Mapping the primary factors driving spatiotemporal variations of surface soil moisture in the Yellow River Basin of China

. (2) Among the three driving factors, climate, NDVI and land use accounted for 45%, 18% and 8% of the regional surface soil moisture variations, respectively. Climate controlling factors are mainly concentrated in the southwest, south, east and northeast, NDVI controlling factors are mainly concentrated in the central Loess Plateau and the northern Hetao plain, and land use controlling factors are mainly distributed in and around some big cities. Additionally, 29% of the area was controlled by the combined effects of these three factors, with no dominant controlling factor evident with scattered distribution. (3) From the perspective of multi-dimensional zonality, the degree of climate influence is high in the east and west, low in the middle, and increases with the increase of altitude. The influence degree of vegetation increased first and then decreased from west to east. The influence degree was greater in the central area, and the influence increased first and then decreased slightly with the altitude. The peak value appeared in the middle altitude area at 1000 m. And the degree of influence of human activity intensity is slightly lower in the central part.