International LCLUC Regional Science Team Meeting in South...
Transcript of International LCLUC Regional Science Team Meeting in South...
Integration of Environmental Changes in the Chindwin River Basin using Remote Sensing
Kay Thwe Hlaing – Associate Professor, Bago UniversityVitor Vieira Vasconcelos ‐ SEI‐Asia
Yangon, 13‐15 January, 2016
International LCLUC Regional Science Team Meeting in South and Southeast Asia
Contents
• Why remote sensing?• Objectives• Methodology• Data used• Results
– Land cover– Deforestation– Mining expansion– Changes in river geomorphology
• Conclusions
Why remote sensing?
• Unclear state of Chindwin Basin– Lack of integrated ground truth, surveys and databases
• Huge basin (114,112 km2)• Available global datasets (with uncertainties)– Land cover– Deforestation
Study Area
Objectives
• Link the past to the present in Chindwin Basin– Study land‐use change– Understand change in river morphology
Deforestation – Chindwin River, Kaw Yar village
Deforestation for banana makes the river banks vulnerable and then causes river bank erosion. Chindwin river, Kaw Yar village, Homalin Township
Methodology
• Validation of global databases for land cover• Analyis of global databases for deforestation• Supervised classification of satellite images
– Maximum likelihood clusters, visual interpretation and ground truth from field work
– Mining areas – 1989 to 2015– Changes in channel morphology (water and sandbanks) – 1973 to 2015
Data used
• Validation of 9 global datasets of land cover– GLCNMO proved the most coherent (500m resolution)
• Deforestation global datasets– Based on landsat images, from 1990‐2013
• Landsat images for mining and changes in river morphology– Limitations:
• Resolution of 30 meters• Better use in dry season (less clouds)
Environmental CharacterizationLoktak Lake valley (India)
Upper Chindwin valleys and mountains
Lower Chindwin Valley
•Results
Needleleaf forest (pine trees)
Broadleaf evegreen forest
Broadleaf deciduous forest
Cropland / Mosaic with Cropland
Forestcovers86%of the basin
Land cover
Deforestation
Global Datasets: GLCF; GSFC. 2014. GLCF Forest Cover Change 1990, 2000, Global Land Cover Facility, University of Maryland. Hansen, M.C., et al. 2013. High‐Resolution Global Maps of 21st‐Century Forest Cover Change. Science 342: 850–53.
2000‐20131990‐2000
Logging or shifting cultivation pattern:Deforestation + Regeneration
Crops advancingover the forest
Deforesting for mining
Regeneration of forests decreased after 2000.
• Hypothesis:
More deforested areas converted to mining and agriculture
no regeneration in these areas
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2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013
Annual Deforestation in Chindwin Basin
Yearly Deforested Area
Area (Km2)
Annual deforestation increased nearly 3 times from 2000 to 2013
Limitation of the study• The datasets monitored deforestation, but not forest degradation (from selective logging)
• Trend for Myanmar:
Thiha (2011) Current Land Use Cover Change: research priorities in Myanmar. NASA LCLUC, GOFC‐GOLD, MAIRS Workshop on Land Cover Land Use Change in South East Asia, October 7‐9, 2011. http://lcluc.umd.edu/Documents/ScienceTeamMtg/2011_11/presentations/Current%20Land%20Use%20Land%20Cover%20Research%20Priorities%20in%20Myanmar_Thiha.pdf
Forest Cover in Myanmar
Source: Forest Resources Assessment (FRA) Forestry Department and FAO
Selective logging for fuelwood or furniture
is degrading the forests
Closed forests turn into open forests.
Mining in Chindwin Basin
Letpadaugn Copper Mine – Monywa. Source: Canadian Friends of Burmahttp://www.irrawaddy.org/burma/massive‐land‐confiscation‐for‐copper‐mine.html
Paluzawa Coal Mine – Kalewa. Source: Energy International. http://www.sngj.cc/en/list/?20_1.html
Jade Mining in Hpakan. Source: http://sciencythoughts.blogspot.com/2015/01/at‐least‐two‐dead‐following‐landslide.html
Gold mining in Homalin.
Copper mining: 22.6 km2
Coalmining: 0.2 km2 Jade Mining: 322.5 km2
Gold Mining (Homalin andHugawng Valley): 322.5 km2
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1989 1996 2002 2007 2011 2015
Evolution of Mining Areas in Chindwin River Basin
Lower Uru (Homalin) Uper Uru (Hpakan) Upper Chindwin (Hugawng Valley)
Area (Km2)
Remote Sensing Study of Mining Expansion in Chindwin Basin
Hpakan Homalin Hugawng
Mining contributed with 9% of conversion from forests to open
land during 2002‐2011, in Chindwin Basin
Changes in the River Course of Chindwin and Ayeyawady
• Study changes in the Chindwin and Ayeyarwady river channel, to understand processes of:– River bank erosion– Sedimentation
Ayeyarwady Bank Erosion. Photo: Sei Tun / UNESCAP (2013)http://www.irrawaddy.org/wp‐content/uploads/2013/09/8.‐Pic‐Irrawaddy‐river‐erosion1.jpg
Bank erosion in Chindwin River
River Valley
oBank erosion• loss of land, houses, infrastructure
o Inundated agricultural land during flood
• It is possible to detect the river valley were the meanders keep changing along the years.
• Villages, agricultural land and structures in these valleys face more risk of:
ValeyValley
Bluff(outer bank)
Natural Levee(inner bank)
Source: Wilkerson, C. Landscapes and Physical Geography of Victoria Falls, Zimbabwe. Final Assessment. Available at: http://chantellewilkerson1202.blogspot.com/2012/04/final‐assessment‐and‐fluvial‐landscape.html
Dec 1973
Bluff on the border of the river valley
Feb 1989
Erosion areas from 1973 to 1989
Jan 20011973
1989
Deposited areas
Eroded areas
2014
Erosion(2001 to 2014)
Erosion(2001 to 2014)
Monywa
Pakokku Myingyan
Changes in River Channel from 1973 to
2015
• It is better to build infrastructure on river borders (bridges, pumping, etc.) on stretches of the river that have been stable over the decades
• In the red areas of the map, the river keeps “dancing” (changing its course) along the years
• If you build a village or a infrastructure there, the river may come back again and destroy it
Impact and risk of bank erosionVillages in the confluence of Chindwin and Ayeyarwady
Conclusions• From 1990 to 2013, deforestation did not change significantly the
total land cover of the basin– Approximately 3% of forest loss from 1990 to 2013– However, deforestation on the river banks increases vulnerability to bank
erosion
• Deforestation rate is accelerating and forest regeneration is decreasing in the basin
• Gold and jade mining expansion is accelerating in Chindwin Basin –potential impacts on water quality and sedimentation processes
• Deforesting the river banks is probably increasing the speed and the spatial extension of river bank erosion
• River bank erosion increases, the sedimentation process on the river bed, bringing prejudice for the fluvial transportation system that is very important for Myanmar
Recommendations
• A geomorphological and remote sensing zoning of bank erosion risk would be helpful to advise government and people on:– Avoiding new houses and other infrastructures such as bridges and pumping stations in areas of higher risk
– Protecting villages in higher danger– Conserving or regenerating forests on river banks with higher risk of erosion
• Comparison of river channel changes with– Hydrological data– Hydraulic model (Hec‐Ras)
• Forecast areas with higher risk of bank erosion– Cellular Automata model
• Flood maps based on satellite image– Correlate with hydrological data to create flood frequency map
• Map turbidity along rivers in the basin– Correlate water quality data with river color in satellite images
Recommendations for further remote sensing studies