A timely and cost-effective method of creating inundation maps could assist first responders in allocating resources and personnel in the event of a flood or in preparation of a future disaster. The Height Above Nearest Drainage (HAND) model could be implemented into an on-the-fly flood mapping application for a Canada-wide service. The HAND model requires water level (m) data inputs while many sources of hydrological data in Canada only provide discharge (m³/sec) data. Synthetic rating curves (SRCs), created using river geometry/characteristics and the Manning’s formula, could be utilized to provide an approximate water level given a discharge input. A challenge with creating SRCs includes representing how multiple different land covers will slow impact flow due to texture and bulky features (i.e., smooth asphalt versus rocky river channel); this relates to the roughness coefficient (n). In our study, two methods of representing multiple n values were experimented with (a weighted method and a minimum-median method) and were compared to using a fixed n method. A custom ArcGIS tool, Canadian Estimator of Ratings Curves using HAND and Discharge (CERC-HAND-D), was developed to create SRCs using all three methods. Control data were sourced from gauge stations across Canada in the form of rating curves. Results indicate that in areas with medium to medium–high river gradients (S > 0.002 m/m) or with river reaches under 5 km, the CERC-HAND-D tool creates more accurate SRCs (NRMSE = 3.7–8.8%, Percent Bias = −7.8%—9.4%), with the minimum-median method being the preferred n method.

及时且具有成本效益的绘制淹没地图的方法可以帮助急救人员在发生洪水或为未来的灾难做准备时分配资源和人员。最近排水系统之上的高度 (HAND) 模型可以实施到加拿大范围内服务的实时洪水测绘应用程序中。HAND 模型需要水位 (m) 数据输入，而加拿大的许多水文数据源仅提供排放量 (m ³/秒）数据。使用河流几何形状/特征和曼宁公式创建的综合评级曲线 (SRC) 可用于提供给定排放输入的近似水位。创建 SRC 的一个挑战包括表示由于质地和体积大的特征（即，光滑的沥青与岩石河道），多种不同的土地覆盖将如何减缓影响流动；这与粗糙度系数 ( n ) 有关。在我们的研究中，我们试验了两种表示多个n值的方法（加权方法和最小中值方法），并与使用固定n值的方法进行了比较方法。开发了一种自定义 ArcGIS 工具，即使用 HAND 和放电的加拿大评级曲线估算器 (CERC-HAND-D)，以使用所有三种方法创建 SRC。控制数据以评级曲线的形式来自加拿大各地的测量站。结果表明，在中高河流坡度 (S > 0.002 m/m) 或河段低于 5 公里的地区，CERC-HAND-D 工具可创建更准确的 SRC（NRMSE = 3.7-8.8%，百分比偏差） = -7.8%—9.4%)，最小中值法是首选的n法。