Measuring Water Footprint on a Lake Basin Scale: A Case Study of Lake Dianchi, China

Water scarcity in lake basins has caused severe environmental problems. Water footprint assessment at the basin level is becoming a popular issue in water sustainability research. This study establishes a comprehensive water footprint assessment framework on the scale of a lake basin by using the top–down method. The components of water footprint assessment include agricultural water footprint, industrial water footprint, domestic water footprint, ecological environment water footprint, and virtual water flow, including virtual water imports and exports. This study used Lake Dianchi Basin in China as the case study area, based on published data, quantifying the total water footprint and measuring the water sustainability of Lake Dianchi Basin from 2000 to 2011. The results show that the average annual total water footprint for Lake Dianchi Basin was 28.18 × 10⁸ m³, 95.4% of which was the internal water footprint. Agricultural production used most of the water, accounting for 74.1% of the total water footprint. The per capita water footprint was 960.51 m³/year, which was higher than those in most other regions of China. Lake Dianchi Basin should improve its water sustainability in terms of its internal and external water footprints. Importing water from other regions in both real and virtual forms should be considered in terms of the external water footprint. This study provides new insights on water footprint assessment methodology at the basin level and for improving basin water resource management from the macroscopic angle.