The water footprint of coffee in Yunnan, China
摘要
In order to measure the impact of Yunnan coffee cultivation and primary processing on the water resources and water environment, this study calculated the water footprint (WF) of the cultivation and processing stages of Yunnan coffee by employing the methodology described in the Water Footprint Evaluation Manual (Hoekstra 2011). The results showed that the WF of coffee cherries at cultivation stage was 832m3/t, of which green WF accounted for 70.3% and grey WF accounted for 29.7%. At the primary processing stage, different processing methods and effluent discharge scenarios could lead to significantly different grey WF. Under the scenario of direct discharge of waste water, the grey WF of green coffee was 76,125 m3/t and 6544 m3/t for wet and semi-wet processing, respectively, and it could be reduced by 95–99% when the wastewater was discharged according to standards. When using micro-water processing or dry processing, the grey WF was zero. The WF of green coffee was 5203 m3/t under conventional cultivation, micro -water processing scenarios, which corresponds to a virtual water content of only 43.4 L for a cup (125 ml) of coffee. The coffee cherry micro-water processing technology significantly reduces water consumption during processing and eliminates wastewater generation, making it highly commendable for widespread adoption.