针对典型感潮河网地区水环境污染日趋严重与洪涝灾害频发的问题,为优化河网水动力和降低河道漫溢风险,基于Info Works ICM(integrated catchment management)模型建立福州市仓山区龙津阳岐片区城市水文模型与一维河网水动力耦合模型,以2...针对典型感潮河网地区水环境污染日趋严重与洪涝灾害频发的问题,为优化河网水动力和降低河道漫溢风险,基于Info Works ICM(integrated catchment management)模型建立福州市仓山区龙津阳岐片区城市水文模型与一维河网水动力耦合模型,以2022年6月14日实测降雨及河道水位数据对模型参数进行校准,平均纳什效率系数为0.78,平均洪峰误差为1.5%。设计并模拟3种晴天工况和3种“卢碧”台风雨天工况,结果表明:晴天从无调控到工况3,随着引水量的增加,河网平均流速逐步增加,总体增加66.4%,河道水动力提升显著;雨天从原有调控工况到工况3,随着河道预降水位值增大,关键断面平均超警历时逐步减少,总体下降73%,河道漫溢风险明显降低。构建河网水文水动力耦合模型和工况优选,可为仓山区进一步提升河网水动力与城市汛期洪涝灾害防治能力的方案制定提供决策依据,也可为其他同类研究提供借鉴。展开更多
笔者近一年来多次驾船往返新港至黄埔、新港至赤湾港之间,途经香港水域、赤沥浅滩等复杂水域,现将航行体会粗略整理一下提供给同行们。 一、重载船由横栏岛至赤湾航行方法 1.航行方法: 南下出台湾海峡后,采取沿岸航行,有利陆标定位,即...笔者近一年来多次驾船往返新港至黄埔、新港至赤湾港之间,途经香港水域、赤沥浅滩等复杂水域,现将航行体会粗略整理一下提供给同行们。 一、重载船由横栏岛至赤湾航行方法 1.航行方法: 南下出台湾海峡后,采取沿岸航行,有利陆标定位,即把针岩头(41.8)放在舷,向横澜岛航进。船舶抵横澜岛《闪(2)20秒24 n mi1e(角)。(雷应答)》正横,方位330°(T),横距0.66 n mi1e,改向240。(T),航进3.76 n mi1e。展开更多
Using hydrographic data sampled during four successive late summer-early autumn cruises in 2004-2007, vertical stratification along transects in the lee of Taiwan Island was analyzed to investigate upper ocean respons...Using hydrographic data sampled during four successive late summer-early autumn cruises in 2004-2007, vertical stratification along transects in the lee of Taiwan Island was analyzed to investigate upper ocean responses to orographically induced dipole wind stress curl (WSC). Results indicate that mixed-layer depth (MLD) and its relationship with thermocline depth varied under different local wind forcings. Average MLD along the transects from the 2004 to 2007 cruises were 18.5,30.7,39.2 and 24.5m, respectively. The MLD along the transects deepened remarkably and resulted in thermocline ventilation in 2005 and 2006, whereas ventilation did not occur in 2004 and 2007. Estimates indicate that frictional wind speed was the major factor in MLD variations. To a large degree, the combined effects of frictional wind speed and Ekman pumping are responsible for the spatial pattern of MLD during the cruises.展开更多
The temporal variations in the frequency of tropical cyclones (TCs) traversing the Taiwan and Hainan Islands (TH islands), were analyzed using a best-track TC dataset from the Joint Typhoon Warning Center for the peri...The temporal variations in the frequency of tropical cyclones (TCs) traversing the Taiwan and Hainan Islands (TH islands), were analyzed using a best-track TC dataset from the Joint Typhoon Warning Center for the period 1945-2007. Results show that the oscillations were interannual and interdecadal on the timescales of 2-8 and 8-12 years, respectively. It is also shown that the number of TCs formed in the western North Pacific basin (WNP) and of those traversing the TH islands varied intraseasonally. These results also held for typhoons traversing the TH islands, although the oscillations were less apparent. This study identified interrelationships between the frequency of TCs making landfall on the TH islands and the East Asia summer monsoon (EASM), the South Asia summer monsoon (SASM), and the South China Sea summer monsoon (SCSSM). The SCSSM significantly influenced the number of TCs traversing Hainan Island, but had little influence on the number of TCs traversing Taiwan Island. By contrast, the SASM influenced the numbers of TCs traversing both of the TH islands, shown by correlation coefficients of 0.41 for Taiwan Island and -0.25 for Hainan Island. In addition, the frequency of TC landfall on Taiwan Island increased during years of enhanced EASM, as indicated by a correlation coefficient of 0.4.展开更多
文摘针对典型感潮河网地区水环境污染日趋严重与洪涝灾害频发的问题,为优化河网水动力和降低河道漫溢风险,基于Info Works ICM(integrated catchment management)模型建立福州市仓山区龙津阳岐片区城市水文模型与一维河网水动力耦合模型,以2022年6月14日实测降雨及河道水位数据对模型参数进行校准,平均纳什效率系数为0.78,平均洪峰误差为1.5%。设计并模拟3种晴天工况和3种“卢碧”台风雨天工况,结果表明:晴天从无调控到工况3,随着引水量的增加,河网平均流速逐步增加,总体增加66.4%,河道水动力提升显著;雨天从原有调控工况到工况3,随着河道预降水位值增大,关键断面平均超警历时逐步减少,总体下降73%,河道漫溢风险明显降低。构建河网水文水动力耦合模型和工况优选,可为仓山区进一步提升河网水动力与城市汛期洪涝灾害防治能力的方案制定提供决策依据,也可为其他同类研究提供借鉴。
文摘笔者近一年来多次驾船往返新港至黄埔、新港至赤湾港之间,途经香港水域、赤沥浅滩等复杂水域,现将航行体会粗略整理一下提供给同行们。 一、重载船由横栏岛至赤湾航行方法 1.航行方法: 南下出台湾海峡后,采取沿岸航行,有利陆标定位,即把针岩头(41.8)放在舷,向横澜岛航进。船舶抵横澜岛《闪(2)20秒24 n mi1e(角)。(雷应答)》正横,方位330°(T),横距0.66 n mi1e,改向240。(T),航进3.76 n mi1e。
基金Supported by the Knowledge Innovation Program of Chinese Academy of Sciences (No. KZCX2-YW-Q11-02)the National Basic Research Program of China (973 Program) (No. 2011CB403503)the National Natural Science Foundation of China (Nos. 40876009,41176028)
文摘Using hydrographic data sampled during four successive late summer-early autumn cruises in 2004-2007, vertical stratification along transects in the lee of Taiwan Island was analyzed to investigate upper ocean responses to orographically induced dipole wind stress curl (WSC). Results indicate that mixed-layer depth (MLD) and its relationship with thermocline depth varied under different local wind forcings. Average MLD along the transects from the 2004 to 2007 cruises were 18.5,30.7,39.2 and 24.5m, respectively. The MLD along the transects deepened remarkably and resulted in thermocline ventilation in 2005 and 2006, whereas ventilation did not occur in 2004 and 2007. Estimates indicate that frictional wind speed was the major factor in MLD variations. To a large degree, the combined effects of frictional wind speed and Ekman pumping are responsible for the spatial pattern of MLD during the cruises.
基金Supported by the Knowledge Innovation Program of Chinese Academy of Sciences (No. KZCX2-YW-Q11-02)
文摘The temporal variations in the frequency of tropical cyclones (TCs) traversing the Taiwan and Hainan Islands (TH islands), were analyzed using a best-track TC dataset from the Joint Typhoon Warning Center for the period 1945-2007. Results show that the oscillations were interannual and interdecadal on the timescales of 2-8 and 8-12 years, respectively. It is also shown that the number of TCs formed in the western North Pacific basin (WNP) and of those traversing the TH islands varied intraseasonally. These results also held for typhoons traversing the TH islands, although the oscillations were less apparent. This study identified interrelationships between the frequency of TCs making landfall on the TH islands and the East Asia summer monsoon (EASM), the South Asia summer monsoon (SASM), and the South China Sea summer monsoon (SCSSM). The SCSSM significantly influenced the number of TCs traversing Hainan Island, but had little influence on the number of TCs traversing Taiwan Island. By contrast, the SASM influenced the numbers of TCs traversing both of the TH islands, shown by correlation coefficients of 0.41 for Taiwan Island and -0.25 for Hainan Island. In addition, the frequency of TC landfall on Taiwan Island increased during years of enhanced EASM, as indicated by a correlation coefficient of 0.4.
