Figure 1. We saw a group being educated on the harms of illegal feeding. Taken by Dr. Gretchen Coffman

Curious about rivers, especially since there seem to be none that are natural in Singapore? If so, the restored Kallang River at Bishan-Ang Mo Kio Park is an excellent place to visit! Following restoration, you can expect greater flood control, richer biodiversity, improved water quality, and more!

Unfortunately, on my field trip with my NUS GE3255 Applied, Riparian and Coastal Systems class, we witnessed cases of illegal feeding. Such acts, while well-intentioned, harm the ecosystem greatly – increasing the reliance of wildlife on the feedings, disrupting the natural food chain, and more. Nevertheless, we cannot fault people in Singapore for being curious about rivers! So, here are some simple experiments that you (and your children) can conduct to learn more about rivers and their surrounding environment!

Firstly, you can appreciate the increased biodiversity following the improved floodplain vegetation using the any plants and animals using the app iNaturalist or Seek! You will even contribute to the data of wildlife sightings nearby!

Figure 2. We saw a beautiful grey heron when visiting the restored Kallang River.

Next, you can measure the aerial cover of trees around the river. For my class’ field trip, we used a densitometer for greater accuracy. However, you can measure aerial cover using your smartphone too! Take a photo of the tree crown you’re standing under while keeping your phone flat. Compare your picture with the chart below and estimate the percentage cover in your picture. You can also use the Canopeo App. Repeat this from several other points and calculate the average for the area! Higher tree cover is better near rivers as the shade keeps waters cool for aquatic organisms.

Figure 3. Chart to estimate aerial cover; taken from AWFWiki

Lastly, you can measure the speed of water flow, or velocity! Velocity can be measured with a flow probe, or even measuring tape and just about any floating object, like an orange. You can try the latter yourself! Find a mostly straight and obstacle-free portion of the river and measure 10 meters. Then, drop a buoyant object, like twigs or leaves, into the water upstream of the 10m. Start the timer when it’s dropped and stop timing when it reaches 10m.

Figure 4. Simplified diagram of the procedure

 

Calculate the velocity of the stream with this equation:

Velocity (m/s) = 10m / [time taken to flow, s]

The velocity at different points of the river shows changes in the river. Increases in river steepness and volume, and wider, rougher channels increase velocity, and vice versa. Remember, you should NEVER litter in the river, even if it’s for science.

These are some kid-friendly experiments allowing hands-on exploration and rids the usual “exploration” through illegal feeding of wildlife. Let’s work together to keep our ecosystems healthy!