China is a mountainous country,and Southwest mountain areas cover the most mountain areas in China and have the most serious problems.Taking Zhaotong city as the study area,based on 902 rural household questionnaires ...China is a mountainous country,and Southwest mountain areas cover the most mountain areas in China and have the most serious problems.Taking Zhaotong city as the study area,based on 902 rural household questionnaires of 11 villages in 2 counties and Tobit model,this paper analyzes the geographical differences and influencing factors of energy consumption for non-production purposes of rural households living in different terrain conditions.This research finds that:(1) Coal takes up the main part of energy consumption in valley areas and coal consumption is mainly affected by per capita cultivated land area,household income,proportion of rural household energy expenditure in total expenditure,coal price,and family population size.Firewood takes up the main part of energy consumption in high mountain areas and firewood consumption is mainly affected by per capita firewood forest area,distance to purchase coal,household income,electricity price,and coal price.(2) Only when the distance is greater than 20 kilometers,that is the average distance of rural households living in middle mountain areas(1,600m^1,800m) to purchase coal,the transportation condition has a significant impact on coal consumption.(3) In high mountain areas,prices of coal and electricity are the main factors influencing energy consumption choice of rural households.Too high prices of coal and electricity would to some extent lead rural households to choose firewood as the main energy consumption type.Compared to coal,rural households prefer to choose electricity.展开更多
This paper utilizes the Theil and decoupling indices to analyze variation in carbon productivity as well as the factors that influence regional carbon productivity in China and proposes carbon emission reduction count...This paper utilizes the Theil and decoupling indices to analyze variation in carbon productivity as well as the factors that influence regional carbon productivity in China and proposes carbon emission reduction countermeasures. The authors conclude that most provinces exhibit year-on-year rising carbon productivity, a trend which decreases moving from east to western China. When applied to carbon productivity, the Theil index presents distinct regional differences. Moreover, the regional variance in carbon productivity is consistently reduced in eastern China and becomes smaller in central China. The difference, however, grows in western China. Carbon productivity grows with the highest speed in central China and the lowest speed in western China. Overall variation in carbon productivity mainly arises from intra-regional difference, whereas inter-regional difference mainly contributed by eastern China. In recent years; both the decoupling index, a dynamic value equal to the rate of change rate in carbon emissions divided by the rate of change in GDP during a given period of time, and carbon productivity vary in different economic development stages. Even if under the same decoupling state, carbon productivity remains different in three regions, i.e., that of the eastern region is higher than the other two regions .展开更多
Land-use patterns can affect various nutrient cycles in stream ecosystems, but little information is available about the effects of urban development on denitrification processes at the watershed scale. In the present...Land-use patterns can affect various nutrient cycles in stream ecosystems, but little information is available about the effects of urban development on denitrification processes at the watershed scale. In the presented study, we investigated the controlling factors of denitrification rates within the streams of the Han River Basin, Korea, with different land-use patterns, in order to enhance the effectiveness of water resource management strategies. Ten watersheds were classified into three land-use patterns （forest, agriculture and urban） using satellite images and geographic information system techniques, and in-situ denitrification rates were determined using an acetylene blocking method. Additionally, sediment samples were collected from each stream to analyze denitrifier communities and abundance using molecular approaches. In-situ denitrification rates were found to be in the order of agricultural streams （289.6 mg N20-N m-2 d-1） 〉 urban streams （157.0 mg N20-N m-2 d-1） 〉 forested streams （41.9 mg N20-N m-2 d-l）. In contrast, the average quantity of denitrifying genes was the lowest in the urban streams. Genetic diversity of denitrifying genes was not affected by watershed land-use pattern, but exhibited stream-dependent pattern. More significance factors were involved in denitrification in the sites with higher denitrification rates. Multiple linear regression analysis revealed that clay, dissolved organic carbon and water contents were the main factors controlling denitrification rate in the agricultural streams, while dissolved organic carbon was the main controlling factor in the urban streams. In contrast, temperature appeared to be the main controlling factor in the forested streams.展开更多
基金support provided by National Natural Sciences Foundation of China (No. 41271146)National Key Technology R&D Program (No. 2008BAH31B01)
文摘China is a mountainous country,and Southwest mountain areas cover the most mountain areas in China and have the most serious problems.Taking Zhaotong city as the study area,based on 902 rural household questionnaires of 11 villages in 2 counties and Tobit model,this paper analyzes the geographical differences and influencing factors of energy consumption for non-production purposes of rural households living in different terrain conditions.This research finds that:(1) Coal takes up the main part of energy consumption in valley areas and coal consumption is mainly affected by per capita cultivated land area,household income,proportion of rural household energy expenditure in total expenditure,coal price,and family population size.Firewood takes up the main part of energy consumption in high mountain areas and firewood consumption is mainly affected by per capita firewood forest area,distance to purchase coal,household income,electricity price,and coal price.(2) Only when the distance is greater than 20 kilometers,that is the average distance of rural households living in middle mountain areas(1,600m^1,800m) to purchase coal,the transportation condition has a significant impact on coal consumption.(3) In high mountain areas,prices of coal and electricity are the main factors influencing energy consumption choice of rural households.Too high prices of coal and electricity would to some extent lead rural households to choose firewood as the main energy consumption type.Compared to coal,rural households prefer to choose electricity.
文摘This paper utilizes the Theil and decoupling indices to analyze variation in carbon productivity as well as the factors that influence regional carbon productivity in China and proposes carbon emission reduction countermeasures. The authors conclude that most provinces exhibit year-on-year rising carbon productivity, a trend which decreases moving from east to western China. When applied to carbon productivity, the Theil index presents distinct regional differences. Moreover, the regional variance in carbon productivity is consistently reduced in eastern China and becomes smaller in central China. The difference, however, grows in western China. Carbon productivity grows with the highest speed in central China and the lowest speed in western China. Overall variation in carbon productivity mainly arises from intra-regional difference, whereas inter-regional difference mainly contributed by eastern China. In recent years; both the decoupling index, a dynamic value equal to the rate of change rate in carbon emissions divided by the rate of change in GDP during a given period of time, and carbon productivity vary in different economic development stages. Even if under the same decoupling state, carbon productivity remains different in three regions, i.e., that of the eastern region is higher than the other two regions .
基金Supported by the National Research Foundation of Korea(No.2013056833)
文摘Land-use patterns can affect various nutrient cycles in stream ecosystems, but little information is available about the effects of urban development on denitrification processes at the watershed scale. In the presented study, we investigated the controlling factors of denitrification rates within the streams of the Han River Basin, Korea, with different land-use patterns, in order to enhance the effectiveness of water resource management strategies. Ten watersheds were classified into three land-use patterns （forest, agriculture and urban） using satellite images and geographic information system techniques, and in-situ denitrification rates were determined using an acetylene blocking method. Additionally, sediment samples were collected from each stream to analyze denitrifier communities and abundance using molecular approaches. In-situ denitrification rates were found to be in the order of agricultural streams （289.6 mg N20-N m-2 d-1） 〉 urban streams （157.0 mg N20-N m-2 d-1） 〉 forested streams （41.9 mg N20-N m-2 d-l）. In contrast, the average quantity of denitrifying genes was the lowest in the urban streams. Genetic diversity of denitrifying genes was not affected by watershed land-use pattern, but exhibited stream-dependent pattern. More significance factors were involved in denitrification in the sites with higher denitrification rates. Multiple linear regression analysis revealed that clay, dissolved organic carbon and water contents were the main factors controlling denitrification rate in the agricultural streams, while dissolved organic carbon was the main controlling factor in the urban streams. In contrast, temperature appeared to be the main controlling factor in the forested streams.
