REPLACING OR AUGMENTING "PAPER" LABORATORY EXERCISES WITH LABORATORY/FIELD EXPERIENCE

Having utilized paper exercises for many years in an introductory Geohydrology Course the author felt that in most cases something was lacking in student preparation. That was the lack of the students’ ability to develop a conceptual model of the surface and groundwater relations. The decision was made to bring more of the class into the field when the opportunity arose to visit a local site. This site was only 40 minutes away and an innovative laboratory/field experience was developed.

The site was a small glacial valley in a coastal environment and an engineering report was available. This report was the result of a study on the potential for contamination of a proposed municipal water supply in that small glacial water shed in coastal Massachusetts. The water department was concerned about the possibility of abutters releasing contaminants into the aquifer system. This engineering report consisted of geology, historical and current land use, projected additional development and projected ground water with drawl.

Data extracted for the students use has consisted of topographic maps and basic geology supplanted with a series of drilling data along the valley axis. (Unfortunately this longitudinal data has led to two dimensional or linear thinking when geological interpretation is attempted.) The students create a longitudinal cross section utilizing drill data, analyze the topographic map and give a brief analysis of the area. In general the student conclusions are in agreement with the engineering report.

However after the students actually visit the site some doubt slowly develops with respect to the conclusions in the engineers report.

At the site students are asked to present or modify their conceptual model based on the additional field observations. Those field observations serve to create discussions about their original “paper” laboratory. The class then moves on to obtain stream flow data using a Marsh-McBirney flow meter at several points along the stream. As the flow data are not what textbooks state, confusion starts to develop as well as an energetic discussion. With time observations and conclusions improve. Next the students are supplied with pumping data from the municipal wells and patterns become much clearer. The outcome is that students begin to understand the relations between surface and ground water.