Home

Physical Geography
  Tectonics and Geology
  Climatic Change
  Climate at Present and in the Past
  Soils
  Rivers, Lakes, Seas and Wetlands
  Permafrost
  Biodiversity

Biomes & Regions
  Arctic Environments
  Boreal Forests
  Mixed and Deciduous Forests
  Steppe and Forest-steppe
  Arid Environments
  The Mountains of Northern Russia
  The Mountains of Southern Siberia
  The Caucasus
  The Mountains of Central Asia
  Lake Baikal
  The Far East

Environmental Problems
  Radioactive Contamination
  Oil and Gas Development
  Air Pollution
  The Aral Sea Problems
  Deforestation and Degradation of Forests
  Nature Protection and Conservation

Images of Russian Nature
  Geographic Index
  Systematic Index
  Alphabetical Index

Nature Reserves
  Northern Russia
  Central Russia
  Povolzhye (Volga river basin)
  Southern Russia
  Ural Mountains
  Western Siberia
  Eastern Siberia
  Far East


Ôîòîãðàôèè ïðèðîäû Ðîññèè
  Ãåîãðàôè÷åñêèé êàòàëîã
  Ñèñòåìàòè÷åñêèé êàòàëîã
  Àëôàâèòíûé êàòàëîã


Nature Landscapes of the World
  Europe
  Asia
  North America
  South America
  Africa
  Australia
  Antarctic

Field Ecology Education
  Instructive Videos
  Instructive Manuals


Ýêîëîãè÷åñêèé Öåíòð Ýêîñèñòåìà íà Facebook Ýêîëîãè÷åñêèé Öåíòð Ýêîñèñòåìà ÂÊîíòàêòå

Þòóá êàíàë Ýêîñèñòåìà YouTube EcosystemaRu

Ñêà÷àòü íàøè ïðèëîæåíèÿ èç ìàãàçèíà RuStore
Ñêà÷àòü íàøè ïðèëîæåíèÿ èç ìàãàçèíà RuMarket Ñêà÷àòü ïðèëîæåíèÿ Ýêîñèñòåìû èç ìàãàçèíà NashStore
Ñêà÷àòü ïðèëîæåíèÿ Ýêîñèñòåìû èç ìàãàçèíà GetApps Xiaomi
Ñêà÷àòü ïðèëîæåíèÿ Ýêîñèñòåìû ÝêîÃèä èç ìàãàçèíà Google Play / Play Market
Ñêà÷àòü ïðèëîæåíèÿ Ýêîñèñòåìû ÝêîÃèä èç AppStore / iTunes
Âèäåî-360 ïî ýêîëîãèè íà íàøåì Youtube êàíàëå

Bird Decoys for European Birds: Songs, Calls, Sounds, Bird voices - application for Android download from Google Play / Play Market for free



Share this page with your friends:



( ) : : = = + +


Russian Nature

Home | Physical Geography | Biomes & Regions | Environmental Problems | Images of Russian Nature | Nature Reserves

Our Field Ecology Center published more than 180 methodical materials for nature studies. Some of them are in English:
Mobile educational application: Ecological Field Studies Techniques on Play.Google Mobile field guide Birds of North America: Songs and Calls Decoys on Play.Google WILD FLOWERS OF RUSSIA Field Identification Guide on Play.Google Mobile field guide Birds of Russia on Play.Google Mobile field guide Birds of Russia Songs, Calls and Voices on Play.Google Mobile field guide Birds of Europe Songs, Calls and Voices on Play.Google Mobile field guide Birds of Europe Songs, Calls and Voices on Play.Google
Mobile Educational Apps and Field Identification Guides for Russian, European and American Birds
Applications for Android and iOS are available at GooglePlay and AppStore


Please put an active hyperlink to our site (www.rusnature.info) when you copy the materials from this page

Environmental problems of Northern Eurasia

The Aral Sea

<<< Environmental Problems in Irrigated Areas | Environmental Problems Index | Conclusions >>>

Overview of Desertification Problems

The catalogue of environmental degradation and other changes in the Aral Sea and its drainage basin has spawned numerous research programmes designed to document the physical changes and identify their causes with a view to devising workable rehabilitation schemes. One such programme, focused on the southern and eastern Aral Sea region (Figure 22.6) and conducted over the period 1991-95, examined degradation of soils, vegetation, and landforms to assess the overall state of desertification in the area (UNEPCOM, 1994; Middleton and Thomas, 1997). The study area of 126 580 km2 was divided into nearly 2000 mapping polygons based on the interpretation of remote sensing images ground-truthed by field studies in key plots. The resulting base map, compiled at a scale of 1:2.5 m, was digitized so that thematic maps could be incorporated into a geographical information system (CIS).

UNEPCOM study area

Fig. 22.6 UNEPCOM study area. After Middleton and Thomas (1997)

Examination of the human-induced causes of desertification in the study area confirmed the development of irrigation systems to be a major initiator of degradation, but three other human activities were also prominent: poorly managed pastoralism, technological developments such as road-building and drilling for water and oil, and the overexploitation of vegetation for domestic use. Using each of these four activities as a starting point, sixteen main chains of causes and consequences of desertification were identified. These causal chains are outlined in Table 22.7 with an indication of their relative importance given by the proportion of the study area where they occur and are dominant. Areas of rising ground water levels which threaten the structural stability of buildings in Nukus, for example, are shown in Figure 22.7.

The 16 main desertification causal chains identified in the UNEPCOM study area

Table 22.7 The 16 main desertification causal chains identified in the UNEPCOM study area

Rising ground water levels mapped in the UNEPCOM study

Fig. 22.7 Rising ground water levels mapped in the UNEPCOM study. After Middleton and Thomas (1997)

Overintensive grazing is reported to be widespread, leading to degradation of vegetation communities, compaction of soils, and accelerated erosion. Localized degradation due to drilling has led to the destruction of vegetation and salinization of soils. The destruction of trees and woody shrubs (Figure 22.8) occurs principally for fuel wood, but clearance for agricultural expansion and destruction by human-induced fires play secondary roles. The loss of woody vegetation cover has resulted in the disappearance of associated grass species and increased soil erosion.

Clearance of trees and shrubs mapped in the UNEPCOM study

Fig. 22.8 Clearance of trees and shrubs mapped in the UNEPCOM study. After Middleton and Thomas (1997)

The overall state of desertification in the UNEPCOM study area, an overview of degradation of soils, geomorphology, and vegetation, is shown in Figure 22.9. As the map indicates, there are no parts of the Aral Sea study area at this scale of analysis where desertification has reached a very extreme state. Small parts of the area (8.2 per cent in total) are in an extreme state, but more than one-third of the territory (36.7 per cent) is in a moderate state of desertification. About half of the whole area is in a slight or very slight state of desertification (26.4 per cent and 23.7 per cent, respectively), while 1.5 per cent of the study area is not currently suffering desertification of soils, geomorphology, or vegetation.

State of desertification in the UNEPCOM study area

Fig. 22.9 State of desertification in the UNEPCOM study area. After Middleton and Thomas (1997)

<<< Environmental Problems in Irrigated Areas | Environmental Problems Index | Conclusions >>>

 

 


Recommend this page to your friends:


* *