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911.
Futoshi Nakamura Nobuo Ishiyama Satoshi Yamanaka Motoki Higa Takumi Akasaka Yoshiko Kobayashi Satoru Ono Nao Fuke Munehiro Kitazawa Junko Morimoto Yasushi Shoji 《河流研究与利用》2020,36(6):921-933
In recent years, we have experienced mega‐flood disasters in Japan due to climate change. In the last century, we have been building disaster prevention infrastructure (artificial levees and dams, referred to as “grey infrastructure”) to protect human lives and assets from floods, but these hard protective measures will not function against mega‐floods. Moreover, in a drastically depopulating society such as that in Japan, farmland abandonment prevails, and it will be more difficult to maintain grey infrastructure with a limited tax income. In this study, we propose the introduction of green infrastructure (GI) as an adaptation strategy for climate change. If we can use abandoned farmlands as GI, they may function to reduce disaster risks and provide habitats for various organisms that are adapted to wetland environments. First, we present a conceptual framework for disaster prevention using a hybrid of GI and conventional grey infrastructure. In this combination, the fundamental GI, composed of forests and wetlands in the catchment (GI‐1) and additional multilevel GIs such as flood control basins that function when floodwater exceeds the planning level (GI‐2) are introduced. We evaluated the flood attenuation function (GI‐1) of the Kushiro Wetland using a hydrological model and developed a methodology for selecting suitable locations of GI‐2, considering flood risk, biodiversity and the distribution of abandoned farmlands, which represent social and economic costs. The results indicated that the Kushiro Wetland acts as a large natural reservoir that attenuates the hydrological peak discharge during floods and suitable locations for introducing GI‐2 are concentrated in floodplain areas developing in the downstream reaches of large rivers. Finally, we discussed the network structure of GI‐1 as a hub and GI‐2 as a dispersal site for conservation of the Red‐crowned Crane, one of the symbolic species of Japan. 相似文献
912.
建立了考虑水位骤降条件下的下伏隧道堤防模型,依托湘江某下伏隧道堤防工程,基于堤防边坡渗流原理,结合有限元应力计算,探讨了不同水位骤降速率下的浸润线情况,计算了堤防安全系数。研究结果表明:湘江水位骤降速率越快,浸润线变化范围越大,浸润线变化范围与水位降落速率成正比;湘江水位骤降速度在3 m/d^4 m/d,水位降到28.8 m时,堤岸失去稳定;水位骤降并非整个过程中堤岸均处于失稳状态,而是水位降至某高度后堤岸失稳,骤降速率增快对堤防安全系数有一定负面作用。研究结果对隧道下穿堤防建设具有一定指导意义。 相似文献
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915.
Seasonal Water Level Manipulation for Flood Risk Management Influences Home‐Range Size of Common Bream Abramis brama L. in a Lowland River
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The increased threat of flooding from climate change requires ever greater management of rivers to alleviate flood risk. Although the impacts of river modification on fish communities are well documented, the effects of river management practices on fish behaviour have received relatively little attention. Here, a long‐term (4 years) acoustic telemetry study was used to analyse the spatial–temporal behaviour of common bream in a lowland river system (River Witham, Lincolnshire, UK) in which water levels are artificially manipulated biannually as part of a flood storage strategy. Levels are lowered in the autumn and increased again in the spring, to increase in‐river winter flood storage capacity. Home‐range size varied according to season, with home ranges being larger in the spring and summer months in comparison with those recorded during the autumn and winter months. When water levels within the river system were artificially manipulated, the bream responded by altering their home‐range size, increasing it after the levels had been raised and reducing it following the lowering of the river levels. This is in contrast to the cumulative overall distances bream were recorded to travel, which were unaffected by water level manipulation, suggesting water level manipulation did not affect activity levels. Although such changes in behaviour do not necessarily equate to a negative impact on fitness, reduced home‐range size brought about by water level manipulation does have implications for habitat availability and the number of competitive, predatory and parasitic interactions encountered. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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杜广志 《中小企业管理与科技》2021,(6)
为降低铁路单线隧道接触网弓形腕臂预配施工难度,论文研究了一种接触网弓形腕臂预配平台,结合单线隧道内弓形腕臂数据精测技术及计算软件,精确测量预配,保证弓形腕臂的安装精度和质量,使弓形腕臂在现场施工中一次成优。论文结合实际,就某铁路单线隧道接触网弓形腕臂预配平台作具体分析。 相似文献
918.
文章在简要介绍广西蒙山新古排水电站工程概况的基础上,对引水隧洞开挖过程中遇到的各类隧洞塌方原因作了详细的分析,并对塌方分类、预防和处理措施作了论述。针对隧洞施工中发生的大塌方问题,监理工程师根据设计图纸文件及水工支护施工技术规范,提出了“超前临时支撑法”施工处理措施,且对该施工处理技术进行简要概述,这在引水隧洞开挖过程中起到了参谋和决策作用。 相似文献
919.
1996年汛期,黄河流域平均降雨量比多年同期均值偏多3.6%,但干支流来水来沙量普遍偏少,属枯水沙年份。黄河上游主要水库蓄水量偏少。花园口站出现洪峰流量大于3000m^3/s的洪水共3次,其中最大洪峰流量为7600m^3/s。“96.8”洪水虽然洪峰流量、含沙量并不大,但其洪水位之高,传播时间之长、漫滩之严重在许多河段均超过历史记录。渭河华县亦亦出现有水文记载以来的最高水位。 相似文献
920.
黄河宁蒙河段冰期洪水波运动过程中的变形分析 总被引:1,自引:0,他引:1
河道中冰盖的存在会影响到洪水波的演进变形。以黄河宁蒙河段为研究对象,将马斯京根法尝试应用于冰期洪水计算,分析了马斯京根法参数与糙率的关系,比较了冰盖冻结增厚和融化减薄过程对洪水波变形的影响差异。研究结果表明,将马斯京根法应用于冰期洪水计算是可行的;断面的糙率越大,洪水波传播时间越久,变形越大;冰盖冻结增厚过程中,洪水波的变形存在先增加再减少而后又增加的现象;冰盖融化减薄过程中,洪水波随冰厚的减薄而变形增大。相同冰厚下,两种过程的变形程度存在交点。交点之前的冰厚范围,冰盖融化减薄时的洪水波变形更大;交点之后的冰厚范围,冰盖冻结增厚时的洪水波变形更大。 相似文献