0000000000671728
AUTHOR
J. Eichhorn
Numerical Modelling of the Urban Climate
Three-dimensional numerical models of the urban climate have been developed in order to simulate climatic changes and air pollution in urban regions due to anthropogenic activities. Two versions are presented. Model A covers mesoscale γ and uses the roughness length to characterize surface structure. The microscale version B approximates the actual urban build-up by rectangular blocks. Model A results agree reasonably well with observations. For complex building structures, the microscale model must be applied. Model B results on neutral flow and pollutant transport within a particular building configuration are discussed.
Selection of biological and chemical parameters indicating or affecting the vitality of Norway spruce
Abstract Thirty-two young and old Norway spruce trees ( Picea abies (L.) Karst.) showing different degrees of damage were investigated in a forest stand in the Taunus Mountains (FRG). The old trees showed visual symptoms of damage such as discolouration of the needles and needle loss. Over 70 biometric, physiological and chemical parameters were determined for needle and soil samples. Interrelationships between these variables were described by correlation analysis. The most discriminant variables between different groups of trees were found by Fisher weighing. This reduced data set was used for principal component analysis and for the classification of various parameters according to diffe…