Estimating the Impact of Land Use Change on the Soil Erosion Hazard in the Zambezi River Basin

The formulation of the environmentally sound and sustainable policy for land use and water resources management requires development of methods necessary to predict the consequences of various human activities on the environment. The IIASA Water Resources Project (WAT) addresses this issue in several ways, one of them is the development of a Decision Support System for Large River Basins. Its objective is to elaborate a set of models and PC-AT interactive software package capable of analyzing problems that may arise in developing hydropower and irrigation systems, land use management and agricultural activity. The Zambezi river basin was selected as a case study for the implementation of the above methodology. This paper is devoted to soil erosion problem in the Zambezi river basin. Its importance for water resources planners arises inter alia from the fact that erosion processes may seriously influence the operation of reservoir systems due to silt deposition diminishing storage capacity. The model for estimating soil erosion hazard was used in combination with a number of land use scenarios. For these scenarios areas subject to particularly high erosion hazard were selected for the Zambezi. The paper presents a good starting point for further investigations on land use/climate/water resources interface

Effects of Particulate Air Pollution on Cardiovascular Health: A Population Health Risk Assessment

Particulate matter (PM) air pollution is increasingly recognized as an important and modifiable risk factor for adverse health outcomes including cardiovascular disease (CVD). However, there are still gaps regarding large population risk assessment. Results from the nationwide Behavioral Risk Factor Surveillance System (BRFSS) were used along with air quality monitoring measurements to implement a systematic evaluation of PM-related CVD risks at the national and regional scales. CVD status and individual-level risk factors were collected from more than 500,000 BRFSS respondents across 2,231 contiguous U.S. counties for 2007 and 2009. Chronic exposures to PM pollutants were estimated with spatial modeling from measurement data. CVD outcomes attributable to PM pollutants were assessed by mixed-effects logistic regression and latent class regression (LCR), with adjustment for multicausality. There were positive associations between CVD and PM after accounting for competing risk factors: the multivariable-adjusted odds for the multiplicity of CVD outcomes increased by 1.32 (95% confidence interval: 1.23–1.43) and 1.15 (1.07–1.22) times per 10 µg/m3 increase in PM2.5 and PM10 respectively in the LCR analyses. After controlling for spatial confounding, there were moderate estimated effects of PM exposure on multiple cardiovascular manifestations. These results suggest that chronic exposures to ambient particulates are important environmental risk factors for cardiovascular morbidity

The dispersal of metal mining wastes in the catchment of the river Geul (Belgium - The Netherlands)

The metal mining industry has caused large quantities of heavy metals to enter countless river systems. The consequent spread of heavy metals is determined largely by how these metals bind with silt and soil particles and the transport pathways of these particles in the alluvial parts of river systems. Once the slib-bound metals have been taken up into one of the hydrological subsystems, such as the underwater soil and the banks, they continue to be subject to geomorphological, chemical and hydrological processes. After sedimentation, both the silt and the metals bound to it may be remobilized by physical disturbance of the river bed or banks. Chemical processes may contribute to changes in the form of binding of the metals or to solution of the metals, and to their entry into adjoining waters (groundwater, soil water or surface water) or absorption by plants. Remobilized metals, either bound to silt or in solution, can be transported again and redeposited, or may precipitate in both the river bed and the flood plain. Complex interactions take place between all these processes, which can also change in nature in the course of time. A better understanding of the dynamic conditions (i.e. transport, sedimentation and remobilization) that heavy metals are exposed to in a river system is extremely important in predicting the behaviour and the dangers of heavy metals in a fluvial environment. The research was performed in the river Geul basin, which runs through Belgium and the Netherlands. The source of the Geul is in northwest Belgium, and the river flows through the South Limburg marl region to the river Meuse. Lead and zinc ores have been extracted and processed near the Belgian towns of Plombières and Kelmis from the late Middle Ages until the mid twentieth century. The discharge of process water and the storage of mine waste on the banks of the Geul have caused large quantities of heavy metals to enter the river system. The consequent spread has led to increased concentrations of heavy metals in the river silt and the banks. The presence of heavy metals is a potential threat to people and animals in the area. The natural meandering nature of the river Geul means that old, strongly contaminated sediments are transported repeatedly, and ultimately discharged into the river Maas. The Geul thus contributes to the pollution of this river, the second largest in the Netherlands and a source of drinking water. The objective of this study is a quantitative survey of the spread of heavy metals in the Geul basin. Many of the processes deemed to be relevant were studied, with an emphasis on a cohesive, geographical approach. Ultimately a balance was drawn up of sediment and heavy metals, with reference to the insight gained and the database assembled. There were the following more specific objectives within this generally formulated objective: to determine the position of the sources of heavy metals; to analyse the hydrological factors that influence the transport of silt and heavy metals and to quantify the burden of these substances; to map out flood areas and the contamination of the banks; to determine the sedimentation velocity of contaminated silt and the flood plain capacity; to analyse the forms of binding of heavy metals in silt and soil; to estimate the environmental consequences of the presence of heavy metals

De Bosatlas Nederland van Boven

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De Bosatlas van het Voedsel

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