The Driving Effects of the Total Water Use Evolution in China from 1965 to 2019

Abstract

To understand the influence mechanism of the total water use evolution in a certain region more deeply, it is necessary to accurately identify the driving effects of the total water use evolution, and quantitatively analyze the influence of the driving effects on the total water use evolution. In this research, we studied the driving effects of the total water use evolution in China from the perspective of multi-year long time-series in the whole country for the first time. Through the logarithmic mean Divisia index (LMDI) decomposition method, we constructed an LMDI decomposition model for the regional total water use evolution, and decomposed the total water use evolution in China and its five stages from 1965 to 2019 into the water use intensity effect (WUIE), sector proportion effect (SPE), per capita total economy effect (PCTEE), and total population effect (TPE). We also considered the driving effects of the total water use evolution when the population or economic proportion changed in the six major districts in China for the first time. Based on the LMDI decomposition method, we separately added the district population proportion variable and the district economic proportion variable to contrast a logarithmic mean Disivia index-population (LMDI-P) decomposition model and a logarithmic mean Divisia index-economic (LMDI-E) decomposition model for the regional total water use evolution. Compared with the LMDI decomposition model, the district population proportion effect (DPPE) and the district economic proportion effect (DEPE) were separately added. We calculated the value and proportion of the driving effects of the total water use evolution in China and analyzed their influence mechanisms. Our findings provide better decision-making reference for water resource planning and management in China. The results show the following: (1) According to the overall situation from 1965 to 2019, the prohibitive role played by the PCTEE (total 22,263.79 × 108 m3) and the TPE (total 2945.38 × 108 m3) with respect to the total water use increasing in China offset the inhibitive role played by the WUIE (total −16,094.31 × 108 m3) and the SPE (total −5930.02 × 108 m3) with respect to the total water use increasing in China; (2) According to the overall situation from 1965 to 2019, both the DPPE and DEPE had heterogeneity in the total water use evolution in the six major districts in China. The DPPE played a prohibitive role in the three population inflow districts (Southeast China, Central South China, and Northwest China) with respect to the total water use increasing (total 291.09 × 108 m3), and an inhibitive role in the other three population outflow districts (North China, Central South China, and Southwest China) with respect to the total water use increasing (total −207.78 × 108 m3). The DEPE played a prohibitive role in the three economically developed districts (North China, Southeast China, and Central South China) with respect to the total water use increasing (total 428.26 × 108 m3), and an inhibitive role in the other three economically underdeveloped districts (Northeast China, Southwest China, and Northwest China) with respect to the total water use increasing (total −477.74 × 108 m3).