The February 2000 floods on the Sabie River, South Africa: an examination of their magnitude and frequency.
The February 2000 floods on the Sabie River, South Africa: an examination of their magnitude and frequency.
复制标题
2000 年 2 月南非萨比河洪水：对其规模和频率的检验。
DOI：
10.4102/koedoe.v44i1.184
复制
发表时间：
2001
期刊：
影响因子：
1.1
通讯作者：
M. Rountree
中科院分区：
文献类型：
--
作者：
B. P. Moon;G. Jewitt;A. Large;M. Rountree
据许多观察家报告，2000年2月影响南部非洲大部分地区的洪水是人们记忆中最大的一次。然而，洪水的力量破坏了受影响河流上的大多数测量站，其中许多测量站的建造并不是为了测量如此大的流量。本文通过模拟萨比河洪峰流量的水力学和几何学特性，并将其与河道糙率特性联系起来，对克鲁格国家公园受基岩影响的萨比河2000年2月6日的洪峰流量进行了估算。收集了克鲁格国家公园内萨比河沿着6个站点的河道类型断裂处沿着河流的岸线测量形式的峰值水面坡度数据。每种渠道类型内的洪水条件被认为近似于均匀流。横截面位于主要支流输入之间，允许估计近似的子流域流量贡献。结果表明，在克鲁格国家公园的克鲁格门入口处，流量峰值约为3000 mVs，在靠近莫桑比克边境的Skukuza增加到约5500 mVs，在靠近莫桑比克边境的Lower Sabie增加到约7000 mVs。这些估计比较好的模拟降雨径流总量为4300 mVs在Skukuza，但是，降水输入在低草原似乎表明，流量仅上升到4950 mmVs在下萨比。根据根据实测流量校准的ACRU水文模型生成的模拟流量数据，从未经历过如此规模的洪水，因此表明重现期超过60年的记录。
The floods that affected much of Southern Africa in February 2000 have been reported as the largest in living memory by many observers. However, the force of the floods damaged the majority of the gauging stations located on the affected rivers, many of which were not constructed to measure flows of such a magnitude. This paper presents an estimation of the peak flood discharge on 6 February 2000 for the bedrock influenced Sabie River in the Kruger National Park, by simulating the hydraulic and geometric characteristics of the peak flow and relating these to the roughness character of the channel. Peak water surface slope data in the form of strandline measurements at channel type breaks along the river were collected for six sites along the Sabie River within the Kruger National Park. Flood conditions within each channel type were considered to approximate to uniform flow. The cross-sections are located between major tributary inputs allowing for approximate sub-catchment flow contributions to be estimated. The results indicate that the flow peaked at around 3000 mVs at the Kruger Gate entrance to the Kruger National Park, increasing to approximately 5500mVs at Skukuza and 7000 mVs at Lower Sabie close to the Mozambique border following inputs from the Sand River sub-catchment. These estimates compare well with the simulated rainfall runoff total of 4300 mVs at Skukuza, however, precipitation inputs over the lowveld appear to indicate that the discharge only rises to 4950 mmVs at Lower Sabie. A flood flow of this magnitude has never been experienced based on the simulated flow data generated by the ACRU hydrological model calibrated against measured flows therefore suggesting a return period in excess of the 60 years of record.