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Esperanza Huamán

One ruler, 12 posts

How much water is that? From a glass to a glacier

Every explainer counts some water. Here they sit on one ruler, each step ten times bigger than the one before, and the gaps are part of the picture.

Scientist with a measuring staff beside a turquoise glacial lake.
  1. 10-1 litresNothing at 10^-1
  2. 100 litresNothing at 10^0
  3. 101 litresNothing at 10^1
  4. 102 litresA bathAbout a hundred and fifty litres.
  5. 103 litresA household for a dayWashing, cooking, animals and the garden.
  6. 104 litresA village tankShared by forty families.
  7. 105 litresA field, one wateringA hectare of potatoes.
  8. 106 litresA canal for a dayA stone canal, running all day.
  9. 107 litresA river for an hourA small river, counted at the gauge.
  10. 108 litresNothing at 10^8
  11. 109 litresNothing at 10^9
  12. 1010 litresA reservoirWhere a valley keeps its dry-season water.
  13. 1011 litresA hot summer’s meltWhat a big glacier gives up in one season.
  14. 1012 litresA glacierA billion cubic metres of ice, and more.

Latest explainers

One new explainer every Sunday, from a glass of water to a whole glacier.

  • Retreating Andean glacier with meltwater streams.

    What a small glacier holds

    A glacier you can walk beside, and how many bathtubs of water are locked in it. Read it after “How much water a large glacier holds”.

    13 min read
  • Gloved hand adjusting a stream gauge in meltwater.

    What a river level reading means

    The number on a river gauge, what the metres mean and why a river can drop in a day. Builds on “Where a glass of water comes from”.

    11 min read
  • Stone irrigation canal through terraced fields at dawn.

    How much water a canal carries in a day

    How a stone canal feeds a valley, how fast the water moves and how much goes by in a day. Builds on “How a village tank is shared out”.

    12 min read

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Valley Water Notes

A short letter every Sunday: one piece of water news explained, with the numbers made small.

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Water sample bottles and a laptop on a rustic kitchen table.

About

About me

I work in the mountains above a valley in the Andes, measuring how much water comes off the ice and down the streams. Most weeks I am out with a gauge, a notebook and a thermos. Most evenings I am at my kitchen table with sample bottles and a laptop, writing down what I saw.

When a headline says there is a water shortage, I am often asked what that means for the people in the valley. Is the glacier gone? Is the river low? Is it the canal, or the rain? The answer is usually a number, and the number is usually hard to picture. So I explain it: I put a glass, a bath, a canal and a glacier on one ruler, and you can see where the news fits.

I do not take sides and I do not tell you what to think. I explain how water behaves, what the words in a story mean and how to check a number for yourself.

What I sell are the things I use in the field: a glossary, a glacier field guide, explainer packs and sheets for reading river levels, plus two video courses. A letter goes out every Sunday, and it is free.