UNIVERSITY OF MARYLAND BALTIMORE COUNTY

DEPARTMENT OF GEOGRAPHY

Geography 416 - Hydrology

Spring 1998	Andrew J. Miller

MW 10:00-10:50, F 9-10:50	Office: SS 211-A

SS 005	Phone: 455-3151

email: miller@ umbc.edu

Required text: Dingman , 1994, Physical Hydrology (Macmillan)

Class home page: http :// research.umbc.edu /~miller/ geog416 .html

For each set of assigned readings, I will provide guidance in class regarding the order in which topics will be covered and the relative emphasis to be placed on each. This syllabus is a plan that will be adjusted as we proceed through the semester; any changes will be announced in class.

Dates	Topics	Readings

Jan. 28-30	Introduction to the hydrologic cycle; dimensions and unit conversions; watersheds as unit of analysis; basic mass-balance calculations	ch. 1, ch.2;

Appendix A

Feb. 2-6	Introduction to probability and frequency analysis	ch. 2, Appendix C
Feb. 9-13, 16-20	Global water budget and climate; precipitation	ch. 3, pp.40-79; ch. 4
Feb. 23-27	Infiltration and soil moisture	ch. 6
Mar. 2	FIRST EXAM
Mar. 4-6	Infiltration	ch. 6
Mar. 9-13	Evapotranspiration	ch. 7
Mar. 16-20	Snow and snowmelt	ch. 5
Mar. 23-27	SPRING BREAK
Mar.30-Apr.8	Groundwater	ch.8
Apr. 10	SECOND EXAM
Apr. 13-20	Stream response to storms; hydrograph analysis	ch. 9
Apr. 22-29	Unit hydrographs ; runoff-generating mechanisms	ch. 9
May 1-6	Flow routing	ch. 9
May 11-13	Flood frequency analysis, flood hazards and managment	TBA
May 18	FINAL EXAM, 8-10 a.m. (or possible take-
home)

Geography 416 - Hydrology

Study guide 1

We will start with a brief general introduction to hydrologic science, the elements of the hydrologic cycle, and the systems approach to analysis of hydrologic processes. Start by reading chapter 1 (pp. 1-5), focusing on figures 1-1 and 1-2. Fig. 3-16, p. 47, adds some actual numbers to fig. 1-1.

In order to begin any detailed discussion of hydrologic processes, we next must develop some familiarity with the physical quantities involved and the basic physical laws that govern those processes. Read ch. 2, pp. 6-9, and Appendix A, pp. 471-477. (Also see the links available from the class home page that discuss basic units, dimensions, and unit conversions.) We will spend some time talking about dimensions (e.g. length, area, volume, mass, velocity, acceleration, force, time, temperature) and the particular units in which those dimensions are measured and described (feet or meters for length; ft2 or m2 for area; m/s for velocity; m/ s2 for acceleration; seconds; degrees Celsius; etc.) In order to use those units properly, we must of course know how to perform unit conversions, and this is a major focus of Appendix A. Note also that basic dimensions and associated units and conversion factors are listed in the inside front cover of the textbook, but I will supplement this with a class handout of conversion factors that is easier to work with. You will need to use this in order to solve the first homework assignment, which is due on Monday. I expect you to work cooperatively on this assignment in class on Friday.

Appendix B discusses fundamental properties of water. I am not requiring you to read it at this point, but I recommend you at least look through it for background information.

In performing any kind of hydrologic analysis, we generally identify a hydrologic system in terms of inputs, outputs, and storage. Therefore we must familiarize ourselves with the basic conservation or mass-balance equation as it is used by hydrologists. Page 7 lists some of the fundamental laws of physics; page 8 and the beginning of page 9 discuss the basic water balance, which involves both amounts of water (generally expressed as volume) and rates of flow (generally expressed in volume per unit time).

In performing a mass-balance analysis, the typical system (at least in surface-water hydrology) is the drainage basin or watershed, described on pages 14-15. Water-balance calculations using the basic conservation law are generally applied to watersheds, as discussed on pages 16-20.

The homework assignment requires you to perform water-balance calculations involving several components of the hydrologic cycle applied to a watershed with a reservoir at its downstream end, and also gives you a workout in performing unit conversions. As a supplement to the homework assignment, I will provide a topographic map, and you will be asked to delineate the watershed divide and the drainage network in class on Friday.

Another critical issue in hydrology is the concept of temporal variability. We know that precipitation, evaporation, runoff, and most other variables describing natural processes are not constant over time but are continually changing, and therefore in order to understand what is going on we must collect data as a time series (pp. 9-14). The analysis of time series requires some understanding of probability and statistics; Appendix C provides a quick overview and pp. 20-26 include some discussion of the statistical properties of hydrologic time series. Not all of the discussion on these pages will be covered in class. I will provide more guidance on what is important for our purposes. We will discuss some examples in class and the next homework assignment will include some simple statistical analyses .

Next week: Topics we will emphasize in basic probability and statistics (mostly, but not all, in Appendix C):

[please note that since different sources may use different symbols for the same concept, my notes may not always be 100% consistent with the notation in Appendix C; I will keep the book open in order to watch out for this, but please ask if the notation used confuses you at any point]

Discrete and continuous random variables

Histograms, probability distributions and quantiles

Probability density functions and cumulative frequency distributions, both empirical and theoretical (note that a flow duration curve as discussed on pp. 11-14 is simply an empirical cumulative frequency distribution)

Moments of a distribution (first 3: mean, variance, skewness) and other measures of central tendency, e.g. median, mode

Standard deviation and coefficient of variation

How moments may be used to specify a probability distribution

Covariance and correlation

Exceedence probability and return period

Use of the binomial distribution in predicting the probability of an event occurring in some particular sequence

Normal distribution

Standard errors

other topics, such as Student's t and the chi-squared distribution, confidence intervals, hypothesis testing, persistence and autocorrelation , etc. will be introduced later as needed

Related topics in chapter 2:

-	flow duration curves

-	propagation of measurement errors (pp.20-23)