Global dataset of historical yields of major crops (1.2+1.3 aligned version)

The Global Dataset of Historical Yield (GDHY_v1_2_v1_3) offers annual time series data of 0.5-degree grid-cell yield estimates of major crops worldwide for the period 1981-2020. The crops considered in this dataset are maize, rice, wheat and soybean. The unit of yield data is tons per hectare (t/ha). The grd-cell yield data were estimated using the satellite-derived vegetation index and FAO-reported country yield statistics. Maize and rice have the data for each of two growing seasons (major/secondary). "Winter" and "spring" are used as the growing season categories for wheat. Only "major" growing season is available for soybean. These growing season categories are based on the global crop calendars (Sacks et al. 2010, DOI: 10.1111/j.1466-8238.2010.00551.x). The geographic distribution of harvested area changes with time in reality, but we used the time-constant data in 2000 (Monfreda et al., 2008, doi:10.1029/2007GB002947). Many missing values are found in the first (1981) and last (2020) years because grid-cell yields are not estimated for these years since the growing season is not completed when it spans two calendar years. The data for the period 1981-2010 are the same with the version 1.2 (GDHY_v1_2). For the period 2011-2020, a newly created version 1.3 using the satellite products that are different with earlier versions was alighned to ensure the continuity of yield time series. This version is therefore called "the alighned version v1.2+v1.3".

全球历史产量数据集（GDHY_v1_2_v1_3）提供了1981-2020年全球主要作物的0.5度网格单元产量估算年度时间序列数据。本数据集涵盖玉米、水稻、小麦与大豆四类作物，产量数据单位为吨每公顷（t/ha）。网格单元产量数据通过卫星反演植被指数与联合国粮食及农业组织（Food and Agriculture Organization，FAO）公布的国家产量统计数据估算得到。玉米与水稻包含主、副两个生长季的对应数据；小麦的生长季划分为冬小麦季与春小麦季；大豆仅提供主生长季的数据。上述生长季划分标准基于全球作物物候历（Sacks等，2010，DOI: 10.1111/j.1466-8238.2010.00551.x）。现实中收获面积的地理分布随时间动态变化，但本数据集采用2000年的恒定面积数据（Monfreda等，2008，DOI:10.1029/2007GB002947）。由于部分生长季跨两个日历年且尚未完成，1981年与2020年的网格单元产量未完成估算，因此这两年存在大量缺失值。1981-2010年的数据与v1.2版本（GDHY_v1_2）完全一致。针对2011-2020年时段，研究团队采用与早期版本不同的卫星产品构建了v1.3版本，并对其进行对齐处理以保障产量时间序列的连续性，因此该整合版本被命名为"对齐版v1.2+v1.3"。

搜集汇总

背景与挑战

背景概述

这是一个全球历史产量数据集，覆盖1981-2020年，提供玉米、水稻、小麦和大豆的0.5度网格单元产量估计，单位为吨/公顷。数据基于卫星植被指数和FAO国家统计估算，考虑了作物的生长季节（如玉米和水稻分两个季节），并通过对齐v1.2和v1.3版本确保时间序列连续性。数据集特点包括全球网格化覆盖、主要作物产量时间序列、以及使用固定收获面积分布。