In this lesson, students complete a very fun lab where they use a specially designed container (and a lot of water) to build a topographic profile. This introductory lesson serves to introduce what a topographic map actually is (a representation of a 3D area on a 2D surface) and have students create one by pouring progressively more water into a plastic mold, where they then use a plastic overlay to trace out where the water meets the land. This, over successive trials, creates the similar topographic/contour line shape, which students directly experience through the increasing water levels and the subsequent shrinking land surfaces. They finish up with some brief analysis questions, which are posted below. Finally, this is a materials-intensive lab, although it can definitely be completed within one class period. The materials list is below.
[Note: For embedded comments, checks for understanding (CFUs), and key additional information on transitions and key parts of the lesson not necessarily included in the below narrative, please go to the comments in the following document: 7.12 - Topographic Maps Lab (Entire Lesson w/comments). Additionally, if you would like all of the resources together in a PDF document, that can be accessed as a complete resource here: 7.12 - Topographic Maps Lab (Entire Lesson)[PDF]. Finally, students may need their Earth Science Reference Tables [ESRT] for parts of the lesson (a document used widely in the New York State Earth Science Regents course) as well.]
Students come in silently and complete the (attached) Do Now. In this case, the Do Now is different than what it usually is. In this one, I actually wanted to give students a preview of the information they'll be learning in this lesson. They had previously, in middle school, learned about topographic maps, so this Do Now serves more as an activator of prior knowledge (from many years ago) then a pure review, as most of my other Do Now do (see below for more context here). After time expires (anywhere from 2-4 minutes depending on the type of Do Now and number of questions), we collectively go over the responses (usually involving a series of cold calls and/or volunteers), before I call on a student and ask them to read the objective out loud to start the lesson.
As a general note, the Do Now serves a few purposes:
In this first part of the lesson, we take a quick few minutes to introduce the overall concept of topographic maps. Using the provided image at the bottom of the Introduction as a resource, we collectively read the paragraph at the top of the paper as a class. We introduce the concept of both contour lines and contour intervals in the context of how they apply to map reading, and then we do a super quick check of the information on the image. For example, I ask them to find out the contour interval on the map on the Introduction (it's 10 meters), and then ask them to provide their rationale. Also, a key misconception that you should introduce here so that students are more self-aware when doing the lab and its associated analysis section. The contour interval does not measure horizontal distance, only the change in vertical distance, or elevation. The horizontal distance is measured by using the associated map scale, which is traditionally provided on most topographic maps that students will see.
The Procedure, Materials, & Analysis is the bulk of where students will spend their time, as this is the place in the lesson cycle where students actually perform the lab. As soon as we're done with the very brief Introduction, we transition into the lab itself. I have students move their desks (my students are in a traditional classroom - not a lab classroom) into groups of four. I have already set up bins with all the requisite materials that students need, so once they've transitioned into those lab groups, I have a student volunteer pass out those kits to each group. While my volunteer(s) are passing out the kits, I have the students in lab groups read over both the objective, materials, and procedure, highlighting or annotating any information they don't understand. Additionally, once they've gotten their kits, I ask them to double-check to make sure that they've received all the materials listed in their Procedure, Materials, & Analysis section.
[Materials Note: This lesson works much better if you put food coloring in the water that students are using - any color should work fine. However, to prevent students from having to add food coloring to their individual beakers, I filled up and stopped the large sink in my room and added enough food coloring to the vat of water to fully darken its color. Whenever students needed extra water (they need about 2000 mL to fill up the container), I had one pre-nominated student go up and scoop up more from my sink in the back of the room. When they were done with the lab, I just had them take all the water and pour it back in the sink in the back, which also re-filled it for the next class]
Once they have their materials and have read through the associated information, they have my full permission to start. I don't do any modeling of the procedure for them (nor do I think it's necessary) simply because in part of this lab, which is toward the end of my academic year, I want to assess their fidelity to the procedural steps - how well can they execute a written procedure - or, if they're struggling, how quickly can they solve problems together? The lab itself is relatively straightforward. Mostly, it entails adding specific amounts of water and then placing a clear and writeable plastic cover over the landscape to draw contour lines where the water meets the land. While they're doing this, I'm circulating to make sure that they're following the procedural steps appropriately and doing everything safely and correctly. To note, Lab Sample and Lab Work II are pictures of my students during this stage of the lab. You can see the profiles and the red water as well as the top profiles they're drawing onto.
Once they're done and they've effectively filled up their entire profile (see the Lab Work picture for what this will look like when it's all filled), I have them use permanent markers and transparencies to copy down what's on their clear plastic cover onto their own transparency, and then label the associated contour lines. I do this so everyone gets the chance to draw the contour lines (seeing, for example, that they never touch or cross, and that they go up by regular intervals), but also so that I can have a reference for grading and feedback purposes (the kits are re-usable, and the writing easily washes off for the next class). I have some examples here: Student Transparency & Student Transparency II.
Once each group is done, they're instructed to re-assemble their kit, dump out the used water back in the sink, and then dry off and clean up their respective lab tables. After that, there are some questions on the Procedure, Materials, & Analysis resource that they're tasked with.
As noted above, once students are actually completed with the lab, I ask them to quickly clean up and get started on the brief Procedure, Materials, & Analysis section, which has just a few questions after their procedure is complete (this section is brief because the process of set up, performing the lab, and clean up itself takes awhile, and since this is supposed to be an exploratory and introductory activity, we will expound on many of the features of topographic maps in later lessons).
As students are working on that, they're also asked to reference the attached Rubric for information on how they're going to be graded. When I grade this lesson, as the Rubric states, I focus mostly on their transparencies and their completeness and correctness of their topographic profiles. Additionally, I also dock points from groups (although I almost never do this) who misuse materials or perform procedures in a way that are not intended with their use (for example, I get easily frustrated when students use rulers as windmills on the end of their writing utensils - you'll know what I'm talking about if you've ever seen it!).
As a final point, I definitely feel this lab can be completed in one period. If you're worried about the materials-intensive nature of this lab, or about finishing in the appropriate amount of time (especially since this isn't one you can easily just pick up with the next day), I'd highly recommend have a hard stop in your lessons with bout 5-6 minutes left of the class period. What this means is that as soon as the timer goes off/you let the class know/there is a signal that you devise, all work must stop and clean up immediately needs to start. It doesn't matter what students are doing, where they are in the lab, or anything else - their sole task is to clean up and get the room in order for the next period. Procedures like this are especially important for my classroom because, as noted above, I don't teach in a lab class - there are normal desks, and I share the room with other content areas, so if a Biology class is doing something next period, my room has to be in order and ready to go.