Impact of climate change and drought regime on water footprint of crop production: the case of Lake Dianchi Basin, China

Water availability for agricultural production may be significantly influenced by climate change. A decline in precipitation along with an increase in temperature will augment crop irrigation water requirement, especially during drought periods. Water footprint (WF) was provided to assess water resources utilization in the agricultural production process under climate variation. This paper analyzes the impact of climate change on WF of crop production at Lake Dianchi Basin, China, during 1981–2011. Results indicate that: (1) Crop evapotranspiration and irrigation water requirement of crop products presented an uptrend owing to the climate factors variation in the study period. (2) The total WF, mainly influenced by temperature and precipitation, experienced a steady upward tendency, exhibiting a trend of 50.42 m³ ton⁻¹ yr⁻¹. WF_green showed a decreasing tendency, while WF_blue showed the opposite, with an abrupt growth appeared in 2010 due to the extreme drought. (3) SPEI can be effectively used to identify and track regional drought events, which could result in the increase in WF_blue. WF_green was positively correlated with the average SPEI, whereas WF_blue showed the opposite. Nevertheless, water use efficiency and agricultural adaption management should be improved to cope with climate change.