MIRCA-BC-USMX: Irrigated and planted fractions over the continental United States and Mexico for years 1992, 2002, and 2012

The MIRCA-BC-USMX project contains a spatially explicit mean annual cycle of monthly planted and irrigated fractions at 0.0625 degree (6 km) spatial resolution over the continental United States and Mexico for years 1992, 2002, and 2012. These fractions were generated by (1) reconciling the MIRCA2000 Global Monthly Irrigated and Rainfed Crop Areas dataset (Portmann et al., 2010) with the cropland and pasture classes of year 2001 of the harmonized NLCD_INEGI land cover dataset (Bohn and Vivoni, 2019b); (2) bias-correcting the irrigated and planted fractions to match state-by-state total irrigated and planted areas from government records in the United States (USDA, 2016) and Mexico (SADER, 2014; SAGARPA, 2016). These fractions have been added to land surface parameter files for the Variable Infiltration Capacity (VIC) model (Liang et al., 1994) version 5.1 (Hamman et al., 2018), extended to include the irrigation module of Haddeland et al. (2006), available on GitHub. The parameter files were taken from the MOD-LSP project, available on Zenodo (Bohn and Vivoni, 2019a). The VIC 5 image driver requires a "domain" file to accompany the parameter file. This domain file is also necessary for disaggregating the daily gridded meteorological forcings to hourly for input to VIC via the disaggregating tool MetSim (Bennett et al., 2018). We have provided a domain file compatible with the meteorological forcings of Livneh et al (2015) and the MIRCA-BC-USMX parameters, on Zenodo (Bohn et al., 2019a,b). Contents: Input Files county_codes.csv - table mapping the numerical codes for counties with the county names used by the US Census Bureau and USDA. This was created by parsing this information from US Census tables from years 1990, 2000, and 2010 and USDA tables from years 1992, 2002, and 2012 and manually reconciling discrepancies across years. Thus the names may not match county names in the original files exactly from year to year, but rather represent my own naming convention. However these discrepancies were rare. mun_us.0.01_deg.asc.tgz and mun_mx.0.0.01_deg.asc.tgz - gzipped tar archives containing mun_us.0.01_deg.asc and mun_mx.0.01_deg.asc, which are ascii-format ESRI grid files created by rasterizing publicly available shapefiles of US and Mexican counties/municipios. These have 0.01 degree (1 km) spatial resolution and pixels have numerical values equal to the codes in county_codes.csv. Output Files fplant_firr_bc.$LCYEAR.nc, where $LCYEAR is one of ("s1992","2001", or "2011") - NetCDF-format files at 0.0625 degree (6 km) resolution containing 12 monthly maps each of bias-corrected "fplant" (planted area fraction) and "firr" (irrigated area fraction) for a specific historical year.The value of $LCYEAR indicates the snapshot of the NLCD_INEGI harmonized land cover classification with which fplant and firr were reconciled (so that these area fractions would not exceed the total agricultural/pastoral area given by NLCD_INEGI). Values of fplant and firr were bias corrected so that state-wide total areas matched government records from USDA (USDA, 2014) and SAGARPA (SADER, 2014; SAGARPA, 2016). For $LCYEAR = ("s1992", "2001", "2011"), the agricultural census year used in the bias correction was (1992, 2002, 2012). fplant_firr_bc.2011.mun_mx.nc - same as fplant_firr_bc.2011.nc, but bias-corrected at the municipio level in Mexico. County-level bias correction was not possible in the US due to lack of sufficient resolution USDA records. Similarly, municipio-level records were not available in Mexico prior to year 2003. params.USMX.NLCD_INEGI.$LCYEAR.$YEAR1_$YEAR2.with_irrig.nc - VIC 5 image driver-compliant input parameter files into which fplant and firr of the given $LCYEAR have been inserted. $YEAR1 and $YEAR2 indicate the first and last years of MODIS data used to estimate the annual cycle of monthly LAI, fcanopy, and albedo (independent of the values of fplant and firr). params.USMX.NLCD_INEGI.2011.$YEAR1_$YEAR2.with_irrig.mun_mx.nc - same as params.USMX.NLCD_INEGI.2011.$YEAR1_$YEAR2.with_irrig.nc but with fplant and firr bias-corrected at the municipio level in Mexico. These parameters were created with scripts archived on GitHub (Bohn, 2019).MIRCA-BC-USMX项目包含一套空间显式的月尺度种植与灌溉占比年均循环数据集，空间分辨率为0.0625°（约6千米），覆盖美国本土与墨西哥，时间节点涵盖1992、2002与2012年。该数据集的占比通过以下两步生成：（1）将MIRCA2000全球月度灌溉与雨养作物面积数据集（Portmann等，2010）与协调化NLCD_INEGI土地覆盖数据集（Bohn与Vivoni，2019b）中2001年的耕地与牧场类别进行匹配校准；（2）对灌溉与种植占比进行偏差校正，使其与美国（美国农业部，2016）和墨西哥（墨西哥农业、畜牧与农村发展部（SADER，2014）、墨西哥农业与水利部（SAGARPA，2016））官方记录的各州/省总种植与灌溉面积相匹配。 该占比数据已被添加至可变下渗能力（Variable Infiltration Capacity, VIC）模型5.1版本（Liang等，1994；Hamman等，2018）的陆面参数文件中，该模型已扩展集成Haddeland等（2006）提出的灌溉模块，相关代码可在GitHub获取。上述参数文件源自Zenodo平台上的MOD-LSP项目（Bohn与Vivoni，2019a）。 VIC 5图像驱动程序需要配套的“域文件（domain file）”与参数文件一同使用。该域文件同样可用于将逐日格点气象强迫数据通过降尺度工具MetSim（Bennett等，2018）转换为逐小时尺度，以作为VIC模型的输入。我们已在Zenodo平台（Bohn等，2019a,b）提供了适配Livneh等（2015）气象强迫数据与MIRCA-BC-USMX参数的域文件。 ### 输入文件 1. county_codes.csv：用于将县级编码与美国人口普查局及美国农业部所使用的县级名称进行映射的表格。该表格通过解析1990、2000、2010年美国人口普查表格以及1992、2002、2012年美国农业部表格中的相关信息，并手动协调不同年份间的名称差异后生成。因此各年份的名称可能与原始文件中的县级名称不完全一致，而是采用了自定义的命名规范，但此类差异较为罕见。 2. mun_us.0.01_deg.asc.tgz 与 mun_mx.0.01_deg.asc.tgz：gzip压缩的tar归档文件，内含ASCII格式的ESRI网格文件mun_us.0.01_deg.asc与mun_mx.0.01_deg.asc。这些网格文件通过将公开可用的美国与墨西哥县级/市政边界矢量文件栅格化得到，空间分辨率为0.01°（约1千米），像素值与county_codes.csv中的编码一一对应。 ### 输出文件 1. fplant_firr_bc.$LCYEAR.nc，其中$LCYEAR为"s1992"、"2001"或"2011"中的一项：分辨率为0.0625°（约6千米）的NetCDF格式文件，包含对应历史年份的12张月度偏差校正后“种植占比（fplant）”与“灌溉占比（firr）”空间分布图。$LCYEAR代表用于与fplant和firr进行匹配校准的NLCD_INEGI协调化土地覆盖分类快照，以确保该占比不会超过NLCD_INEGI给出的总农业/牧草地面积。fplant与firr的数值已进行偏差校正，使其全州/省总种植与灌溉面积匹配美国农业部（USDA，2014）与墨西哥农业与水利部（SAGARPA，2014；SADER，2016）的官方记录。当$LCYEAR为"s1992"、"2001"或"2011"时，偏差校正所使用的农业普查年份分别为1992、2002、2012年。 2. fplant_firr_bc.2011.mun_mx.nc：与fplant_firr_bc.2011.nc内容一致，但针对墨西哥市政级行政单元进行了偏差校正。由于美国农业部缺乏足够分辨率的县级记录，无法对美国进行县级尺度的偏差校正；同理，墨西哥在2003年之前也未公开可用的市政级统计记录。 3. params.USMX.NLCD_INEGI.$LCYEAR.$YEAR1_$YEAR2.with_irrig.nc：符合VIC 5图像驱动程序要求的输入参数文件，已将对应$LCYEAR的fplant与firr数据嵌入其中。$YEAR1与$YEAR2代表用于估算月度叶面积指数（LAI）、冠层覆盖度（fcanopy）与反照率年循环的MODIS数据的起止年份，该部分计算与fplant和firr的数值无关。 4. params.USMX.NLCD_INEGI.2011.$YEAR1_$YEAR2.with_irrig.mun_mx.nc：与params.USMX.NLCD_INEGI.2011.$YEAR1_$YEAR2.with_irrig.nc内容一致，但采用了墨西哥市政级尺度偏差校正后的fplant与firr数据。上述参数文件通过存档于GitHub的脚本生成（Bohn，2019）。