Vol 44, No 6 (2017)

Proportions of the overland, delayed, and groundwater runoff are given for different phases of the hydrological regimes of rivers under different landscape–climate conditions in Russia. The concept of runoff hydrological regime is in agreement with the formation features of the annual and seasonal runoff on small watersheds under current climate conditions. The increase in winter runoff is due to the impulse discharge regime of soil water and groundwater, which receive additional recharge during frequent thaws and at weak freezing of the aeration zone. Variations in the values of runoff, total precipitation, and mean temperature were shown to be both synchronous and periodic.

The factors that govern the distribution and transformation of tidal waves in the macrotidal estuary of the Mezen River have been considered, including tide range in the mouth section, water discharge in the river’s lower reaches, estuary shape, and bed resistance coefficient. Data on variations of water discharge over period 1920–2008 are given. The parameters of estuary channel narrowing in horizontal and vertical sections have been considered. The effect of narrowing and bed hydraulic friction on tide wave amplitude has been evaluated. Froude number values for the tidal estuary suggest that tidal bore can form at the Mezen mouth. The conditions of the propagation of tidal waves to the mouths of different rivers and tidal bore formation in them are considered.

Two versions of a mass-balance model, simulating biotic energy flow in aquatic ecosystems are given. The first (original) version was developed with the use of Stella software package. As this package is difficult to assess for users, the author proposed a model in Excel format, based on the same balance principle as that used in the original model. Both model versions are governed by a small number of input parameters and intended to forecast the biomass and annual production of primary producers, reducers, and consumers of different orders, including fishes.

The ecological state of 18 small rivers in Minsk Region was for the first time estimated by jointly used macrophyte-based characteristics, including saprobity index, biological macrophyte index for rivers, and a scale of cenotic/supercenotic organization of aquatic and coastal-aquatic plants. Rivers with relatively safe ecological status were shown to dominate, while other rivers are in a safe and satisfactory state. The proposed approach to determining the ecological quality of watercourses is based on the calculation of a complex characteristic, i.e., an integral macrophyte index of small river ecological status; this index has been developed in the context of a classification scheme of surface water quality in the National Environmental Monitoring System of the Republic of Belarus.

Persistent economic growth in Chinese southwestern Yunnan Province is setting aquatic ecosystems in its plateau lakes under enormous pressure. While several different systems have previously been used to study these lakes, no existing methodology adequately measures both the chemical and biotic parameters of these water bodies. Here, we present a novel Biotic Monitoring Yunnan Lakes (BMYL) index that provides a general assessment tool for ecological deterioration that is caused by organic pollution. Principal Component Analysis is used to analyze the occurrence of families of macroinvertebrates and chemical properties of the lakes. In brief, families of macroinvertebrates were given a score from 10 to 1 based on sensitivity to organic enrichment and eutrophication. Sampling at each lake yielded an Average Score per Lake (ASPL) which is calculated by dividing the total BMYL by the total number of scoring families. High ASPL values characterize a biologically intact lake containing relatively large numbers of high scoring taxa, while lower ASPL values denote a polluted lake that does not support many high scoring taxa. The results of the BMYL show a notably more accurate characterization of the long-term health of concerned aquatic ecosystems than studies that use abundance levels of species or a simple analysis of chemical parameter.