Livneh Historical Observations Days with Heavy Precipitation

The Climate Resilience Information System (CRIS) provides data and tools for developers of climate services. This layer has historical variables in decadal increments from 1950 to 2020 derived from historical observations of air temperature and precipitation. The variables included are: Annual number of days with total precipitation greater than or equal to 1 inch Annual number of days with total precipitation greater than or equal to 2 inches Annual number of days with total precipitation greater than or equal to 3 inches Annual number of days with total precipitation greater than or equal to 4 inches Annual number of days with total precipitation greater than or equal to 5 inches Daily non-zero precipitation 90th percentile value (inches) Daily non-zero precipitation 95th percentile value (inches) Daily non-zero precipitation 99th percentile value (inches) Annual number of days with precipitation exceeding the 90th percentile for non-zero precipitation days Annual number of days with precipitation exceeding the 95th percentile for non-zero precipitation days Annual number of days with precipitation exceeding the 99th percentile for non-zero precipitation days This layer uses data from the Livneh gridded precipitation and other meteorological variables for continental US, Mexico and southern Canada. Further processing by Esri is explained below. For each variable, there are mean values for the defined respective geography: counties, tribal areas, HUC-8 watersheds. The process for deriving these summaries is available from the CRIS Website’s About the Data. Other climate variables are available from the CRIS Data page. Additional geographies, including Alaska, Hawai’i and Puerto Rico will be made available in the future. Geographies This layer provides historic values for three geographies: county, tribal area, and HUC-8 watersheds. County: based on the U.S. Census TIGER/Line 2022 distribution. Tribal areas: based on the U.S. Census American Indian/Alaska Native/Native Hawaiian Area dataset 2022 distribution. This dataset includes federal- and state-recognized statistical areas. HUC-8 watershed: based on the USGS Washed Boundary Dataset, part of the National Hydrography Database Plus High Resolution. Time Ranges Historic climate threshold values (e.g. Days Over 90°F) were calculated for each year from 1950 to 2020. To ensure the layer displays time correctly, under 'Map properties' set Time zone to 'Universal Coordinated Time (UTC)' and under 'Time slider options' set Time intervals to '1 Decade'. Data Citation Livneh, B., T. J. Bohn, D. W. Pierce, F. Munoz-Arriola, B. Nijssen, R. Vose, D. R. Cayan, and L. Brekke, 2015: A spatially comprehensive, hydrometeorological data set for Mexico, the U.S., and Southern Canada 1950 - 2013. Scientific Data, 2, https://doi.org/10.1038/sdata.2015.42. Data Export Exporting this data into shapefiles, geodatabases, GeoJSON, etc is enabled.气候韧性信息系统（Climate Resilience Information System，简称CRIS）为气候服务开发者提供数据与工具。本图层包含1950年至2020年以十年为步长的历史变量，这些变量源自气温与降水的历史观测数据。所涵盖的变量如下：年累计降水量≥1英寸的天数、年累计降水量≥2英寸的天数、年累计降水量≥3英寸的天数、年累计降水量≥4英寸的天数、年累计降水量≥5英寸的天数、日非零降水量90分位值（单位：英寸）、日非零降水量95分位值（单位：英寸）、日非零降水量99分位值（单位：英寸）、年非零降水日中降水量超过90分位值的天数、年非零降水日中降水量超过95分位值的天数、年非零降水日中降水量超过99分位值的天数。 本图层采用源自美国本土、墨西哥与加拿大南部的Livneh格点化降水数据及其他气象变量，Esri的进一步处理流程详见下文。针对每个变量，本图层提供指定地理分区的平均值，涵盖县、部落区域及HUC-8流域。此类汇总数据的生成流程可于CRIS官网的“数据概览”板块查询。其他气候变量可于CRIS数据页面获取。未来将推出包含阿拉斯加、夏威夷及波多黎各在内的更多地理分区数据。 ### 地理分区 本图层提供三类地理分区的历史数据：县、部落区域及HUC-8流域。 1. 县界：基于美国人口普查局2022版TIGER/Line矢量数据。 2. 部落区域：基于美国人口普查局2022版《美国印第安人/阿拉斯加原住民/夏威夷原住民区域数据集》，该数据集包含联邦及州政府认可的统计区域。 3. HUC-8流域：基于美国地质调查局（USGS）的冲刷边界数据集（Washed Boundary Dataset），该数据集隶属于《国家水文数据库Plus高分辨率版》（National Hydrography Database Plus High Resolution）。 ### 时间范围 本数据集针对1950年至2020年的每一年计算了历史气候阈值（如日最高气温≥90°F天数）。为确保图层时间显示正确，请在“地图属性”中将时区设置为“协调世界时（UTC）”，并在“时间滑块选项”中将时间间隔设置为“10年”。 ### 数据引用 Livneh, B.、T. J. Bohn、D. W. Pierce、F. Munoz-Arriola、B. Nijssen、R. Vose、D. R. Cayan及L. Brekke，2015年：1950-2013年墨西哥、美国及加拿大南部空间全覆盖水文气象数据集，《科学数据》（Scientific Data），第2卷，https://doi.org/10.1038/sdata.2015.42。 ### 数据导出 支持将本数据集导出为Shapefile、地理数据库、GeoJSON等格式。