摘要
文章基于近60年来的钦江水沙数据,通过变差系数和贡献率计算法分析钦江在极端天气下的水沙变化。结果表明:1)热带气旋年正常天气的平均流量为32 m^(3)/s,热带气旋过境的平均流量为290 m^(3)/s,是正常天气的9.06倍;热带气旋年的正常天气的平均输沙量是0.05×10^(4)t,热带气旋过境期间的平均输沙量为1.15×10^(4)t,是正常天气期间的23倍。2)洪水年正常天气的平均流量在375 m^(3)/s,而洪水期平均流量在2725 m^(3)/s左右,是正常天气平均流量的7.27倍。洪水年的正常天气的平均输沙量为0.07×10^(4) t,而洪水期的平均输沙量为1.14×10^(4)t,是正常天气输沙量的16.28倍。3)热带气旋对钦江的径流量平均多年贡献率为10.75%,输沙量贡献率为20.95%;洪水对钦江的径流量平均多年贡献率为16.75%,输沙量贡献率为30.07%。极端天气对钦江的水沙变化具有重要贡献,极端天气发生期间钦江具有“水沙激增”的特征,且极端天气对钦江水沙的影响具有年际变化特点,其热带气旋过境时径流量与输沙量的峰值有逐渐减小趋势,受热带气旋活动影响的减小可能是其中的原因之一。
Small and medium-sized mountain rivers have characteristics of short processes,rapid flow rates,and quick responses to extreme weather,thereby playing an important role in the global marine geochemical cycle.Understanding the changes in water and sediment characteristics of small and medium-sized rivers in response to extreme weather can provide scientific support for disaster prevention and mitigation and channel management of river basins.This study analyzed data from the past 60 years to understand the variations in the characteristics of water and sediment in the Qinjiang River of the Beibu Gulf under extreme weather conditions by estimating their variation coefficients and contribution rates.The results of the analyses show the following:(1)The Qinjiang River has an average discharge of 32 and 290 m^(3)/s in normal and tropical cyclone weather conditions,respectively.During a tropical cyclone year,the average flow rate is 9.06 times that during normal weather.The average sediment transport rates during normal weather and tropical cyclones are 0.05×10^(4) and 1.15×10^(4) t,respectively,wherein the latter is 23 times higher.(2)The average flow rates during normal weather and flood periods are 375 and 2,725 m^(3)/s,respectively;the latter is 7.27 times higher.The average sediment transport rates in normal weather and flood period are 0.07×10^(4) and 1.14×10^(4) t,respectively,wherein the latter is 16.28 times higher.(3)The average annual contribution rates of tropical cyclones and floods to the runoff and sediment discharge of the Qinjiang River are 10.75%and 20.95%and 16.75%and 30.07%,respectively.Extreme weather contributes significantly to the variations in the water and sediment characteristics of the Qinjiang River.During extreme weather,the Qinjiang River exhibits a surge of water and sediment with inter-annual variations.The peaks of runoff and sediment transport during the transit of tropical cyclones tend to decrease gradually over the years,probably because of the reduction in the impact of their
作者
许珊珊
杨夏玲
黎树式
潘嘉嘉
梁喜幸
Xu Shanshan;Yang Xialing;Li Shushi;Pan Jiajia;Liang Xixing(School of Geography and Planning,Nanning Normal University,Nanning 530001,China;Guangxi Key Laboratory of Marine Environment Change and Disaster in Beibu Gulf,Beibu Gulf University,Qinzhou 535011,China;Guangxi Coastal Hydrology Center,Qinzhou 535000,China;State Key Laboratory of Estuarine and Costal Research,East China Normal University,Shanghai 200241,China)
出处
《热带地理》
CSCD
北大核心
2023年第11期2135-2145,共11页
Tropical Geography
基金
北部湾大学海洋科学广西一流学科[“平陆运河建设背景下钦州湾动力地貌对水沙变化的响应”(DRB006)
“《广西北部湾河口海岸研究与实践》教材建设”(DTC003)]
国家自然科学基金“北部湾南流江三角洲潮滩响应热带气旋的动力地貌过程”(42366008)。
关键词
极端天气
水沙变化
钦江
北部湾
extreme weather
water and sediment variation
Qinjiang River
Beibu Gulf
