Abstract

The very beginning of the hydrometrical sediment gauge measurements goes back to the early 50ies as a consistent part of the National wide gauge network in Bulgaria. We already have collected suspended sediment information, based on an unique procedure and equipments, so as we might analyze and summarize it, based on the knowledge and experience about the event.

The paper deals with the frequency of samples collection and their distribution in the river cross section, pulsation of the turbidity and its variation throughout the year, according to the hydrological regime of the river etc. It is pointed out that due to the changes listed the outline of the rating curves alters as well as the assessments of the annual total sediment load.

A specially designed software for the rating curves is presented in the paper. It allows diversity of curves to be designed with appropriate reliability. The lab treatment is completely computerized as well. The software applied reduces quite a lot the time for the sample treatment and sediment load evaluation.

The collected suspended sediment data is stored on an hydrological data bank of ours own, together with river water temperature and ice regime of rivers data. The data bank has been designed in Excel with a direct access and easy dialogue with the consumers. It has graphic units for diversity of relationships, mapping and even access to GIS. Some of the final results have been presented in appropriate form to reveal the climate change impact on the hydrological events.

A comparison between them and the “standard” equipment is done.

Some doubt on this have been discussed by several authors, but now a special equipment for it is offered. Once the efficiency of sample types should be revealed, then free and successful comparison between river sediment load data might be performed as well as the exchange of data among the authors.