Making Sense of the Water Cycle while Playing in the Forest

Transformative Ecological Activities for Kids and Their Grownups

Introduction

As we discussed in Water is Life, and as land-based peoples have known for thousands of years, water is essential for life on Earth. One of the most important differences between how factories and forests process material is that factories are linear, and forests are cyclical. Factories require the extraction of resources in a way that exploits ecosystems, producing toxic products and massive amounts of waste. Forests and other ecosystems are amazingly efficient at recycling materials and energy and produce no waste, toxic or otherwise. This is why, as we mention in Patterns that Connect and discuss further in Observing Closed Loops in Nature, cycles are among our favorite patterns! In this post, we introduce fun and engaging ways to observe each step in the water cycle, questions to ask kids to engage kids in making sense of this crucial cycle, and ways to share the sense others have made of the water cycle. We do not recommend using these steps as a unit study but rather share them with you to use as you bump into the water cycle in various contexts in the forest.

Activities

Precipitation

In the context of the water cycle, precipitation is water falling from the atmosphere onto the surface of the Earth in either a liquid form as rain, or in a solid form as snow, sleet, or hail. I like to talk with kids about precipitation when it’s precipitating or soon after. I start the conversation by asking kids what’s happening or happened that resulted in the soil being wet or covered in snow. Kids usually name the form of precipitation saying it rained or snowed. Then, I’ll check if they know the word precipitation by asking them if they know the word for all forms of water falling from the sky. If not, I’ll introduce them to the word and ask them to say it out loud.

Infiltration

When talking about the water cycle, infiltration is the process of water soaking into soil. It is one of three things that happen to water after it hits Earth’s surface. I like to talk with kids about infiltration when we're near a creek, watering a garden, playing with mud, or while it’s raining.

Small creeks are great places to point out both infiltration and groundwater flow. In the spring, after our rainy season has passed, we often find spots where creeks go underground and reappear later. These spots make infiltration and groundwater flow apparent. If you dig a hole at those spots or near a creek, you can observe water filling those holes. Digging such holes a bit further away from rivers and creeks is also a technique for finding water in a survival situation that is safer to drink than water taken directly from a creek or river.

Wherever we bump into infiltration, I start conversations with my usual types of questions. What’s happening here? Why do you think water sinks into the ground? The last thing I ask about this topic is, does anyone know the official scientific name for water sinking into the ground? If no one does, I share the word infiltration and ask them to repeat it once with me.

Pooling

Meteorologists, scientists who study weather, use the word pooling to describe what happens when liquid water collects on the surface of the Earth. Like infiltration, it is one of three things that happen after water precipitates and hits the Earth’s surface. My favorite time to talk about pooling is while kids are jumping in puddles. We also observe and talk about pooling when we’re watering a garden, while it’s raining, when we’re playing around with water running from a hose, and when we come upon any large pools of water including ponds or lakes.

Runoff

Runoff, like pooling, is a technical term that is also descriptive. It is the third path water can take when it hits the Earth’s surface. When water falls on a slope and doesn’t infiltrate or pool up on the soil’s surface, it runs off. We see runoff while it’s raining hard or during a rapid snowmelt. Runoff is especially dramatic when hard rain falls on bare Earth. We also observe runoff when we see creeks, streams, or rivers. Runoff over a board surface like bare soil is called surface runoff or sheeting. Runoff in a channel is called channel or streamflow runoff. As more fully described in our post, Getting Muddy with Flowing Water, we also like to observe and talk about runoff when we’re redirecting water trickling from a hose.

Surface runoff is often a bad outcome from an ecological perspective as it leaches nutrients from the soil. This happens more frequently in areas that have been disturbed by humans and is especially hazardous when it happens in places that are being factory-farmed, as runoff from the concentrated nutrients in fertilizers can result in excess nutrients in estuaries, ponds, lakes, and coastal areas. The excess nutrients lead to eutrophication (an excess of nutrients) with a resulting bloom of algae and plants that end up depriving water animals of oxygen resulting in their death.

Evaporation

Precipitation is water falling to the Earth from the sky. Infiltration, pooling, and runoff are what happens to water when it hits the ground. Evaporation is how water gets back into the atmosphere from the Earth's surface, including the surface of bodies of water. Unlike other water cycle processes, the transformation of liquid water into water vapor is invisible and therefore harder to grasp. What we can observe is liquid water going somewhere when the only place to go is into the air.

I like to demonstrate evaporation by spreading a small amount of water onto a surface that kids know is waterproof: a piece of waterproof clothing or a few drops spread over the surface of a piece of metal work well. You can also demonstrate evaporation by filling a pot with water up to a marked level, boiling the water for a while, and comparing the water level after boiling with the level before boiling. In either case, when the water disappears, I ask kids where they think it went.  Perhaps the best way to demonstrate evaporation is to do so along with demonstrating condensation as described in the condensation section of this blog

Transpiration

Evapotranspiration is the process of water evaporating from the surface of plant leaves and being drawn up from the soil, along with dissolved minerals, through a plant's roots, and then through fibers in the plant's circulatory system known as phloem channels. This process is essential for all vascular plants and accounts for much of the evaporation of water from land. I don’t know of any way to make transpiration visible. In the following section, we describe an indirect way to help kids see evaporation by demonstrating condensation.

Condensation

The final step in the water cycle for us to discuss is condensation: the process through which gaseous water, also known as water vapor, turns into liquid water. Of course, there is no first or final step in any cycle. This sequence just seemed best to us for purposes of talking about them. Condensation is the process of gaseous water vapor becoming liquid water. We see condensation happening when we look at clouds and fog. Clouds are composed of tiny droplets of partially condensed water vapor that form when warm moisture-laden air rises and meets cooler temperatures above the Earth’s surface. Fog is a mass of small water droplets that form just above the Earth’s surface. We also see condensation happen when we breathe out on cold days and take a cold can out of the refrigerator on a warm day.

My two favorite demonstrations of condensation are temporarily placing a plastic bag over a bunch of leaves on a broad-leaf tree on a sunny day. The air inside the bag will become moisture-laden from the transpired water vapor and condense on the inside of the bag. This is also a way to get some water in a survival situation if you happen to have plastic bags. Condensation is also behind the survival technique of using a solar still.

This is often an opportune time to discuss differences between the patterns that connect represented by broad leaves and pine needles. Board leaves are sheets, which maximize surface area leading to more transpiration. Needles are fibers that reduce surface area decreasing transpiration rates. Maybe ask your kids to talk about where each would be advantageous.

The other method is to hold cold metal (e.g., the blade of an ax that’s been in the shade) over boiling water. Boiling water makes it turn into vapor (i.e., evaporate) faster. The water vapor will then condense on the metal.

Science

Earth Systems Science is the study of how the Earth functions from a systems perspective. You may recall from The Build a System Game field trip that the basic idea of systems thinking is that any system, in addition to being explained in terms of the behavior of its parts, can also be described in terms of how its subsystems are interrelated. The major subsystems of the Earth System are called the Earth’s spheres: the hydrosphere (water), the atmosphere (air), the lithosphere, (Earth’s surface), and the biosphere (life). While modern science reserves the word element to apply to the hundred or so basic chemicals that form the basis of all regular matter in the universe, the concept of the Earth’s spheres in Earth Systems Science bears an interesting resemblance to various forms of 5-element theory. 

The major relationships between the spheres are called material cycles. The most important material cycles for maintaining life on Earth are the water cycle, the carbon cycle, the nitrogen cycle, and to a lesser degree, the phosphorus and sulfur cycles. Earth Systems Science also includes the study of how energy flows through Earth systems and how feedback systems maintain homeostasis (i.e., a relatively steady internal state) on Earth in terms of temperature and the proportion of various elements and compounds in the various Earth spheres.

The water cycle is the simplest material cycle consisting mostly of physical rather than chemical or biological processes and has the most visible manifestations making it a good first material cycle to explore. As discussed in the activities section of this post and illustrated below, the water cycle has the following basic steps. Water moves from the Earth’s surface to the atmosphere via evaporation or transpiration. In the atmosphere water vapor condenses to form tiny droplets of water that form into clouds. When the droplets get big enough they fall to the ground in the form of precipitation. When water hits the ground, it runs off, pools, or infiltrates the soil. Once on the Earth’s surface again, the whole process repeats. 

Let’s take a look at each of these processes. Evaporation happens when liquid water turns into gaseous water (water vapor). Water mainly moves from bodies of water (i.e., the hydrosphere) into the atmosphere via evaporation. Transpiration is the predominant process that transports water from the surface of the Earth (i.e., the lithosphere, the Earth’s solid crust, or specifically the pedosphere, the Earth’s soil). Transpiration is the one water cycle process that directly involves living beings. It is the movement of water through plants from roots to leaves and the evaporation of that water from the surface of the leaves. Plants lose most of the water they absorb through transpiration. They use very little of the water they uptake to build themselves. It’s hard to think of that water as lost because it is that loss that serves the role of a plant’s heart. As water evaporates from the surface of leaves, the plant’s roots suck up water through xylem tubes bringing that water up the plant. Xylem tubes are half of a plant's circulatory system. Phloem tubes make up the other half. They circulate nutrient fluids down from a plant's leaves to other parts of the plant. 

The terms that describe what happens when precipitation hits soil are relatively self-explanatory. Runoff is when water hits the ground and flows over the soil’s surface. If not for pooling, our kids would have no puddles to jump in! Infiltration is when water soaks into the soil, replenishing groundwater.

There is general agreement among Earth Systems scientists that human activities have had major impacts on what they call the hydrological cycle. In addition, humans have poisoned the world's oceans and many of its tributaries through runoff from factory-farmed land and by dumping industrial and household waste into our oceans and their tributaries. Human constructions, including damns, aqueducts, reservoirs, and irrigation systems have also impacted the hydrological cycle as have other factory farming practices. Additionally, changes in the global climate brought on by anthropogenic increases in greenhouse gasses and changes in the hydrological cycle impact each other in multiple ways.

Those of us who use permaculture and other forms of eco-agriculture to tend the wild, as First Nations peoples have been doing for thousands of years (check out Tending the Wild for detailed descriptions of how the First Nations Peoples of the West ended and evolved with the flora), are very interested in not poisoning our groundwater and reducing water loss from the soil due to both evaporation and transpiration. We lessen water loss due to evapotranspiration (the movement of water from the soil to the atmosphere due to the combination of evaporation and transpiration) by adding organic matter to our soil (see Composting and Deep Mulching) and by providing natural shade from taller plants for herbaceous and ground cover plants that don’t need a full day of direct sunlight (see Relational Gardening). We are also generally interested in reducing runoff. Runoff causes erosion and often leaches valuable nutrients from our soil. Tenders of the wild do, at times, use runoff to redirect water flow for irrigation systems. Finally, we are generally okay with pooling and sometimes encourage it by creating water catchment ponds. 

Education

Rather than marching through curriculum units in a prescribed linear fashion, we recommend exploring ideas opportunistically as you bump into them, much as we explore natural phenomena as we bump into them in the forest. In the case of the activities in this post, we present them thematically for ease of reference. I have and would never do them all as a thematic unit with children. Here’s a recent journal entry that illustrates how some of these activities arose along with many others in the context of a typical and wonderful two-hour session.

Journal

Today was a great day. We had a wonderful and relaxed time playing and learning in the forest. The day also illustrated much about nurturing transformative ecological learning environments and communities. I love the word nurturing applied to learning communities. I use the same word to describe permaculture gardening. Mostly, we nurture the conditions for growth. Sometimes, we plant seeds. Often we don’t need to plant seeds because, when we do, we plant perennials, and our annuals often reseed themselves.

It all started with a plan (as shown above) that we didn’t follow and ended with us having a great day wandering, playing, and talking, including doing some of the things on the plan and skipping many others.

In circle, everyone checked in, but the only request of the group was to go to Sunset Rock. During my turn, I talked about moving through grief and still being sad but also beginning to have happy moments remembering how much of a gift my relationship with my dog-person, Marx, was. Next, we did the first items in my plan in our yard. We checked out the plastic bag I had wrapped around some leaves and branches earlier in the day. It had collected a lot of water that had transpired from the leaves and condensed inside the bag. We discussed transpiration and condensation as parts of the water cycle and a tool for getting freshwater in survival situations. As we toured my yard, we smelled trees and flowers, talked about how the apple tree was budding leaves and the cherry tree was budding flowers, at some kale that had overwintered, identified plants in and out of the garden, and started talking about signs of spring (bugs, birds, lizards, flower and leaf buds). Before heading out, we reviewed where we were likely to run into rattlesnakes and what to do if we did.

Out in the forest, we had lots of opportunities to talk about additional parts of the water cycle (not really part of my plan) as we bumped into signs of channel runoff, groundwater flow, and infiltration, in addition to our earlier discussion of evaporation, transpiration, and condensation. We also did a lot of identifying trees and other plants, including moss, mistletoe, and lichen. One of the kids was particularly interested in lichen, which gave me the opportunity to tell my lichen dad joke: you seem to be really liching that lichen. We also played the hide-along-the-trail game, looked at tree skeletons to see how branches grow, chewed on pine needles and talked about why they are sour, ate Manzanita flowers and talked about why they are sweet (plants make sugar from our outbreaths), and watched a stink bug do its thing.

The members of this group naturally do a lot of taking care of each other. I made a point of highlighting this. Our oldest group member is very kind and gentle. I talked with him today, asking him to consider making his wants and needs clear to me, as my fear is that he focuses more on others’ needs than his own.

Parents sometimes ask me if the curriculum is different for my two classes. Here’s the thing about emergent negotiated curriculum. The curriculum is different, not only for every group, it’s different for every individual in every group. 

My absolute favorite part of our time together came at the very end. We often end class at Climbing Rock because it is a fun and beautiful place that is only a few minutes from where caregivers pick up their kids. On this day we ended up there with about twenty minutes left. The part of me that worries about whether I’ve supported enough learning during a given time (yes, after all those years there is still a part of me that worries about this) was completely satisfied with our day, so I was doing some whittling when one of the kids who just restarted class after having been away for several semesters, announced that she wanted to play the interaction game. I had this on my plan, but figured we'd get to it next week or whenever. With very little support from me, she ended up getting the whole group super excited about the game culminating in them enacting a multigenerational life cycle involving an acorn dropping from an oak tree, being eaten by a squirrel and pooped out, which grew into another tree that an acorn woodpecker came to and started drumming on the tree. This was a fantastic demonstration of what happens when we nurture the conditions for growth, plant some seeds, and sit back and watch them grow! 

Wrap Up

Water is essential to life on Earth. So are the cyclical processes that recycle all the chemicals vital to life on Earth. We all depend on the Earth’s remarkable ability to recycle water, purify it, and rain it down on us. Humans have managed to poison our oceans and many of its tributaries and to disturb the global water cycle. Regenerative agriculture and ecological living are positive moves for mitigating the damage we have done to one of our most precious resources. In future posts, we’ll talk about the carbon and nitrogen cycles, how industrial culture has disturbed them, and some positive moves we can make to support those cycles.