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Pesticides in air and in precipitation and effects on plant communities

Table of contents

Executive summary
 
Dansk sammendrag
 
1 Modelling atmospheric transport and deposition of pesticides up to 2 km from a source
1.1 Introduction
1.2 Some important properties
1.2.1 Solubility in water
1.2.2 Vapour pressure
1.2.3 Henry’s law coefficient
1.2.4 The adsorption coefficient Koc
1.3 Turbulence, atmospheric transport and diffusion
1.4 Surface exchange
1.5 Intermezzo: Main conclusions on meteorology and surface exchange
1.6 Emission
1.6.1 Emission of pesticides from fallow soil
1.6.2 Emission of pesticides from plants
1.6.3 Improvement in the modelling of the emission of pesticides
1.7 Removal of material by precipitation
1.7.1 Cloud physical processes
1.7.2 Exchange of gases between drops and the air
1.7.3 Scavenging of gases
1.7.4 Scavenging of particles
1.8 Intermezzo: Main conclusions on wet deposition and a comparison with dry deposition
1.9 Conversion from the gaseous to the particulate phase
1.10 Photochemical reaction
1.11 Spray drift and other forms of deposition
1.12 Modelling the deposition close to the source
1.12.1 K-model
1.12.2 Verification of the vertical diffusion calculated with the model
1.12.3 Situation modelled in all further model calculations
1.12.4 Influence of friction velocity/wind speed
1.12.5 Influence of atmospheric stability
1.12.6 Vertical concentration profiles
1.12.7 Reduction of the emission rate on the emission field due to upwind emissions
1.12.8 Effect of surface roughness
1.12.9 Effect of surface resistance
1.12.10 Possibility of long-range transport
1.12.11 Maximum sum of dry and wet deposition
1.12.12 Comparison of dry and wet deposition with spray drift due to sedimentation
1.13 Intermezzo: conclusions on the model results
 
2. Discussion and conclusions
 
3. Acknowledgement
 
4. References
 
Appendix I
 
Appendix II
 
Appendix III

 

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