Influence of bogs and forests in the river basin on the water run-off of the riversof the taiga zone of Western Siberia

Researches ofinfluence of marshiness and forests on the water flow of average (with the basin area from 2000 to 50000 km2) and small (with the basin area upto 2000 km2) rivers of the taiga zone of Western Siberia are made. The object of research are the tributaries of the Ob river - the Chaya, the Iksa,the Andarma, the Bakchar, the Kluch, the Vasyugan, the Gorchak, the Parabel, the Kenga, and the Chuzik. Researches included two basicstages. At the first stage, with the use of remote data (Landsat 7), the boundaries of the river basins were received. The estimation of forest landand marshiness of the river basins was also made as a result of the analysis of the remote data information, materials of hydrological observationof Roshydromet (Hydrometeorological Centre of Russia) and the authors survey. At the second stage, comparison of the remote data and thehydrological data was executed using statistical analysis. The analysis of the remote data has shown that the basin area of all the researchedaverage rivers has declined. In case of the small rivers with highly boggy basins the opposite situation is observed - the areas of their basinshave expanded if to compare with the already known data. The changes can be connected with the following: 1) less precise topographical mapsthat helped define the areas of bogs and forest, and 2) distinctions in methodology of research. For example, in our work the lines of run-off andthe certain changes in the structure of river basin ecosystems (the period between measurements is about 50 years) were taken into account.Thus, we have calculated the modules of the average, maximal and minimal water flow (during the winter and summer-autumnal periods) andcarried out their correlation analysis, which allowed us to reveal statistically significant connections between the morphometric and the hydrologicalcharacteristics. It was shown that the values of the module of the minimal flow grow with the increase of the total area of forest andbogs, and the values of the maximal flow decrease. The inverse relationship between the module of the maximal flow and the total area of forestland or marshiness of the river basin is shown in the areas of the corresponding ecological systems of 5000-6000 km2. It allows assuming that itis this factor that divides the taiga rivers into small (azonal) and average (zonal). As a whole, bogs and forest are not factors, which unequivocallyinfluence the water flow of the rivers in the taiga zone of Western Siberia.

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