The continuous rain data from 1961 to 2007 in Heze city was analyzed in this paper.The results showed that continuous rain increased from north to south.Continuous rain processes took place most frequently in summer,n...The continuous rain data from 1961 to 2007 in Heze city was analyzed in this paper.The results showed that continuous rain increased from north to south.Continuous rain processes took place most frequently in summer,next in autumn,and the least in winter.Using wavelet to analyze the sequence of seasonal and annual continuous rain,it had a 5 years cycle oscillation at 2Y(year) level and a 20 years cycle oscillation at 10Y level.An abrupt climate change of continuous rain took place in 1986.Continuous rain was in a more period from 2001 to 2010 and would decrease gradually within the period.展开更多
Based on a comprehensive eco-geochemical survey of Shandong Province, the differences in pesticide residue situation and contents of DDTs and HCHs in the soils of Yantai City and Southwest Shandong Province(abbreviate...Based on a comprehensive eco-geochemical survey of Shandong Province, the differences in pesticide residue situation and contents of DDTs and HCHs in the soils of Yantai City and Southwest Shandong Province(abbreviated as SSP) were studied in this paper. The results showed that the detection rates of DDTs and HCHs in the soil of SSP were apparently higher than Yantai City. However, the mean contents of DDTs and HCHs in the soil of Yantai were 9 and 25 times of SSP, respectively, and higher than the mean contents of many other cities and areas. p,p′-DDE was the main pesticide residual form in the soil of SSP. It is recognized as the degradation product of DDTs in oxidation environment in past, nevertheless, 5.52% of the soils in Yantai City still have a little of DDT input recently, which has posed a big impact on soil environment quality. β-HCH was the main form of the four isomers of HCHs in Yantai City, and α-HCH/γ-HCH in SSP was low. These reveal that the residual time of HCHs in the soils of both the two areas has a long period. After primary analysis, the risk of DDTs and HCHs in the soil of SSP is low, but DDTs in the soil of Yantai City still has a certain risk.展开更多
文摘The continuous rain data from 1961 to 2007 in Heze city was analyzed in this paper.The results showed that continuous rain increased from north to south.Continuous rain processes took place most frequently in summer,next in autumn,and the least in winter.Using wavelet to analyze the sequence of seasonal and annual continuous rain,it had a 5 years cycle oscillation at 2Y(year) level and a 20 years cycle oscillation at 10Y level.An abrupt climate change of continuous rain took place in 1986.Continuous rain was in a more period from 2001 to 2010 and would decrease gradually within the period.
基金Supported by Shandong Province Land and Resources Survey Project(2006709)Ministry and Province Cooperation Project(1212010310306)
文摘Based on a comprehensive eco-geochemical survey of Shandong Province, the differences in pesticide residue situation and contents of DDTs and HCHs in the soils of Yantai City and Southwest Shandong Province(abbreviated as SSP) were studied in this paper. The results showed that the detection rates of DDTs and HCHs in the soil of SSP were apparently higher than Yantai City. However, the mean contents of DDTs and HCHs in the soil of Yantai were 9 and 25 times of SSP, respectively, and higher than the mean contents of many other cities and areas. p,p′-DDE was the main pesticide residual form in the soil of SSP. It is recognized as the degradation product of DDTs in oxidation environment in past, nevertheless, 5.52% of the soils in Yantai City still have a little of DDT input recently, which has posed a big impact on soil environment quality. β-HCH was the main form of the four isomers of HCHs in Yantai City, and α-HCH/γ-HCH in SSP was low. These reveal that the residual time of HCHs in the soils of both the two areas has a long period. After primary analysis, the risk of DDTs and HCHs in the soil of SSP is low, but DDTs in the soil of Yantai City still has a certain risk.
