Assessment of meteorological factors and human activities impact on wheat and maize water requirements in the Yellow River Basin

Abstract

Crop water requirement (CWR) is crucial in agricultural water management. Understanding the CWR of different grain crops is essential to efficiently using water resources and sustainable food production. Based on the meteorological data from 1961 to 2020, the spatio-temporal variations of CWR for winter wheat, spring wheat, summer maize and spring maize were analyzed in the Yellow River Basin (YRB). The driving factors for CWR spatial heterogeneity and temporal variation of the four grain crops were explored by geographical detector and path analysis models, respectively. Moreover, the logarithmic mean divisia index model was used to explore the main driving factors of regional total water requirement for four crops. The results revealed that CWR increased 0.505, 0.058 and 0.077 mm per year for winter wheat, spring wheat and spring maize respectively, whereas it decreased 0.633 mm per year for summer maize over the past 60 years. From the rapid growth stage, the effects of net radiation and air temperature on the spatial heterogeneity of CWR gradually increased, while the effect of precipitation was just the opposite. Except for the meteorological factors, soil type could also be the main driving factor for CWR spatial heterogeneity of wheat and spring maize. Meanwhile, wind speed and net radiation were the main meteorological factors for CWR temporal variations of summer maize and the other three grain crops. Moreover, crop planted area and cropping pattern were the major factors in temporal variations of regional total CWR for the four crops in different sub-regions. Overall, these findings provided important implications for the sustainable utilization and rational allocation of agricultural water resources under climate change in the YRB.

Keywords: Climate change; Crop water requirement; Human activities; Meteorological factors; Yellow River Basin.