Integration of Environmental Changes in the Chindwin River Basin Using Remote Sensing
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International LCLUC Regional Science Team Meeting in South and Southeast Asia Integration of Environmental Changes in the Chindwin River Basin using Remote Sensing Kay Thwe Hlaing – Associate Professor, Bago University Vitor Vieira Vasconcelos ‐ SEI‐Asia Yangon, 13‐15 January, 2016 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 Deforestation for banana makes the river banks vulnerable and then causes Yar village 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) •Results Environmental Characterization Loktak Lake valley (India) Upper Chindwin valleys and mountains Lower Chindwin Valley Land cover Needleleaf forest (pine trees) Forest covers Broadleaf evegreen forest 86% of the basin Broadleaf deciduous forest Cropland / Mosaic with Cropland Deforestation 1990‐2000 2000‐2013 Deforesting for mining Logging or shifting cultivation pattern: Crops advancing Deforestation + over the forest Regeneration 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. Regeneration of forests decreased after 2000. • Hypothesis: More deforested areas converted to mining and agriculture no regeneration in these areas Annual Deforestation in Chindwin Basin Area (Km2) 400 350 300 250 200 150 100 50 0 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 Yearly Deforested Area 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: Forest Cover in Myanmar Selective logging for fuelwood or furniture is degrading the forests Closed forests turn into open forests. Source: Forest Resources Assessment (FRA) Forestry Department and FAO 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 Mining in Chindwin Basin Coalmining: 0.2 km2 Jade Mining: 322.5 km2 Paluzawa Coal Mine – Kalewa. Jade Mining in Hpakan. Source: Source: Energy International http://sciencythoughts.blogspot.com/20 . http://www.sngj.cc/en/list/?20_1.html 15/01/at‐least‐two‐dead‐following‐ landslide.html Gold Mining (Homalin and Copper mining: 22.6 km2 Hugawng Valley): 322.5 km2 Letpadaugn Copper Mine –Monywa. Gold mining in Homalin. Source: Canadian Friends of Burma http://www.irrawaddy.org/burma/massive‐land‐ confiscation‐for‐copper‐mine.html Remote Sensing Study of Mining Expansion in Chindwin Basin Mining contributed with 9% of conversion from forests to open land during 2002‐2011, in Chindwin Basin Area (Km2) Evolution of Mining Areas in Chindwin River Basin 350 300 250 200 150 Hpakan Homalin 100 Hugawng 50 0 1989 1996 2002 2007 2011 2015 Lower Uru (Homalin) Uper Uru (Hpakan) Upper Chindwin (Hugawng Valley) 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) Bank erosion in Chindwin River http://www.irrawaddy.org/wp‐content/uploads/2013/09/8.‐Pic‐ Irrawaddy‐river‐erosion1.jpg River Valley • 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: Valley o Bank erosion Valey • loss of land, houses, Bluff infrastructure (outer bank) o Inundated agricultural land during flood 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 FebJanDec 1989 2001 1973 1973 2014 1989 Deposited areas Bluff on the border of the river valley Erosion (2001 to 2014) Erosion Erosion areas from (2001 to 2014) 1973 to 1989 Eroded areas 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 erosion Villages 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 Recommendations for further remote sensing studies • 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.