Solution and suspension cargo measurement of Johnsbach in Gesäuse National Park

The aim of this work is to obtain an estimation of the behaviour and quantity of solution and suspension cargo in Johnsbach. The geological situation in the catchment area as well as additional factors such as drain and precipitation make an assessment without data collection on the ground problematic. This survey represents an important part of the entire sediment transport of the clot, which is examined in the course of other projects. Water samples were taken at predetermined measuring points in the clod and drain measurements were carried out on a total of 6 terrain days between February and June. The drainage measurement was carried out using the salt dilution method. The water samples for the floating and solution freight analysis were taken with the help of the so-called single point measurement and were examined at a later stage in the laboratory. This was followed by the gravimetric determination of the suspended cargo and the solution freight was analysed using the methods of atomic spectroscopy and chromatography. The results of the suspended cargo tests were very different, the concentration in the flow ranges from 0.46 mg/l to 14.39 mg/l. At the different measuring points, the concentrations were also very different and are related to the discharge behaviour of the Johnsbach. Generally speaking, the concentration of suspended substances increases with increasing outflow. In general, the solution freight concentration does not show such large differences. It increases over the course of the flow and is strongly related to the electrical conductivity. However, compared to the outflow, the solution freight concentration decreases with increasing outflow. The composition of the ions m water is partly derived from the rock deposit in the catchment area: Calcium, sulfate and magnesium are the main ingredients here. In terms of the influence on the entire sediment transport, the values of suspended cargo represent a rather subordinate role. The amount of dissolved substances is many times larger than the suspended substances (referred to the period from February to June). However, it is difficult to give a forecast in this regard, as the period of measurements was too short to get a meaningful result. In summary, it can be found that the transport of suspended cargo in the Johnsbach is highly variable and depends on the outflow and some other factors such as precipitation, material availability, etc. In comparison, the solution freight is the more constant size. Dissolved substances are always present and, as expected, reflect the geolo-gic situation in the catchment area of the clot.