A study on the comprehensive utilization of water resources from the perspective of water footprint and water ecological footprint: A case study of Anyang City, China

Agriculture is the largest freshwater consumer, accounting for nearly 70% of global freshwater consumption. The agricultural water footprint and water resources ecological footprint which is used to describe the ecological environment and socioeconomic functions of water resources are two complementary indicators of water resources use in relation to human consumption. Anyang, a typical shortage area of fresh water resources in the North China Plain, was selected as a study area to estimate water consumption of agriculture. In this work, we estimate the temporal and spatial variation of green, blue and grey water footprint of five crops in Anyang during 1990–2018 based on the water footprint (WF) theory, water resources ecological footprint (EF w ) and water resources carrying capacity (EC w ) methods. To analyze the EF w of specific crops, the paper develops the framework between agricultural WF and EF w , and quantifies the EF w of specific crops. The results show that the WF green , WF blue and WF grey of Anyang all increased from 1188, 1560 and 511 million m³ in 1990 to 1440, 1736 and 1010 million m³ in 2018, respectively, which is mainly resulted from the increase of cultivated area and agricultural nitrogen amount. Winter wheat and maize were the two leading crops in both green and blue water consumption, taking 31.35%, 55.25% of the total WF green and 71.32%, 22.52% of total WF blue , respectively. The average unit mass WF green and WF blue of crops show a reduction trend in the period between 1990 and 2018 because of the urbanization of farmland and the increase of crop yields. Both water ecological carrying capacity (EC w ) per capital and the water ecological deficit (ED w ) per capital of Anyang decreased. Anyang has been in a state of water ecological deficit since 2000. The results imply that Anyang imports a large number of water resources from other areas for its consumption since 2000. This study is expected to contribute to agricultural water management by providing suitable information to policy-makers. Also, the results indicate that it is urgent to make strict water resources management measures and water pollution prevention to improve the water use efficiency in Anyang in order to ease pressure on water scarcity.