.  (more…)

**Check out the new reservoirs dashboard**

California has had an issue with drought, especially for the past few years now.  Recently, 2016-2017’s El Nino weather patterns has brought a significant amount of rain to the state and helped alleviate some, but not all, of the major issues.  
I’ve been very curious to understand how the rain storms we experience are lessening the impact of the drought, and whether one wet season (like 2016-2017) can really “get the state out of a drought”.  One way to assess this is to look at the status of California reservoirs.

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