Reduction pathways identification of agricultural water pollution in Hubei Province, China

The differentiated management of agricultural water pollution plays a significant role in alleviating water quality crisis, which is an important factor to guarantee sustainable water use and agriculture. The key is to accurately identify the differentiated pathways to reduce water pollution due to agricultural activities. Taking Hubei Province as a case study, this study comprehensively explored the actual spatial–temporal characteristics and main influencing factors of agricultural grey water footprint (AGWF) for the time period from 2010 to 2019 at the provincial and municipal levels by creatively combining the Dagum Gini coefficient, Moran’s I index and Generalized Divisia Index Method (GDIM). On the basis, the Tapio decoupling model was used to examine the status quo of AGWF reduction in the context of economic development and to classify the two-dimensional decoupling state between AGWF and agricultural GDP (AGDP), aiming at guiding the implementation of zoning management. The analysis yield four significant results: (1) Compared with 2010, the AGWF of Hubei Province in 2019 has achieved negative growth both at the provincial and municipal levels. The AGWF of Hubei Province and its 17 prefecture-level cities presented a trend of first rising and then declining. On the whole, AGWF was positively correlated with AGDP at the municipal level. (2) During the whole study period, the difference in AGWFs of 17 subregions in Hubei Province basically remained in a “relatively unbalanced” state. There was no significant spatial dependence among the subregions on the whole. (3) AGDP and permanent resident population were the main promoting factors of AGWF increase, while AGWF intensity, AGDP per capita and agricultural water use (AWU) intensity were the main inhibiting factors. Among them, AGDP and AGWF intensity respectively played the largest promoting and inhibiting effects on the increase of AGWF. (4) AGWF and AGDP of 17 prefecture-level cities in Hubei Province have all achieved strong decoupling, indicating that AGWFs in these regions have achieved both quantity and efficiency control. These cities were divided into different categories and given differentiated zoning management measures. This study puts forward a complete analytical framework for differentiated zoning management of regional agricultural water pollution. The research findings of this paper can provide important policy implications for other cases as well.