Simultaneous Measurement of Physical Parameters in Rivers

Research project P 14433 Simultaneous Measurement of Physical Parameters in Rivers Helmut MADER 26.6.2000 Exclusively the observation and in situ measurement make it possible to understand the complexity and the functioning criteria of ecosystems within water streams. The description of physical parameters and the characterizing habitat factors are the basis for a theoretical and applied limnological research, resulting with an estimation of the habitat changes caused by the use of rivers. At the moment, the measurement of base data in small and medium rivers is very complicated (measurement techniques and instrumentation), time and cost intensive, and moreover, results with a high rate of errors in calculated parameters. In effort to describe the habitats on small and medium rivers very close to the "real world situation", it is a must to improve the description of velocity distribution within rivers-sites. For analyses of habitats, more or less simultaneous velocity measurements are needed. By using a new standardized simultaneous measurement technique within river specific structures, measuring time will be reduced, parallel to a significant increase of velocity data quality. The initial loss by use of simplified simulation models can be avoided by time extensive in situ data collection of "real world velocity distributions". The project focuses on the development of a new instrumentation for simultaneous velocity and position measurement and on the optimization of the measurement technique to describe the pattern of currents in heterogeneous, well structured small and medium rivers. The main goal is to develop and test a multifunctioning instrumentation by using a combination of GPS or total station, laser or acoustic doppler current meter and a pressure transducer or sonar for physical data collection. Measurement techniques shall ensure time and cost efficient data collection very close to the "real world situation", using 2 D or 3D velocity vectors, measured simultaneously within river specific structures. The new equipment for simultaneous velocity field measurement will be tested and calibrated in the hydraulic laboratory of the IWHW. Measured data will be compared by existing methods within in situ measurements at nature like rivers and on the scale model of a nature like river site in the hydraulic laboratory.