Estimating emissions from forest fires in Thailand using MODIS active fire product and country specific data   总被引：1，自引：0，他引：1  

Agapol Junpen  Savitri Garivait  Sebastien Bonnet 《Asia-Pacific Journal of Atmospheric Sciences》2013,49(3):389-400

Studies on air pollution and climate change have shown that forest fires constitute one of the major sources of atmospheric trace gases and particulate matter, especially during the dry season. However, these emissions remain difficult to quantify due to uncertainty on the extent of burned areas and deficient knowledge on the forest fire behaviours in each country. This study aims to estimate emissions from forest fires in Thailand by using the combination of the Moderate Resolution Imaging Spectroradiometer (MODIS) for active fire products and country-specific data based on prescribed burning experiments. The results indicate that 27817 fire hotspots (FHS) associated with forest fires were detected by the MODIS during 2005–2009. These FHS mainly occurred in the northern, western, and upper north-eastern parts of Thailand. Each year, the most significant fires were observed during January–May, with a peak in March. The majority of forest FHS were detected in the afternoon. According to the prescribed burning experiments, the average area of forest burned per fire event was found to fall within the range 1.09 to 12.47 ha, depending upon the terrain slope and weather conditions. The total burned area was computed at 159309 ha corresponding to the surface biomass fuel of 541515 tons dry matter. The forest fire emissions were computed at 855593 tons of CO₂, 56318 tons of CO, 3682 tons of CH₄, 108 tons of N₂O, 4928 tons of PM_2.5, 4603 tons of PM₁₀, 357 tons of BC and 2816 tons of OC.  相似文献   

A geochemistry study of arsenic speciation in overburden from Mae Moh Lignite Mine, Lampang, Thailand     

Kanitta Wongyai  Savitri Garivait  Oliver Donald 《Environmental Earth Sciences》2013,70(5):2047-2053

The aim of this study was to investigate the geochemical characteristics of arsenic in the solid material samples of the Mae Moh Mine and also the Mae Moh power plants fly ash samples were systematically studied. Arsenic concentration in overburden, coal lignite and fly ash are variable (depending on source of solid samples). The results show that the strata of overburden, J seam of coal and fly ash are rich in arsenic and also relatively soluble from fly ash; it occurs as a surface precipitate on the ash particle. The experimental study on speciation in the strata also indicates that the arsenic speciation of Mae Moh solid samples are mainly arsenate, As (V), which are approaching exceed 80%. Arsenic content in the main of overburden is in the range of 14.3–888.8 mg/kg, which is larger than the arsenic background soil values. Solid materials polluted wastewater; the arsenic speciation was present predominantly as arsenate in the surface water of a series of Mae Moh solid materials basins.  相似文献   

Alkalinization and acidification of stream water with changes in atmospheric deposition in a tropical dry evergreen forest of northeastern Thailand          下载免费PDF全文

Hiroyuki Sase  Jesada Luangjame  Hathairatana Garivait  Bopit Kietvuttinon  Thiti Visaratana  Masato Kamisako  Ryo Kobayashi  Seiichi Ohta  Junko Shindo  Kentaro Hayashi  Hideshige Toda  Kazuhide Matsuda 《水文研究》2017,31(4):836-846

Field surveys on atmospheric deposition and stream water chemistry were conducted in an evergreen forest in northeastern Thailand characterized by a tropical savanna climate with distinct dry and wet seasons. Atmospheric deposition of ion constituents by throughfall and stemflow was shown to increase in the beginning and end of the wet season, reflecting the precipitation pattern. The pH and electrical conductivity of stream water increased with alkalinity and base cation concentrations due to mineralization of organic matter by the first rain and retention of anions in soil during the start of the wet season. After initial alkalinization, the pH and alkalinity declined rapidly with the highest SO₄^2? concentration displayed in the middle towards the end of the wet season. The magnitude of peaks in SO₄^2? concentration (13.5–60.6 μmol_c/L) reflects deposition during the first 2 months of the wet season (March and April) in respective years (60.8–170 mol_c/ha). Release of SO₄^2? with H⁺, which is retained in soil during the early wet season, may cause acidification later in the season. The deposition and concentration of SO₄^2? declined over 6 years. However, the pH of stream water declined with increasing concentrations of SO₄^2? and other major ions. The release of materials accumulated in the ecosystem was facilitated by the decrease in SO₄^2? concentration/deposition and increased precipitation in the middle–late wet season. The retention‐release cycle of SO₄^2? largely contributed to both seasonal and interannual variations in stream water chemistry in the tropical savanna climate studied.  相似文献   

Atmospheric Particulate Concentration Measured in an Urban Area Bandung     

P. Lestari  Savitri 《Pure and Applied Geophysics》2003,160(1-2):107-116

— Atmospheric particulate concentration for total suspended particles (TSP) and for PM₁₀ (particulate matter under 10 micron) was measured in Jalan Braga and ITB campus, Bandung. Six samples were collected over one- or two-day time periods using High Volume Sampler (HVS) for TSP and Low Volume Sampler (LVS) or Anderson Cascade Impactor for PM₁₀. Samples were further analyzed to determine concentrations of metals, sulfate and nitrate. Concentration of NO_x (NO and NO₂) was also measured hourly and simultaneously during the sampling period. The results from this study show that the atmospheric particulate concentration in Jalan Braga for TSP ranged from 304.04 to 363.17, and for PM₁₀ concentration ranged from 277.02 to 336.44 μg/m³. The lead concentrations were 1.42–2.37 μg/m³ in the TSP and 0.81–1.57 μg/m³ in the PM₁₀. The nitrate concentrations were 5.89–6.51 μg/m³ and 2.27–3.45 μg/m³ for the TSP and PM₁₀, respectively. The hourly NO_x concentration varied between 0.14–0.35 ppm. The total elements (metals, sulfate and nitrate) found in the samples contribute from 20 to 25% of the total particulate concentration.  相似文献   

Bottom up approach to estimate air pollution of rice residue open burning in Thailand     

Penwadee Cheewaphongphan  Savitri Garivait 《Asia-Pacific Journal of Atmospheric Sciences》2013,49(2):139-149

Rice residue open burning is a farmer activity potentially contributes to global warming. This study was conducted with the objective of examining the spatial and temporal distribution of emissions from rice residue open burning in Thailand by using questionnaire survey and field experimentation. A sample of 1000 Thai farmers was interviewed in order to study the fire behaviours of farmers. One hundred and twenty rice sampling plots were selected for measuring rice residue characteristics. Of the farmer’s fire behaviour, 45% of farmer regularly uses prescribed burning technique for land preparation activities. The amount of rice residue was approximately 117.7 Mt. Although nearly 60% of total residue was subjected to burning in the fields, only 15% of rice residue is actually burned in the fields because the residue and soil have high moisture content. The burning emissions are computed at 1.67 Mt of CO, 0.04 Mt of NO_x, 0.35 Mt of PM_2.5, 0.12 Mt of PM₁₀, and 0.01 Mt of BC. Approximately 30%, 26%, and 17% of all emissions are contributed by the lower-northern, central, and western regions of Thailand, respectively. Moreover, 31% and 30% of all emissions are annually emitted from December to January and April to May over one month periods following each harvesting season. The comparisons of rice residue burning emissions provided by this study and previous studies have found the emissions discovered in this study to range from one to five times higher than the finding of previous studies. This finding demonstrates the importance of the assessment of activity data specific to farming fire characteristics.  相似文献