碳普惠制是一种以城市居民为主体的温室气体自愿减排机制。将乘坐地铁出行作为低碳行为纳入碳普惠制,是建设全民参与型低碳社会的重要探索。本文提出了替代法和均值法两种市民乘坐地铁出行减碳量的核算方法,并以广州市为例,计算了2015...碳普惠制是一种以城市居民为主体的温室气体自愿减排机制。将乘坐地铁出行作为低碳行为纳入碳普惠制,是建设全民参与型低碳社会的重要探索。本文提出了替代法和均值法两种市民乘坐地铁出行减碳量的核算方法,并以广州市为例,计算了2015年广州市民乘坐地铁出行的减碳量。结果显示:替代法下广州市民乘坐地铁出行的减碳量约为0.5419 kg CO_2/人次,均值法下约为0.5155 kg CO_2/人次,如果按2015年广州市地铁系统的客运量计算,替代法和均值法下全市地铁系统的年减碳量分别约为130万t CO_2和124万t CO_2。其中,替代法主要参考已有的CCER方法学设计,具有一定的理论基础,但其替代出行模式的确定受被调查对象的主观影响较大,而均值法以城市现有的机动化出行模式为基准线,较少受到人为因素的干扰,均值法被认为更适合于计算碳普惠制下市民乘坐地铁出行的碳减排量。展开更多
作为现行碳排放权交易机制的延伸和有效补充,碳普惠制着眼于社会公众低碳行为减碳量的核算和交易。将公交车出行作为低碳行为纳入碳普惠制,是促进全民参与低碳社会建设的重要探索。文章借鉴CCER方法学并综合考虑交通数据的可获得性,提...作为现行碳排放权交易机制的延伸和有效补充,碳普惠制着眼于社会公众低碳行为减碳量的核算和交易。将公交车出行作为低碳行为纳入碳普惠制,是促进全民参与低碳社会建设的重要探索。文章借鉴CCER方法学并综合考虑交通数据的可获得性,提出了替代法和均值法两种居民公交车出行减碳量的核算方法,并以广州市为例,计算了2015年广州居民公交车出行的减碳量。结果显示,替代法核算广州居民公交车出行的减碳量为0.287 8 kg CO2/人次,均值法减碳量为0.351 4 kg CO2/人次,如果按2015年广州市公交车系统的客运量计算,替代法和均值法核算全市公交车系统的年减碳量分别约为750 000 t CO2和920000 t CO2。其中,替代法所需的替代出行模式受被调查对象的主观影响较大,而均值法以城市现有的机动化出行为基准线排放,受主观因素干扰较小,更适合核算居民公交车出行的碳减排量。展开更多
Intensive grazing in spring-summer has been responsible for environmental degradation of the Gurbantunggut Desert in recent years. The coverage of plants and biological crusts, sand surface stability and physicochemic...Intensive grazing in spring-summer has been responsible for environmental degradation of the Gurbantunggut Desert in recent years. The coverage of plants and biological crusts, sand surface stability and physicochemical characteristics of soil on the dune surface were conducted in 2002 （winter grazing） and 2005 （spring-summer grazing）. The results showed that over 80% of the total area of the dune surface was covered by well-developed biological crusts and plants in 2002, when the interdune and middle to lower part of dune slopes were stabilized and only the crest had 10-40 m wide mobile belt. Affected by spring-summer grazing in 2005, over 80% of the total cover of biological crust was destructed and the plant coverage only reached 1/5 of that in 2002, especially the ephemeral plant cover had a great change. The value of sand transport potential in 2005 only reached 1/3 of that in 2002, but the total surface activity in 2005 was 1.6 times stronger than that in 2002. Meanwhile the mobile area began to expand from the dune top to the whole dune surface following spring-summer grazing. Compared with 2002, medium sand content of the dune surface soil increased by 13.9%, while that of fine and very fine sands decreased by 7.4% and 8.0% respectively in 2005 and the soil organic matter in 2005 was only about 1/2 of that in 2002. It is obvious that the presence of snow cover and frozen soil in winter could avoid the surface structure destruction in winter, while spring-summer grazing made excessive damage to biologic crusts and ephemeral plants. Spring is the main windy season in Gurbantunggut Desert and therefore intensive activity of dune surface occurred following spring-summer grazing, which led to a great loss of fine sand and organic matter. It can be seen that grazing season have a significant influence on the sustainable development of the desert ecosystem in Northwest China.展开更多
文摘土壤重金属污染高光谱反演的特征波段提取方法和反演模型的选择是影响反演精度的关键;二者如何优化组合,提高反演精度是目前亟需解决的难题。在华南典型铬(Cr)污染区,采集了92组土壤样品,使用电感耦合等离子体质谱(inductively coupled plasma mass spectrometry,ICP-MS)检测Cr含量,并使用ASD Field Spec4地物光谱仪在实验室收集其高光谱信息。光谱信息预处理采用平滑滤波(SG)+标准正态化(SNV)+二阶微分(SD)变换组合,减弱土壤散射和噪声的影响。选择竞争性自适应重加权采样(CARS)、逐步投影算法(SPA)、无信息变量消除(UVE)、遗传算法(GA)四种算法提取特征波段。选择多元线性回归(MLR)、偏最小二乘法(PLSR)、支持向量回归(SVR)和人工神经网络(ANN)四种反演模型建立特征波段与Cr含量之间的关系。通过对比不同特征波段提取方法和反演模型组合对土壤Cr含量反演的结果发现:采用CARS和UVE特征波段提取方法可以显著提高PLSR、MLR和SVR模型的预测效果;SPA方法能够提高ANN模型的预测效果;通过SG+SNV+SD+CARS+PLSR组合方式,提取位于800~1000、1400~1700以及2100~2450 nm之间的98个特征波段,建模后模型验证,决定系数R2为0.97,均方根误差RMSE为5.25 mg·kg^(-1),平均绝对误差MAE为4.35 mg·kg^(-1),相对分析误差RPD为3.94,表明该模型在预测土壤Cr含量具有优异的性能。以土壤Cr污染高光谱反演为例,通过比较不同特征波段提取方法与反演模型组合的反演精度,确定最优模型,为小样本土壤重金属污染反演的建模提供了思路。
文摘碳普惠制是一种以城市居民为主体的温室气体自愿减排机制。将乘坐地铁出行作为低碳行为纳入碳普惠制,是建设全民参与型低碳社会的重要探索。本文提出了替代法和均值法两种市民乘坐地铁出行减碳量的核算方法,并以广州市为例,计算了2015年广州市民乘坐地铁出行的减碳量。结果显示:替代法下广州市民乘坐地铁出行的减碳量约为0.5419 kg CO_2/人次,均值法下约为0.5155 kg CO_2/人次,如果按2015年广州市地铁系统的客运量计算,替代法和均值法下全市地铁系统的年减碳量分别约为130万t CO_2和124万t CO_2。其中,替代法主要参考已有的CCER方法学设计,具有一定的理论基础,但其替代出行模式的确定受被调查对象的主观影响较大,而均值法以城市现有的机动化出行模式为基准线,较少受到人为因素的干扰,均值法被认为更适合于计算碳普惠制下市民乘坐地铁出行的碳减排量。
文摘作为现行碳排放权交易机制的延伸和有效补充,碳普惠制着眼于社会公众低碳行为减碳量的核算和交易。将公交车出行作为低碳行为纳入碳普惠制,是促进全民参与低碳社会建设的重要探索。文章借鉴CCER方法学并综合考虑交通数据的可获得性,提出了替代法和均值法两种居民公交车出行减碳量的核算方法,并以广州市为例,计算了2015年广州居民公交车出行的减碳量。结果显示,替代法核算广州居民公交车出行的减碳量为0.287 8 kg CO2/人次,均值法减碳量为0.351 4 kg CO2/人次,如果按2015年广州市公交车系统的客运量计算,替代法和均值法核算全市公交车系统的年减碳量分别约为750 000 t CO2和920000 t CO2。其中,替代法所需的替代出行模式受被调查对象的主观影响较大,而均值法以城市现有的机动化出行为基准线排放,受主观因素干扰较小,更适合核算居民公交车出行的碳减排量。
基金National Basic Research Program of China,No.2009CB421303National Natural Science Foundation of China,No.40771032National Science Supporting Program,No.2007BAC17B03
文摘Intensive grazing in spring-summer has been responsible for environmental degradation of the Gurbantunggut Desert in recent years. The coverage of plants and biological crusts, sand surface stability and physicochemical characteristics of soil on the dune surface were conducted in 2002 （winter grazing） and 2005 （spring-summer grazing）. The results showed that over 80% of the total area of the dune surface was covered by well-developed biological crusts and plants in 2002, when the interdune and middle to lower part of dune slopes were stabilized and only the crest had 10-40 m wide mobile belt. Affected by spring-summer grazing in 2005, over 80% of the total cover of biological crust was destructed and the plant coverage only reached 1/5 of that in 2002, especially the ephemeral plant cover had a great change. The value of sand transport potential in 2005 only reached 1/3 of that in 2002, but the total surface activity in 2005 was 1.6 times stronger than that in 2002. Meanwhile the mobile area began to expand from the dune top to the whole dune surface following spring-summer grazing. Compared with 2002, medium sand content of the dune surface soil increased by 13.9%, while that of fine and very fine sands decreased by 7.4% and 8.0% respectively in 2005 and the soil organic matter in 2005 was only about 1/2 of that in 2002. It is obvious that the presence of snow cover and frozen soil in winter could avoid the surface structure destruction in winter, while spring-summer grazing made excessive damage to biologic crusts and ephemeral plants. Spring is the main windy season in Gurbantunggut Desert and therefore intensive activity of dune surface occurred following spring-summer grazing, which led to a great loss of fine sand and organic matter. It can be seen that grazing season have a significant influence on the sustainable development of the desert ecosystem in Northwest China.
