2016 ASEE Annual Conference & Exposition

In traditional hydraulics classes, students get little if any hands-on experience with hydrology. Labs that do include hydrology apparati often only demonstrate a simple rainfall-runoff relationship with a uniform media. Students do not see effects of slope, vegetation, development, impoundments, and other landscape characteristics. This often leads to poor understanding of hydrologic processes and lack of interest. To improve a current lab with a hydrology apparatus, an open-ended lab activity was designed. Students were shown how the hydrology apparatus worked and what materials were available. Materials included AstroTurf and a foam pad to simulate vegetation, a plastic mat to simulate impervious area and blocks for houses and buildings. In addition, other hydrologic variables may be changed including basin slope, landforms (hills and valleys), degree of initial saturation, rainfall rates, and rainfall duration. They were then asked to develop 2 testable questions based on a review of current literature, and develop a procedure. Once the instructor approved their testable questions and procedure, the students conducted their lab experiment and wrote a lab report.

This newly designed hydrology lab was first tested with 16 volunteers. Experience level varied from graduate students to undergraduate students who had not taken hydrology. A pre- and post-test was given to the volunteers to evaluate how the lab improved conceptual understanding and enthusiasm for the lab. The pre-test consisted of hydrology conceptual questions, and the post-test included the same hydrology conceptual questions in addition to questions that allowed students to rate the effectiveness of the lab. The volunteers had an average gain of 0.31 out of 1.0 possible. The two students who did not have any previous experience with hydrology achieved the highest gains of 0.47 and 0.62. This is likely because they knew less about the concepts covered in the lab, and scored low on the pre-test. The following semester, the new lab was assigned to 32 students in an Engineering Hydraulics Lab. Hydrology is a pre-requisite to the lab class, so all students understood the basic concepts covered in this lab. The same pre- and post-test was given to the students. The students had an average gain of 0.30, which is very similar to volunteer results. Both the volunteers and students in the class thought that the lab improved their understanding of hydrology as well as their confidence in answering hydrology conceptual questions.

Using an existing piece of equipment and relatively inexpensive materials, an open-ended lab was created that improved student understanding of hydrology and created enthusiasm for this area of engineering. Students had to think critically to develop testable questions and a procedure. Due to the open nature of the lab, this process also fostered student ownership of their learning. Because this hydrology apparatus is so large, next steps include building smaller, desktop models that can be used in the classroom setting. This will enable this open-ended lab activity to be disseminated to a larger population of students.