Sectorial Water Use Trends in the Urbanizing Pearl River Delta, China

Abstract

Assessing and managing water use is crucial for supporting sustainable river basin management and regional development. The first consistent and comprehensive assessment of sectorial water use in the Pearl River Delta (PRD) is presented by analysing homogenized annual water use data from 2000 to 2010 in relation to socio economic statistics for the same period. An abstraction of water use, using the concept of water use intensity, and based on equations inspired by those used in global water resource models, is developed to explore the driving forces underlying water use changes in domestic, industrial and agricultural sectors. We do this at both the level of the region as a whole, as well as for the nine cities that constitute the PRD separately. We find that, despite strong population and economic growth, the PRD managed to stabilize its absolute water use by significant improvements in industrial water use intensities, and early stabilisation of domestic water use intensities. Results reveal large internal differentiation of sectorial water use among the cities in this region, with industrial water use intensity varying from -80 to +95% and domestic water use intensity by +/- 30% compared to the PRD average. In general, per capita water use is highest in the cities that industrialised first. Yet, all cities except Guangzhou are expected to approach a saturation value of per capita water use much below what is suggested in recent global studies. Therefore, existing global assessments probably have overestimated future domestic water use in developing countries. Although scarce and uncertain input data and model limitations lead to a high level of uncertainty, the presented conceptualization of water use is useful in exploring the underlying driving forces of water use trends.

Water use in a heavily urbanized delta : scenarios and adaptation options for sectorial water use in the Pearl River Basin, China

“…Chen (2006a) concludes that the water management system in the PRD neglects managing the water uses because the PRD is a water abundant region. In previous work, I confirm that on annual time scales the PRD has enough water supplies to fulfil its water use2 (Yao et al 2015). Nevertheless, seasonal water shortages have occurred due to the severe salt intrusion.…”

“…To obtain consistent trends of sectorial water uses during the study period, data homogenization as reported by Yao et al (2015) was also applied here. …”

“…A value of 50 L/person-day was used as DSWI min the minimum requirement (Gleick 1996). The maximal domestic structural water use intensity (DSWI max ) and the curve parameter (γ) are fitted to the PRD based on its reported water-use records from 2000 to 2010, following a previous study (Yao et al 2015 assume that technological transition in the agricultural sector follows a similar rate as in the manufacturing sector. …”

“…In addition, the PRD has a very different technological improvement path compared to China (Yao et al 2015). Being allocated in the right-upper corner of the HE classification I employ here, the PRD has a better economic and institutional starting position for technological improvement compared to many other regions in China.…”

“…Ultimately, national and global sustainable development can only be achieved by the cumulative efforts of each individual region where practical adaptive measurements are employed. Previous research on China's Pearl River Delta (PRD) suggests that a global assessment may be insufficient to reflect future trends of sectorial water uses on a regional scale (Yao et al 2015). Against this background, in this paper I attempt to address water-use development at a regional level in the near future in a way that is consistent with global socioeconomic scenarios.…”