Assessing water footprint at river basin level: a case study for the Heihe River Basin in northwest China

Abstract

Abstract. Increasing water scarcity places considerable importance on the quantification of water footprint (WF) at different levels. Despite progress made previously, there are still very few WF studies focusing on specific river basins, especially for those in arid and semi-arid regions. The aim of this study is to quantify WF within the Heihe River Basin (HRB), a basin located in the arid and semi-arid northwest of China. The findings show that the WF was 1768 million m 3 yr −1 in the HRB over [2004][2005][2006]. Agricultural production was the largest water consumer, accounting for 96 % of the WF (92 % for crop production and 4 % for livestock production). The remaining 4 % was for the industrial and domestic sectors. The "blue" (surface-and groundwater) component of WF was 811 million m 3 yr −1 . This indicates a blue water proportion of 46 %, which is much higher than the world average and China's average, which is mainly due to the aridness of the HRB and a high dependence on irrigation for crop production. However, even in such a river basin, blue WF was still smaller than "green" (soil water) WF, indicating the importance of green water. We find that blue WF exceeded blue water availability during eight months per year and also on an annual basis. This indicates that WF of human activities was achieved at a cost of violating environmental flows of natural freshwater ecosystems, and such a WF pattern is not sustainable. Considering the large WF of crop production, optimizing the crop planting pattern is often a key to achieving more sustainable water use in arid and semi-arid regions.

Sensitivity and uncertainty in crop water footprint accounting: a case study for the Yellow River basin

“…Aldaya and Llamas, 2008;Zeng et al, 2012;Sun et al,referring to an average value for a certain area and period. However, the water footprint of a crop is always estimated based on a large set of assumptions with respect to the modelling approach, parameter values, and data sets for input variables used, so that outcomes carry substantial uncertainties (Mekonnen and Hoekstra, 2010;Hoekstra et al, 2011).…”

Water consumption from hydropower plants – review of published estimates and an assessment of the concept

“…2.2 and 2.3 are all based on annual data (i.e., the evaporation rates and power production are both annual numbers). This is not always explicitly expressed, and there are studies calculating the water footprint on a monthly basis (e.g., Zeng et al, 2012;Hoekstra et al, 2012). As the periodicity is important to consider, an example derived from the work of Yesuf (2012) is presented (Fig.…”

“…Zeng et al (2012) demonstrates the water footprint sustainability assessment, defined by Hoekstra et al (2011) on a river basin level, where a "sustainability concern" should be raised when the water footprint exceeds the available blue water component (Hoekstra et al, 2011). The blue water is defined as the blue water resources under natural conditions and without human intervention, subtracted the environmental flow requirements.…”

Climate change, growing season water deficit and vegetation activity along the north–south transect of eastern China from 1982 through 2006

“…Therefore, the fully physically-based evapotranspiration model that captures main meteorological variables in its formation is more desirable (McVicar et al, 2012a), particularly for evaluating the vegetation ecohydrological responses to changing climates (Tan, 2007;Donohue et al, 2009;Scheiter and Higgins, 2009;Donohue et al, 2012). Vegetation change in coverage or composition and their relationships with local or regional water balance have been extensively studied at different spatial scales (Niehoff et al, 2002;Hundecha and Bárdossy, 2004;Sun et al, 2005Sun et al, , 2006Zhang and Schilling, 2006;McVicar et al, 2007;Wei and Zhang, 2010;Zeng et al, 2012;Zang et al, 2012), particularly with dramatic forest disturbance such as intensive logging (Zhang et al, 1999;Andréassian, 2004;Brown et al, 2005) or forest fires (Lavabre et al, 1993). These significant forest disturbances dramatically change the vegetation coverage and consequently alter the hydrological processes.…”