Study results in this paper have indicated that the Holocene climate in Xinjiang, Northwestem China has been alternating between wet and dry conditions, and was punctuated with a series of abrupt climate shifts. A sed...Study results in this paper have indicated that the Holocene climate in Xinjiang, Northwestem China has been alternating between wet and dry conditions, and was punctuated with a series of abrupt climate shifts. A sediment core taken from Barkol Lake in the northern Xinjiang of Northwest China was analyzed at 1 cm interval for grain-size distribution. Abrupt climate shifts revealed by the grain-size proxy occurred at ca 1.4, 3.0, 4.3, 5.6, 8.0 cal kyr B.E, which were well correlated to both the abrupt shifts recorded in the North Atlantic Ocean （NAO） and the Holocene sea surface temperature （SST） cooling events in the Arabian Ocean. The correlation indicated that the climatic changes in the extreme arid Northwest China were associated with the NAO, probably via the North Atlantic Oscillation-affected westerly winds. The strength and position of westerly winds probably modulated the Siberian-Mongolian high- pressure system （winter monsoon）, and played an important role in climate change of Northwest China. Moreover, an evident drought interval during the middle Holocene was also revealed by grain-size proxy.展开更多
The relative importance of each pollution factor in analytical hierarchy process (AHP) method comes from pooling expert opinions in general. Because expert opinions are based on information and judgment criteria, dete...The relative importance of each pollution factor in analytical hierarchy process (AHP) method comes from pooling expert opinions in general. Because expert opinions are based on information and judgment criteria, determining their weight may lead to uncertainty.. Therefore, an improved AHP method had been developed. The process of the improved AHP method involved four key procedures. The weights of pollution factors were completely related to the objective monitoring data through the standardization of these procedures. The environmental comprehensive quality of water and sediment of Xuanwu Lake, Nanjing, China had been evaluated. The environmental quality comprehensive indices (EQCI) of the water in 1991-1995 and 1996-2000 were 3.32 and 1.85, respectively, indicating that the water quality improved. The EQCI of the sediment in 1995 and 2000 indicates that the sediment contamination decreased from 1995 to 2000. Such results agreed with the fact that the lake had been under comprehensive control. However, with the classical AHP method, the EQCI of the sediment in the northwestern part of the lake may have indicated that sediment contamination increased from 1995 to 2000. The discrepancy may have resulted from the judgment difference of the experts. The improved AHP method can avoid arbitrariness of subjective judgment and can reflect the real influential factors of environment pollution in different periods or regions.展开更多
The Chinese government started a take restoration project in Poyang Lake region 10 years ago, and the expost mOnitor of the migrants＇ livelihoods was limited, This paper compares the composition difference of domesti...The Chinese government started a take restoration project in Poyang Lake region 10 years ago, and the expost mOnitor of the migrants＇ livelihoods was limited, This paper compares the composition difference of domestic income and domestic consumption between migration and non-migration villages in Poyang Lake region. The results show that the migrants＇ domestic income has increased in the last 10 years, which originated from the tncreasing trend of active and extensive rural labor migration, while the resettlement has not influenced the domestic income significantly. The resettlement stimulates younger farmers to work.far away from home whose wages contribute nearly 80% of domestic income, The resettlement decreases their savings due to higher expenditure of daily life for those who work far away from home, and higher expenditure of food for those who stay at home, losing cultivated lands with irrigation system for vegetable. On the other hand. the increase of rural labor migration leads the migrants who stay at home to have access to more cultivated lands for rice and cotton, and the farmers also apply more fertilizer in the same cultivated land for more agriculture products. The resettlement makes most of migrants spend their savings on the improvement of their housing conditions due to not enough governmental financial support for new building. After the analysis, some factors that influence migrants＇ income and consumption are discussed. The paper may contritbute to the building of Poyang Lake Ecological Economic Zone.展开更多
基金Under the auspices of National Natural Science Foundation of China (No. 49761007)Open Foundation of National Laboratory of Western China’s Environmental Systems,Lanzhou University
文摘Study results in this paper have indicated that the Holocene climate in Xinjiang, Northwestem China has been alternating between wet and dry conditions, and was punctuated with a series of abrupt climate shifts. A sediment core taken from Barkol Lake in the northern Xinjiang of Northwest China was analyzed at 1 cm interval for grain-size distribution. Abrupt climate shifts revealed by the grain-size proxy occurred at ca 1.4, 3.0, 4.3, 5.6, 8.0 cal kyr B.E, which were well correlated to both the abrupt shifts recorded in the North Atlantic Ocean （NAO） and the Holocene sea surface temperature （SST） cooling events in the Arabian Ocean. The correlation indicated that the climatic changes in the extreme arid Northwest China were associated with the NAO, probably via the North Atlantic Oscillation-affected westerly winds. The strength and position of westerly winds probably modulated the Siberian-Mongolian high- pressure system （winter monsoon）, and played an important role in climate change of Northwest China. Moreover, an evident drought interval during the middle Holocene was also revealed by grain-size proxy.
基金National Natural Science Foundation of China, No.40771186.
文摘The relative importance of each pollution factor in analytical hierarchy process (AHP) method comes from pooling expert opinions in general. Because expert opinions are based on information and judgment criteria, determining their weight may lead to uncertainty.. Therefore, an improved AHP method had been developed. The process of the improved AHP method involved four key procedures. The weights of pollution factors were completely related to the objective monitoring data through the standardization of these procedures. The environmental comprehensive quality of water and sediment of Xuanwu Lake, Nanjing, China had been evaluated. The environmental quality comprehensive indices (EQCI) of the water in 1991-1995 and 1996-2000 were 3.32 and 1.85, respectively, indicating that the water quality improved. The EQCI of the sediment in 1995 and 2000 indicates that the sediment contamination decreased from 1995 to 2000. Such results agreed with the fact that the lake had been under comprehensive control. However, with the classical AHP method, the EQCI of the sediment in the northwestern part of the lake may have indicated that sediment contamination increased from 1995 to 2000. The discrepancy may have resulted from the judgment difference of the experts. The improved AHP method can avoid arbitrariness of subjective judgment and can reflect the real influential factors of environment pollution in different periods or regions.
基金supported by the Key Projects in the National Science & Technology Pillar Program during 11th 5-year Plan Period of China (Grant No.2007BAC23B)
文摘The Chinese government started a take restoration project in Poyang Lake region 10 years ago, and the expost mOnitor of the migrants＇ livelihoods was limited, This paper compares the composition difference of domestic income and domestic consumption between migration and non-migration villages in Poyang Lake region. The results show that the migrants＇ domestic income has increased in the last 10 years, which originated from the tncreasing trend of active and extensive rural labor migration, while the resettlement has not influenced the domestic income significantly. The resettlement stimulates younger farmers to work.far away from home whose wages contribute nearly 80% of domestic income, The resettlement decreases their savings due to higher expenditure of daily life for those who work far away from home, and higher expenditure of food for those who stay at home, losing cultivated lands with irrigation system for vegetable. On the other hand. the increase of rural labor migration leads the migrants who stay at home to have access to more cultivated lands for rice and cotton, and the farmers also apply more fertilizer in the same cultivated land for more agriculture products. The resettlement makes most of migrants spend their savings on the improvement of their housing conditions due to not enough governmental financial support for new building. After the analysis, some factors that influence migrants＇ income and consumption are discussed. The paper may contritbute to the building of Poyang Lake Ecological Economic Zone.
