Nearshore Monitoring with X-Band Radar: Maximising Utility in Dynamic and Complex Environments
Nearshore Monitoring with X-Band Radar: Maximising Utility in Dynamic and Complex Environments
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使用 X 波段雷达进行近岸监测：在动态和复杂的环境中最大限度地发挥效用
DOI：
10.1002/essoar.10504567.1
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Atkinson J
中科院分区：
文献类型：
--
作者：
Atkinson J
沿海管理和工程工作需要有数据来量化近岸水深变化的性质和范围。然而，由于费用高和后勤复杂，测深调查通常不经常进行。这项研究表明，地基X波段雷达提供了一个具有成本效益的替代方案，以相对较高的频率监测大面积近岸地区的海底变化。通过为验证雷达数据和量化不确定性而开发的强大数据处理和质量控制框架，使用在英国索尔彭斯安装18个月的雷达获得了测深图。分析包括水位和波高的校准;使用并行多波束调查验证雷达得出的水深;应用一种方法来减少数据分散和异常值的影响;以及评估由于波高和方向不同而造成的数据质量的时空变异。对于波高>1 m且波浪接近雷达的角度相对较小的情况，雷达导出深度的精度在40 x 40 m空间分辨率下为{±}0.5 m。在索尔彭斯，量化的变化超过这个错误是可能的时间尺度短至三个星期，和近岸体积的变化被认为是一个相当的幅度在该地区的历史沿岸运输率。使用雷达可以向沿海管理人员提供近海水深变化的预警，这种变化可能影响脆弱的沿海地点;从而可以调动可能需要的资源来保护生命和财产。
Data quantifying the nature and range of bathymetric changes in the near-shore are required for coastal management and engineering works. However, due to high costs and complex logistics, bathymetric surveys are usually infrequent. This study demonstrates that ground-based X-band radar offers a cost-effective alternative to monitor seabed changes at relatively high frequency and over large near-shore areas. Through a robust data processing and quality control framework developed to validate radar-derived data and quantify uncertainties, bathymetric maps were obtained using an 18-month radar installation at Thorpeness, U.K. The analysis incorporates calibration of water levels and wave heights; validation of radar-derived water depth using concurrent multibeam surveys; the application of a method to reduce the influence of data scatter and outliers; and assessment of spatio-temporal variability of data quality due to varying wave heights and direction. For conditions when the wave height is >1 m, and the angle of wave approach relative to the radar is relatively small, the accuracy of the radar-derived depths is shown to be {plus minus}0.5 m at 40x40 m spatial resolution. At Thorpeness, quantification of changes exceeding this error was possible at time-scales as short as three weeks, and near-shore volume changes are seen to be of a comparable magnitude to historical longshore transport rates in the area. The use of radar can provide to coastal managers an early warning of changes in offshore bathymetry likely to impact vulnerable coastal locations; thereby allowing mobilisation of resources that may be required to protect lives and property.