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The present paper provides a scientific assessment of the inter-decadal variability of the Asian summer monsoon and its significant effect on precipitation patterns in China. The paper consists of four parts. The first part shows the observed inter-decadal weakening of the Asian summer monsoon since the end of 1970s. The second part describes the impact of the weakening Asian summer monsoon on precipitation in China, which caused the major monsoon rainbelt to shift southward from North China to South China over about 30 years, with a 60-80 oscillation dominating. The third part projects the future change of the Asian summer monsoon in the warmer climate by using IPCC AR4 climate models. It has been found that major monsoon rainfall belts in East Asia will move northward in the 2040s, with summer precipitation in North China increasing considerably and stably. Finally, in the fourth part, the implication of the adaptation to the above climate change and related water management will be discussed including the water transport engineering project from the Yangtze River to the Yellow River and North China. [ABSTRACT FROM AUTHOR]

Researches on the impact of common ions onto sediments are of great importance for the study of the heavy metal adsorption mechanisms. Considering the surface sediments from the relatively clean reach in the Baotou section of the Yellow River as the adsorbent, this work presents the impacts of common ions (Na+, Mg2+, K+, Ca2+, Cl−, SO4 2−, and NH4 +) on heavy metals (Cu2+, Zn2+, Cd2+, and Pb2+) adsorption. The experimental results reveal that the adsorptive capacities of the heavy metals are controlled by different adsorption mechanisms in different ion concentration ranges. With the increase of the ionic strength, the adsorption of the heavy metals increases for the compression of the electric double layer, whereas decreases for the decreasing of the ionic activities of the heavy metals. The competitive adsorption and complexations between the heavy metals and common ions are also important factors controlling the heavy metal adsorption. According to the experimental results and the real concentration of common ions in the Baotou section of the Yellow River, the increase of the concentrations of Na+, Mg2+, K+, and Ca2+ would cause the increase of Zn2+ adsorption and reduce the Zn pollution. The NH4 + from the industrial discharge of the tributaries has a strong impact on the heavy metal adsorption. [ABSTRACT FROM AUTHOR]

Baotou City is a representative heavy industrial city in the drainage basin of the Yellow River. This paper studies the pollution of a contaminated section (Baotou section) of the Yellow River, China, with a known anthropogenic heavy metal input from the industrial discharge. The distribution of heavy metals (Cu, Pb, Zn and Cd) in the overlying water, filtered water (overlying water filtered through a 0.45-µm filter membrane) and sediments was determined in the Baotou section of the Yellow River. The results of this research indicate that heavy metal pollutants transport mostly through the carriers of suspended particulates and sediments in the fluvial environment. Baotou City's industrial discharge draining into the Yellow River from the tributaries (the Kundulun River and the Sidaosha River) increases the concentrations of Cu, Pb, Zn and Cd in the mainstream and influences heavy metals speciation. Speciation analyses show that the Cd is easily enriched in the secondary phase (bioavailable form), followed by Pb. Furthermore, based on the acute water quality criteria (WQC-Acute) and chronic water quality criteria (WQC-Chronic) set by the United States Environmental Protection Agency, the acute sediment quality criteria (SQC-Acute) and the chronic sediment quality criteria (SQC-Chronic) are calculated respectively using the developed equilibrium partitioning approach (EqP). By comparing heavy metal contents in sediments with SQC-Acute and SQC-Chronic respectively, we note that Pb and Cd have posed a high risk to the quality of water environment and to the aquatic ecosystem health of Baotou section of the Yellow River. [ABSTRACT FROM AUTHOR]