摘要
本研究说明了如何将全球已有的地球系统数据集用于世界上信息缺乏的地区进行水资源评价。8km分辨率的地理空间分析表明:64%的非洲人口所依赖的水资源是有限的和非常不稳定的。在那些有河流的地方,河流廊道水流对于增加当地径流、减少气候波动的影响以及改善淡水获取条件都是非常关键的。农田在非洲最干旱的地区有很大比例,其中39%的灌溉无法持续。25%的人口面临着严重的水资源长期过度使用和水资源压力,另外13%的人口中每代人都会经历一次干旱造成的水资源压力。令人感到矛盾的是,对于绝大多数非洲人来说,水资源压力程度仍然很低,反映了较差的水资源基础设施与服务,以及较低的水资源利用水平。用水的适度增长可以降低对经济发展的制约,减少污染,以及降低对人类健康的挑战。开发一种明确的地理空间指示器,该指示器能综合集成生物地球物理、社会经济和工程设计等方面的信息,这将成为未来全球水资源评价中一个重要的步骤。
This study demonstrates the use of globally available Earth system science data sets for water assessment in otherwise information-poor regions of the world. Geospatial analysis at 8 km resolution shows that 64% of Africans rely on water resources that are limited and highly variable. Where available, river corridor flow is critical in augmenting local runoff, reducing impacts of climate variability, and improving access to freshwater. A significant fraction of cropland resides in Africa's driest regions, with 39% of the irrigation nonsustainable. Chronic overuse and water stress is high for 25% of the population with an additional 13% experiencing drought-related stress once each generation. Paradoxically, water stress for the vast majority of Africans typically remains low, reflecting poor water infrastructure and service, and low levels of use. Modest increases in water use could reduce constraints on economic development, pollution, and challenges to human health. Developing explicit geospatial indicators that link biogeophysical, socioeconomic, and engineering perspectives constitutes an important next step in global water assessment.
