Abstract The goal of this study is to infer the nature of suspended particles from settling, advection, and resuspension processes. Previous studies have not shown that the influence of physical and biogeochemical nature on the behavior of suspended particles. Therefore we expect to observe differential hydrodynamic behavior of suspended particles of different nature in the study. The size distribution of suspended particles is a variable of sediment transport. Size and density, which play a major role in distribution of particles through the water column, are two of primary factors in determining the settling velocity of suspended particles. The sites of the field experiments were located on the Kao-ping Shelf and Kao-ping Submarine Canyon in Southern Taiwan in order to observe resuspension and settling processes. The field experiments were conducted to deploy moored instruments at the two study sites for collecting the time series data. The experiments also included profiling of temporal and special particle and hydrographic parameters along the Kao-ping Submarine Canyon using R/V Ocean Researcher III. In this study we employed a multidisciplinary approach to the study of suspended particles on a plainer inner shelf and sinuous submarine canyon. Base on the observations on the Kao-ping Shelf, the concentration of coarse-grained suspended particles near the bottom was greater than near the surface, and the fine-grained suspended particles was greater near the surface than the bottom. Coarse-grained suspended particles had better correlation with salinity of which nonlithogenic matters were the primary constituents. Fine-grained suspended particles, which consist mainly of lithogenic matters, were affected more by the current. Initial analysis of the data showed that local current speed controlled the distribution of different sizes particles. When strong currents were present, there were more coarse-grained suspended particles. Conversely, there were more fine-grained suspended particles. Regarding the temporal and special observations in the Kao-ping Submarine Canyon, the concentration of suspended particles increased with depth. The compositions of suspended particles measured by LISST-100 and water samples in the submarine canyon showed opposite trends. It revealed that different methods lead to different results. The two sediment trap arrays deployed in submarine canyon were influenced by oscillatory tidal currents. In spring tide there was high concentration of settling particles, which is composed of nonlithogenic materials. Suspended particles in the lower part of the submarine canyon did not all come from the upper part of the canyon but were transported by strong tidal currents to the observed site. The distributions of different sizes particles were the result by different hydrodynamic behavior due to nature of particles. Oscillatory tidal currents could affect the transports of suspended particles from the Kao-ping continental shelf to the Kao-ping Submarine Canyons.

ABSTRACT It is important to improve ambient air quality by reducing the emission from mobile sources. In order to investigate the characteristics of mobile sources, the statistic of traffic flow and the measurement of suspended particles were conducted in the Gonguan air quality monitoring station of Miaoli County in this investigation. Through chemical mass balance (CMB) receptor model and backward trajectory model, the location and contribution of emission sources were further identified. Accordingly, the improvement strategies for mobile sources were further proposed to improve local ambient air quality. In order to know the traffic flow variability of motor vehicles, passenger cars, motorcycle, heavy-duty diesel trucks, and buses were recorded every 15 minutes by a video camera for both weekend and weekdays. In the meantime, TSP and PM10 were simultaneously collected with high-volume samplers. The metallic content and water-soluble ionic species of particulate matter were analyzed with an inductively coupled plasma-atomic emission spectrophotometer (ICP- AES) and an ionic chromatography (IC). Chemical composition of suspended particles was then be used for source apportionment with the CMB model. Finally, the improvement strategies for mobile source management were further proposed through the correlation of traffic flow and vehicle emission rate. The results showed that the PM10/TSP ratios of suspended particles collected at the rooftop of a four-floor building was higher than those sampled at the air quality monitoring station for all quarters except the third quarter. PM>10 is the main factor for the concentration difference of suspended particles sampled on the rooftop of the building as well as at the monitoring station. Results from traffic flow records showed that passenger cars were the major source contributing greatly to the traffic flow, while no significant variation of buses was observed in the traffic flow. The linear regression of PM>10 concentration and vehicles for different wind directions (i.e. northwest, southwest and northeast) was undertaken. The results showed that, when the winds were blown from the northwest and southwest, the determination coefficients (R2) of the regression were 0.1226 (passenger cars), 0.4821 (motorcycles), 0.1014 (heavy-duty trucks), 0.3113 (buses), and 0.1919 (total traffic flow) respectively. It was 0.6140 (passenger cars), 0.6227 (motorcycles), 0.7761 (heavy-duty trucks), 0.2111 (buses), and 0.6309 (total traffic flow), respectively, for the northeast winds. It concluded that the traffic flow has significant influence on the concentration of suspended particle at the downwind sites. Among the vehicles, heavy-duty trucks played a key role. Consequently, reducing truck flow has to be paid more attention for the improvement of ambient air quality. During the sampling period, Ca, Fe, and Al were the most abundant metals of suspended particles, while Mg, K, Zn, and Cu ranked the second. Besides, the metallic contents of suspended particles sampled at the rooftop were generally lower than those collected at the monitoring station. It suggested that street dusts had major contribution to Gonguan air quality monitoring station. Among the water-soluble ionic species, sulfate (SO42-), nitrate (NO3-), and ammonium (NH4+) were major anions, converting mainly from SO2, NOx, and NH3. The results showed that the metallic contents in the second quarter were higher than that in the fourth quarter. However, an opposite trend was observed for anions. The Back Trajectory Model and CMB were applied to analyze the suspended particle. The results showed that the seasonal variation of air pollutants was also affected by the monsoon. Though air pollutants emitted from the nearby waste incinerators and industrial districts could be transported to the sampling site, resulting in unavoidable influence on suspended particles, tail gas and fugitive dusts emitted from vehicles were the most important sources contributed to the ambient air quality. The results indicated that motor vehicles were the major source of ambient suspended particles on the road sites. Therefore, the reduction of traffic emission should be the first step of the improvement strategies for ambient air quality. Especially, the emission of road dusts resulting from the drive-through of heavy-duty trucks should be paid more attention. This study proposed two strategies for improving ambient air quality: one for raising the road serving level and the other for reducing vehicles on road at the traffic crowd section. After the road serving level was improved, the TSP, NOx, CO and THC were respectively decreased about 41, 5,765, 316, and 62 g/day. The concentration of TSP, NOx, CO, and THC was respectively decreased about 95.66 £gg/m3, 38.59 ppb, 1.93 ppm, and 1.90 ppm. After carrying out special vehicle on the road control strategy, TSP, NOx, CO, and THC could be respectively decreased about 2,136, 19,291, 169,843, and 3181g/day. The concentrations of TSP, NOx, CO, and THC were respectively decreased about 96.03 £gg/m3, 52.25 ppb, 2.05ppm and 1.69ppm.. Thus, ambient air quality can be effectively improved if the heavy-duty trucks can be controlled during the rush hour. Furthermore, a substitute road for heavy-duty trucks is another option for the improvement of ambient air quality.

Kaohsiung city for the south Taiwan industry strategic place, the Siaogang area is a heavy industry stands in great numbers the area, the rendering plant, the steel plant, petrifies the factory, the incineration plant, the shipyard, the airport and so on, moreover also has transport means and so on the container truck, carriage vehicle, airplane, The air quality fraction defective occupies crown of the whole city. Kaohsiung important empty unclean control key of suspended particulate pollution, This research is for the purpose of discussing Physicochemical characteristic analysis of air suspended particles in the heavy industry peripheral area, understood in the heavy industry peripheral area air the suspended particles pollutant originates. Physicochemical characteristic analysis discussion atmosphere pollutants to influence Siaogang area. This research in May 2009 period picks each time continual sampling 24 hours to carry on each week twice sampling respectively, the East, West, South and North central area average in the Siaogang area 5 points, altogether gathers 20 samples. Another gathers motorcycle/automobile/diesel car/boiler/voltaic arc boiler/fritting furnace/road dusts different of samples, altogether 14 samples. This research uses air sampling instrument (GAST) carries on the sampling to air of the Siaogang area. Using the scanning type electron microscope (Scanning electron microscope, SEM) and instruments and so on XRD (X-ray Diffractometer, XRD) carry on the metallic element and the physicochemical characteristic analysis. The time can of because of the Siaogang area atmosphere in the suspended particulate matter origin type and the contribution quantity, relevance of in order to help control of air suspended particles in the heavy industry peripheral area pollutant and the source of pollution. This research the main of purpose this study by under construction in the air in the surrounding areas of heavy industry in the pollutants of sampling technology, and discussion of pollutants by the scene size distribution and inorganic salts, and so particulate surface characteristics and analysis for the structure and composition. This research also use a variety of discussion on the valuable instrument analysis to peripheral areas of heavy industry in the pollutants in air of surface and microstructure characteristics, the result of the above analysis, may further in-depth understanding of the heavy industries in peripheral areas of pollutants characteristics, also took granular than in the air pollutants and other kinds of granular pollutant emission sources and physicochemical characteristics of the apparent, discussion of heavy industry in peripheral areas of major sources of granular pollutants for source decrement measures. Future expected completion of roads, schools, residential, farmland, rivers the downwind side of the land of bare ground, farming, construction site River dust, straw, dead wood, rubber, PVC plastic, PE/PP plastics non-heavy industry surrounding area of micro photo, composition and organizational analysis, and than the judgment against a database of all particulate sources.

Measuring the concentration of particles in water is important in many areas. Industries might measure it to run more efficiently while scientists might measure it to study the pollution of a body of water. Regardless of the area, the standard for taking a measurement is done by filtering out the particles by hand. This is a very slow and expensive method, so other alternative methods have been developed. However, all the alternative methods can only estimate the concentration. Therefore, Deepoid AB aims to investigate if ultrasound can be used to measure the concentration of particles in water.\parThis thesis shows that a direct ultrasound signal can be used to measure changes in the concentration of particles in water. It also shows how this method is much faster than measuring the concentration of particles in water by hand.

Os geotêxteis não-tecidos desempenham, dentre outras funções, papel relevante na filtração e drenagem de solos. Nesta função, necessitam ter vazios suficientemente grandes para permitir a livre passagem de água e, ao mesmo tempo, vazios suficientemente pequenos para impedir o arraste de partículas, de sorte a evitar a erosão interna do solo. Critérios de dimensionamento para atender a ambos os requisitos estão disponíveis na literatura e são utilizados com sucesso há vários anos. Uma situação menos estudada e compreendida refere-se ao desempenho desses geotêxteis na filtração de água com sólidos em suspensão. Trata-se de uma situação tida como crítica, pela possibilidade de colmatação do geotêxtil por essas partículas, de acordo com diferentes mecanismos. Neste trabalho, verifica-se o desempenho, em laboratório, de geotêxteis não-tecidos frente à filtração de suspensões de solo em água, tal qual poderia ocorrer por ocasião de enxurradas. Nessa perspectiva, tenta-se verificar qual poderia ser o desempenho desses geotêxteis quando utilizados para compor sistemas de proteção da entrada de estruturas de captação de água, como bocas de lobo e bueiros. O trabalho utiliza um geotêxtil não tecido de fibras curtas, fabricado a partir de poliéster e suspensões contendo bentonita e uma areia fina argilosa, solo típico da região de São Carlos, em diferentes concentrações. Estabelecem-se correlações entre diferentes características e propriedades dos geotêxteis estudados e estuda-se o mecanismo de colmatação, que em geral ocorreu para todos os geotêxteis, em intervalos de tempo associados às características do geotêxtil e à concentração de solo na suspensão. As severas condições de colmatação observadas e o comprometimento da permeabilidade dos geotêxteis sugerem que para as concentrações de solo utilizadas, os geotêxteis não seriam capazes de cumprir com a proteção da entrada de estruturas de drenagem. / Nonwoven geotextiles play an important role in filtration and drainage of soils, among other functions. In these functions, they need to have large enough internal voids to allow free passage of water and at the same time these voids should be small enough to prevent the passing of particles and preventing piping formation or erosion of soil. Design criteria to satisfy both requirements are available in the literature and have been used successfully for many years. A topic that has not been deeply addressed refers to the performance of geotextiles on filtration of water with suspended solids since the possibility of geotextile clogging is real, impairing its behavior. In this work, the performance of nonwoven geotextiles in laboratory tests designed to observe the filtration of water containing solid particles in suspension is addressed. The tests were devised trying to understand what could be the performance of these geotextiles when used to compose inlet protection systems for drainage structures, such as culverts. The study used nonwoven short-fibers geotextile, made of polyester and suspensions containing bentonite and clayey fine sand, a typical soil of São Carlos area, Brazil, in different concentrations. The laboratory test results show that there exist correlations among different characteristics and properties of geotextiles studied and allowed to evaluate the mechanism of clogging, which generally occurred for all geotextiles, in time intervals associated to some characteristics of the geotextile and to the soil concentration in suspension. The severe clogging observed and the reduction of permeability of geotextile suggest that, for the solids concentration used, the geotextiles could not protect the entrance of drainage structures.

Vários métodos de amostragem e análise de partículas em suspensão na atmosfera foram discutidos. Os métodos mais utilizados, gravimétrico e refletância foram testados comparativamente e quanto à correlação entre seus resultados em dois locais distintos. Os fatores intervenientes nos resultados obtidos foram estudados quanto à sua influência. Os métodos gravimétrico e reflectância foram analisados quanto a exatidão dos resultados fornecidos e quanto ao seu significado higiênico em função da correlação existente entre concentração de partículas na atmosfera e danos à saúde. A presente investigação levou o autor a concluir por uma significante diferença entre os resultados fornecidos pelos métodos em estudo, por uma correlação estratificada e variável de local para local entre eles, e por inadequacidade dos valores fornecidos por cada um dos métodos em estudo quanto ao fato de não fornecerem os valores de concentração de partículas na atmosfera mais correlacionados com danos à saúde. O autor sugere o uso ou o desenvolvimento de um método que pelo menos separe as partículas nas frações respirável e não respirável e que permita uma análise posterior de cada uma das frações. Sugere ainda que concomitantemente sejam efetuados estudos epidemiológicos de correlação entre os valores obtidos e danos à saúde para determinação de novos padrões de qualidade do ar para partículas em suspensão na atmosfera. / Various methods to evaluate concentrations of suspended particulate matter were discussed. The two most commonly ueed methods, gravimetric high volume sampler and DECD reflectance method were tested to compare and correlate their results in two different places. The interfering factors were studied to deter mine their influence on the results. The hivol and reflectance methods were analysed according to the accuracy of the results and according to the hygienic significance as they correlate with health effects. This investigation brought the author to the conclusion that there is a significant statistical difference between the results of the two methods. There are correlations between the methods, which are stratified and vary from one place to the other. Finally, however the results are not the best estimate of the concentratios of suspended particulate matter that correlates with health effects. The author suggests the use or the development of a new method that at least can separate the particles sampled into two fractions, one respirable and another non-respirable. Both fractions must be collected in such a way and in such quantities that allow for adequate analysis afterwards. It is suggested also, that epidemiological studies to correlate the results with health effects must be carried on et the same time in arder to set new air quality standards for suspended particute matter.

Vários métodos de amostragem e análise de partículas em suspensão na atmosfera foram discutidos. Os métodos mais utilizados, gravimétrico e refletância foram testados comparativamente e quanto à correlação entre seus resultados em dois locais distintos. Os fatores intervenientes nos resultados obtidos foram estudados quanto à sua influência. Os métodos gravimétrico e reflectância foram analisados quanto a exatidão dos resultados fornecidos e quanto ao seu significado higiênico em função da correlação existente entre concentração de partículas na atmosfera e danos à saúde. A presente investigação levou o autor a concluir por uma significante diferença entre os resultados fornecidos pelos métodos em estudo, por uma correlação estratificada e variável de local para local entre eles, e por inadequacidade dos valores fornecidos por cada um dos métodos em estudo quanto ao fato de não fornecerem os valores de concentração de partículas na atmosfera mais correlacionados com danos à saúde. O autor sugere o uso ou o desenvolvimento de um método que pelo menos separe as partículas nas frações respirável e não respirável e que permita uma análise posterior de cada uma das frações. Sugere ainda que concomitantemente sejam efetuados estudos epidemiológicos de correlação entre os valores obtidos e danos à saúde para determinação de novos padrões de qualidade do ar para partículas em suspensão na atmosfera. / Various methods to evaluate concentrations of suspended particulate matter were discussed. The two most commonly ueed methods, gravimetric high volume sampler and DECD reflectance method were tested to compare and correlate their results in two different places. The interfering factors were studied to deter mine their influence on the results. The hivol and reflectance methods were analysed according to the accuracy of the results and according to the hygienic significance as they correlate with health effects. This investigation brought the author to the conclusion that there is a significant statistical difference between the results of the two methods. There are correlations between the methods, which are stratified and vary from one place to the other. Finally, however the results are not the best estimate of the concentratios of suspended particulate matter that correlates with health effects. The author suggests the use or the development of a new method that at least can separate the particles sampled into two fractions, one respirable and another non-respirable. Both fractions must be collected in such a way and in such quantities that allow for adequate analysis afterwards. It is suggested also, that epidemiological studies to correlate the results with health effects must be carried on et the same time in arder to set new air quality standards for suspended particute matter.

In der vorliegenden Arbeit werden für ein stark anthropogen beeinflusstes Einzugsgebiet die komplexen Zusammenhänge zwischen Witterung, Landnutzung, Erosion, Gerinneabfluss, Stofffrachten und Makrozoobenthos analysiert. Dafür wurde eine Messstation eingerichtet, an der Fließgeschwindigkeit, Trübung, pH Wert und Leitfähigkeit kontinuierlich gemessen wurden. Mit Hilfe eines durchflussgesteuerten Probennehmers wurden Wasserproben entnommen und im Labor auf verschiedene Inhaltsstoffe (Nährstoffe, Schwermetalle) analysiert sowie die Konzentration von Feinsediment bestimmt. Es konnte eine Beziehung zwischen Trübung und Sedimentkonzentration abgeleitet werden. Die chemischen Analysen zeigten einen komplexen Zusammenhang zwischen der Erosion von landwirtschaftlichen Flächen, dem Stoffeintrag von versiegelten Arealen (Verkehrsflächen, Dächer) aber auch witterungs- und vegetationsbedingte saisonale Effekte. Ein Vergleich der Eigenschaften der Schwebstoffe/Feinsediment im Landwasser mit denen von Ackerboden (Maisfelder) zeigte, dass diese die „chemische Handschrift“ der Ackerböden trugen. Mit Hilfe der Modelle EROSION 3D und ICECREAM wurden die abgetragenen Bodenmengen für das Einzugsgebiet bzw. für ausgewählte Hänge quantifiziert. EROSION 3D überschätzt den Bodenaustrag aus dem Untersuchungsgebiet deutlich. Das Modell ist ungeeignet, um für das Einzugsgebiet reale Abtragswerte mit den zur Verfügung stehenden flächenhaften Eingangsdaten zu berechnen. Bereits für Einzelhänge werden zu große Bodenabträge berechnet. Verstärkend kommt hinzu, dass auf Grund der Modellannahme jeder Partikel, der das Gewässer erreicht auch aus dem Einzugsgebiet heraustransportiert wird. Das Modell kann empfohlen werden, um erosionsgefährdete Flächen auszuweisen. In der Untersuchungsperiode von 2009 bis Juli 2011 wurde an Hand von 57 Driftfängen mit unterschiedlichen hydrologischen Randbedingungen die Wirkung der Fließgeschwindigkeit auf den Übergang benthischer Invertebraten in die freie Welle identifiziert. Aus Uferbereichen gelangen zufällig terrestrische Invertebraten in das Gewässer, deren Anteil sich durch gewässernahen Oberflächenabfluss in Folge von Niederschlagsereignissen erhöht. Die Driftdichte nimmt ab Fließgeschwindigkeiten von 0,3 m/s deutlich zu. Oligochaeta, Cyclopoida und Dipolstraca driften verstärkt bei Fließgeschwindigkeiten >0,6 m/s.

To characterize the size distributions, concentrations and sources of heavy metal associated with suspended particles, a total of 12 months of sampling periods were taken by Micro-Orifice Uniform Deposit Impactor (MOUDI) in the Nantzu Export Processing Zone from January to December 2011, The concentrations of suspended particles ranged from 54.7 to 203 £gg/m3. Both autumn and winter had significantly higher levels of suspended particles than in spring and summer. The mass concentrations of fine particles accounted for ~50% of the mass concentrations of suspended particles. The mass concentrations of PM2.5 accounted for 50.2-70% of the mass concentrations of PM10. The mass concentrations of PM1 accounted for 24-38.3% of the mass concentrations of PM10. These results indicated that fine particles dominated in atmospheric particulates in Nanzih Export Processing Zone. In addition, among the PM10, PM2.5 and PM1, significant correlations were found. The crustal elements (Al, Fe, Ca, Mg, K and Na) and sulfate are dominant during the sampling periods, which accounting for ~95% of the total concentrations. The crustal elements were observed mainly in coarse particles, while sulfate was found mainly in fine particles. The concentrations of all crustal elements decreased in summer could be attributed to the meteorological conditions and chemical mechanism. By using the enrichment factor (EF) to distinguish the sources of heavy metals in PM10, PM2.5 and the results showed that EF values of crustal elements in PM10 ranged from 1 to 10, suggesting PM10 might come from the resuspension of soil and road dust. In addition, Pb, Zn, As, Se, Mo, Sb and sulfate were observed at higher EF values in both PM2.5 and PM1, indicating the influence of anthropogenic emissions in fine particles. The results from Pearson¡¦s correlations indicated that PM10 in the Nantzu Processing Zone were mainly from the resuspension of soil and road dust, while fine particles (PM2.5 and PM1) may be from the traffic emissions and petrochemical industry in Nanzih and Renwu.

In recent years, the Asian dust storms occurred frequently. It was estimated that approximately eight hundred million metric tons of Asian dusts transported to the atmosphere yearly. During the dust storm period, Asian dusts not only induce poor air quality, but also reduce atmospheric visibility and influence human health. In order to investigate the physicochemical characteristics and source allocation of Asian dusts, this study collect the Asian dusts in the Pescadores Islands during the years of 2002~2006. In addition, this study collected top soils in three regions of Inner Mongolia and resuspended the soil samples in a resuspension chamber to analyze their chemical composition. Moreover, this study applied enrichment factor analysis (EF) and grey relational analysis to allocate the potential sources of Asian dusts and compare them with the transportation routes obtained from backward trajectory. During Asian dust storm periods, the concentration of atmospheric particulate matter (PM10) in the Pescadores Islands increased significantly, probably is 3~6 times of PM10 during non-dust storm periods. Among them, coarse particles (PM2.5-10) particularly rose from 10~30 £gg/m3 to 80~130 £gg/m3 and the size distribution changed from bi-modal distribution to single modal distribution of coarse particles during Asian dust storm periods. This study further analyzed the chemical composition of Asian dusts, including water-soluble ionic species, carbon contents, and metallic contents. For fine particles (PM2.5), the order of water-soluble ionic species was SO42- > NH4+ > NO3- > Cl- > Ca2+ > Na+ > K+ > Mg2+ > F-. For coarse particles (PM2.5-10), the order of water-soluble ionic species was Cl- > SO42- > NO3- > Na+ > Ca2+ > NH4+ > Mg2+ > K+ > F-. The carbon contents distributes mainly in fine particles. The major contents of both fine and coarse particles were crustal elements (i.e. Al, Fe, Na, Mg, K, Ca, and Sr). In addition to the analysis of physicochemical characteristics of Asian dusts, this study applied HYSPLIT MODEL to figure out their transportation routes by backward trajectory. According to the backward trajectories, this study compartmentalized Asian dusts storm transportation routes into three categories: Eastward Transportation and Retraced (ETR), Southeasterly Transportation and Circumrotated (STC), and Straight Southeasterly Transportation (SST). Analyzing the spatial and temporary background variables to investigate the influence of transportation routes on Asian dusts¡¦ physicochemical characteristic. This study revealed that the physicochemical characteristics were very similar for same category of Asian dust storms, which can be used to allocate the source regions of Asian dust storms. This study resuspended the soil samples collected in Inner Mongolia inside a resuspension chamber and collected the suspended particles (PM2.5, PM2.5-10) for chemical analysis. Chemical analysis results indicated that the fingerprints of chemical composition for different regions were similar but still distinguishable, which can be used to identify the source areas of Asian dusts. This study further compare and correlate the Asian dusts collected at the Pescadores Islands during Asian dust storm periods with the soils collected in Inner Mongolia chemically by enrichment factor and grey relational analysis. This study further compared the source allocation of Asian dust storms obtained from enrichment factor, grey relational analysis, and backward trajectory and found the results of these three methods were quite similar. For enrichment factor analysis, 88% of similarity was obtained by using two separate reference elements (Al and Fe). The similarity of backward trajectory and grey relational analysis reached as high as 83%. Moreover, the backward trajectory and enrichment factor were similar up to 75%, while the grey relational analysis and enrichment factor were similar up to 69%. Overall, two out of three aforementioned methods can effectively allocate the source regions of Asian dusts by 94%, while all three methods can successfully allocate the source regions of Asian dusts by 56%. Comparison of three aforementioned methods showed that they can be applied to allocate the source regions of Asian dusts.