SDSU

Research Guides Research Guide

Contact

For immediate help on this subject and others contact the reference desk.

Robert Carande
Bibliographer
Office: Love Library 108E
Phone: (619) 594-4851
Email: carande@mail.sdsu.edu
Reference Desk
General Research Assistance
Location: 1st Floor Library Addition
Phone: (619) 594-6724
Email: eref@rohan.sdsu.edu

Books

For SDSU book holdings check the Library Catalog [ http://libpac.sdsu.edu ]. The Catalog is the online tool used for finding books and multimedia in the SDSU Library. Books can be searched by keyword, author, title, or subject.

Books in Other Libraries

To find and order books from San Diego area libraries use Circuit [ http://circuit.sdsu.edu/ ] (San Diego) or Interlibrary Loan [ http://library.sdsu.edu/borrowing-other-libraries ].

Aerial Photographs & Satellite Imagery

Online Resources

Print Resources

Finding Information

Aeronautical charts

Atlases

California

Earthquakes & Geology

Election Information

Energy Resources

General Resources

Historical Resources

Parks, Forests, and Wilderness Areas

Transportation Resources

Weather Resources

Fire insurance maps

Books

Microform

Online Resources

Special Collections

Gazetteers

Books

Online Resources

Geologic maps

Index

Online Resources

San Diego County Geologic Maps

National wetlands inventory maps

Nautical charts

Domestic Waters Charts and Publications

National Imagery and Mapping Agency Nautical Charts

Online Resources

Print Resources

Outline maps

Topographic maps

WWW Searching

Citation Guides

Citation Help

Tips

How to Find Topographic Maps

Topographic maps show the shape and elevation of the land, usually by contours. They usually include both natural features (e.g. rivers, mountains, valleys) and manmade features (e.g. roads, major buildings, dams). The wide range of information provided by topographic maps make them extremely useful for research. They are also heavily used for recreational purposes such as finding campgrounds or trails.

The United States Geological Survey (USGS) is the agency responsible for most of the topographic mapping of the United States. They produce maps at a variety of scales, including 1:24,000; 1:100,000; and 1:250,000. The maps are published as quadrangles ("quads"). Indexes are available to help locate the necessary quad.

More information is available from:

Maps for America (Map Index Table & Gov Pubs/US I 19.2:M 32/12/987) includes information about the history, characteristics and production of US Geological Survey maps.

Topographic maps are located in the Media Center. . Assistance is available during Media Center hours by coming in person or by calling (619) 594-6757..

The Map Collection includes these major USGS series:

1:24,000

Find all USGS topographic maps here.

This series, also called 7.5 minute or 7.5', is the most detailed (1 inch = 2,000 feet) of the topographic series of the United States. It is also the most heavily used in the Map Collection. The SDSU Library receives all quads for the United States. The library also keeps previous editions for states west of the Mississippi, which are useful for historical research.

Index: Use the appropriate state index on the Map Index Table to get the name of the quad(s) you're interested in. The Geographic Names Information System (GNIS) from USGS also indexes these maps. Search results give the name of the USGS 7.5' topo quad that covers a given feature.

Maps: Assistance is available during Media Center hours by coming in person or by calling (619) 594-6757. Filed in the USGS map drawers alphabetically by quad name within each state. Maps for Puerto Rico, U.S. Virgin Islands, and central Pacific islands are available at various scales and are filed in the map drawers for those areas. Note: the quads for San Diego county are filed in the San Diego drawers.

1:63,360 Alaska

Find all USGS topographic maps here.

This series, also called 15 minute or 15', is produced for the state of Alaska. The SDSU Library owns all Alaska quads published to date.

Index: Use the Alaska index on the Map Index Table to get the name of the quad(s) you're interested in.

Maps: Assistance is available during Media Center hours by coming in person or by calling (619) 594-6757. Filed in the USGS Alaska map drawers alphabetically by quad name.

1:100,000

Find all USGS topographic maps here.

The Library receives all current maps for the United States, but does not have previous editions.

Index: Use the appropriate state index on the Map Index Table to get the name of the quad(s) you're interested in.

Maps: Assistance is available during Media Center hours by coming in person or by calling (619) 594-6757. Filed in the USGS map drawers alphabetically by quad name within each state. Note: the quads for San Diego county are filed in the San Diego drawers.

1:250,000

Find all USGS topographic maps here.

The Library has all current maps for the United States, but does not have the previous editions.

Index: Use the appropriate state index on the Map Index Table to get the name of the quad(s) you're interested in.

Maps: Filed in the USGS map drawers alphabetically by quad name within each state.

Note: the quads for San Diego county are filed in the San Diego drawers.

State

Find all USGS topographic maps here.

The Library has all current  and historical editions of San Diego County topographical maps.

Maps: Assistance is available during Media Center hours by coming in person or by calling (619) 594-6757..

Posted: 2016-04-25

Keywords: topographic maps


How to Find Fire Insurance Maps

Fire insurance maps were originally produced for the insurance industry to assess the risk of fire and the cost of insurance. A major producer of these maps was the Sanborn Company. The maps were usually at scales of 50 to 100 feet to an inch and included detailed information about residential and commercial buildings such as building material, number of stories, and street address. Other relevant features were also shown such as the type of business and the location of utilities, water pipes, and fire hydrants.

These historical maps provide a unique and valuable look at American cities during the first half of the twentieth century. Publications that provide more information are:

Fire Insurance Maps in the Library of Congress (Gov Pubs Micro/US LC 5.2:F51) identifies the towns and cities of these maps, their original dates of publication, and the latest years of changes made to the original maps.

Fire Insurance Maps : Their History and Applications by Diane L. Oswald (located in 3rd Floor Books at HG9771 .O85 1997).

Map legends are available online from The Sanborn Map Company. See the original legend and the black and white version.

The library owns the original map books for San Diego and select cities as well as a microform collection. For information about fire insurance maps owned by other libraries, see the Western Association of Map Libraries Union List of Sanborn & other Fire Insurance Maps.

The library also owns the original, full-color map books for the cities of Coronado, La Jolla, La Mesa, National City, and San Diego. These are located in Special Collections. See the Special Collections web page for information about hours and policies.

The microfilm collection, located in the Current Periodicals & Microforms Center (1st floor, Love Library), includes the maps of San Diego and a few other cities produced by the Sanborn Map Company between about 1884 and 1970. This microfilm collection is in black and white and so it loses much of the information originally relayed with color (e.g. type of building material). The maps are arranged alphabetically by name of city or town; within each city or town, in chronological order in the order that they appear. They were reproduced from the original copies in the Geography and Map Division of the Library of Congress. Updates were made regularly to original maps, and so the microfiche collection is a snapshot of the maps as they were at a particular time. Fire Insurance Maps in the Library of Congress, listed above, is a useful companion to the set because it gives the original dates of publication and the latest years of changes made to the original maps.

Posted: 2011-08-02

Keywords: maps, fire, insurance


How to Find National Wetlands Inventory Maps

In 1977, the Fish and Wildlife Service began the National Wetlands Inventory (NWI), a systematic effort to classify and map America's remaining wetlands. Maps were created which could be used in a variety of ways, including land use planning, wildlife habitat management, water quality planning, soil and water conservation loans, zoning, flood hazard planning, and research.

The National Wetlands Inventory defines wetlands according to the Classification of Wetlands and Deepwater Habitats of the United States, a system that describes wetlands by soils, hydrology, and vegetation. This publication is available on the web or in the library (Gov Pubs/US I 49.89:79/31/corr).

National Wetlands Inventory Maps are located in the Government Publications & Maps Division (3rd floor, Love Library). Assistance is available during reference hours at the Reference Services Division reference desk (1st floor, Library Addition) by coming in person or by calling (619) 594-6728.

We own a limited number of the maps for selected western states (AK, AZ, CA, CO, ID, MT, NV, NM, OR, TX, UT, WA) and the US Summary maps. They are in black and white on microfiche at call numbers beginning with I 49.6/7-2:. There are machines to view and print the microfiche ($ .10/page), though they are limited to 8 1/2 x 11 paper.

To find the particular map you are looking for, a word search on "San Diego" and "national wetlands inventory maps" brings up San Diego (San Diego NW) CA [microform] : National Wetlands Inventory maps at the call number I 49.6/7-5:32117-E 1/993. Please ask a librarian if you need assistance finding these maps.

Maps of the San Diego area can be found at these call numbers:


Map                                                            Call #
El Cajon (San Diego NE)                           49.6/7-5:32116-E 1
Oceanside (Santa Ana SW)                       49.6/7-5:33117-A 1
San Diego NW                                           49.6/7-5:32117-E 1

Posted: 2011-08-02

Keywords: national wetlands, maps


Map Basics

Scale

Scale is the relationship between distance on the map and distance on the ground. For example, a 1:24,000 scale map means that for every 1 inch on the map, it represents 24,000 inches on the ground. In order for a map to fit onto a sheet of paper, all the rivers, roads, mountains, etc. contained must be shown proportionately smaller than they really are.

Thus, The scale of a map dictates how much information can be shown. A small scale map (e.g. a 1:1,000,000 map of the world) shows a large area but without much detail. A large scale map (e.g. a 1:20,000 map of a city) shows a small area and includes a lot of detail. Remember the saying "the larger the number, the smaller the scale."

Scale can be noted in three ways:                                  Examples:
Representative fraction                                                       1:24,000
Verbal or inch-to-mile scale                                                 One Inch Equals One Mile
Bar scale                                                                             0-----|-----1-----|-----2-----|-----3

For more information see:

Fact Sheet 015-02 (February 2002) from the USGS

Projections

Projection refers to the mathematical method by which the three-dimensional Earth's surface is being portrayed onto a two-dimensional piece of paper (or computer file). There are many variations, but there are three types of projection methods on which all others are based: Conical, Cylindrical, and Azimuthal. Each method distorts the globe differently.

For more information, see:

Geographic Coordinate System (Latitude / Longitude)

The geographic coordinate system uses degrees of latitude and longitude to describe a location on the earth's surface. Latitude, marked on maps by horizontal lines called parallels, is measured in degrees either north or south of the equator. Longitude, marked on maps by vertical lines called meridians, is measured in degrees either east or west of the prime meridian (usually Greenwich, England). Each degree of latitude or longitude is divided into 60 minutes; each minute is divided into 60 seconds. An example of these geographical coordinates is 39°12' 00'' N and 120°42' 00'' W.

The same coordinates can also be given as decimal degrees, for example, 39.2° N and 120.7° W or 39.2° and -120.7° (west and south are shown as negative). In the decimal degree system the degrees are the same, but rather than using minutes and seconds, smaller increments are represented as a percentage of a degree.

To convert coordinates between Degrees, Minutes, Seconds and Decimal Degrees, see:

Universal Transverse Mercator (UTM)

The UTM system divides the earth into 60 north-south zones, excluding the polar regions. UTM zones are numbered 1 through 60, starting at the international date line (longitude 180°) and proceeding east. Each zone covers 6 degrees of longitude and is divided into horizontal bands of 8 degrees of latitude. These bands are lettered, south to north, beginning at 80° S with the letter C and ending with the letter X at 84° N. See Peter H. Dana's UTM Zone Numbers map.

To convert between geographic coordinates and UTM:

Public Land Survey

The Public Land Survey System, also called the Township and Range System or Public Land Rectangular Survey System, was created by the Land Ordinance of 1785 and called for the systematic partitioning of public lands in the United States. The land was divided into townships covering six square miles. Each township was then divided into 36 sections of one square mile. Sections were further divided into quarter sections of 160 acres. These in turn could be divided into quarters again, making lots of 40 acres.

In order for this square grid of townships to extend across the United States, different meridians and baselines were created.

For more information see:

Citing Maps

See the Citing Maps guide from Ohio Wesleyan University.

Circulation Policy

Items in the Map Collection are for library use only and do not normally circulate. Exceptions are made for maps in good condition that are needed for classroom presentations or duplicating (e.g. full-size reproduction, scanning, digitizing, etc). Users must have a valid library card. Ask at the reference desk for more information.

 

Posted: 2011-08-02

Keywords: map basics, how to read maps, scale, projections, latitude, longitude, geographic coordinate system, universal transverse mercator, public land survey


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Printed 2016-05-01
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