Spatio-Temporal Variations in Farmland Water Conditions in the Yanhe River Basin

To gain a deeper understanding of the influence of climate change on water cycling and water resources, it is important to investigate the changes in farmland moisture profits and losses and the influencing factors. In view of this, using the Yanhe River Basin as an example, we adopted the Penman–Monteith model to calculate the amounts of moisture profit and loss in the basin and analyzed the spatio-temporal variations of moisture profit and loss from 2003 to 2015. Based on our results, the Yanhe River Basin was characterized by water shortage from 2003 to 2015. From 2003 to 2007, the water deficit of the basin was obvious, while from 2007 to 2011, the water shortage was moderate. From 2011 to 2015, the area experienced an aggravated water deficit. Overall, from 2003 to 2015, the area proportions of the regions with normal and mild water deficits decreased by 32.65% and 18.98%, respectively, while the area proportion of the regions with acute water deficits increased by 32.97%. In terms of the spatial distribution of moisture profits and losses in the Yanhe River Basin, the water deficit was gradually mitigated from northwest to southeast. Precipitation and near-surface air specific humidity were the main factors influencing the water conditions in the river basin.