Livneh Historical Observations Precipitation Totals

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 total precipitation (inches) Annual highest precipitation total for a single day (inches) Annual highest precipitation total over a 5-day period (inches) Annual highest precipitation total over a 10-day period (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 total precipitation for all days exceeding the 90th percentile (inches) Annual total precipitation for all days exceeding the 95th percentile (inches) Annual total precipitation for all days exceeding the 99th percentile (inches) 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, 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年间以十年为增量的历史变量，数据源自气温与降水的历史观测资料。涵盖的变量如下： 年总降水量（单位：英寸）、单日最高降水量（单位：英寸）、连续5日最高降水量（单位：英寸）、连续10日最高降水量（单位：英寸）、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）、超过90分位阈值的所有日降水量总和（单位：英寸）、超过95分位阈值的所有日降水量总和（单位：英寸）、超过99分位阈值的所有日降水量总和（单位：英寸）。 本图层采用源自美国本土、墨西哥及加拿大南部的Livneh格点化降水与其他气象变量数据集，相关数据经Esri进一步处理，具体处理流程详见下文。针对每个变量，已针对预设的三类地理单元计算对应平均值：县界、部落区域、HUC-8流域。此类汇总统计数据的生成流程可于CRIS官网的“数据概览”栏目获取。CRIS数据页面还提供其他气候变量数据集。未来将新增包含阿拉斯加、夏威夷及波多黎各在内的更多地理单元图层。 ### 地理单元 本图层为三类地理单元提供历史气候数值：县界、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矢量数据集制作。 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（United States Geological Survey, USGS）冲刷边界数据集，属于国家高精度水文数据库（National Hydrography Database Plus High Resolution）的组成部分。 ### 时间范围 本数据集针对1950年至2020年的每一年计算历史气候阈值（例如“日最高温超过90华氏度的天数”）。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“1十年”。 ### 数据引用 Livneh, B., T. J. Bohn, D. W. Pierce, F. Munoz-Arriola, B. Nijssen, R. Vose, D. R. Cayan, and L. Brekke, 2015: 适用于墨西哥、美国及加拿大南部1950-2013年的空间全覆盖水文气象数据集. 《科学数据》, 2, https://doi.org/10.1038/sdata.2015.42. ### 数据导出 支持将本数据导出为Shapefile、地理数据库（geodatabase）、GeoJSON等格式。