# 地形圖

## 地圖規範

• V形規則：如果等高線呈V形，通常該處為河谷，排水溝通過上流的V點處。這種地形由侵蝕造成。
• O形規則：閉合的環形裡面通常是上坡，四周則為下坡，而圓心就是最高的地方。如果環形表示地勢下降，一些地圖會使用從裡向外輻射的短線表示，稱為「陰影線」。
• 等高線間距：等高線靠得較近表示地勢較陡，反之如果距離較遠則是相對較平的地勢。如果有兩條以上等高線合併在一起則表示峭壁

## 國家地形圖系列的發行部門

### 瑞士

(the Federal Office of Topography, Swisstopo)製作七個不同比例尺的瑞士地形圖。

## 地形圖出版商

• 國家地理學會出版的Trails Illustrated系列地圖。最初是一家獨立的公司並在1990年代後期被國家地理學會收購。
• Tom Harrison，一家加利福尼亞州的地圖出版商，多次出版加利福尼亞州的地圖。
• Alpine Mapping Guild出版了大量以登山為主題的地圖，特別是中亞地區山脈和安第斯山脈的地圖。

## 全球的1-公里地形圖

 每一塊圖片的解析度都在1800×1800像素(文件大小約為1MB，60像素=1度，1像素=1分)

## 注釋和參考文獻

1. ^ "A topographic map is a detailed and accurate graphic representation of cultural and natural features on the ground." Centre for Topopgraphic Information - Topographic Maps: Frequently Asked Questions
2. ^ "Traditionally, the main division of maps is into topographic and thematic maps. Topographic maps supply a general image of the earth's surface: roads, rivers, buildings, often the nature of the vegetation, the relief and the names of the various mapped objects." M.-J. Kraak and F. Ormeling, Cartography: Visualization of Spatial Data, Longman, 1996, ISBN 0-582-25953-3, p. 44.
3. ^ The range of information is indicated by the title of a map produced in 1766: A Topographical Map of Hartfordshire from an Actual Survey in which is Express'd all the Roads, Lanes, Churches, Noblemen and Gentlemen's Seats, and every Thing remarkable in the County, by Andrew Dury and John Andrews, reprinted by Hertfordshire Publications in 1980. This showed the relief by using hachures.
4. ^ Library of Congress: Geography and Maps, General Collections
5. ^ Peter Barber, The Map Book, Weidenfeld & Nicolson, 2005, ISBN 0-297-84372-9, pp. 232, 250.
6. ^ Organizing the U.S. Geological Survey. The United States Geological Survey: 1879-1989. U.S. Geological Survey, U.S. Department of the Interior. 2000-04-10 [2007-06-19].
7. ^ The Four Great Surveys of the West. The United States Geological Survey: 1879-1989. U.S. Geological Survey, U.S. Department of the Interior. 2000-04-10 [2007-06-19].
8. ^ Ordnance Survey, Explorer Map Symbols; Swisstopo, Conventional Signs; United States Geological Survey, Topographic Map Symbols.
9. ^