Using Leaves as a Model for Teaching Watershed Concepts in Natural Resources Science and Engineering Programs

Abstract

This article examines the effects of using leaves, something most students see every day and have some familiarity with, as an analogy for the concept of watersheds in an undergraduate water resources engineering course. The ultimate goal of the leaf/watershed analogy and associated instruction is to increase students' understanding of hydrology principles, which in turn may facilitate better watershed management through increased public awareness, increased adoption of appropriate best management practices, and improved policy decisions. The assessment was performed with junior and senior undergraduate students enrolled in a Water Resource Engineering course. The assessment results showed that overall, students benefitted from the leaf analogy as a tool for learning watersheds. However, this effect varied depending on students' learning style preferences. core ideas• Watershed is an important concept in science and engineering of natural resources.• Introducing watershed concept using a leaf that students see every day is novel.• Using leaf analogy, watershed concept can be taught universally. Awatershed is a natural unit of land on which water from direct precipitation and snowmelt collects in a channel and flows downhill to a common outlet (Elshorbagy, 2005). The watershed is an important concept in engineering (e.g., civil, natural resources, water resources, ecological, and environmental) and sciences (e.g., geography, geology, ecology) because watersheds are more than just drainage areas in and around our communities. In engineering, they are the basis for the design of infrastructure and its management (Ruddell and Wagener, 2015). Watersheds are necessary because they provide many of us with our drinking water supply, support habitat for plants and animals, and provide us with recreational opportunities and aesthetic beauty to enjoy nature. It is the basic unit of all hydrologic analysis and designs and has three fundamental functions: (1) collection of water, (2) storage of various amounts of water for various durations, and (3) discharge of water as runoff (Elshorbagy, 2005).However, the concept of watersheds can be challenging to teach in engineering courses for several reasons. First, like many human-defined, regional-scaled geologic features such as tectonic plates, a watershed is generally conceived at such a large spatial scale that makes it difficult for people to grasp (e.g., Libarkin, 2005). Second, the dynamic and stochastic nature of watersheds challenges teachers to teach and students to understand the concepts (Loucks et al., 2005). Understanding this nature and the uncertainties in the watersheds (e.g., incomplete process understanding) also requires systems thinking. That is, what happens at one point in the watershed can influence what we see in other parts. System thinking is a tool through which we develop a deeper understanding of the system's characteristics and behavior (Anandhi, 2017;Anandhi et al., 2016;Batzri et al., 2015). Third, students are often challenged by the land...