A Pilot Global Assessment of Environmental Water Requirements and Scarcity
A Pilot Global Assessment of Environmental Water Requirements and Scarcity
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DOI：
10.1080/02508060408691785
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发表时间：
2004-09
影响因子：
2.6
通讯作者：
V. Smakhtin;C. Revenga;P. Döll
中科院分区：
文献类型：
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作者：
V. Smakhtin;C. Revenga;P. Döll
摘要本文首次尝试估算在全球范围内维持依赖淡水的生态系统所需的水量。这一总的环境需水量包括与生态有关的低流量和高流量部分，并取决于环境用水管理的目标。这两个组成部分都涉及到河流流量的变化和估计的概念规则，从全球水文模型模拟的流量时间序列。水压力指标进一步界定，这表明世界河流流域的可利用水的比例，目前提取直接供人类使用，这种使用是在冲突与环境用水的要求。本文对世界128个主要河流流域和流域的环境需水量进行了估算。它表明，大约20%至50%的平均年河流流量在不同的流域需要分配给淡水依赖的生态系统，以保持他们在公平的条件。在亚洲和北非、澳大利亚部分地区、北美和欧洲的许多发展中国家，这是不可能的，因为这些国家目前的直接取水总量（主要用于灌溉）已经满足了估计的环境用水需求。目前，超过14亿人生活在环境用水高度紧张的河流流域。这一数字将随着取水量的增加而增加，如果环境用水的分配仍然超出河流流域管理的通常做法。本文件建议，环境需水量的估算应成为全球水资源评估和全球粮食生产预测的组成部分。
Abstract This paper presents a first attempt to estimate the volume of water required for the maintenance of freshwater-dependent ecosystems at the global scale. This total environmental water requirement consists of ecologically relevant low-flow and high-flow components and depends upon the objective of environmental water management. Both components are related to river flow variability and estimated by conceptual rules from discharge time series simulated by the global hydrology model. A water stress indicator is further defined, which shows what proportion of the utilizable water in world river basins is currently withdrawn for direct human use and where this use is in conflict with environmental water requirements. The paper presents an estimate of environmental water requirements for 128 major river basins and drainage regions of the world. It is shown that approximately 20 to 50 percent of the mean annual river flow in different basins needs to be allocated to freshwater-dependent ecosystems to maintain them in fair conditions. This is unlikely to be possible in many developing countries in Asia and North Africa, in parts of Australia, North America, and Europe, where current total direct water withdrawals (primarily for irrigation) already tap into the estimated environmental water requirements. Over 1.4 billion people currently live in river basins with high environmental water stress. This number will increase as water withdrawals grow and if environmental water allocations remain beyond the common practice in river basin management. This paper suggests that estimates of environmental water requirements should be the integral part of global water assessments and projections of global food production.