2017年8月8日九寨沟发生7.0级地震,景区内部分景观破损,其中诺日朗瀑布钙华体局部出现小规模坍塌。通过调查研究,查明了瀑布景观钙华的震损现状,结合二维离散元分析软件Universal Distinct Element Code(UDEC)对变形破坏过程进行了模拟...2017年8月8日九寨沟发生7.0级地震,景区内部分景观破损,其中诺日朗瀑布钙华体局部出现小规模坍塌。通过调查研究,查明了瀑布景观钙华的震损现状,结合二维离散元分析软件Universal Distinct Element Code(UDEC)对变形破坏过程进行了模拟分析,揭示了钙华震损过程分为振动蠕变、持续拉张、倾倒折断和溃屈破坏4个阶段。综合地质环境背景分析,景观钙华形成的地质环境条件和景区水流系统处于基本稳定状态,景观体处于相对稳定的发展阶段,层湖叠瀑景观不会消亡。展开更多
Located in southwestern China, Jiuzhaigou National Park is one of the most popular tourism destinations in China, famous for its unique aquatic ecosystems and beautiful forests. However, plants in the park may be at h...Located in southwestern China, Jiuzhaigou National Park is one of the most popular tourism destinations in China, famous for its unique aquatic ecosystems and beautiful forests. However, plants in the park may be at high ozone risk as a result of the intensive use of diesel tour buses in the park. In addition, Jiuzhaigou is close to a region with relatively high regional anthropogenic NO x emissions. During the growing season, also the peak season of tourism, we measured ozone concentration at two sites within the Park and these were: Jiuzhaigou Bureau (JB) and Long Lake (LL). The results indicate that ozone concentrations were not high enough to cause foliar injury during the monitoring period, although the risk of ozone to plants was higher in spring than in summer and autumn. Diurnal ozone cycles at JB and LL displayed significantly higher ozone concentrations in the daytime than in the nighttime, suggesting photochemical production of ozone during the day and ozone deposition during the night as a result of the nocturnal boundary layer. In parallel with the seasonal change of background surface ozone in the Northern Hemisphere, maximum daily 8-h average ozone concentration (MDA8) and daily ozone concentration decreased from spring to autumn at the two sites. This temporal variation in Jiuzhaigou was most likely associated with the downward mixing of ozone-rich air from the free troposphere, because all the high-ozone events (MDA8 > 70.0 ppb) were observed in spring and ozone-rich air from the free troposphere was the dominant cause. In summary, our data suggest that ozone concentrations in Jiuzhaigou were more affected by the regional-scale of background pattern in air quality and meteorological conditions than by local tourist activities.展开更多
文摘2017年8月8日九寨沟发生7.0级地震,景区内部分景观破损,其中诺日朗瀑布钙华体局部出现小规模坍塌。通过调查研究,查明了瀑布景观钙华的震损现状,结合二维离散元分析软件Universal Distinct Element Code(UDEC)对变形破坏过程进行了模拟分析,揭示了钙华震损过程分为振动蠕变、持续拉张、倾倒折断和溃屈破坏4个阶段。综合地质环境背景分析,景观钙华形成的地质环境条件和景区水流系统处于基本稳定状态,景观体处于相对稳定的发展阶段,层湖叠瀑景观不会消亡。
基金funded by the International Program of the Ministry of Science and Technology of China (2010DFA91280) 111 Project(B08037)
文摘Located in southwestern China, Jiuzhaigou National Park is one of the most popular tourism destinations in China, famous for its unique aquatic ecosystems and beautiful forests. However, plants in the park may be at high ozone risk as a result of the intensive use of diesel tour buses in the park. In addition, Jiuzhaigou is close to a region with relatively high regional anthropogenic NO x emissions. During the growing season, also the peak season of tourism, we measured ozone concentration at two sites within the Park and these were: Jiuzhaigou Bureau (JB) and Long Lake (LL). The results indicate that ozone concentrations were not high enough to cause foliar injury during the monitoring period, although the risk of ozone to plants was higher in spring than in summer and autumn. Diurnal ozone cycles at JB and LL displayed significantly higher ozone concentrations in the daytime than in the nighttime, suggesting photochemical production of ozone during the day and ozone deposition during the night as a result of the nocturnal boundary layer. In parallel with the seasonal change of background surface ozone in the Northern Hemisphere, maximum daily 8-h average ozone concentration (MDA8) and daily ozone concentration decreased from spring to autumn at the two sites. This temporal variation in Jiuzhaigou was most likely associated with the downward mixing of ozone-rich air from the free troposphere, because all the high-ozone events (MDA8 > 70.0 ppb) were observed in spring and ozone-rich air from the free troposphere was the dominant cause. In summary, our data suggest that ozone concentrations in Jiuzhaigou were more affected by the regional-scale of background pattern in air quality and meteorological conditions than by local tourist activities.
