The effects of groundwater table and flood irrigation strategies on soil water and salt dynamics and reed water use in the Yellow River Delta, China

Vegetation management in shallow groundwater table environments requires an understanding of the interactions between the physical and biological factors that determine root-zone soil salinization and moisture. In this study, the effects of groundwater depth and flood irrigation strategies on water and salt dynamics and reed water use were analyzed in the shallow groundwater region of the Yellow River Delta in China using the HYDRUS-1D model. The results indicated that there is a conflict between water, salt stress, and reed water use with variations in groundwater depth. A water table depth of 3.5 m is the minimum limit to maintain a safe level of soil salinity, but at this depth, the environmental stress on reeds is worsened by the decrease in soil water storage. Maintaining the flood pulses on the wetland, especially during May, may be critical for restoring the reed wetland in the Yellow River Delta.     

Integration of a fish bioenergetics model into a spatially explicit water quality model: Application to menhaden in Chesapeake Bay

Although fish are usually thought of as victims of water quality degradation, it has been proposed that some planktivorous species may improve water quality through consumption of algae and sequestering of nutrients via growth. Within most numerical water quality models, the highest trophic level modeled explicitly is zooplankton, prohibiting an investigation of the effect a fish species may be having on its environment. Conversely, numerical models of fish consumption do not typically include feedback mechanisms to capture the effects of fish on primary production and nutrient recycling. In the present study, a fish bioenergetics model is incorporated into CE-QUAL-ICM, a spatially explicit eutrophication model. In addition to fish consumption of algae, zooplankton, and detritus, fish biomass accumulation and nutrient recycling to the water column are explicitly accounted for. These developments advance prior modeling efforts of the impact of fish on water quality, many of which are based on integrated estimates over an entire system and which omit the feedback the fish have through nutrient recycling and excretion. To validate the developments, a pilot application was undertaken for Atlantic menhaden (Brevoortia tyrannus) in Chesapeake Bay. The model indicates menhaden may reduce the algal biomass while simultaneously increasing primary productivity.     

The effectiveness of cluster approach to improve environmental corporate performance in an industrial district of SMEs: a case study

This paper aims to assess the effectiveness of the so-called ‘Eco-Management and Audit Scheme (EMAS) cluster approach’ when applied to environmental policies, by focusing on the case history of the industrial paper production cluster located in the Province of Lucca (Italy). The Lucca cluster represents approximately 20% of Italian paper production, and Italy is the fourth leading paper producer in Europe. In the last 10 years, environmental policies have been developed under the common ‘umbrella’ of a strong public and private partnership based on stakeholder networking within the application of the EU EMAS Regulation. This article evaluates the outcome of such an approach, by comparing the environmental performance indicators for the Lucca’s paper industry using data collected from more than 40 plants before and after the adoption of this voluntary tool. The results show considerable improvements for many environmental performance indicators, consistently with the implementation of the cluster approach.