Dimensions of Watershed Areas and Some Indicators of the Zoobenthos Structure of Watercourses in Northeast Asia

Abstract

The purpose is to examine the dependence of some indicators of the structure of benthic animal communities on the parameters of watercourse catchments. Materials and methods. The task was solved by methods of correlation and regression analysis. The parameters of watercourse basins (area, perimeter, order of watercourses and their total length) were obtained using ARCGIS geoinformation system. Results and discussion. High, sometimes close to functional, degrees of correlation were observed between catchment size indicators. The zoobenthos indicators – population density and number of major groups of organisms – tended to change in a regular way with changes in catchment parameters. These changes were described by a fractional-rational function. Like other dimensional indicators of the basins, the order of watercourses can be used to analyse the structure of benthic animal communities. Conclusion. The considered changes in zoobenthos structure in watercourses of different orders indicate some relationships between these parameters, both at the level of zoobenthos as a whole and at the level of the main groups of animals dominating in the benthos. These relationships, as a rule, are not directly proportional. Most often they are described by fractionally rational functions.