As an essential factor of the earth’s critical zone, soil water has a remarkable influence on nutrient cycle and energy flow in terrestrial ecosystems and has attracted the attention of considerable scholars. Based on the online database of Web of Science, the bibliometric analysis was performed to evaluate the evolution feature of soil water research from 1934 to 2019. The results showed a rapid growth of scientific outputs with a gradually increasing proportion of internationally collaborative articles. Environmental Sciences, Water Resources, and Soil Science were the most frequently used subject categories, and the Journal of Hydrology had the highest number of publications in this field. The institutions from the USA and China were the most active, and the USA occupied a leading position in soil water research, producing the most articles and having the most considerable number of citations. Clusters of authors were mostly located in North America, Western Europe, West Asia, and East Asia. Keywords analysis demonstrated that climate change, drought, evapotranspiration, remote sensing, and irrigation were the current research hotspots. Scientific issues focusing on the interaction between soil water and environmental factors, drought forecast, relationships between soil structure and water/solute transport, improving the accuracy and depth of soil moisture monitoring with satellite, and spatio-temporal scaling transform require further research.

Accidental pollution incidents have caused a major threat to water safety of drinking water sources. However, few studies have focused on quantitative risk assessment of pollution incidents in a watershed which contains drinking water sources. A coupling model consisting of the Seveso III Directive, SWAT, and MIKE21 models was constructed for risk assessment of sudden pollution incidents at the watershed scale. The potential hazard of risk sources (e.g., industrial enterprises), the vulnerability of risk receptors (e.g., drinking water intakes), and the environmental risk of different sub-regions of the watershed were evaluated by this model. In addition, a case study was applied in Hongfeng Lake watershed (HLW), where the Hongfeng Lake drinking water source is located. The results showed that about 68% of the industrial enterprises in the HLW were potentially hazardous according to the Seveso III Directive, including 5 high hazard enterprises, 13 medium hazard enterprises, and 37 low hazard enterprises, most of which were concentrated in the coal mining, chemical production, and building material industries. The HLW was divided into the Yangchang River watershed (YRW), the Maiweng River watershed (MRW1), the Maxian River watershed (MRW2), the Houliu River watershed (HRW), and the lake area by the hydrological characteristics, among which, the vulnerability index of YRW was the largest. Besides, it was essential to consider the vulnerability assessment of drinking water intakes when conducting an environmental risk assessment in the HLW. Regional environmental risk grade of YRW, MRW1, MRW2, HRW, and the lake area was high, medium, low, low, and none, respectively. The environmental risk assessment results showed good consistency with the pollution characteristics and spatial distribution of industrial enterprises in the HLW. Furthermore, the theory of a three-level prevention system for “risk sources–water body connection–water intakes” was proposed for environmental risk management in the HLW. Overall, the case study in the HLW indicated that the coupling model proposed in this study had a good compatibility for environmental risk assessment of sudden water pollution incidents in a watershed.

The hydraulic properties of paleosols on the Chinese Loess Plateau (CLP) are closely related to agricultural production and are indicative of the environmental evolution during geological and pedogenic periods. In this study, two typical intact sequences of the first paleosol layer (S1) on the southern CLP were selected, and soil hydraulic parameters together with basic physical and chemical properties were investigated to reveal the response of soil hydraulic properties to the warm and wet climate conditions. The results show that: (1) the paleoclimate in the southern CLP during the last interglacial period showed a pattern of three warm and wet sub-stages and two cool and dry sub-stages; (2) when the climate was warm and wet, the soil saturated hydraulic conductivity decreased and the content of macro-aggregates increased, and when the climate was cool and dry, the soil saturated hydraulic conductivity increased and the content of macro-aggregates decreased, indicating that the paleoclimate affected both the grain size of wind-blown sediment and pedogenic process; and (3) in the soil water characteristic curves, the soil water content showed variation in peaks and valleys, indicating that the dust source and pedogenesis of the paleosol affected the water holding capacity. The findings confirmed that on the southern CLP, the warm and wet climate improved soil aggregate stability and water holding capacity, while reducing soil water conductivity. These results reveal the response of soil hydraulic properties to the climate evolution on the southern CLP, which indicate soil water retention and soil moisture supply capacities under an ongoing global warming scenario.