随着点源污染的控制与处理技术日趋完善,非点源污染成为重要的水污染源。武强溪作为流入千岛湖的第二大支流,量化武强溪流域非点源污染负荷,解析非点源污染时空分布特征,提出适合削减武强溪流域污染物的最佳管理措施(best management pr...随着点源污染的控制与处理技术日趋完善,非点源污染成为重要的水污染源。武强溪作为流入千岛湖的第二大支流,量化武强溪流域非点源污染负荷,解析非点源污染时空分布特征,提出适合削减武强溪流域污染物的最佳管理措施(best management practices,BMPs)对千岛湖水污染高效治理至关重要。该研究基于土壤水分评估工具(Soil and water assessment tool,SWAT)分析了武强溪流域径流量、总氮输出负荷量的时空分布特征,探究了不同管理措施及组合的削减效果,提出了武强溪流域非点源污染针对性的治理措施。结果表明:1)SWAT模型对于武强溪流域径流量和总氮输出负荷量的模拟具有较好的适用性,径流量校准期和验证期的决定系数(coefficient of determination,R^(2))分别为0.86、0.97,纳什系数(nash-sutcliffe coefficient,NSE)分别为0.83、0.96,百分比偏差(percent bias,PBIAS)分别为15.8%、-6.3%,总氮校准期和验证期的决定系数分别为0.87、0.74,纳什系数分别为0.63、0.66,百分比偏差分别为31.6%、21.2%;2)该流域径流量和总氮负荷主要集中在3—7月,分别占全年输出量的71.67%和75.76%。综合考虑氮的来源和流失途径,将耕地和林地面积占比大、坡度陡的子流域设置为总氮的关键污染源区。考虑调整化肥施用量/配方、改变耕作方式和设置植被缓冲带等削减非点源污染的手段,进行总氮输出负荷削减效率的情景模拟,表明10 m植被缓冲带是减少总氮输出负荷的最佳单一控制策略,总氮削减率可达到69.90%;实施综合管理措施对总氮的污染削减效果更佳,10 m植被缓冲带与施肥量减少20%可使总氮削减率达到74.79%。研究结果可为千岛湖水质管理与控制提供理论基础。展开更多
Xi’an, called Chang’an in the Tang Dynasty (618-907), was a famous open city then and a tourist attraction today. First built at the time of the Western Han (206 BC-8 AD), Chang’an was 70 kilometres from the presen...Xi’an, called Chang’an in the Tang Dynasty (618-907), was a famous open city then and a tourist attraction today. First built at the time of the Western Han (206 BC-8 AD), Chang’an was 70 kilometres from the present-day Xi’an. Tang rulers adopted an open policy from Emperor Taizhong——the展开更多
People can taste various sweet and succulent fruits in the summer. But what makes one’s month water most is litchi, the queen of fruits. Su Dongpo, the great writer of the Song Dynasty (960-1279), wrote in a poem tha...People can taste various sweet and succulent fruits in the summer. But what makes one’s month water most is litchi, the queen of fruits. Su Dongpo, the great writer of the Song Dynasty (960-1279), wrote in a poem that he would like to stay in Lingnan (one of the litchi producing areas) forever because he could eat 300 litchi there everyday. For political reasons, Su Dongpo展开更多
Wine, like tea, is a favorite drink of the Chinese people. No matter where you are, at a family dinner or at a state banquet, you can see its presence. "One thousand cups of wine are not enough when you are drink...Wine, like tea, is a favorite drink of the Chinese people. No matter where you are, at a family dinner or at a state banquet, you can see its presence. "One thousand cups of wine are not enough when you are drinking with a close friend" and "good wine is enjoyed when one is a little drunk." Such beautiful sentiments are expressed by all wine admirers. Great statesman Cao Cao of the Three-Kingdoms period (AD 220-280) wrote in a poem, "Only Du Kang (a famous wine of the time named after the brewer) can dispel my worries." So, since ancient times people have sought temperary relief through wine. The main function of wine is to bring excitement展开更多
When you visit a Chinese home, you will be given a cup of hot tea irrespective of the geographical location, cultural background and nationality of the host. This is part of China’s ritual and culture. However, tea d...When you visit a Chinese home, you will be given a cup of hot tea irrespective of the geographical location, cultural background and nationality of the host. This is part of China’s ritual and culture. However, tea drinking customs vary in certain parts of China. Min-chao congou tea. Min-chao refers to the areas covering southern Fujian Province and Chaozhou and Santou in Guangdong Province. congou means the special skill of making tea.展开更多
文摘随着点源污染的控制与处理技术日趋完善,非点源污染成为重要的水污染源。武强溪作为流入千岛湖的第二大支流,量化武强溪流域非点源污染负荷,解析非点源污染时空分布特征,提出适合削减武强溪流域污染物的最佳管理措施(best management practices,BMPs)对千岛湖水污染高效治理至关重要。该研究基于土壤水分评估工具(Soil and water assessment tool,SWAT)分析了武强溪流域径流量、总氮输出负荷量的时空分布特征,探究了不同管理措施及组合的削减效果,提出了武强溪流域非点源污染针对性的治理措施。结果表明:1)SWAT模型对于武强溪流域径流量和总氮输出负荷量的模拟具有较好的适用性,径流量校准期和验证期的决定系数(coefficient of determination,R^(2))分别为0.86、0.97,纳什系数(nash-sutcliffe coefficient,NSE)分别为0.83、0.96,百分比偏差(percent bias,PBIAS)分别为15.8%、-6.3%,总氮校准期和验证期的决定系数分别为0.87、0.74,纳什系数分别为0.63、0.66,百分比偏差分别为31.6%、21.2%;2)该流域径流量和总氮负荷主要集中在3—7月,分别占全年输出量的71.67%和75.76%。综合考虑氮的来源和流失途径,将耕地和林地面积占比大、坡度陡的子流域设置为总氮的关键污染源区。考虑调整化肥施用量/配方、改变耕作方式和设置植被缓冲带等削减非点源污染的手段,进行总氮输出负荷削减效率的情景模拟,表明10 m植被缓冲带是减少总氮输出负荷的最佳单一控制策略,总氮削减率可达到69.90%;实施综合管理措施对总氮的污染削减效果更佳,10 m植被缓冲带与施肥量减少20%可使总氮削减率达到74.79%。研究结果可为千岛湖水质管理与控制提供理论基础。
文摘Xi’an, called Chang’an in the Tang Dynasty (618-907), was a famous open city then and a tourist attraction today. First built at the time of the Western Han (206 BC-8 AD), Chang’an was 70 kilometres from the present-day Xi’an. Tang rulers adopted an open policy from Emperor Taizhong——the
文摘People can taste various sweet and succulent fruits in the summer. But what makes one’s month water most is litchi, the queen of fruits. Su Dongpo, the great writer of the Song Dynasty (960-1279), wrote in a poem that he would like to stay in Lingnan (one of the litchi producing areas) forever because he could eat 300 litchi there everyday. For political reasons, Su Dongpo
文摘Wine, like tea, is a favorite drink of the Chinese people. No matter where you are, at a family dinner or at a state banquet, you can see its presence. "One thousand cups of wine are not enough when you are drinking with a close friend" and "good wine is enjoyed when one is a little drunk." Such beautiful sentiments are expressed by all wine admirers. Great statesman Cao Cao of the Three-Kingdoms period (AD 220-280) wrote in a poem, "Only Du Kang (a famous wine of the time named after the brewer) can dispel my worries." So, since ancient times people have sought temperary relief through wine. The main function of wine is to bring excitement
文摘When you visit a Chinese home, you will be given a cup of hot tea irrespective of the geographical location, cultural background and nationality of the host. This is part of China’s ritual and culture. However, tea drinking customs vary in certain parts of China. Min-chao congou tea. Min-chao refers to the areas covering southern Fujian Province and Chaozhou and Santou in Guangdong Province. congou means the special skill of making tea.
