Deluvial processes in the south agrolandscapes Tomsk region and their ecological geomorphological aspects

The results of long-term researches (1985–2012) of deluvial process in agrolandscapes of the southeast of the Western Siberia are presented. Deluvial process is washing away of soils by thawed and rain snow (a water erosion of soils); it is one of the main forms of migration of substance in the agrolandscapes, leading to a decrease in fertility of soils and efficiency of a soil cover, etc. The work purpose is an assessment of intensity and dynamics of development of diluvial process on an arable land of the southern part of Tomsk region and identification of ecological aspects of this process. It is established that: 1) Natural factors such as relief, lithology and climate are favorable for development of diluvial process. The steepness of slopes of an arable land changes from 0–1° to 10–12°, sometimes more. On the surface there are deposited loess rocks that soak overnight in water (for 2–120 minutes); soils have low resistance to erosion and runoff. For the territory, intensive storm activity is characteristic, during one heavy rain there are up to 80.5 mm of precipitations. Average annual water reserves in snow vary from 100 to 140 mm, in some years up to 180 mm. 2) The intensity of soil erosion, heavy rains in the area between Tom-Yaya is 40–100 m3/ha in the event of loss of rainfall over 50 mm/day, more runoff from the slopes of arable land is 0.5–8 m3/ha. 3) The intensity of soil erosion by melted snow water varies from 0.5–1.0 m3/ha to 50–80 m3/ha, depending on weather conditions of snowmelt, slope, length, exposure, slope, soil fertility status, etc. The main contribution to the development of soil erosion is made by thawed snow water. 4) The analysis of literature and our data show that during snowmelt from 0.6 to 15 kg/ha of humus, from 0.13 to 1.8 kg/ha of nitrogen, 0.11–0.90 kg/ha of phosphorus, etc. are annually carried away by melting waters from 1 ha of arable land.

Keywords

Authors

References