Spatio-temporal dynamics of nutrients in the upper Han River basin, China

The upper Han River basin with an area of approximately 95,000 km(2), is the water source area of the Middle Route of China's South to North Water Transfer Project. Thus, water quality in the basin's river network is of great importance. Nutrients including dissolved inorganic nitrogen (DIN), NO(3)(-)-N, NH(4)(+)-N, and dissolved phosphorus (DP) were analyzed in 41 sites during the period of 2005-2006. Cluster analysis (CA), analysis of variance (ANOVA) and general linear models (GLM) were performed to explore their spatio-temporal variations in the basin. The results revealed that the DIN, NO(3)(-)-N and NH(4)(+)-N increased over the 2 year study period, and their concentrations in the wet season was higher than those in the dry season. The seasonal variation in nitrogen was strongly associated with seasonal pattern of precipitation and there was a negative relationship between DP concentration and river flow. Cluster analysis indicated high nutrient contents in the urban and agricultural production areas. The research will help articulate water resource management strategy for the interbasin water transfer project.     

An Ecologically Oriented Operation Strategy for a Multi-Reservoir System: A Case Study of the Middle and Lower Han River Basin,China

Constructing and operating a multi-reservoir system changes the natural flow regime of rivers, and thus imposes adverse impacts on riverine ecosystems. To balance human needs with ecosystem needs, this study proposes an ecologically oriented operation strategy for a multi-reservoir system that integrates environmental flow requirements into the joint operation of a multi-reservoir system in order to maintain different ecological functions throughout the river. This strategy is a combination of a regular optimal operation scheme and a series of real-time ecological operation schemes. During time periods when the incompatibilities between human water needs and ecosystem needs for environmental flows are relatively small, the regular optimal operation scheme is implemented in order to maximize multiple human water-use benefits under the constraints of a minimum water-release policy. During time periods when reservoir-induced hydrological alteration imposes significant negative impacts on the river’s key ecological functions, real-time ecological operation schemes are implemented in order to modify the outflow from reservoirs to meet the environmental flow requirements of these functions. The practical use of this strategy is demonstrated for the simulation operation of a large-scale multi-reservoir system which located in the middle and lower Han River Basin in China. The results indicate that the real-time ecological operation schemes ensure the environmental flow requirements of the river’s key ecological functions, and that adverse impacts on human water-use benefits can be compensated for by the regular optimal operation scheme. The ecologically oriented operation strategy for a multi-reservoir system that is proposed in this study enriches the theoretical application of the multi-reservoir system joint operation which considers environmental flow requirements.     

Phosphorus sorption and fraction characteristics in the upper, middle and low reach sediments of the Daliao river systems, China

Stream sediments play an important role in the transport and storage of phosphorus in the stream ecosystems. This research investigated the sorption and fraction of P in the sediments of a long-term seriously contaminated river, the Daliao river system, using isotherm sorption and selective sequentially extraction tests. Results indicated that the total content of P in the sediments was 479–1202 mg kg⁻¹, depending on iron content in the sediments. The content of potential bioavailable P, including soluble and loosely bound P, Al bound P, Fe bound P, and reductant soluble P was only 10–20% of total P in the sediments of the Hun river and Taizi river, while it was 40–55% in the sediments of the Daliao river, the downstream of the river system. Equilibrium phosphorus concentration without net P sorption (EPC₀) was from 0.05 to 0.54 mg L⁻¹, with an increasing trend from upstream to downstream, indicating increasingly release potential. On the other hand, the upstream sediment generally sorbed more P than the downstream sediment for each river at the same equilibrium P concentration. The binding energy constant of P on the strong sites of the sediments generally decreased from 2.24 to 2.65 L mg⁻¹ at upstream to 0.41 L mg⁻¹ at downstream or estuary, suggesting that the strong binding sites have been occupied and partly saturated by the phosphate added by point and diffuse sources along the river. On the other hand, molar ratio of Fe to TP contents in the sediments showed sorption capacity of the sediments to P might be under-saturated. The added or sorbed P by the isotherm test was primarily bound to Fe oxides and secondly to Al oxides. Long-term pollution of the river lead to the decrease of P sorption capacity of the river sediment and the increase of P release potential.     

Patterns and sources of PCDD/Fs and dioxin-like PCBs in surface sediments from the East River, China

The contamination status of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) was preliminarily investigated in surface sediments collected from the East River during April 2007. The contamination levels of PCDD/Fs and DL-PCBs ranged from 2.1 to 9.8 with mean concentration of 4.5 pg WHO₉₈-TEQ g⁻¹ and ranged from 0.042 to 0.45 with mean concentration of 0.19 pg WHO₉₈-TEQ g⁻¹, respectively. All sediments were characterized by the elevated levels of PCDDs, especially OCDD. Higher concentrations of PCDD/Fs were found in the sediments from Guangzhou and Dongguan. Source analysis revealed that PCDD/Fs in the sediments from Guangzhou were mainly from the secondary copper smelters and steel-making plants, and PCDD/Fs in the sediment from Dongguan were mainly from MSWIs. PCP and paper mills were unlikely to be the main sources.     

The smartphone and its punishment: Social distancing of cellular transgressors in ultra-Orthodox Jewish society,from 2G to the Corona pandemic

Over the past 20 years, the leaders of Israel's ultra-Orthodox (haredi) community carried out an intensive campaign against the diffusion of mobile phones in their enclave society. It included a variety of resistance strategies that escalated in parallel to the consistent increase in mobile phone penetration into the community. If at first the “cellphone danger” was contained by the successful “kosherphone,” a new threat appeared in the form of the smartphone. In this article we explore the severe rabbinic sanctions directed against those who deviate from the communal norm by using a smartphone. We analyze the general “lawfare” strategy of social distancing they adopted, and offer a close reading of the specific religious-law decrees, interpreting them through the historical and legal lens of halakhah (Jewish law). This socio-legal analysis constructs the way haredi leadership understands the role of the smartphone in two contexts. One is the rapidly changing contemporary media environment; the other is the social dynamic affecting this island community, as it encounters the surrounding national and global culture through digital media. The article concludes with a preliminary analysis of the implications of the Corona pandemic on the campaign against the smartphone.