Abstract
Water environmental problems of the lower reach of the Yellow River, such as drying up, groundwater pollution including nitrate and salinization, have deteriorated since 1970s when various projects relevant to water diverting were carried out. These problems were analyzed with the integration of both natural processes and human activities through case studies in Shandong Province. Based on the literature, main changes in climate and vegetation were incorporated with human activity and its impacts in a chronicle order, and the drying up in the lower reach was concluded to be the result of human activity upon a fragile natural condition through analyses on long-term rainfall-discharge data series. Salinization is a process closely related to water cycling and groundwater flow system, while the sources of nitrate pollution mainly come from anthropogenic wastes and fertilizers, and the distribution of nitrate is affected mainly by the occurrence of zero-flux-plain (ZFP) and water movement.
