How to navigate in deserts

libre17 March 2025 9

The desert surface is a huge sandy or stony expanse. There is no continuous vegetation cover, only individual plants. Orienteering in deserts Boundless monotonous sands in the form of ridges, dunes or dunes stretch before the human eye. When moving in the desert at a distance of ten or even one hundred kilometers it is often impossible to find any noticeable landmarks.

Besides, there are many areas with moving sands, which, moving under the action of wind, fill roads, paths and in a short time completely change the terrain.

All this makes orienteering in deserts very difficult. Cloudy days in the desert area are a rare phenomenon, so you can orientate here by the Sun, Moon and stars.

How to determine the north direction in the desert

During the day, the north-south direction can be determined with the help of a gnomon. To understand the principle of its operation, on a sunny day take a sheet of drawing paper, attach it to a piece of plywood or other material and draw several concentric circles on it with an arbitrary radius. Orienteering with a gnomon In the center of the circles in a plumb position fix a long needle. Then mark the intersection of the shadow of the end of the needle before and after noon with the circles. Connect the points obtained on each circle with straight lines and divide them in half. The straight line ( NS in the figure) drawn through the division points is the north-south direction. With the help of a gnomon you can check the magnitude of deviation of the magnetic arrow from the geographical meridian.

Obelisks (gnomon) are widespread on the territory of Armenia. Here one can often see well-cut basalt or tuff columns several meters high, installed at crossroads, near temples, springs, on squares of ancient villages. All of them are typical gnomons - primitive instruments for measuring time and determining latitude.

One of them was discovered recently at the base of the Echmiadzin Cathedral on the site of a former pagan temple. Now it is installed on a pedestal near the same cathedral.

Orienteering in the flat desert

In flat desert terrain and in semi-desert the north-south line is determined by two directions: sunrise and west of the Sun. To do this on the ground mark a stake point A, after 10 meters during sunrise in the direction of its center mark point C. At sunset, at the same distance in the direction of its center mark point B. Point O marks the middle of the line BC. The north-south line will be the direction AD, passing through the point O.

Having thus determined the sides of the horizon at this point, you can check them by the readings of the bussol (bussol - a device for measuring the angles between the magnetic meridian and the direction to any object (azimuths). Directions to the rising and setting Sun It is faster and easier in the desert to determine the sides of the horizon at night by Polaris. The direction to Polaris coincides with the north-south direction if the line connecting Polaris with the fourth star of the constellation Cassiopeia and with the second from the end star in the "tail" of the constellation Big Dipper, will be approximately perpendicular to the horizon line. When observing in southern latitudes, it should be taken into account that Polaris deviates from the meridian by a maximum of 1°30'.

Traces on rocks

Wind easily destroys soft rocks: limestones, sandstones, woods, etc. Under its influence, parallel furrows separated by sharp ridges often appear in such rocks. For example, on the upper part of the limestone plateau of the Libyan Desert there are many furrows up to 1 m deep stretched in the direction of the constant north wind. The wind also polishes rocks and stones.

The weathered side of the rock is always clearly visible. On the Mangyshlak peninsula (Caspian Sea), which is a semi-desert with poor vegetation, the so-called cellular physical weathering prevails.

The rocks exposed to it resemble bee honeycombs. Caught up by a swift gust of wind, sand grains, being in rotational motion, hit the rocks and bore hollows in soft rocks.

Knowing the wind direction, this and similar cases can also be navigated.

Frozen waves

The sandy surface under the influence of the prevailing wind is like waves frozen in one direction. This feature is used for orienteering in the desert. Sand, driven by the wind, lies on the already settled sand. This is how dunes appear in the desert.

The side of the barchan facing the wind is always flat. The leeward side is steep, almost sheer, even sometimes with a small canopy, which with time falls down or is carried away by the wind and flies down or is carried away by the wind and flies further.

By the barchans the desert traveler can always, determine the direction he needs. Thus, along the Amudarya valley the barchan sands of the Priamudarya barchan strip stretch for tens and hundreds of kilometers. Desert dunes In an open area with sandy soil, the wind forms sand ripples in the form of parallel rolls perpendicular to the wind direction. Often such ripples are formed on the windward compacted slope of barchans. In the desert Good indicators of the sides of the horizon are small sand accumulations formed by the wind near distinguishable obstacles (surface irregularities, boulders, stones, bushes, etc.). On a sandy hillock, for example, a lone bush grows. On one side of it, it is easy to notice a triangular accretion in the form of a sandy spit, stretched out with a sharp edge in the direction of wind movement.

Similarly, one can determine the countries of the world in ridge sands, where rows are usually arranged in the direction of the prevailing wind. It is easier to orientate in the territory of Ustyurt desert with its precipitous chinks and Betpak-Dala, where in the south-east on the horizon one can see elevations adjacent to the spurs of Chiili mountains.

In order not to lose the way when moving on barchan or bumpy sands, one marks in the distance some landmark (at night - a bright star), coinciding with the direction of movement, and continues the way.

Artificial landmarks in the desert

Artificial landmarks, for example mazars - Mohammedan tombs, are of great help in determining the sides of the horizon in the desert. Mazar Usually they are located on elevated places, at crossroads of trails. The mazar walls are oriented by the countries of the world. Other artificial landmarks of the desert are suburgans, obo, oyukas. Suburgans are Buddhist sacred signs.

They indicate the way to the places where religious rites are performed and are often located on roads, which are of general economic importance. Therefore, suburgans are peculiar road beacons. Suburban A new suburgan Obo - sacred signs made of piles of stones, usually located at the crossroads of trails and, as a rule, on elevated places, thanks to which they can be seen from afar.

Oyuks are road signs, mainly to wells, built on elevated places in the form of pyramids of brushwood and saxaul at the forks of trails. In choosing the direction to an oasis or a settlement, animal tracks, remains of equipment of pack animals killed on the caravan routes, and traces from fires serve as wayfinders.

Besides, during the works in the deserts to ensure safety, as well as when searching for lost people or caravan in certain places put small posts with conditional inscriptions, build mounds of quadrangular, round or other shapes.

The easiest way to signal from the top of a barchan or a hillock is to use a predetermined sign - smoke from a smoke bomb or a fire with the addition of a desert plant - saltwort. It is even better to use rockets for light signaling.

Shepherd "navigation"

Shepherds ' beacons - peculiar artificial landmarks - are scattered all over the territory of the Turan plain in the ancient delta of the Syr Darya (the interfluve of the Amu Darya and Syr Darya). From horizon to horizon are yellow mountains of shifting sand. But in the distance something rises on the crest of a dune.

It is a log topped with a bundle of reeds burnt in the sun - a shepherd's beacon. It will lead you to the lake at the bottom of the barchan, overgrown with dense reeds. Sometimes there is no well or borehole in the vicinity of the beacon. The landmark indicates only the direction to the nearest watering place.

Shepherds know their steppe locale well. Having recognized the beacon, they will quickly figure out where to drive the flock. Topographers and surveyors use the name and appearance of beacons to "bind" them, i.e. determine their location relative to known settlements, roads or uzboys (dry beds and river valleys).

The lighthouses are not distinguished by sophistication of architecture. One is made of saxaul, another of clay and reeds, the third - there are such - of animal bones! They are only lighthouses in their essence. After all, in the sands, as in the sea, there are only waves all the way to the horizon, with the only difference that sand waves are frozen.

It is very easy to get lost among such monotony. If a shepherd does not lose his way on the crossing, the flock will arrive at its destination with a gain. If the shepherd has lost his way, the flock may get into the thickets of poisonous itsegen, which is sometimes used to poison domestic animals. An oasis in the desert Navigation, if this word is understood broadly, as it is known, was the privilege of seafarers only. However, were it not the pastoralists, in their long journeys, who first began to think about methods of orienteering? In the difficult struggle for his existence, man mastered the desert.

Adapting to it, comprehending its harsh laws, he invented lighthouses. The most diligent topographers sometimes cannot reflect all those changes that take place in this or that geographical area in such a mobile and timely manner as shepherds do with the help of their beacons.

Therefore, shepherd beacons should not be neglected.