MIRCA2000
收藏资源简介：
Crop water requirements of irrigated crops and crop water use of rainfed crops is calculated by the Global Crop Water Model (GCWM) for the period 1998-2002 based on a soil water balance performed in daily time steps.Crop yields of rainfed and irrigated crops are distinguished by downscaling yields reported in national and subnational agricultural statistics (Monfreda et al., 2008) by considering drought stress simulated for rainfed agriculture. Virtual water contents are calculated as ratio between crop water use and crop yield. Domestic virtual water flows are determined by calculating a balance between crop production and crop consumption at grid cell level and establishing flows from surplus cells (major production areas) to deficit cells (highly populated regions). Crop growing areas, sowing and harvest dates were derived from the global data set of monthly irrigated and rainfed crop areas around the year 2000 (MIRCA2000). Consequently, crop water use (blue and green) is computed for the crops wheat, rice, maize, barley, rye, millet, sorghum, soybeans, sunflower, potatoes, cassava, sugar cane, sugar beet, oil palm, rapeseed/canola, groundnuts/peanuts, pulses, citrus, date palm, grapes/vine, cocoa, coffee, cotton and unspecified other crops (other perennial crops, other annual crops, fodder grasses). For the calculation of crop yields, virtual water contents and virtual water flows we distinguish in addition the usage of maize, rye and sorghum for grain or forage. Virtual water flows are computed for crops traded mainly as primary commodities (all specific crops except of sugar cane, sugar beet and cotton). The data set has a spatial resolution of 5 arc-minutes by 5 arc-minutes. Format: ASCII-grids (global, 5 arc-minute) or text files (country data). For a detailed description of each folder see https://www.uni-frankfurt.de/45218023/MIRCA and https://www.uni-frankfurt.de/45218031/Data_download_center_for_MIRCA2000.
本数据集由全球作物水模型（Global Crop Water Model, GCWM）基于以日为时间步长的土壤水量平衡计算，得到1998-2002年期间灌溉作物的需水量与雨养作物的耗水量。通过对国家及次国家农业统计数据（Monfreda等，2008）中的产量进行降尺度处理，并考虑雨养农业的干旱胁迫模拟，区分雨养与灌溉作物的产量。虚拟水（Virtual Water）含量以作物耗水量与作物产量的比值计算得到。国内虚拟水流量通过计算栅格单元层面的作物生产与消费平衡，确定从盈余单元（主要生产区）到亏缺单元（人口稠密地区）的流量。作物种植面积、播种与收获日期源自2000年前后全球灌溉与雨养作物月度面积数据集（MIRCA2000）。进而针对以下作物计算作物耗水量（蓝水与绿水）：小麦、水稻、玉米、大麦、黑麦、粟、高粱、大豆、向日葵、马铃薯、木薯、甘蔗、甜菜、油棕、油菜/甘蓝型油菜、花生、食用豆类、柑橘类作物、海枣、葡萄、可可、咖啡、棉花，以及其他未特指作物（其他多年生作物、其他一年生作物、饲用牧草）。在计算作物产量、虚拟水含量及虚拟水流量时，还需区分玉米、黑麦与高粱的籽粒与饲用用途。虚拟水流量的计算对象为主要以初级商品形式贸易的作物（除甘蔗、甜菜与棉花外的所有特定作物）。本数据集的空间分辨率为5角分×5角分，数据格式包括ASCII栅格（全球范围，5角分）与文本文件（国家级数据）。各文件夹的详细说明参见：https://www.uni-frankfurt.de/45218023/MIRCA 及 https://www.uni-frankfurt.de/45218031/Data_download_center_for_MIRCA2000。
