The first application desert in China | Badain Jaran Desert

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Badain Jaran Desert

Map of the location of Badain Jaran Desert

Badain Jaran Desert (BadainJaran Desert), located in the north of Alashan right Banner of Alashan League in Inner Mongolia Autonomous region, west of Yabre Mountain, north of Beidashan Mountain, east of weak water and south of Guizi Lake, covers an area of 44300 square kilometers, which is the second largest desert in China.

Among them, there are more than 10,000 square kilometers of desert in the northwest with no human footprint so far. We know that deserts are often called forbidden areas for life because of lack of water, but the extremely arid Badain Jaran Desert has the spectacle of coexistence of sand mountains and lakes, which puzzles people all over the world. The tall sand mountains and various desert lakes are also the two bright spots of this application.

"Thousand Lakes in the Desert"

NASA satellite image of Badain Jaran Desert (lake in blue)

Aerial photos show that there are 144 inland lakes in the Badain Jaran Desert, of which 113 have been named, 12 of which are freshwater lakes, hence the name "Desert Thousand Lakes". There are thousands of eye springs in the Badain Jaran Desert, among which the spring of Yinde Ritu Lake is the most famous. The island in the middle of the lake, which is less than 3 square meters, can gush 108 springs.

The location of the lake for depth measurement

By using the combination of ultrasonic sounder and RTK-GPS measurement system, scholars have measured the depth of 10 lakes with large area in Badain Jaran Desert, and obtained complete lake morphology data. These lakes have the characteristics of shallow horizontal bottom lakes unique to lakes in arid areas.

According to the calculation, the total area of all the lakes here is up to 23km2, which is distributed in the low-lying land between the hills.

The ecological environment next to the lake is suitable for many animals and plants.

Plants such as Reed, willow and seabuckthorn grow thickly around the lake, and plants such as sand bamboo, Allium mongolicum, Artemisia annua, Achnatherum splendens, Nitraria, Calligonum and Haloxylon ammodendron are often grown in the sandy land along the lake.

The existence of lakes also provides a habitat for many animals, so the Badain Jaran Desert, where waterbirds play and fish fly, also enjoys the reputation of "desert north and south of the Yangtze River".

Fuchsia lakes in the desert

So the number of lakes in the Badain Jaran Desert is not the largest. However, the Tengger Desert Lake does not have the geomorphological landscape features of the staggered development of the tall and magnificent sand dunes and lakes in the Badain Jaran Desert.

The lakes in the Badain Jaran Desert are not always clear and blue, and some lakes show beautiful colors such as red and purple, which is very amazing.

Lake genesis

Since 1980s, many scholars at home and abroad have carried out extensive research on the formation mechanism of lakes and groundwater in Badain Jaran Desert, and mainly formed the following four theories:

The hinterland between the high sand mountains seems to be the main reservoir of precipitation.

The first is the cause of modern atmospheric precipitation recharge in the hinterland of the desert:

It is considered that the lake in Badain Jaran Desert is formed by the replenishment of atmospheric precipitation, and the precipitation is controlled by the topographical characteristics of the high sand mountain, which seeps along the sand layer and seeps out in the intermound depression to form a lake. The high sand mountain is the main reservoir of water. The water level of the lake fluctuates due to the changes of climate and precipitation.

A shrinking lake

The second is the replenishment of local precipitation and the cause of the shrinkage of large lakes during the humid period.

In the desert lake distribution area at the end of the Pleistocene, there may have been a unified large lake with an area larger than 4000km2, but since the late Holocene, the climate has gradually developed to drought. Many existing lakes are the result of the continuous decline of the lake surface and the gradual shrinkage of the water body under the influence of the arid environment, and the lake area will continue to decrease or even disappear completely in the future.

A lake accompanied by sand mountains

Then there is the cause of the mixture of near-source ancient water and modern water:

This theory holds that the precipitation (i.e. ancient water) formed in the late Pleistocene glacial environment of Beidashan Mountain in the south of the lake area and the Yabley Mountain in the southeast is the main part of recharge of groundwater in desert area. modern atmospheric precipitation and flood infiltration also recharge some shallow groundwater and mix with ancient water. Groundwater is discharged in low-lying places between sand dunes to form desert lakes.

The temple beside the lake

The last possibility is the cause of remote modern water supply:

According to the mode of water transportation, it can be divided into three types:

The main results are as follows: (1) according to the theory of water diversion and recharge of deep faults, it is considered that the modern precipitation, meltwater of ice and snow or leakage of large lakes in the Qinghai-Tibet Plateau or Qilian Mountains run along the NE-trending deep fault zone to the lake area in the southeast of the desert, and the age of groundwater is relatively young. Between 30 and 50 years.

(2) the precipitation in the Badain Jaran Desert is not enough to maintain the evaporation in the lake area, while the Heihe River leaks in the Jinta-Dingxin basin and may be recharged along the deep Altun fault to the lake area in the southeast of the desert from west to east.

(3) the lake area in the southeast of the desert can maintain water balance, on the one hand, it is recharged by groundwater from the alluvial fan aquifer in the front of the Qilian Mountains, on the other hand, due to the tectonic uplift in the northwest of the desert, the underground ancient water collects from the northwest to the southeast of the desert.

"Desert Everest" and "Mingsha Kingdom"

Bilutu, Peak

In addition to having a large number and variety of lakes, sandy mountains in the desert are also unique. The Badain Jaran Desert, which is located in the center of Alashan Desert, is between 1200 and 1700m above sea level, of which the relative height of Sandy Mountain can reach more than 500m, of which Bilutu Peak is 1617 meters above sea level and its vertical height is about 435m, which can be called Mount Everest in the desert.

Mingsha Mountain in Baori Tolgoi

Baori Tolgoi's Mingsha Mountain is more than 200 meters high, with steep peaks, sand ridges such as blades, scattered high and low, and the roar of falling sand resounding for several kilometers. It is known as "the Sand Kingdom of the World".

Sandy mountain genesis

Schematic diagram of sand dune morphology

Researchers at home and abroad have different views on the reasons for the formation of sand mountains in the Badain Jaran Desert.

Some scholars believe that the southeast of Badain Jaran is blocked by the Yabre Mountains, resulting in the disturbance of gravity waves perpendicular to the Yabre Mountains, and the perennial southwest wind blows in this area, the sand grains accumulate in front of the mountain, and the updraft in the gravity waves brings the sand to higher places, which over time accumulates into tall sand mountains.

Some scholars believe that the area of Badain Jaran is originally a hilly landform. After desertification, sand grains are directly covered on the hills to form tall sand mountains.

Process diagram of water content and temperature varying with depth in sand l