Assessing the water challenge of a new green revolution in developing countries

被引:276
作者
Rockstrom, Johan
Lannerstad, Mats
Falkenmark, Malin
机构
[1] Stockholm Environm Inst, SE-10691 Stockholm, Sweden
[2] Stockholm Resisience Ctr, SE-10691 Stockholm, Sweden
[3] Linkoping Univ, Dept Water & Environm Studies, SE-58183 Linkoping, Sweden
[4] Stockholm Int Water Inst, SE-11151 Stockholm, Sweden
关键词
consumptive water use; food security; water productivity; water resource management;
D O I
10.1073/pnas.0605739104
中图分类号
O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];
学科分类号
07 ; 0710 ; 09 ;
摘要
This article analyzes the water implications in 92 developing countries of first attaining the 2015 hunger target of the United Nations Millennium Development Goals and then feeding a growing population on an acceptable standard diet. The water requirements in terms of vapor flows are quantified, potential water sources are identified, and impacts on agricultural land expansion and water tradeoffs with ecosystems are analyzed. This article quantifies the relative contribution from infiltrated rainwater/green water in rainfed agriculture, and liquid water/blue water from irrigation, and how far water productivity (WP) gains can go in reducing the pressure on freshwater resources. Under current WP levels, another 2,200 km(3).yr(-1) of vapor flow is deemed necessary to halve hunger by 2015 and 5,200 km(3).yr(-1) in 2050 to alleviate hunger. A nonlinear relationship between vapor flow and yield growth, particularly in low-yielding savanna agro-ecosystems, indicates a high potential for WP increase. Such WP gains may reduce additional water needs in agriculture, with 16% in 2015 and 45% by 2050. Despite an optimistic outlook on irrigation development, most of the additional water will originate from rain-fed production. Yield growth, increasing consumptive use on existing rain-fed cropland, and fodder from grazing lands may reduce the additional rain-fed water use further by 43-47% until 2030. To meet remaining water needs, a cropland expansion of approximate to 0.8% yr(-1), i.e., a similar rate as over the past 50 years (approximate to 0.65% yr(-1)), seems unavoidable if food production is to occur in proximity to local markets.
引用
收藏
页码:6253 / 6260
页数:8
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