Caroni River Basin Soil Map

A Soil Map of the Caroni River Basin in Trinidad

The purpose of this map is to show the soil textures in the Caroni River Basin. The dataset source is here: https://www.arcgis.com/home/item.html?id=1b97fe85db144d19ae71b60fa1bbf6ef which appears to be linked to this study: https://sta.uwi.edu/ffa/sites/default/files/ffa/USDA%20soil%20Taxonomy%20Upgrade-Trinidad%20and%20Tobago.pdf

Similar to the Land Cover Map, I had to dumb down the data a lot to get to this stage. Soils have a billion different properties that distinguish them. As a water resources engineer, I mainly care about how “hydraulically conductive” they are, meaning how well water can pass through them. Soil textures play a big role in how conductive they are, so that is what I have chosen to present. You can imagine in the case of water falling on sand, most of it will infiltrate into the ground, whereas water that falls on clay will mostly stay on top of it.

I tried to be clever with the colours here. Sand is usually shown as yellow so that is what I chose for sand. I chose red for clay since it is not good for infiltration and sometimes clay is red? Then the remaining primary colour is blue so that went to loam. Blue and yellow make green so that is sandy-loam, and blue and red make purple so that is loamy clay. The goal is for the user to easily distinguish the colours and possibly even guess what they mean.

Clay makes up the majority of the soils in the watershed followed by sand. It is interesting that the Northern and Central Ranges contain the clay, while the Caroni plains are mainly comprised of sand. This makes sense as runoff from the ranges is deposited in the plains which makes it good for agriculture. The strip of loam along the east-west corridor also stands out. Possibly has something to do with the development?

Had a hard time deciding where to put the map title. I think it ended up in the right spot.