What is hydrography?

We explain what hydrography is, its importance in geography and its characteristics. In addition, its relationship with hydrology.

1. What is hydrography?

Hydrography is a branch of geography that is dedicated to the systematic description and study of the bodies of water on the planet , especially inland waters, that is, of the water resources of each specific region. In that sense, it approaches other geographical disciplines such as hydrology, geomorphology , oceanography and climatology .

The disciplinary approach to hydrography comprises two distinct branches:

• Marine hydrography . Specialized in the collection and study of information about the ocean : the ocean floor, the coasts, tides and currents , and especially the way to capture all that information cartographically.
• The hydromorphometric . Dedicated to the study of river basins: their shapes, dimensions, composition, etc.

The term hydrography comes from the sixteenth century, as an attempt to establish an analogy with geography, but applied to the percentage of the world that is underwater ( geo = land / hydro = water). However, throughout history , this discipline demonstrated its usefulness not only theoretical, but applied to the cartographic as well as the economic and military.

For that reason, it is part of the national geographic services of most countries. There is even an international hydrographic information network , carried out by the Hydrographic Organization , founded in 1921 and based in Monaco.

On the other hand, the term hydrography is used to name the whole of the water resources of a given region.

2. Hydrography characteristics

Hydrography:

• He focuses his studies on continental water resources , without excluding everything related to the sea , without going into specialized fields of disciplines such as oceanography.
• It shares its interests with other geographical and cartographic branches , especially as regards the understanding of the natural resources of each region. However, this approach should not be confused with that of hydrology, dedicated to the study and distribution of the waters present in the earth’s crust and atmosphere .
• He is interested in matters such as river basins, river sedimentation or river basins. In short, he is interested in the way in which continental waters flow to the oceans and endorheic lakes.

3. Importance of hydrography

Hydrography is a fundamental science for the use of the water resources of a given geographical region, which together represent a very low percentage of the total water of our planet, so that they must be administered with a scarcity criterion.

On the other hand, hydrographic information is key to the best and most accurate geographic knowledge of regional geography, which in turn brings economic and military advantages over those who ignore the world around them.

4. Uses of the rivers

From the hydrographic point of view, the rivers have the following uses and uses:

• They allow irrigation , a key activity in the development of agriculture , which translates into better and more abundant food generation .
• They allow river navigation , which is a highly practical form of transport in nations devoid of marine coast, or even in those that combine its coasts with rivers of good size that allow the merchandise to reach the interior of the territory.
• They allow the generation of hydroelectric power , by means of the construction of dams or the use of natural jumps to install turbines moved by the water. This type of energy is extremely economical and reliable.
• They are suitable for fish farming and fishing , which are economic activities that also provide food for the population.
• They have recreational uses , such as swimming , water sports and spas, which affects culture and tourism .
• They have mining potential , since rivers often carry valuable minerals that can then be filtered or collected in different ways.
• Provide abundant water for various industries chemical, construction or manufacturing .

5. Hydrography and Hydrology

As we said before, both hydrography and hydrology share certain specific contents, but they do so from perspectives and in very different contexts.

Hydrography focuses on the understanding and registration of the water resources of the continental crust and / or the oceanic crust, from a perspective very close to geography. Instead, hydrology  deals with the distribution and properties of water on the planet , both in soils , oceans, atmosphere and glacier masses.

Thus, the meeting point of both disciplines is the rivers and the seas , but hydrology goes much further, since it aspires to be, basically, the science of water on our planet.

6. Hydrography in Mexico

The Mexican nation has a vast network of waters up to 600 kilometers long, which includes rivers and other surface sources, which cross approximately 60% of the total territory .

To this are added numerous underground deposits (95% of the total Mexican water resources), which provide around 75% of the water for human consumption, since the climatic differences between the different regions of the territory produce marked differences in moisture .

Thus, the north of the country is much more arid, with scarce rainfall and stationary water presence, while in the south the rains are more constant, given its humid tropical climate. This configuration makes access to drinking water one of the main difficulties faced by the Mexican population, especially that residing in remote regions.

On the other hand, Mexico has important coasts both in the Atlantic Ocean (the Gulf of Mexico) and in the Pacific , and an important chain of lakes and lagoons, many of them of volcanic origin. It also has important rivers such as the Bravo, Lerma, Yaqui, Balsas, Mayo, Colorado, Papaloapan, Isthmus, Tonalá, Pánuco and Usumacinta.