Agricultural Water Use Efficiency and Influencing Factors in Guangdong Region Based on Super-Efficiency SBM Model

To enhance agricultural water use efficiency in Guangdong Province, agricultural water use and related variables from 20 prefecture-level cities (excluding Shenzhen) in Guangdong Province spanning the period 2010-2021 are utilized to analyse agricultural water use efficiency. The global super-efficiency SBM model is employed to evaluate agricultural water use efficiency, analyze its spatio-temporal distribution characteristics, and identify influencing factors through a panel Tobit model. The results indicate: (1) From 2010 to 2021, agricultural water use efficiency in all prefecture-level cities demonstrated an upward trend, with a notably accelerated growth rate after 2016, reaching an average annual growth rate of 8.3%. (2) Agricultural water use efficiency in Guangdong Province exhibits significant spatial clustering characteristics: the Pearl River Delta region consistently maintained a relatively high level of efficiency; the Eastern Guangdong region, which had lower-than-average efficiency prior to 2015, surpassed the provincial average after 2016; the western Guangdong region, which was on par with the provincial average before 2015, but lagged behind the provincial average after 2016; while Northern Guangdong consistently lagged behind the provincial average. (3) Key factors influencing agricultural water use efficiency include annual average precipitation, economic development level, crop planting structure, investment in science and technology, and water-saving irrigation infrastructure. Among these, annual precipitation and crop planting structure exhibit inhibitory effects, whereas the remaining factors contribute positively. To sum up, the spatio-temporal distribution characteristics and key influencing factors of agricultural water use efficiency in Guangdong Province have been systematically elucidated. Empirical basis has been provided for the efficient utilization of regional agricultural water resources and the formulation of differentiated water-saving policies.