Geophysical and hydrological data assimilation to monitor water content dynamics in the rocky unsaturated zone

In recent years, geophysics is increasingly used to study the flow and transport processes in the vadose zone. Particularly, when the vadose zone is made up of rocks, it is difficult to install sensors in the subsurface to measure hydrological state variables directly. In these cases, the electrical resistivity tomography (ERT) represents a useful tool to monitor the hydrodynamics of the infiltration and to estimate hydraulic parameters and state variables, such as hydraulic conductivity and water content. We propose an integrated approach aimed at predicting water content dynamics in calcarenite, a sedimentary carbonatic porous rock. The uncoupled hydrogeophysical approach proposed consists in 4D ERT monitoring conducted during an infiltrometer test under falling head conditions. Capacitance probes were installed to measure water content at different depths to validate the estimations derived from ERT. A numerical procedure, based on a data assimilation technique, was accomplished by combining the model (i.e., Richards’ equation) with the observations in order to provide reliable water content estimations. We have used a new data assimilation method that is easy to implement, based on the ensemble Kalman filter coupled with Brownian bridges. This approach is particularly suitable for strongly non-linear models, such as Richards’ equation, in order to take into account both the model uncertainty and the observation errors. The proposed data assimilation approach was tested for the first time on field data. A reasonable agreement was found between observations and predictions confirming the ability of the integrated approach to predict water content dynamics in the rocky subsoil.     

Integrated water resources management (IWRM) for climate change adaptation

Regional Environmental Change -     

Sustainable management measures for healthcare waste in China

This paper discusses actions aimed at sustainable management of healthcare wastes (HCW) in China, taking into account the current national situation in this field, as well as the requirements deriving from the Stockholm Convention on Persistent Organic Pollutants and the WHO recommendations. By the end of 2005, there were 149 low-standard HCW disposal facilities in operation in China, distributed throughout different areas. According to the National Hazardous Waste and Healthcare Waste Disposal Facility Construction Plan, 331 modern, high-standard, centralized facilities will be built up in China in municipal level cities. Although incineration is still the main technical option for HCW disposal in China, it is expected that, especially for medium and small size facilities, non-incineration technologies will develop quickly and will soon become the main technical option. The basic management needs – both from the point of view of pollution control and final disposal – have been defined, and a system of technical and environmental standards has been formulated and implemented; however, there are still some shortages. This is particularly true when considering the best available techniques and best environmental practices developed under the Stockholm Convention, with which the present technological and managing situations are not completely compliant. In this framework, the lifecycle (from generation to final disposal of wastes) of HCW and holistic approaches (technology verification, facilities operation, environmental supervision, environmental monitoring, training system, financial mechanism, etc.) towards HCW management are the most important criteria for the sustainable and reliable management of HCW in China.     

Cs,Co and K uptake by lettuce plants in two distributions of soil contamination

¹³⁷Cs and ⁶⁰Co, two of the radionuclides more representative of discharges from nuclear facilities, are of interest for radiological protections because of their great mobility in biosphere and affinity with biological systems. The aim of the present work is the investigation of the possible influence of the vertical distribution of ¹³⁷Cs and ⁶⁰Co in soil upon their uptake by lettuce as function of plant's growth. An experiment ad hoc has been carried out in field conditions. The results show that (i) the transfer of ¹³⁷Cs and ⁶⁰Co from soil to lettuce is independent by their distribution in soil, (ii) the soil–plant transfer factors of ¹³⁷Cs and ⁶⁰Co show a similar trend vs. growth stage, (iii) the ⁴⁰K transfer factor trend is different from those of anthropogenic radionuclides, and (iv) ¹³⁷Cs and ⁶⁰Co specific activities are about 1 Bq/kg, in the mature vegetable with soil activity from 9 to 21 kBq/m².     

Evaluation of drinking water treatment and quality in Takua Pa, Thailand

After 2004 Indian Ocean Tsunami, which hit and devastated several Countries in Southeast Asia, University of Brescia and Mahidol University started a project on water monitoring and treatment for drinking purposes in Takua Pa district (Thailand), the most damaged by the tsunami. In particular, this paper presents the results of a study conducted to evaluate the effectiveness of Takua Pa drinking water treatment plant and to identify actions that could be adopted to improve its performances. The results show that, even if the effluent usually meets Thai guide values, except for pH which is already too acid in the influent, the plant needs several structural and managerial improvements, such as filtration and sedimentation upgrade, coagulation/flocculation and final disinfection re-organization, use of proper registers to better plan and control employees activities. Moreover, it was determined that water quality in the distribution network is characterized by turbidity and organic matter values higher than those evaluated in the plant effluent.     

Use of sulfadimethoxine in intensive calf farming: evaluation of transfer to stable manure and soil

After prophylactic treatment of 50 calves with 62mgkg(-1)day(-1) of sulfadimethoxine (SDM) for five days, the levels of the drug over time were followed in feces, bedding and stable manure, and then in the soil of a manured field and surrounding drainage courses. Analysis were done by HPLC after applying to the different matrices a quick and simple extraction procedure. The half-life of the drug in bedding was very short (24h). In stable manure the degradation rate of the drug slowed down and the calculated half-life was 64 days, with 390microgkg(-1) of SDM still detectable after three months maturation. However, in a five months matured stable manure obtained from other groups of calves subjected to the same prophylactic treatment, levels of SDM were <50muicrokg(-1) (LOD of the analytical method). After field fertilization with this manure, no traces of SDM were found in soil (LOD 10microgkg(-1)) or in the water (LOD 2microgl(-1)) from the surrounding drainage courses. Using the internationally recognised DAPHTOXKIT-Ftrade mark, a SDM toxicity test toward Daphnia magna was performed in the range 10-100mgl(-1). The test gave negative results both after 24 and 48h, confirming that microcrustaceans are less sensitive than other models to the toxicity of antibacterials. However, based on data from other authors, concerning algal toxicity and microbial inhibition, and on the analytical results from the current field study, the calculated worst-case EC50/PEC ratio for SDM both in freshwater and in soil was still >1000.     

Assessing differences in chemical disaster proneness: The community chemical hazard vulnerability inventory*

The burgeoning number of accidents with dangerous chemicals makes it incumbent upon community and regional planners to systematically deal with this problem. The first step invariably involves the assessment of the likelihood and type of incident which may impact a given area so that disasters may be averted or, at least, their effects mitigated. This paper presents one such assessment scheme, the Community Chemical Hazard Vulnerability Inventory (CCHVI). This instrument, aside from considering the type and volume of substances posing a threat to a designated area, considers the physical and human resources available, as well as the general state of readiness of the area (including such things as the interface of emergency-related organizations). The use of such vulnerability assessment instruments allows local emergency planners to identify particular dangers within their communities and permits regional planners to allocate funds for planning according to relative needs.     

Introduction to the Issue

We are pleased to introduce this second issue of the Reviewof Environmental Economics and Policy. Like every issue, thisone includes several articles, a focused symposium, and a setof regular features. In the first of three articles, John Graham describes "The EvolvingRegulatory Role of the U.S. Office of Management and Budget,"where he was the "regulatory czar" as administrator of the Officeof Information and Regulatory Affairs (OIRA) from 2001 to 2006.In his essay, Graham responds to the perception of OMB as antiregulatoryby describing the history of OIRA's proactive