Effects of multidimensional urbanisation on water footprint self-sufficiency of staple crops in China

Abstract

Rapid urbanisation in developing countries has exerted ever-increasing pressure on food and water resource systems. Existing studies mostly focus on impacts of population urbanisation on agricultural water use, disregarding the multidimensional characteristics of urbanisation. Accounting for four dimensions of urbanisation: population, economy, spatial distribution, and society, we assessed the impact of multidimensional urbanisation on the water footprint self-sufficiency rate (WFSS) of three staple crops, that is, the ratio of the water footprint (WF) of crop production to the WF of crop-related consumption, through the case for China over 2000–2017. The socio-economic driving factors and spatial heterogeneity of crop WFSS were further tested. Results show that <30% of high-crop WFSS provinces supplied more than 70% of low-crop WFSS provinces. Social urbanisation and economic urbanisation were the governing positive and negative driving factors of the rice WFSS, respectively. Population urbanisation was the dominant factor attenuating wheat WFSS during the study period, while playing a reverse role in maize WFSS. Impacts of different dimensions of urbanisation on crop WFSS were heterogeneous and even contradictory depending on the crop type, the different processes of urbanisation, and the water endowment and economic level of the provinces. The quantile regression results further indicate that population urbanisation, spatial urbanisation and social urbanisation had greater impact on the higher WFSS (i.e., resulted in virtual water export) of rice and wheat. The current analysis challenges the conventionally monotonous urbanisation-water relationships, and suggests that additional dimensions of urbanisation should be considered when assessing the effects of urbanisation on agricultural water use.