Methods and accounts for water withdrawal at the city level and evaluation of sectoral water saving in China

Zhang, Zongyong (2021) Methods and accounts for water withdrawal at the city level and evaluation of sectoral water saving in China. Doctoral thesis, University of East Anglia.

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Abstract

In the context of the freshwater crisis, two-thirds of the cities in China suffer from freshwater scarcity, and there are restrictions on the use of water by industries. Although ‘Redline Regulation’ policies as core regulations were set to save water through improving water-withdrawal efficiency, China still has transnationally low efficiency owing to poor sectoral water-saving initiatives. Control on efficiency still lacks targeting and prioritization to specific sectors and cities.

To save water at the city level has become a priority strategy of regulation and requirement in water field for China, yet how to conduct and realize it among various cities or sectors has not been fixed. Although high water-consumption activities are proposed in a few cities, comparison across the whole cities and economic-sectors could not be realized. Accounting for sectoral water withdrawal at the city level could help planners regulate water use in different sectors to improve water use efficiency. Thus, high-resolution water accounting methods and datasets in terms of spatiality and economic-sector are critical for China’s water saving. What is more, it is meaningful to investigate sectoral water-saving potential and implication for alleviating scarcity, to promote sustainable water use and economic development.

Yet due to lack of measured efficiency data, there remains a dearth of water withdrawal accounting methods and datasets, as well as water availability and scarcity data, no matter for total or sectoral amounts for prefectural cities. These data limitations from water statistics and accounting in China are significant, long-lasting for two decades (typically data from 1995 are still being utilized in research, and urgently need to be updated). Compared to developed countries, such as Australia etc., water accounting in China has already fallen behind. Disaggregated sectoral water withdrawal accounting is not readily available for China. Not all cities in China have the water accounting as ‘routine’ management activities. Approximately one fifth of 343 cities do not collect or develop water data statistics (with no bulletins). For data of the other four fifths of cities, there are only total numbers of six types provided (with differences in terms of statistical calibers etc.). New accounting methodology is needed to develop, which should be suitable for new cases according to specific statistical conditions of different sectors, and China’s own actual state. This is quite different from developed countries. Water withdrawal statistics in China are patchy, and water data across all sectors at the city level appear to be relatively insufficient.

Hence, in administrative and territorial scopes, I develop a general framework to, for the first time, account for water withdrawal of 65 economic-social-environmental sectors in cities of China. This novel methodology is based on water withdrawal efficiency, as benchmark performance, from point-sourced surveys in China (led and carried out by the Ministry of Ecology and Environment) in 2015. It features in selection of 22 driving forces, and I connect each size indicator with its unique water-withdrawal efficiency. The general framework is applied because only inconsistent water statistics collected from different data sources at the city level are available.

Applying this general framework, I account for water withdrawal of all 65 economic-socio-environmental sectors for all 343 prefectural cities in China, using a 2015 data benchmark. Then I compare different scopes and methods of official accounts and statistics from various water withdrawal datasets. I further account for total water availability, and water scarcity status in each of 343 prefectures. These high-resolution water accounts in terms of spatiality and economic-sector are unprecedented in China.

From the water withdrawal datasets, I first find 1) different from conventional perceptions that agriculture is usually the largest water user, industrial and household water withdrawal may also account for the largest percentages in the water-use structure of some cities, for example Luoyang (central) for industrial water withdrawal; and Guangzhou (south) and Qingdao (east) for household water withdrawal. 2) The difference among annual household water use per resident in the urban areas of different cities is relatively small (as is the case for rural areas), but that between urban and rural areas is large. Thus, increased attention should be paid to controlling industrial and urban household water use in particular cities, such as Xi’an (west), Shaoxing (east), Taizhou (east), Luoyang (central), and Chongqing (southwest).

These high-resolution water scarcity accounts throw light upon cities suffering from water scarcity, and low water-efficiency sectors at the city level: I find 3) agricultural and industrial sectors with high water-withdrawal intensity exist in representatively small developing cities. 4) The top 10% of low-efficiency industrial sectors represent 46% industrial water withdrawal. Examples of 3) and 4) are listed below: papermaking and product manufacturing in Chenzhou (central), Lincang (southwest) and Qiqihar (northeast); liquor, beverage and tea manufacturing in Jingdezhen (mid-east), Anqing (mid-south) and Wuzhou (southwest); electricity and hot water supply in Changde (mid-south); and agricultural-related sectors in Zhoukou (central), Linyi (east) and Fuyang (mid-south). Thus, attention should also be paid to both coordinating production scales in water-scarce cities, and reducing water withdrawal intensities for stringent management.

What is more, to investigate sectoral water-saving potential and implication for alleviating stress, I build water-saving scenarios in 41 industrial and 5 agricultural sectors across 180 water-scarce cities, by assuming a convergence of below-average efficiencies to the national sector-average for technology improvement.

I find overall industrial water-withdrawal efficiency could improve by 20%, satisfying the redline regulation. 18.9 km3 (±3.2%) water saving in industry and 50.3 km3 (±2.3%) in agriculture would be achieved, equivalent to the annual water demand of Russia. A minority of sectors could contribute to most water savings whilst minimizing economic disruptions. In contrast, implementing water efficiency measures in the majority of sectors would result in significant economic change to achieve identical savings. As a result, water efficiency improvements should be targeted towards this minority of sectors: cloth(ing) and chemical manufacturing in industry, and rice, vegetables and fruits cultivation in agriculture. Cities with above-average water saving potential are Suzhou (south), Nanjing (southeast), Xiangtan (mid-south), Guangzhou (south) and so on for industry; Bayannur (north), Kashi (northwest), Akesu (northwest), and Daqing (northeast) etc. for agriculture.

There would be 18 cities with population of 40 million alleviated below the scarcity threshold (40%) and shake off water scarcity at identical water availability levels, for example Xining, Zhangye, Hotan, Haidong (northwest), Jincheng, Yulin (west), Jilin city (northeast), Wuxi and Xiangtan (mid-south). At the national level, mean scarcity level of water-scarce cities would fall by 20 percentage points from 96% to 76%, being alleviated to sub extreme-scarcity level.

Through unique account, I propose that sectoral water saving should be well positioned to alleviate water stress, through improving sectoral water use efficiency, especially by reducing sectoral water withdrawal intensities with little cost to the economy. I think sectors of low efficiency in water scarce cities should be well-targeted. Requiring all sectors to evenly or in-general improve water efficiency does not represent an optimal policy choice. In sum, this complete analysis through unique account would bring a conceptual advance.

Our results help to enable targeted saving strategies and identify priorities, to facilitate more effective water regulation through optimizing efforts for improving efficiency. At last, these geo-data of high resolution could be used directly in input-output models, consumption-based accounting and structural decomposition analyses. The data accounted would facilitate proceeding to in-depth exploration. Data could also help gain in-depth insights, concerning sectoral water withdrawal, and alleviating water stress from local activities.

Item Type: Thesis (Doctoral)
Faculty \ School: Faculty of Social Sciences > School of International Development
Depositing User: Chris White
Date Deposited: 14 Dec 2021 11:02
Last Modified: 14 Dec 2021 11:02
URI: https://ueaeprints.uea.ac.uk/id/eprint/82669
DOI:

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