INTRODUCTION

Hydrology, according to one definition, "encompasses the occurrence, distribution, movement, and properties of the waters of the earth and their environmental relationships." The study of hydrology is becoming increasingly important, with application to topics as diverse as global environmental change, toxic waste contamination, sediment and nutrient pollution of water bodies, water supply management during droughts, flood hazard assessment, and design of stormwater detention ponds. Although our concern in this course is with basic science rather than specific applications or computer models, you may well find it to be a valuable addition to your transcript. Among students who were previously enrolled in this course, a surprising percentage have gone on to internships, graduate school and/or employment where a background in hydrology was an important advantage.

During the semester we will discuss all aspects of the hydrologic cycle, emphasizing quantitative analysis and physical relationships. We will start with some fundamentals on dimensions, units of measurement, and unit conversions; mass balance in hydrologic systems; temporally and spatially distributed hydrologic variables; statistical analysis of time series and of spatial data; and examination of the watershed as the fundamental unit of the landscape. We will continue with a discussion of spatial and temporal patterns of precipitation, which is the source of all the water involved in the land phase of the hydrologic cycle, and we will continue with evapotranspiration , infiltration and soil moisture. The heart of the course concerns surface runoff, streamflow , floods, and associated topics. We will spend a couple of weeks talking about groundwater, but this topic will be covered at an introductory level.

The basic concepts discussed in the course are not terribly difficult to understand; however, application of various methods of data analysis and theoretical modeling for prediction and planning purposes can get quite involved. The textbook covers a large number of methods of analysis, but we will be selective in choosing which ones to discuss in class. Regardless of which particular method is under discussion, you should learn to develop some intuition about how to take a data set and use graphical or mathematical techniques to look for patterns, make predictions or projections, or answer specific questions. I want you not only to be able to use mathematical formulas but also to be able to think about which method is appropriate under which circumstances. Before you accept an answer to a question, ask what assumptions had to be made in order to derive that answer; whether the assumptions are valid; and whether the answer makes sense. Also be certain that all calculations (especially unit conversions) have been checked for accuracy. The result of a quantitative analysis is no better than a wild guess unless the analysis has been accompanied by critical thought about what you are doing and why. Use your calculator and your computer to help you get answers, but don't make the mistake of assuming that they will do your thinking for you.

Assigned readings

The assigned text ( Dingman , 1994, Physical Hydrology) is not as mathematically challenging as some of the textbooks on the market, but it requires considerably more background in math than the books you will encounter inmost other Geography courses. Do not be intimidated by the text; although a number of the analytical techniques and theoretical equations in the book may seem impenetrable to some of you, any equation or method you are responsible for will be discussed and illustrated in class. Although there is no ideal textbook for an undergraduate hydrology course, the book we are using now has been adopted as a standard text by many of the scientific hydrologists I know and is the best compromise I could find for now.

Computer applications are increasingly important in professional practice and in research in hydrology. Some of the tools that are now becoming widely available are extremely sophisticated and provide incredible savings in the amount of labor required by comparison with older modeling systems. As computer models become easier to use, the challenge is to understand their limitations in order to make wise decisions about when and how they should be used. Although we may not have the time to learn how to use many of the models that are becoming more and more common, it is my hope that by the time you complete this class you will have the basic understanding of natural processes to be able to make intelligent use of models, keeping in mind the old maxim "garbage in, garbage out." You should also be aware that hydrologic modeling is increasingly being integrated with CAD and GIS analysis, and combining coursework in both areas could be to your advantage. I am starting to put together a library of commonly available models, but I am not able to devote the time necessary to test them all. If you wish to do some experimenting with models, perhaps as an extra component of the course for honors credit, let me know and I should be able to work something out with you.

Homework

I expect that, even with the basic prerequisite of Math 151 or its equivalent, there will be some diversity of backgrounds among students in the class. We will use the scheduled fourth hour of the class for review of homework problems and problem-solving techniques, and you are encouraged to consult with other students or with me when you run into difficulty. We will spend a lot of time on problem-solving. Assigned problem sets will be handed out at intervals of 1-2 weeks. If you are absent when the assignment is handed out, it is your responsibility to make sure you get the assignment and hand it in on time. (I will try to make sure that homework assignments and handouts are also posted on the web, but where there are images I may not always be able to get the graphics up in a format that can be read.)

It is far more important to complete and hand in as much of each problem set as you can than it is to get every answer right. You will get credit for whatever part of the work is completed successfully. A simple computational error that leads to a wrong answer will lower your score, but you will still be awarded most of the points for the question if everything else is done correctly. On the other hand, errors that lead to answers that are obviously ridiculous will cost you more; because I expect you to apply common sense in analyzing and proofreading your work. Pay attention to what you are doing. Honest mistakes are opportunities for learning and often teach us more than if we had gotten the answer right the first time; I will become less sympathetic only if your work is sloppy and shows a lack of concern for what you are doing. If your work is illegible or so poorly organized that I can't follow what you are doing, I will hand it back without grading it and you will be expected to do it over. Don't forget this; the problem sets are worth 40% of your grade for the course!

The computer is an indispensable tool, and I encourage you to use it in any way that seems appropriate in working out problems (as long as you can explain all of the steps involved). The use of a spreadsheet package like LOTUS 1-2-3, Quattro Pro, or Excel can make your life much easier in doing calculations, and therefore we will spend some time setting up example problems in spreadsheet formats. I advise you to use a spreadsheet (or a mathematical scratchpad like Mathcad or Maple, if you already know how to use one) for performing homework calculations and plotting graphs. If you don't have access to a computer at home, the student microcomputer labs are at your disposal and there are spreadsheets available in both the PC and Macintosh labs; this is a good time to start using them if you haven't done so in the past. If you do have a home computer and you don't have a spreadsheet, it would be advisable to get hold of one. This is an excellent opportunity to learn to use a tool that you will probably be using for decades to come. Don't make a new purchase without talking to me first, however; in my experience we are all better off if we standardize on one program, which probably should be either Quattro or Excel.

Although computer-aided quantitative analysis is an essential component of hydrology, remember also that the analysis is no better than the data being analyzed. We will try to schedule a couple of field exercises so that you can gain some perspective on how hydrologic data are collected - and some skepticism about whether it is wise simply to accept all data at face value without questioning how they were obtained and whether they are reliable. The methods of quantitative analysis are based on theoretical or empirical models of how a hydrologic process works in nature. Without detailed observations, we have no way of validating or falsifying the models.

Exams and attendance

There will be three exams, including the final. I reserve the right to give one or more as a take-home, but I haven't yet decided on the format I will use. Each exam counts as 20% of your grade. All problem sets taken together will count as 40% of your grade.

Keep in mind also that the greatest resource at your disposal is the human resource. I expect you to consult and to work with your classmates. Sharing of information is acceptable and expected in all phases of the class other than exams. I require the homework assignment you turn in to be your own results in your own words, but if you have some difficulty, by all means get help from someone in the class. Even better, you may want to collaborate with each other in thinking about how to do the problems before you sit down to work them out. It is therefore especially important that you attend class and that you consider yourself as part of a team. If you are absent, you will miss critical information and you won't be able to make up for it simply by getting a copy of someone's notes.

This is the way things are done in the real world: if I don't have the expertise needed to tackle a thorny problem, I don't waste years banging my head against the wall. I try to locate someone who has the right expertise and can give me advice on what I need to learn or what technique I might use. Similarly, I don't expect you to waste a lot of time banging your head against the wall or the computer screen. If you have spent an hour or two on a problem and something just isn't making sense, it's definitely time to get help. I am here to provide help if you need it.

With this in mind, I expect everyone in the class to have a computer account and to provide me with an email address. I will make a list of email addresses, including mine, and distribute it to the class. If you have a question, send a message to the whole list. If you don't get the help you need from other students and are still stuck, call me or send me an email and I will try to respond in a timely manner. For some homeworks I may even distribute data sets via email. If you don't know how to use the computing system, read email, edit and save files, etc., now is the time to learn - every employer will expect you to have that kind of knowledge. There are non-credit short courses available through university computing services. In addition you almost certainly know someone who can explain how to go about it. I don't have the time to teach you all the basics of using a computer, but I can give you pointers on specific problems if you run into a brick wall elsewhere.

Prerequisites

The prerequisites for this course are as follows:

1) Physical Geography

2) either Geomorphology, Weather and Climate, or Water Quality

3) Math 151 or equivalent

4) some background in statistics; either Geog 301 or Stat 121, 350, 351, or 355

If you do not meet these requirements, see me. I do make exceptions to the prerequisites, but I will do so only if I am convinced that you are going to be able to handle the material.

Math anxiety

I am well aware that many students view the application of mathematics in problem-solving with the same sense of anticipation as having dental work without anesthesia. Even if you've completed lots of math courses, they may not have taught you how to apply what you learned to different situations. In fact the most important part of this course for many past students has been that we focus on developing enough flexibility in approaching problems that we lose the fear of using mathematics as a tool to answer questions. During the first 1/3 to 1/2 of the semester I have often found that students are resistant to doing the math, not because they can't do it but because they have convinced themselves they can't do it. If you find this process painful, think of it as essential training just like weight training for athletic competition. My job is not to make it painless; my job is to try to keep you on track and to provide enough support to get you through it. Don't give up if it looks hard at first; if you have doubts about whether you can do the work, talk to me and let me give you some feedback before you make any decisions. The parts that are painful now are the most important parts for you to get through. Later on, when you realize you've broken through the psychological barrier, you'll be glad you stuck with it.

Research opportunities

Finally, I want you to know that there are opportunities to do some exciting work in this field. By all means let me know if this is something you would like to consider doing.