WHAT UNDERGRADUATE STUDENTS KNOW ABOUT SURFACE AND GROUNDWATER FLOW

The Earth's Record of Climate is an introductory geology course offered at the University of St. Thomas that explores the science of paleoclimatology and its relevance to the climate change of the last century. Most undergraduate students that enroll in the course believe that climate change is a significant concern, but lack knowledge of the scientific basis or express important misconceptions about the problem. Students build the necessary skills to work with different forms of earth science data including oxygen isotopic data, fossils, and sediment descriptions. They also read and respond to articles on climate change. Students demonstrate their learning with: 1) a final project in which they complete a detailed paleoclimate reconstruction 2) a final exam essay in which they respond in a substantive fashion to a climate change skeptic, and 3) the results of a Knowledge Survey. Knowledge Survey results show a significant increase (1.17 points on a 3 pt scale) in student confidence by the end of the course. Representative comments from student reports on teaching suggest that it both challenges them and increases their interest in earth science. Numerical ratings from student reports on teaching are consistently higher (by 5% on average) than those for an introductory physical geology course that I teach.

Re: The Use of a Knowledge Survey as an Indicator of Student Learning in an Introductory Biology Course

Writing assignments can be a valuable teaching tool to help students learn geology and develop their writing and thinking skills. The view that writing is a process through which students learn, as well as a product that can be evaluated, has stimulated renewed interest in using writing assignments to teach geology. To write, one must go through thought processes such as understanding concepts, organizing material, making comparisons, analyzing data, developing arguments, and drawing conclusions. In introductory geology courses, writing assignments such as in-class responses, journals, abstracts, short papers, laboratory reports, and term projects can help develop valuable thought processes and augment students' comprehension. Many students have never written a paper for a science class and need instruction about expected content, format, and style, and guidance in writing, reviewing, and revising papers. Pre-writing exercises, required or optional rewrites, and critical review by the instructor and peers...

Introductory geology courses comprise an important part of a complete undergraduate education, and federal law stipulates that they must be accessible to all students. Mobility-impaired students, unfortunately, tend to avoid courses with required field trips because of real and perceived barriers to physical accessibility. Inexpensive evaluation, revision, and creation of accessible laboratories are pragmatic approaches that satisfy federal laws and open earth-science careers to talented students with mobility impairments.We have developed three new accessible field exercises for Stanford University's introductory geology course that improved the course rather than compromising its academic merit. In developing two new field trips, we set the following goals: 1) to locate potential sites relevant to material; 2) to eliminate obviously inaccessible locations; 3) to evaluate the remaining sites with, regard to accessibility criteria developed with advice of mobility-impaired students; 4) to test site accessibility with mobility-impaired persons; and 5) to advertise the new field trips. A third exercise creates a hypothetical field problem to teach principles of geologic mapping in an accessible setting.

Iron County is a semi-rural area in southwestern Utah that is experiencing an increase in residential development. Although much of the development is on community sewer systems, many subdivisions use septic tank soil-absorption systems for wastewater disposal. Many of these septic-tank systems overlie the basin-fill deposits that compose the principal aquifer for the area. The purpose of our study is to provide tools for waterresource management and land-use planning. In this study we (1) characterize the water quality of four areas in Iron County (Newcastle, Kanarraville, Summit, and Paragonah) with emphasis on nutrients, and (2) provide a mass-balance analysis based on numbers of septic-tank systems, groundwater flow available for mixing, and baseline nitrate concentrations, and thereby recommend appropriate septic-system density requirements to limit water-quality degradation. We collected 57 groundwater samples and three surface water samples across the four study areas to establish baseline nitrate concentrations. The baseline nitrate concentrations for Newcastle, Kanarraville, Summit, and Paragonah are 1.51 mg/L, 1.42 mg/L, 2.2 mg/L, and 1.76 mg/L, respectively. We employed a mass-balance approach to determine septic-tank densities using existing septic systems and baseline nitrate concentrations for each region. Nitrogen in the form of nitrate is one of the principal indicators of pollution from septic tank soil-absorption systems. To provide recommended septic-system densities, we used a mass-balance approach in which the nitrogen mass from projected additional septic tanks is added to the current nitrogen mass and then diluted with groundwater flow available for mixing plus the water added by the septic-tank systems themselves. We used an allowable degradation of 1 mg/L with respect to nitrate. Groundwater flow volume available for mixing was calculated from existing hydrogeologic data. We used data from aquifer tests compiled from drinking water source protection documents to derive hydraulic conductivity from reported transmissivities. Potentiometric surface maps from existing publications and datasets were used to determine groundwater flow directions and hydraulic gradients. Our results using the mass balance approach indicate that the most appropriate recommended maximum septic-tank densities in Newcastle, Kanarraville, Summit, and Paragonah are 23 acres per system, 7 acres per system, 5 acres per system, and 11 acres per system, respectively. These recommendations are based on hydrogeologic parameters used to estimate groundwater flow volume. Public valley-wide sewer systems may be a better alternative to septic-tank systems where feasible.

For introductory geology courses, which typically enroll both science and non-science majors, a hands-on laboratory is often an effective way to get students of differing abilities and backgrounds interested in practical environmental issues. Solidwaste management and landfills are standard topics of environmental-geology courses, and we have developed a laboratory that teaches students some important aspects about design and monitoring waste-containment systems. The membrane lining in regulated landfills must be rigorously tested to ensure that there are no leaks, and landfills themselves must be monitored constantly to guard against developing leaks. A new method of detecting leaks in landfill liners, based on the parallel properties of electrical and ground-water flow, can be easily simulated in the laboratory of an undergraduate environmental-geology course. In this laboratory we explore the properties of potential, resistance, and flow in electrical systems and show how these relate to hydrologic principles. Using these tools, we construct a landfill model and solve a real field problem in environmental geology.

An analysis of student evaluations of an introductory physical geology course over a five year period showed generally positive feedback from the students about the overall nature of the course. In particular, instructional and pedagogical traits were assessed as being of importance in contributing to the satisfaction of the students with the course.

Learning complex concepts is necessary for student success, but it is often challenging. Learning such concepts can be influenced by students’ study order choices during learning to switch to a new category (interleaved study order) or stay within the same category (blocked study order). Students often prefer stay decisions during learning and make relatively few switch decisions; however, an open question is whether students’ switch decisions are related to their level of prior knowledge in the domain and the learning strategy they use (retrieval practice versus study). To examine these relationships, we recruited undergraduate students from an introductory geology course. Prior to the course modules on rock classification, students self-rated their knowledge, took a prior knowledge test, classified rock exemplars by completing study or retrieval practice trials, and made study order choices. Students then completed assignments and attended lectures in their geology course on igneous, sedimentary, and metamorphic rocks. Next, students self-rated their knowledge, took a new prior knowledge test, completed study or retrieval practice trials, made study order decisions, took final classification tests, and self-reported beliefs about study order choices. Even though students’ knowledge increased after course modules on rock identification, and most students believed that domain knowledge impacts study decisions, prior knowledge did not predict students’ switch decisions. In contrast, students who completed retrieval practice trials made substantially more switch decisions (i.e., interleaved study) than did students who completed study trials.

Jason, a junior faculty member in a geoscience department, has been asked by his chair to take over the training of graduate teaching assistants in the department. He was chosen mainly because he has attended a few teaching workshops and has been trying some new teaching approaches in his introductory geology course. Jason is not sure how one should structure a program to build graduate students' teaching skills. He begins with a literature search in the science education literature to find what other science departments are doing to prepare graduate students for their teaching roles. What are the key items that should be in a professional development program for graduate student instructors? He quickly finds that although many science departments have published articles describing their approach to developing graduate students' teaching skills, very few of these programs have ever been evaluated. So Jason starts a more general search through the literature focusing on teaching approaches that have some research base. His plan is to build a professional development program for graduate student instructors around research-based approaches. In this column, we chronicle Jason's progress, summarize the research in this area and highlight the areas where more research is needed. Graduate Teaching Assistants (GTAs) play a prominent role in undergraduate education at higher education institutions. They are frequently utilized to instruct courses in a cost efficient manner, with the rationale that the experience will prepare them for careers in academia. In fact, GTAs instruct the majority of undergraduate laboratories and discussion sections at research universities (Travers, 1989). As instructors, GTAs frequently make instructional, curricular, and assessment decisions throughout their courses. They decide how information should be presented, what concepts should be emphasized, and how to evaluate student work. Unfortunately, GTAs often make these decisions with little guidance from faculty. By involving GTAs in college science education reform now, we can advance reform efforts, both in the short term, by increasing the quality of instruction in undergraduate science laboratories and discussion sections, and in the long term, when these graduates move on to permanent faculty positions and develop and teach both undergraduate and/or graduate courses. Regrettably, GTAs are often subjected to training programs that offer limited instructional support regarding the teaching of science (Carroll, 1980; Rushin et al., 1997; Golde and Dore, 2001) and they often experience limited support for developing their teaching skills from their departments or advisors (Jones, 1993; Golde and Dore, 2001). In a recent study that surveyed over 4000 doctoral students across disciplines from 27 universities in the U.S., 83% of doctoral students responding to the survey cited enjoyment of teaching as their main reason for pursuing a faculty career (as opposed to 72% who cited enjoyment of research as the primary reason), yet most students lamented the lack of training they received to develop their teaching skills (Golde and Dore, 2001; full text of the report is available online at http://www.phd-survey.org). This comment is representative of many doctoral students in the sciences: have always considered teaching my main reason for pursuing an academic degree. I am amazed at how little preparation I am receiving in how to teach. I am still planning on pursuing a teaching position but am filling in the gaps in education and preparation on my own time with little encouragement from my academic program - quote from a molecular biology doctoral student. (Golde and Dore, 2001) Literature on GTA Training Programs in the Sciences It is estimated that by 2014, 500,000 new professors will be teaching at American colleges and universities (Jones, 1993). Improving undergraduate education for current and future students will depend upon thoughtful and careful attention to the training of these future faculty members, especially in light of the fact that the reason many undergraduate students cite for abandoning science majors is poor teaching (Seymour and Hewitt, 1997). …

Classroom techniques and laboratory exercises have been developed for the benefit of visually impaired students enrolled in an introductory geology course. The students attend lecture sessions with other students enrolled in the course, participate in all field trips and, with the exception of one modification, attempt the same laboratory exercises. Upon completing the course, these students (1) feel they have been totally involved in the class, (2) have been introduced to a number of instruments available to the visually impaired for making various types of measurements/observations and (3) have been introduced to the scientific method as well as some of the concepts of geology. The following laboratory exercises have been developed: (1) doing library research; (2) graphing geologic data; (3) identifying minerals, rocks, and fossils; (4) measuring attributes of the earth and earth materials; (5) solving geologic structural and plate tectonic problems; (6) reading maps and recognizing landscapes, and (7) ...

Complex concepts and ideas are often presented to introductory level students in a simplified form for educational purposes. This simplification sometimes requires that the “whole truth” not be presented. However, the simplified material should be current and factual to the extent that future lessons that build on the introductory material will expand on the originally presented material rather than contradicting it. The presentation of soil classification in many current introductory physical geology textbooks is over 35 years out of date. In addition, the way soil classification terminology is used would be questionable even if it were still current. Individuals teaching introductory geology courses that include sections on soils and the authors of textbooks using incorrect classification terminology should obtain current references on soil classification and correct these deficiencies.

Located at southern coast of China, the Pearl River Delta (PRD) is facing serious water problems in both quantity and quality after its rapid urbanization in the last decade. Most remarkably, the local groundwater, that was used to be the source of drinking water before the urbanization was polluted due to poor management of the septic tanks. In order to study the effects of suburban development on local groundwater flow and water quality in the PRD region, Fengcun of Guangzhou has been chosen as the study area. In Fengcun, drinking water was groundwater before the 1990s, but now piped reservoir water is used by each family because the groundwater has been polluted. This study clarifies the source and process of the groundwater pollution from septic tanks using isotopic and geochemical characteristics, especially nitrate (NO3−) concentrations. Water samples were collected from the wells and ponds in Fengcun in March and July 2005 and in July 2006. Based on the pe–pH diagram, NO3− and ammonium of groundwater are from the effect of human activities, rather than from nitrification and ammonification of N2. NO3− pollution of groundwater is from point sources, and NO3− concentrations decrease from northeast to southwest. Groundwater is polluted rapidly by the leakage of septic tanks. NO3− concentrations of pollution sources were lower than 20 mg l−1 in March 2005, but had increased to about 120 mg l−1 in July 2006. This implies that groundwater protection should be strengthened in rural areas of the PRD. Copyright © 2007 John Wiley & Sons, Ltd.

A new model for coupling surface and subsurface water flows: With an application to a lagoon

The problem of trying to develop introductory geology courses in the secondary schools cannot be solved by transferring college freshman courses and materials (with a few modifications). Secondary-school courses require an approach quite different from the “read-and-listen” method used in colleges. The traditional geology laboratory hardly meets the needs of the secondary-school pupil. Florida State University has adopted a sequence of geology courses specifically designed for the education major (the prospective school teacher). In the first of these courses, the student is taught—by example—that the most effective method of reaching the school pupil is by means of student-built models. Approximately 35 models, simple enough for ninth- or tenth-graders to build and operate, are covered, along with the usual geological glossary of terms and ideas. These models involve the pupil in activities as diverse as measuring the acceleration of gravity, producing a miniature Permian Basin under an infrared lamp, an...

This study used optical brighteners (OB) released from septic systems to show that groundwater flow direction is largely controlled by the structural framework in a faulted karst groundwater system. Effective protection of groundwater resources requires that groundwater systems are adequately characterized and source water protection areas (SWPA) are developed for drinking water wells. Karst aquifers are among the most sensitive to contamination due to high recharge rates, and among the most difficult aquifers to characterize due to heterogeneity, and anisotropy. Because septic systems may be used to treat wastewater within SWPAs for karst aquifers there is a need to characterize these groundwater systems using tracers. The objective of this study was to characterize groundwater flow in a faulted portion of the Edwards aquifer in Bexar County, Texas using OB that are released as incidental tracers from septic systems. This study included measurement of water levels, sampling of groundwater and surface water, analysis for OB, and spatial analysis in a GIS. Results show that OB intensities were highest to the southwest of the septic area, a direction that is sub-parallel to the fault and fracture orientation and nearly perpendicular to the hydraulic gradient. This indicates that movement of OB, solutes, or non-aqueous liquids/solids in a faulted karst system can be largely controlled by fault/fracture orientation and structural relay ramps.