# Assessment of Soft Computing Techniques for the Prediction of Suspended Sediment Loads in Rivers
## 3 Site Description  
### Gauging Stations  
The Elbe River is the third largest waterway in Central Europe, which originates from the Giant Mountains (Krkonose) in the Czech Republic, with a catchment area of 148,268 km\({}^{2}\) and a running length of 1094 km. Overall one-third of the total length lies in the Czech Republic, while the rest of the course runs in Germany. The major parts of its catchment area lie in the low-mountain regions, which are primarily under agricultural use. About 600 km reach of the river downstream of the Czech Republic is free of barrages but has guide banks, groynes and flood protection structures. A detailed description of the catchment characteristics and incoming sediment challenges and their management for the Elbe River has been presented in several studies [65; 66; 67; 68].  
The available daily mean flow series and suspended sediment concentration data of the Elbe River at the Pirna gauging Station (Station No: 501040, catchment area 52,100.9 m\({}^{2}\), location 13\({}^{\circ}\)55\({}^{\prime}\)59\({}^{\prime\prime}\) E, 50\({}^{\circ}\)57\({}^{\prime}\)52\({}^{\prime\prime}\) N) in Saxony state and Magdeburg-Strombrucke gauging Station (Station No: 502180, catchment area 95155.1 m\({}^{2}\), location 11\({}^{\circ}\)38\({}^{\prime}\)44.47\({}^{\prime\prime}\) E, 52\({}^{\circ}\) 7\({}^{\prime}\)49.17\({}^{\prime\prime}\) N) in the Saxony-Anhalt state were obtained from the Federal Institute for Hydrology (BfG), Germany. Figure 1 shows the gauging stations and their catchment area.  
Figure 1: Location and catchment area of the Pirna and Magdeburg-Strombrücke gauging stations ©[PERSON].  
The SSL at the two sites of interest on the river Elbe was measured by the Federal Institute of Hydrology in cooperation with the local boards of the German Waterways and Shipping Administration. Bulk water samples of 5 L were taken on every working day in the middle of the river channel from a boat. The samples were then filtered on paper filters, dried, and the filter residues were gravimetrically determined to the yield concentrations of total suspended matter in PPM. Further, there are small gaps in the measured data that mostly occurred on weekends and also a few large gaps in the available data from the years 1992-2019.  
In this study, available daily mean flow and SSL data of around 27 years from November 1992-November 2019 of both gauging stations were employed for training and testing all the developed models. The daily flow and SSL time series data for the Pirna and Magdeburg-Strombrucke gauging stations are shown in Figures 2 and 3, respectively.  
In the Pirna gauge station, the available observed \(Q\) and SSL data from 3 November 1992, to 21 June 2012 (around 73% of total data) were selected for training and the data from 22 June 2012, to 30 November 2019 (around 27% of the total data) were selected for testing the model. In the Magdeburg-Strombrucke gauging Station, the available observed and SSL data from 3 November 1992, to 9 June 2013 (around 75% of total data) were selected for training and the data from 10 June 2013, to 30 November 2019 (around 25% of the total data) were selected for testing the model. The data length for training and testing datasets was determined by employing the M-test. The training dataset has two benefits; first, it includes the maximum observed peaks of \(Q\) and SSL in the available data and secondly, it also covers the significant possible variations in the dataset, which is helpful in model training. Furthermore, some peaks in \(Q\) and SSL are missing in the available data. Therefore, those peaks are not included in the training and testing period.  
Figure 3: River flow and SSL time series for the Magdeburg-Strombrucke gauging station.  
Figure 2: River flow and SSL time series for the Pirna gauging station.