Abstract This article examines whether Digital Elevation Model (DEM) resolution affects the accuracy of predicted coastal inundation extent using LISFLOOD-FP, with application to a sandy coastline in New Jersey. DEMs with resolution ranging from 10 to 100 m were created using coastal elevation data from NOAA, using the North American Vertical Datum of 1988. A two-dimensional hydrodynamic flood model was developed in LISFLOOD-FP using each DEM, all of which were calibrated and validated against an observed 24-h tidal cycle and used to simulate a 1.5 m storm surge. While differences in predicted inundated area from all models were within 1.0%, model performance and computational time worsened and decreased with coarser DEM resolution, respectively. This implied that using a structured grid model for modeling coastal flood vulnerability is based on two trade-offs: high DEM resolution coupled with computational intensity, but higher precision in model predictions, and vice versa. Furthermore, water depth predictions from all DEMs were consistent. Using an integrated numerical modeling and GIS approach, a two-scale modeling strategy, where a coarse DEM is used to predict water levels for projection onto a fine DEM was found to be an effective, and computationally efficient approach for obtaining reliable estimates of coastal inundation extent.

中文翻译：

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DEM 分辨率对沿海洪水脆弱性建模的影响

摘要 本文研究了数字高程模型 (DEM) 分辨率是否会影响使用 LISFLOOD-FP 预测沿海淹没范围的准确性，并将其应用于新泽西州的沙质海岸线。分辨率范围为 10 到 100 m 的 DEM 是使用 NOAA 的海岸高程数据创建的，使用的是 1988 年的北美垂直基准。在 LISFLOOD-FP 中使用每个 DEM 开发了二维水动力洪水模型，所有这些模型都经过校准和根据观察到的 24 小时潮汐周期进行验证，并用于模拟 1.5 m 风暴潮。虽然所有模型预测淹没区域的差异均在 1.0% 以内，但模型性能和计算时间分别随着 DEM 分辨率的提高而恶化和减少。这意味着使用结构化网格模型对沿海洪水脆弱性进行建模基于两个权衡：高 DEM 分辨率与计算强度相结合，但模型预测的精度更高，反之亦然。此外，所有 DEM 的水深预测都是一致的。使用综合数值建模和 GIS 方法，发现使用粗 DEM 预测水位以投影到精细 DEM 的两尺度建模策略是一种有效且计算效率高的方法，可用于获得可靠的沿海淹没估计程度。