## 3 Results and Discussion  
### Industrial Virtual Water Consumption in Gansu Province between 2007 and 2012  
#### 3.1.1 Water Consumption Coefficients of Various Industries  
Across all three industry categories, the complete water use coefficients are higher than the corresponding direct water use coefficients; this is expected as the concept of complete water use includes both direct and indirect water use (Table 1). In comparison to the secondary and tertiary industries, the complete water use coefficient of the primary industry category is much higher, and the difference between the complete water use coefficient and that of its direct water use coefficient is relatively insignificant, because large quantities of water are directly consumed by many of the industries in the primary industry and their production processes requiring few resources from the secondary and tertiary industries [40]. The secondary and tertiary industries complete water use is significantly higher than direct water use due to the high indirect water use of many of the composite industries that require considerable indirect water use [43; 44]. The catering and lighting industries, for example, consume large amounts of agricultural and electrical products, respectively, resulting in large amounts of indirect water consumption during production. Consequently, these industries are labeled the \"invisible water-consuming industries\" [45; 46]. In comparison with the tertiary industry class, the direct water use coefficient of the secondary industry category is relatively large. Secondary industries like the steel and electricity industries consume large amounts of direct water for cooling and rinsing [47; 48]. These results suggest that improving water use efficiency in primary industries, and decreasing the use of primary industry products in secondary and tertiary industries, be employed to effectively reduce water consumption across all three industry classes [49]. From 2007 to 2012, the complete and direct water use coefficients of both the primary and secondary industries showed a trend of continuous decline. The decline in the complete water use coefficient in the primary industry is mainly related to the decline in the direct water use coefficient, while for the secondary industry the complete water use coefficient was influenced significantly by both direct water use and the use of water-abundant products of the primary industry [40; 50]. The requirements of increasing water use efficiency and water recycling in Gansu province by the 11 th Five-Year Plan (Outline of the Eleventh year plan for National Economy and Social Development in the People's Republic of China) from 2006 to 2010 with \"six necessaries\" principles, including maintaining steady andrapid economic development, accelerating transformation of economic growth modalities, improving self-directed innovation capabilities, promoting the coordinated development of urban and rural areas, strengthening the construction of a harmonious society, and deepening reforms openings [51], also contributed to the decline of direct water use in the primary and secondary industries. It is estimated that about 43 provincial-level pilot projects were designed to promote water-saving, through optimized and upgraded agricultural and industrial sectors [52]. These measures had significant results. Primarily, Gansu focused on promoting water-saving agricultural techniques specific to local conditions [53]. These techniques contributed to a marked decrease in the agricultural irrigation quota, an increase in grain output, and a significant reduction in the direct water use coefficient of primary industry [54]. The success of promoting appropriate local techniques should be noted - since the impacts of technical and infrastructure changes often vary from region to region, it is suggested that each city in Gansu establish context specific measures towards the promotion of coordinated economic and ecological development province-wide.