Environment problem and Soil degradation in Mongolia

O.Batkhishig Institute of GeographyMongolian Academy of Sciences

Introduction• The Mongolia is Central Asian country with extra-continental nature

climate conditions and domination of dry steppe and Gobi-desert nature.

• Over the centuries living people on this land employ by nomadic husbandry. The nature condition of this land was keep pristine feature after long time harmonic relation between human, livestock and nature. These ecosystems have developed under highly variable climates, and are sensitive to grazing management and to changes in rainfall and temperature.

• The pristine grassland ecosystems develop rich fertile soil that have supported nomadic pastoralists for centuries.

Soil degradation and pollution becoming very serious problem in Mongolia, recently.

Up to 60 % of soil cover affected by soil erosion and soil fertility declining.

Soil degradation appears as a major limitation for increased food production.

Last decades Soil pollution in Mongolia increasing, due of gold mining where using mercury and cyanides. Soil pollution impacted on ground and surface water quality.

Result of soil pollution in several places in Mongolia died livestock, and human health problem. Such as Khongor, Boroo, Bayankhongor.

Problem

Causes of Soil degradation

• Climate warming: last 60 years Air temperature increase is 1.9o C,

(world 0.6o C)

3 times faster than world average Precipitation decrease 10 % Permafrost melt accelerating

• Human negative impact Pasture pressure, overgrazing Mining Agriculture soil erosion Road erosion

Permafrost melting

Melted pingos

Soil drying

Wetland decline

Most soil degraded and polluted area

is Central Mongolia, where more human impact

Soil erosion risk map

44,5 % or 700 thousand km2 area occupied by arid land or Gobi desert vulnerable for soil degradation

Pasture pressure, overgrazing impact on soil cover

• Number of livestock in 2007 reached up to 40 million head. Increase 15,7 % or 5,5 mln comparing 2006.

In Mongolian land number of livestock never reached 40 mln.

• Number of Goats increasing due of high price of cashmere. 2007 counts 18 mln or 45.6 % of total livestock.

• Goat is most destructive animal for pasture and soil, eat grass with roots.

• Over 60% of total pastureland is overgrazed. Pasture capacity overloading. But result of surface water shortage many of pastures not used.

A

B

C

0 10 20 km

Turag ---- --Shagnuul --

Noyon -

Sevsuul -

Dalbaa -

Borsog -

B – low grazed

C – non grazed

A - overgrazed

Overgrazing impact on soil

properties in case study of Eastern Hovsgol lake are

Soil temperature and moisture

y = -0.0511x + 13.173y = 0.079x + 9.2521

0

5

10

15

20

25

5 10 20 5 10 20 30 5 10 20 5 10 25 50 5 10 20 40 5 10 20 30 40 5 10 20 30 40 5 10 20 40 5 10 20 40 5 10 20 5 10 20 40 5 10 20 40

SU SL SU SL SU SL SU SL SU SL SU SL

BRG DLB SVL NYN SGL TRG

To C

0

5

10

15

20

25

30

35

40

VW

C %

Moisture VWC % To C Linear (Moisture VWC %) Linear (To C)

Soil humus

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

SU SL R NL SU SL R NL SU SL R NL SU SL R NL SU SL R NL SU SL R NL

Borsog Dalbay Sevsuul Noyon Shagnuul Turag

%

Soil Ammonium and Nitrate

0,0

0,5

1,0

1,5

2,0

2,5

3,0

SU SL R NL

SU SL R NL

SU SL R NL

SU SL R NL

SU SL R NL

SU SL R NL

Borsog Dalbay Sevsuul Noyon Shagnuul Turag

Am

mo

niu

m m

g/1

00g

0,0

2,0

4,0

6,0

8,0

10,0

12,0

Nit

rate

mg

/100

g

Nitrate mg/100g Ammonium mg/100g

Linear (Nitrate mg/100g) Linear (Ammonium mg/100g)

Livestock dung and manure have a direct increasing impact of soil Ammonium Nitrogen content. In the non grazing south slope soils of Dalbay valleys Ammonium content ranges 2,24-2,41 mg/100g, but in the heavy grazing Turag valleys soil Ammonium content ranges up to 3,80 - 4,58 mg/100g or increasing 50-80%.

Soil and pasture degradation accelerating Desertification in Mongolia

DESERTIFICATION

• 90 % of territory affected by desertification by 2006. – Slightly 37,2 % – Strong 34.0 %– Very strong 7.0 %

• last 40 years sand area increased by 3800 km2

This is 8.7 % of all sand area of country – Gobi region 3360 km2 88% – Khangai region 460 km2 12 %

• Between 1990 and 2005 arid area increased 5,4 %.

LAND COVER CHANGE OF MONGOLIA BY NOAA SATELLITE IMAGES

2002 îí

1997 îí1992 îí1992 1997

2006

Water

Coniferous forest

Rocks

Deciduous forest

Glaciers

Grassland steppe

Agricultural field

Dry steppe

Desert

Increasingaridization

Soil wind deflation and dust storms increasing

50 Days in year With dust storms

Agriculture field in Mongolia

Agriculture soil degradation

• Nearly 60% of total arable land or 0,7 million hectare area not more used as a result of degradation.

• It is estimated that over the past 30 years about 35–50 tons of soil have been lost from each hectare of cultivated land due to wind erosion alone.

• 46.5% of arable land was degraded: 12.9% - strong, 28.2% - medium, 58.9 % slightly degraded.

•

Strong, 12.9

Medium, 28.2

Sligthly, 58.9

Arable land degradation of Mongolia, (%)

Soil erodibilityNumber of samples

Average humus content

%

Decrease percentage comparing with non

eroded soils

Non eroded area

388 2.64  

Slight 342 2.50 7.2

Moderate 195 2.08 21.3

Severe 88 1.60 39.4

Changes of soil erosion and humus content

Agriculture soil Erdenesant

Argalant

Pasture and abandoned agriculture field in Argalant soum of Central aimag

Erosion rates

Maximum erosion rates 110.2 t/ha/year

Average erosion 19.29 t/ha/year

Erosion area 59.5 %

Upper and middle slope 8-10o

Sedimentation rates

Maximum sedimentation rates 223.7 t/ha/year

Average sedimentation 25.14 t/ha/year

Erosion area 40.5 %

Lower slope and plain

Agriculture fields of Argalant area

Erosion rates 7.8-11.0 t/ha/year

Average erosion 9.2 t/ha/year

Abandoned year 1990

Plain

Mining soil degradation and pollution

Hongor

Zaamar

Bayankhongor

Uyanga

Baga Gobi

Boroo

Tamsag

Nariin sukhait

Tavan tolgoi

Pollution by mercury and cyanide

Road erosion in arid ares

Ouy tolgoi

Tumurtei

Choir

Mining soil pollution by mercury and Cyanide (2007)

Province (aimag) Places Volume m3 Area hectare

Bayankhongor 13 1189 2,4 well 22

South gobi 5113000 23,6

EastGobi 16

Bulgan 2

Central 2 11610 3,87

Selenge 5 174676,8 22,17

Darkhan-Uul 3 2485 1

Uvurkhangai 420 0,042

Sukhbaatar 128 0,4

TOTAL 203508,8 53,5

Ministry of Nature and Environment of Mongolia, 2008

Road erosion

Gobi (Semidesert) Brown soil

Mining soil erosion

• Since1975 total mining eroded land was 500 mln m3 • 300 mln m3 soil eroded after 1990-s “Gold fever”

Illegal gold diggers in 2007 count 65 000 peolpes. Distributed 16 aimag 80 soum Bayanhongor 24400 Uvurkhangai 15700

84%

16%

Mining soil erosion area

Eroded land 13718.5 ha Reclamation 2553.2 ha

Naturally regenerated soil after 100 years mining erosion

10 cm thick humus layer

Non eroded soil

25 cm thick humus layer

Eroo river basin, North Mongolia

Drying of top part Of Alluvial soils

In 1987 permafrost active layer depth was 1 meter In 2007 no permafrost

Soil propertis change

Alluvial soil covered by sand

Change of soil characteristics of Tuul river valley

Zone

Change value in year 2007 comparing with year 1987

Top soil depth cm.

pH (H2O)

Organic matter %

Exchangable cmol/kg Ca:Mg

Ca2+ Mg2+

Forest-steppe (Terelj) -1,6 0,1 -0,5 -0,4 -3,4 1,5

Steppe (Ovoot) -3,3 -0,2 -0,6 0,0 -1,0 0,3

Salty floodplain (Lun) -0,9 -0,3 -0,3 2,6 -1,5 1,2

Boggy floodplain (Bor bulan)

-1,8 -0,9 -2,5 -13,9 -0,2 -2,2

Average of Tuul river vallye

-1,7 -0,4 -1,2 -4,4 -1,3 -0,1

Zone Change % in year 2007 comparing in year 1987

Forest-steppe (Terelj) -17,9 2,2 -6,3 2,4 -43,9 112,1

Steppe (Ovoot) -16,7 -1,9 -23,1 10,5 -15,3 20,5

Salty floodplain (Lun) -13,3 -4,0 -19,7 9,7 -27,9 93,6

Boggy floodplain (Bor bulan)

-23,3 -11,2 -41,4 -28,1 5,4 -21,3

Average of Tuul river vallye

-18,4 -5,2 -25,8 -6,1 -16,2 41,7

• Last decades Soil degradation in Mongolia increasing result of climate warming and human impact.

• Need to comprehensive methods and approaches against soil erosion and pollution problems.

• This problem threatens not only food production of country also whole economic development.

CONCLUTION

Thank your for attention