MARIN_HYDROLOGY_RAINFALL_DEPTH_1YR_1HR

The data are derived from precipitation gauge station point data from across Marin County, including the Marin OneRain network (primary source), as well as selected data from National Centers for Environmental Information (NCEI) and NOAA Atlas 14. The 1-year, 1-hour rainfall depth is defined as the 1-hour rainfall accumulation that is expected to be equaled or exceeded an average of once per year. The 1-year, 1-hour rainfall depths for the OneRain and candidate NCEI rain gauges were computed using an algorithm developed by Dubin Environmental for this project; NOAA Atlas 14 rainfall statistics were downloaded directly from the Precipitation Frequency Data Server. The rainfall depth point data were interpolated across the County using the Empirical Bayesian Kriging method. The distance from a location to rain gauges, along with raster layers of mean annual precipitation and elevation as correlation variables, were inputs to the Kriging analysis that estimated the 1-year, 1-hour rainfall depths across the County as a raster layer produced with 500-foot pixels. The rainfall depths vary from 0.50 inches to more than 0.85 inches, with a distribution that is consistent with the values computed from the rain gauge data and mean annual rainfall values. The raster data pixels were converted to polygons with no smoothing, and the 1-year, 1-hour rainfall depth values were rounded to 2 decimal places. The polygons were dissolved on the rainfall depth value to group adjacent cells with the same value and reduce the total number of polygons to produce this dataset. The data are intended to support design calculations for full trash capture bioretention systems. Project designers can look up project location-specific 1-year, 1-hour rainfall depths, and then use these depths for bioretention sizing calculations. Data users may request a copy of the original raster dataset (32 bit floating point GeoTIFF) by contacting MCSTOPPP at [e-mail] .本数据集源自马林县全境的雨量站点数据，主要来源为马林县OneRain监测网络，同时纳入美国国家环境信息中心（National Centers for Environmental Information, NCEI）及NOAA Atlas 14的精选观测数据。本研究中，1年一遇1小时降雨深度被定义为年均期望被等于或超过一次的1小时降雨累积量。针对OneRain网络及候选NCEI雨量站的1年一遇1小时降雨深度，采用本项目由杜宾环境（Dubin Environmental）开发的专属算法完成计算；NOAA Atlas 14降雨统计数据则直接从降雨频率数据服务器（Precipitation Frequency Data Server）下载获取。本研究采用经验贝叶斯克里金法（Empirical Bayesian Kriging）对降雨深度点数据开展全县域空间插值，插值分析的输入变量包括插值点位至雨量站的距离、年平均降雨栅格图层及高程栅格图层作为相关辅助变量，最终生成像素分辨率为500英尺的县域1年一遇1小时降雨深度栅格图层。该降雨深度的取值区间为0.50英寸至0.85英寸以上，其空间分布特征与雨量站实测数据及年平均降雨数据的计算结果保持一致。将上述栅格数据的像素转换为未经过平滑处理的多边形，并将1年一遇1小时降雨深度值四舍五入至两位小数；随后按照降雨深度值对多边形进行融合，合并相邻的同值栅格单元以减少多边形总数，最终生成本数据集。本数据集旨在为全垃圾截留式生物滞留系统（full trash capture bioretention systems）的设计计算提供支撑。项目设计师可查询对应项目区位的1年一遇1小时降雨深度，并将其用于生物滞留设施的规模参数计算。数据使用者可通过发送邮件至[e-mail]联系MCSTOPPP，获取原始32位浮点型GeoTIFF栅格数据集。