In global change research, changes of soil organic carbon (SOC) reservoirs intropical and subtropical regions are still unknown. The temporal-spatial variability of SOC stockswas determined in a basin of over 579 km^2...In global change research, changes of soil organic carbon (SOC) reservoirs intropical and subtropical regions are still unknown. The temporal-spatial variability of SOC stockswas determined in a basin of over 579 km^2 in subtropical China from 1981to 2002. ArcGIS8.l softwarewas utilized for spatial analysis of semivariance, ordinary kriging (OK), and probability kriging(PK). Grid and hierarchical approaches were employed for the sampling scenario in 2002 with 106Global Position System (GPS) established spots sampled. Bulk topsoil samples (0—30 cm) werecollected at three random sites on each spot. The SOC content for 1981 came from the SOC map of theSecond National Soil Survey. Geostatistical results of the nugget to sill ratio (0.215-0.640)in therehabilitating ecosystem indicated a moderate spatial dependence for SOC on this large scale. Therange of SOC changed from 2.04 km in 1981 to 7.15 km in 2002. The mean topsoil SOC increased by 4.6%from 10.63 g kg^(-1) (1981) to 11.12 g kg^(-1)(2002). However, during this 21-year period 25.2% ofthe total basin area experienced a decrease in SOC. Also, the probability kriging results showedthat the geometric mean probabilities of SOC <= 6.0 g kg^(-1), <= 11.0 g kg^(-1) and > 15.0 gkg^(-1) were 0.188, 0.534 and 0.378, respectively in 2002, comparing to 0.234, 0.416 and 0.234 inthat order in 1981, respectively. The SOC storage in the topsoil increased by 17.0% during this timewith the main increase occurring in forests and cultivated land,which amounted to 82.5% and 17.0%of the total increase, respectively.展开更多
To clarify temporal changes in the transboundary pollution, we analyzed SCPs （spheroidal carbonaceous particles） in bottom sediments of lakes in China, South Korea and Japan. SCPs provide an unambiguous record of an...To clarify temporal changes in the transboundary pollution, we analyzed SCPs （spheroidal carbonaceous particles） in bottom sediments of lakes in China, South Korea and Japan. SCPs provide an unambiguous record of anthropogenic atmospheric pollution in bottom sediments. Recently deposited SCPs in air and unmelted snow on Mt. Fuji were also characterized. The concentrarion and characteristics of SCPs reflected the environmental and industrial history of the area. Evidence of transboundary air pollution was observed after the 1980s in Yashagaike and Kotaniike ponds in Japan, which are located on the coast of the Sea of Japan. The concentration suggests that the pollutants originated from continental Asia, particularly after the 1980s. The chemical composition of the SCPs allowed the source of emissions to be identified. Chinese SCPs were found at Yashagaike and Kotaniike ponds in Japan, and at Songiiho and Urimji lakes in Korea. The size distributions showed that small SCPs are transported over long distances. On the summit of Mr. Fuji, SCPs transported by the prevailing westerlies from China were found in addition to SCPs emitted in Japan.展开更多
Abstract： Wetland plant communities in the plateau lakes of Yunnan Province, China, have decreased significantly over the past decades. To better understand this degradation, we analyzed the processes and characteris...Abstract： Wetland plant communities in the plateau lakes of Yunnan Province, China, have decreased significantly over the past decades. To better understand this degradation, we analyzed the processes and characteristics of changes in wetland plant communities in two of the largest lakes in Yunnan Province, Dianchi and Erhai lakes. We collected records of native and alien plant communities in the two lakes from literature published from the 195os to current period. We calculated plant community types and their area in some historical periods when related data were reported, and analyzed the relationship between chances in nlant communities and water nollution. InDianehi Lake, 12 community types of native plant communities, covering over 80% of the surface in the 195os and 196os, were reduced to four types covering 2.4% by the late 2ooos. Alien plant communities started to appear in the lake in the late 197os, and have since come to cover 4.9% of the lake surface, thereby becoming dominant. In Erhai Lake, 16 community types of native plant communities, covering 47.1% of the lake surface in the late 197os, declined to lo community types, covering 9.3% of the surface, by the late 2ooos. Alien plant communities appeared in the middle 198os, and at present cover 0.7% of the surface area. It was indicated that changes in plant communities were significant related to water eutrophication. The area occupied by native and alien plant communities was, respectively, negatively andpositively related to the content of nutrients in water. This showed lacustrine pollution played an important role in native plant loss and alien plant invasion in the two plateau lakes.展开更多
A field survey was carried out to collect monthly samples from sewage sludge beds. The samples were collected from three sewage treatment plants namely; Jahra, Rekka, and Um Al-Hayman; over 12 months＇ period started ...A field survey was carried out to collect monthly samples from sewage sludge beds. The samples were collected from three sewage treatment plants namely; Jahra, Rekka, and Um Al-Hayman; over 12 months＇ period started from January and ended by December 2002, 2004 and 2006 to assess the temporal changes on the pollutants associated with sewage sludge. The collected samples were analyzed for organic matters, nutrients and heavy metals. It was observed that the quantities of organic matter, organic carbon and nutrients were varied in a wide range of values. The levels of heavy metals were generally below than reported by the Kuwait Environment Public Authority Limits for application of dry sludge. Temporal changes in the levels of heavy metals and other pollutants may be affected by temporal variation in the level of heavy metals, nutrients and organic matters in the influent of wastewater or in the efficiency of the treatment involved.展开更多
The concept, although it is not new, came to surface in the last ten years with significant technological improvement and became a temporary solution for the port cities where the supply of electricity is in need. A s...The concept, although it is not new, came to surface in the last ten years with significant technological improvement and became a temporary solution for the port cities where the supply of electricity is in need. A ship shaped floatable structure with a huge power generator on board becomes the temporary but effective solution. However, these converted ex-ships are still legally ships in order to admit them sufficiently within the scope of a leading convention, which applies to marine and air pollution from ships. This issue needs research on the legal definition of the ＂ship＂ to clarify if it is a ship and to determine whether that would also fall within the concept of MARPOL.展开更多
Vehicle emissions are one of the major sources of urban air pollution and are also called mobile source emissions. A large amount of gross vehicle emissions is generated by vehicles commuting between residential homes...Vehicle emissions are one of the major sources of urban air pollution and are also called mobile source emissions. A large amount of gross vehicle emissions is generated by vehicles commuting between residential homes and the workplace. Homebuyers generally prefer to purchase residential houses that are relatively less expensive, albeit at the cost of relatively longer commuting times. Consumers usually consider additional travel time, fuel consumption, and other personally concerned factors, with less apprehension about the extra air pollution possibly generated. In cities with populations between 15,000 and 1,000,000, an increase of one additional minute of average commuting time is associated with a reduction of 1.9 dollars in housing price per square foot （p-value： 0.038）. To account for the generation of additional air pollution, this paper numerically characterizes factors related to air pollutants caused by additional travel time due to housing prices. Air pollutants such as CO, CO2, NO2, NO, NOx and SO2 as well as fuel consumption were estimated by MOVES （motor vehicle emissions simulator）. The results will be a useful reference to generate recommendations for more efficient reduction of mobile source air pollution in metropolitan areas through joint efforts by government, agencies, the public, and industry from multiple fields including environment protection, land use, housing markets, transportation management, and law enforcement.展开更多
基金Project supported by the National Key Basic Research Support Foundation of China (No. G1999011801) the Knowledge Innovation Program of Chinese Acacemy of Sciences (Nos. KZCX2-413 and ISSASIP0110).
文摘In global change research, changes of soil organic carbon (SOC) reservoirs intropical and subtropical regions are still unknown. The temporal-spatial variability of SOC stockswas determined in a basin of over 579 km^2 in subtropical China from 1981to 2002. ArcGIS8.l softwarewas utilized for spatial analysis of semivariance, ordinary kriging (OK), and probability kriging(PK). Grid and hierarchical approaches were employed for the sampling scenario in 2002 with 106Global Position System (GPS) established spots sampled. Bulk topsoil samples (0—30 cm) werecollected at three random sites on each spot. The SOC content for 1981 came from the SOC map of theSecond National Soil Survey. Geostatistical results of the nugget to sill ratio (0.215-0.640)in therehabilitating ecosystem indicated a moderate spatial dependence for SOC on this large scale. Therange of SOC changed from 2.04 km in 1981 to 7.15 km in 2002. The mean topsoil SOC increased by 4.6%from 10.63 g kg^(-1) (1981) to 11.12 g kg^(-1)(2002). However, during this 21-year period 25.2% ofthe total basin area experienced a decrease in SOC. Also, the probability kriging results showedthat the geometric mean probabilities of SOC <= 6.0 g kg^(-1), <= 11.0 g kg^(-1) and > 15.0 gkg^(-1) were 0.188, 0.534 and 0.378, respectively in 2002, comparing to 0.234, 0.416 and 0.234 inthat order in 1981, respectively. The SOC storage in the topsoil increased by 17.0% during this timewith the main increase occurring in forests and cultivated land,which amounted to 82.5% and 17.0%of the total increase, respectively.
文摘To clarify temporal changes in the transboundary pollution, we analyzed SCPs （spheroidal carbonaceous particles） in bottom sediments of lakes in China, South Korea and Japan. SCPs provide an unambiguous record of anthropogenic atmospheric pollution in bottom sediments. Recently deposited SCPs in air and unmelted snow on Mt. Fuji were also characterized. The concentrarion and characteristics of SCPs reflected the environmental and industrial history of the area. Evidence of transboundary air pollution was observed after the 1980s in Yashagaike and Kotaniike ponds in Japan, which are located on the coast of the Sea of Japan. The concentration suggests that the pollutants originated from continental Asia, particularly after the 1980s. The chemical composition of the SCPs allowed the source of emissions to be identified. Chinese SCPs were found at Yashagaike and Kotaniike ponds in Japan, and at Songiiho and Urimji lakes in Korea. The size distributions showed that small SCPs are transported over long distances. On the summit of Mr. Fuji, SCPs transported by the prevailing westerlies from China were found in addition to SCPs emitted in Japan.
基金funded by the National Natural Science Foundation of China(Grant No.31560092,U0933601)National Scientific and Technological Basic Work of China(No.2012FY110300)+1 种基金Science Fund of China’s Yunnan Government(Grant No.2015BB018,2009CC024)the State Key Laboratory of Phytochemistry and Plant Resources in West China(Grant No.P2015-KF11)
文摘Abstract： Wetland plant communities in the plateau lakes of Yunnan Province, China, have decreased significantly over the past decades. To better understand this degradation, we analyzed the processes and characteristics of changes in wetland plant communities in two of the largest lakes in Yunnan Province, Dianchi and Erhai lakes. We collected records of native and alien plant communities in the two lakes from literature published from the 195os to current period. We calculated plant community types and their area in some historical periods when related data were reported, and analyzed the relationship between chances in nlant communities and water nollution. InDianehi Lake, 12 community types of native plant communities, covering over 80% of the surface in the 195os and 196os, were reduced to four types covering 2.4% by the late 2ooos. Alien plant communities started to appear in the lake in the late 197os, and have since come to cover 4.9% of the lake surface, thereby becoming dominant. In Erhai Lake, 16 community types of native plant communities, covering 47.1% of the lake surface in the late 197os, declined to lo community types, covering 9.3% of the surface, by the late 2ooos. Alien plant communities appeared in the middle 198os, and at present cover 0.7% of the surface area. It was indicated that changes in plant communities were significant related to water eutrophication. The area occupied by native and alien plant communities was, respectively, negatively andpositively related to the content of nutrients in water. This showed lacustrine pollution played an important role in native plant loss and alien plant invasion in the two plateau lakes.
文摘A field survey was carried out to collect monthly samples from sewage sludge beds. The samples were collected from three sewage treatment plants namely; Jahra, Rekka, and Um Al-Hayman; over 12 months＇ period started from January and ended by December 2002, 2004 and 2006 to assess the temporal changes on the pollutants associated with sewage sludge. The collected samples were analyzed for organic matters, nutrients and heavy metals. It was observed that the quantities of organic matter, organic carbon and nutrients were varied in a wide range of values. The levels of heavy metals were generally below than reported by the Kuwait Environment Public Authority Limits for application of dry sludge. Temporal changes in the levels of heavy metals and other pollutants may be affected by temporal variation in the level of heavy metals, nutrients and organic matters in the influent of wastewater or in the efficiency of the treatment involved.
文摘The concept, although it is not new, came to surface in the last ten years with significant technological improvement and became a temporary solution for the port cities where the supply of electricity is in need. A ship shaped floatable structure with a huge power generator on board becomes the temporary but effective solution. However, these converted ex-ships are still legally ships in order to admit them sufficiently within the scope of a leading convention, which applies to marine and air pollution from ships. This issue needs research on the legal definition of the ＂ship＂ to clarify if it is a ship and to determine whether that would also fall within the concept of MARPOL.
基金The authors acknowledge that this research is supported in part by the United States Tier 1 University Transportation Center TranLIVE # DTRT12GUTC17/KLK900-SB-003, and the NSF （National Science Foundation） under grants #1137732 The opinions, findings, and conclusions or recommendations expressed in this material are those of the author（s） and do not necessarily reflect the views of the funding agencies.
文摘Vehicle emissions are one of the major sources of urban air pollution and are also called mobile source emissions. A large amount of gross vehicle emissions is generated by vehicles commuting between residential homes and the workplace. Homebuyers generally prefer to purchase residential houses that are relatively less expensive, albeit at the cost of relatively longer commuting times. Consumers usually consider additional travel time, fuel consumption, and other personally concerned factors, with less apprehension about the extra air pollution possibly generated. In cities with populations between 15,000 and 1,000,000, an increase of one additional minute of average commuting time is associated with a reduction of 1.9 dollars in housing price per square foot （p-value： 0.038）. To account for the generation of additional air pollution, this paper numerically characterizes factors related to air pollutants caused by additional travel time due to housing prices. Air pollutants such as CO, CO2, NO2, NO, NOx and SO2 as well as fuel consumption were estimated by MOVES （motor vehicle emissions simulator）. The results will be a useful reference to generate recommendations for more efficient reduction of mobile source air pollution in metropolitan areas through joint efforts by government, agencies, the public, and industry from multiple fields including environment protection, land use, housing markets, transportation management, and law enforcement.
