Liu X.,CAS Changchun Northeast Institute of Geography and Agroecology |
Dong G.,China Environmental Monitoring Center |
Wang X.,Hella AutomotiveLighting Ltd Company |
Xue Z.,CAS Changchun Northeast Institute of Geography and Agroecology |
And 3 more authors.
Ecological Engineering | Year: 2013
Over the past three decades, the marshlands in Northeast China's Sanjiang Plain have undergone dramatic loss and fragmentation. This study has analyzed the loss area and pattern of these marshlands for the period 1982-2010 using remote sensing data. The marshlands area decreased 786.69×103ha until 2010. The landscape pattern changes of the marshlands and other land use types were analyzed spatiotemporally for the years of 1982, 2000 and 2010. Results showed that during the period from 1982 to 2010, the gravity center of marshlands migrated 0.2170° southward, then again 0.0848° eastward, moving it a total of 25002.59m. Spatial distribution of the marshlands continually migrated southeastward which was influenced by the landscape characteristics, such as the location of the marshlands in the watershed, geomorphology, and anthropogenic/natural causes, such as the intensity of agricultural development, population and climatic change. The southern and northern marshlands loss rates were very different between 1982-2000 and 2000-2010. The reclamation intensity of cultivated regions in central parts inclined to north of the Sanjiang Plain had been strengthened again, and the reclamation ratio changed from less than 0.5 to nearly 0.8 even to 1 when comparing 1982-2000 with 2000-2010. Increasing air temperature would otherwise have enhanced grain yields and stimulated marshlands conversion into croplands. © 2012 Elsevier B.V.
Yi R.,Yangzhou Environmental Monitoring Center |
Wang Y.,Yangzhou Environmental Monitoring Center |
Zhang Y.,China Environmental Monitoring Center |
Shi Y.,China Environmental Monitoring Center |
Li M.,China Environmental Monitoring Center
Huanjing Kexue Xuebao/Acta Scientiae Circumstantiae | Year: 2015
To investigate the pollution characteristics and influence factors of ozone, this article analyzed the data collected at national environmental and meteorological monitoring stations in 25 cities of Yangtze River Delta in 2013. Results showed that: (1) O3 concentrations in 24 cities exceeded the Class II Ambient Air Quality Standard (GB 3095-2012) to different degrees except Huai'an city. The O3 exceedance rate ranged from 1.6% to 15.1% with an average of 5.8%, which was below the rate of Pearl River Delta (8.9%) and Beijing-Tianjin-Hebei region (9.7%). (2) The pollution levels of O3 were the worst from May to August, but the pollution of PM is relatively mild in the same period with an opposite trend in monthly variation. (3) From the spatial distribution, the O3 pollution in Yangtze River Delta showed continuous distribution. Shanghai and the surrounding cities were more polluted. (4) The number of private cars was significantly related to the annual concentration of NO2 and the number of days with O3 nonattainment, and the correlation coefficients were 0.672 and 0.564 respectively. The peak of daily traffic flow was basically corresponded to O3 hourly concentration peak. (5) High temperature and long-time sunshine led to high O3 concentration. With the increasing of relative humidity and wind speed, O3 exceeded rate and average concentration showed a trend of firstly increasing and then decreasing. ©, 2015, Science Press. All right reserved.
Liu X.-H.,Chinese Academy of Sciences |
Dong G.-H.,China Environmental Monitoring Center |
Zhang Y.,East China Normal University |
Lu X.-G.,Chinese Academy of Sciences |
Jiang M.,Chinese Academy of Sciences
Clean - Soil, Air, Water | Year: 2013
Based on the estimation of greenhouse gases (GHG) emissions and carbon sequestration of the total conversion of marshlands (TMC), marshlands conversion to paddy fields (MCPFs) and marshlands conversion to uplands (MCULs), this study revealed the contribution to the global warming mitigation (CGWM) of paddy fields versus uplands converted from marshlands in the Sanjiang Plain (excluding the Muling-Xingkai Plain on south of Wanda Mountain), Heilongjiang Province, northeast China. The results showed that the total area of MCPFs and MCULs was 504.23×103ha between 1982 and 2005. The CGWM per unit area was 45.53t CO2eq/ha for MCPFs and that was 23.95t CO2eq/ha for MCULs, with an obvious 47.40% reduction. The MCPFs and MCULs ecosystems acted as the carbon sink all of the year. As far as CGWM per unit area is concerned, MCPFs mitigated the greenhouse effect which was greater than MCULs. And it was effective that the implementation of the uplands transformed into paddy fields in Northeast China with regard to marshlands protection and croplands (including paddy fields and uplands) reclamation. Here, the contribution to the global warming mitigation (CGWM) changes when paddy fields and uplands were converted from marshlands was evaluated. Additionally, it could demonstrate the change of CGWM per unit area during this conversion. It was effective that the implementation of the uplands transformed into paddy fields in Northeast China with regard to marshlands protection and croplands reclamation. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.