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Land degradation and mitigation in northern China. Evaluated from the biological production

Runnström, Micael LU (2003)
Abstract (Swedish)
Popular Abstract in Swedish

De semi-arida regionerna i norra Kina är drabbade av många faktorer som påverkar miljön negativt, t.ex. ökenspridning, vind erosion, överbetning, uttömmande av naturresurser. Det redan hårda trycket på ekosystemen i dessa regioner har ökat sedan Kina införde marknadsekonomi. Reformerna sedan 1978 har lett till en snabb ökning av antalet betesdjur och en expansion av jordbruk på lätt-eroderade jordar i de torra stäpp-regionerna. För att utvärdera hur ekosystemen i Inre Mongoliet har påverkats sedan reformerna, har denna studie använt biologisk produktion som en indikator. Tidsserier av satellit data används för att analysera vegetationssäsongen, årlig variation och trender. Satellit-bilder med hög... (More)
Popular Abstract in Swedish

De semi-arida regionerna i norra Kina är drabbade av många faktorer som påverkar miljön negativt, t.ex. ökenspridning, vind erosion, överbetning, uttömmande av naturresurser. Det redan hårda trycket på ekosystemen i dessa regioner har ökat sedan Kina införde marknadsekonomi. Reformerna sedan 1978 har lett till en snabb ökning av antalet betesdjur och en expansion av jordbruk på lätt-eroderade jordar i de torra stäpp-regionerna. För att utvärdera hur ekosystemen i Inre Mongoliet har påverkats sedan reformerna, har denna studie använt biologisk produktion som en indikator. Tidsserier av satellit data används för att analysera vegetationssäsongen, årlig variation och trender. Satellit-bilder med hög geometrisk upplösning används för att studera småskaliga förändringar i markanvändning och vegetationstäckningsgrad. En modell, som beräknar biologisk produktion från tillgängligt solljus (Light Use Efficiency), satellit-uppmätt reflektans från NOAA AVHRR sensorn och klimatdata, har kalibrerats till stäpp regionerna i Inre Mongoliet. Härmed produceras månatliga bilder av GPP (Gross Primary Production) över norra Kina mellan 1982 och 1999. Trots en kraftig ökning av antalet betesdjur i området, visar modell-resultatet en generell positiv trend av GPP sedan 1982. Den årliga variationen av GPP är hög och är korrelerad till en motsvarande hög variation i årlig nederbörd. Analys av hög-upplöst satellit data mellan 1987 och 1996, visar att ytan som indikerar förbättrad vegetationtäckning var tio gånger större än den yta som indikerar en försämrad vegetationsäckning. Analysen visar också att jordbruket expanderade kraftigt och ytan ökade fem-faldigt under dessa nio år. Statistik visar samtidigt att det mesta av jordbruket är konstbevattnat idag. Denna studie kan inte konfirmera att ökenspridning sker i denna region eller att ökningen av antalet betesdjur har påverkat den biologiska produktionen negativt. Femtio år av återplantering av vegetation genom t.ex ’the green wall’, lähägn, flygsådd, dyn-stabilisering, är troligtvis en bidragande orsak till den positiva trenden av GPP, vilket kanske balanserar det ökade betestrycket. (Less)
Abstract
Land degradation is commonly perceived to be severe in many parts of semi arid China. The transition towards market economy since the 1978 reforms, have set marginal dry lands under added pressure in the form of increased livestock numbers and expanding cultivation on erosive soils. To evaluate land degradation since the reforms, this study focuses on mapping and analysing the biological production of the Mu Us Shamo on the Ordos Plateau in the Inner Mongolia Autonomous Region (IMAR). Time series of satellite data are examined for analysing the seasonal dynamics of biological production, annual variability and trends. Images with high geometric resolution are used to study the small-scale changes in land use and vegetation cover. A Light... (More)
Land degradation is commonly perceived to be severe in many parts of semi arid China. The transition towards market economy since the 1978 reforms, have set marginal dry lands under added pressure in the form of increased livestock numbers and expanding cultivation on erosive soils. To evaluate land degradation since the reforms, this study focuses on mapping and analysing the biological production of the Mu Us Shamo on the Ordos Plateau in the Inner Mongolia Autonomous Region (IMAR). Time series of satellite data are examined for analysing the seasonal dynamics of biological production, annual variability and trends. Images with high geometric resolution are used to study the small-scale changes in land use and vegetation cover. A Light Use Efficiency (LUE) model is further adapted to the steppe regions of the IMAR. The model is driven by NOAA AVHRR and climate data, producing monthly estimates of Gross Primary Production (GPP) from 1982 through 1999. Although there have been rapid increases in livestock numbers, the trend of GPP since 1982 is generally positive. The annual variability of GPP is high resulting from the erratic monsoon climate. In Wushen Banner, a central county in the Mu Us Shamo, the area indicating improved vegetation cover between 1987 and 1996 is nearly ten times that of declining vegetation cover. The area of cultivation expanded almost five-fold, to about 2% of the county area, of which, nearly all is irrigated. No abandoned farmland could be detected, indicating short-perspective strategies from intensive farmland reclamation. Severe degradation causing declining biomass production rates and expansion of the desert area cannot be drawn from this investigation. Re-vegetation activities to mitigate land degradation such as the Green Wall, farmland lee-shelters, aerial seeding etc., are likely to be contributing to the increase in biological production in this region, and may act as a balance to the increased utilization of these pastures. (Less)
Please use this url to cite or link to this publication:
author
supervisor
opponent
  • Dr Zhou, Qiming, Hong Kong Baptist University
organization
publishing date
type
Thesis
publication status
published
subject
keywords
marklära, geomorfologi, Fysisk geografi, climatology, kartografi, klimatologi, cartography, pedology, desertification, China, GPP, Mu Us, LUE-model, overgrazing, Physical geography, geomorphology
pages
126 pages
publisher
UB LUND; Micael Runnström, Sölvegatan 12, LUND;,
defense location
F209 Sölvegatan 12, LUND
defense date
2003-10-10 10:15
external identifiers
  • scopus:53849112625
ISSN
0346-6787
ISBN
91-973857-6-X
language
English
LU publication?
yes
id
8423cb27-0bf8-49bd-8931-15df10ecedbf (old id 466196)
date added to LUP
2007-09-06 15:09:23
date last changed
2018-05-29 10:42:32
@phdthesis{8423cb27-0bf8-49bd-8931-15df10ecedbf,
  abstract     = {Land degradation is commonly perceived to be severe in many parts of semi arid China. The transition towards market economy since the 1978 reforms, have set marginal dry lands under added pressure in the form of increased livestock numbers and expanding cultivation on erosive soils. To evaluate land degradation since the reforms, this study focuses on mapping and analysing the biological production of the Mu Us Shamo on the Ordos Plateau in the Inner Mongolia Autonomous Region (IMAR). Time series of satellite data are examined for analysing the seasonal dynamics of biological production, annual variability and trends. Images with high geometric resolution are used to study the small-scale changes in land use and vegetation cover. A Light Use Efficiency (LUE) model is further adapted to the steppe regions of the IMAR. The model is driven by NOAA AVHRR and climate data, producing monthly estimates of Gross Primary Production (GPP) from 1982 through 1999. Although there have been rapid increases in livestock numbers, the trend of GPP since 1982 is generally positive. The annual variability of GPP is high resulting from the erratic monsoon climate. In Wushen Banner, a central county in the Mu Us Shamo, the area indicating improved vegetation cover between 1987 and 1996 is nearly ten times that of declining vegetation cover. The area of cultivation expanded almost five-fold, to about 2% of the county area, of which, nearly all is irrigated. No abandoned farmland could be detected, indicating short-perspective strategies from intensive farmland reclamation. Severe degradation causing declining biomass production rates and expansion of the desert area cannot be drawn from this investigation. Re-vegetation activities to mitigate land degradation such as the Green Wall, farmland lee-shelters, aerial seeding etc., are likely to be contributing to the increase in biological production in this region, and may act as a balance to the increased utilization of these pastures.},
  author       = {Runnström, Micael},
  isbn         = {91-973857-6-X},
  issn         = {0346-6787},
  keyword      = {marklära,geomorfologi,Fysisk geografi,climatology,kartografi,klimatologi,cartography,pedology,desertification,China,GPP,Mu Us,LUE-model,overgrazing,Physical geography,geomorphology},
  language     = {eng},
  pages        = {126},
  publisher    = {UB LUND; Micael Runnström, Sölvegatan 12, LUND;,},
  school       = {Lund University},
  title        = {Land degradation and mitigation in northern China. Evaluated from the biological production},
  year         = {2003},
}