Spatial-temporal assessment of water footprint, water scarcity and crop water productivity in a major crop production region

Irrigated agriculture has had an enormous influence on food security, water security and human well being. Water footprint (how much water is used), water scarcity (how scarce water is), and crop water productivity (how much productivity irrigation adds) are important indicators for evaluating sustainability in irrigated agriculture. Yet these interrelated indicators have not been studied simultaneously at the county level - the basic administrative unit of agricultural planning and water management in countries such as China, India and Japan. To fill this knowledge gap, we performed a demonstration in China's major crop production region, the North China Plain (NCP)'s 207 counties from 1986 to 2010. The results show that the irrigated agriculture's annual water footprint in the North China Plain increased from 53 billion m(3) in 1986 to 78 billion m(3) in 2010. All counties faced water scarcity during 1986-2010 even as the average crop water productivity increased from 0.90 kg m(-3) to 1.94 kg m(-3). There are 173 NCP counties suffering severe water scarcity but still producing significant crop yield with a high water footprint, a red flag of unsustainable irrigated agriculture. This study has implications for revealing potential unsustainable conditions in irrigated agriculture worldwide. (C) 2019 Elsevier Ltd. All rights reserved.