Measuring sustainability as distance to ideal position of economy, society and environment: Application to China's provincial water resources (2004-17).

Water is fundamental for life and hence, ensuring its sustainability is essential. Indices can be useful tools to monitor sustainability, understand trends and take necessary actions. China is one of the world's most water-strained countries, and herein, a spatially and temporally-replicable index is developed to measure the sustainability of water resources in its provinces (from 2004-17). Unlike previous indices that aggregate contributing indicators by taking their mean (weighted, unweighted, arithmetic, geometric, etc.), the present study proposes a distance-approach to measure sustainability - enabling it to circumvent concerns on choice of weights and aggregation method. This method of quantification is in conjunction with the 'tripartite' conceptualization of sustainability - which says that it is the equilibrium among the economy, society and environment. It is assumed that provinces can be plotted in a 3-dimensional plane using numeric values denoting their economic, social and environmental development. Thereafter, the measure of sustainability would be the distance of the province to the ideal point of development in these three dimensions. The economic, social and environmental dimensions of water resources are computed by choosing appropriate indicators and applying TOPSIS (Technique -for Order Preference by Similarity to Ideal Solution). The trends in indices over the years are analyzed using a modified Mann-Kendall test. Further, the indices are checked for any spatial correlation (among the provinces) using Moran's I. Lastly, factors (such as forest cover, fertilizer use and illiteracy) that may act as determinants of the indices are examined through panel regression. The results of the study provide an extensive view of water resources sustainability in China since the past decade, and can be useful for steering the direction of water policy actions in the future.