GDHY_version_1.2
收藏资源简介：
The Global Dataset of Historical Yield (GDHY_v1_2) offers annual time series data of 0.5-degree grid-cell yield estimates of major crops worldwide. The crops considered in this dataset are maize, rice, wheat and soybean. The unit of yield data is t/ha. The grd-cell yield data were estimated using the satellite-derived crop-specific 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 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., 208, doi:10.1029/2007GB002947). Many missing values are found in the first (1981) and last (2011) years because grid-cell yields are not estimated for these years when growing season spans two calendar years.
《全球历史产量数据集》（GDHY_v1_2）提供了全球范围内主要作物0.5度网格单元年度时间序列产量估计数据。本数据集纳入的作物包括玉米、水稻、小麦和大豆。产量数据的单位为吨/公顷。网格单元产量数据是通过卫星获取的特定作物植被指数以及粮农组织（FAO）报告的国家产量统计数据估算得出。玉米和水稻涵盖了两个生长季节（主要/次要）的数据。对于小麦，以“冬季”和“春季”作为生长季节的分类。大豆仅提供主要生长季节的数据。这些生长季节的分类依据于Sacks等人（2010年，DOI：10.1111/j.1466-8238.2010.00551.x）的研究。实际上，收获区域的地理分布随时间而变化，但本数据集采用了2000年（Monfreda等人，2008年，doi：10.1029/2007GB002947）的时间恒定数据。由于生长季节跨越两个日历年，因此在首年（1981年）和末年（2011年）存在许多缺失值，这是因为当年网格单元产量未进行估算。
