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SOIL EROSION AS THE SOURCE OF ORGANIC CARBON DEPOSITED IN THE RIVER VALLEYSстатья
- Автор: Aleksey Sidorchuk
- Сборник: Advances in Environmental research
- Том: 60
- Год издания: 2017
- Место издания: Nova Science Pub Hauppauge, N.Y.,
- Первая страница: 59
- Последняя страница: 98
- Аннотация: Soil erosion is the main source of the sediment and organic carbon accumulation in the upper parts of the river valleys on the southern megaslope of the East European Plain. The total volume of erosion from the arable land during the period of intensive agriculture (the last 300 years) at the Don River basin (425,000 km2) amounts to 16.9 109 ton. The volume of the soil carbon, eroded within these soils amounts to 0.41 109 ton. The mean organic carbon erosion rate was 3.2 t km-2 a-1, increasing from 1 t km-2 a-1 in 18th century to 2.8 t km-2 a-1 in 19th and to 5.6 t km-2 a-1 in 20th-21st centuries. The main area of deposition of this eroded matter is the dry valley bottoms, which occupy about 16,730 km2. Only 23% of eroded sediment leave the dry valleys with basin areas under 1 km2 (which are about 1.6 km long), and only about 5% leave the dry valleys with 100 km2 basin area (which are about 16 km long). Thus, dry valley bottoms occupy only about 4% of the total catchment area of the Don River, and 95% of eroded soil and organic carbon is deposited on this area, i.e. in average 9,900 t/ha. The average thickness of deposition of eroded soils is about 0.9 m. The eroded and buried soils represent the source of carbon dioxide due to oxidation of organic carbon. This emission is not compensated by carbon income to soil, as in now-living soils. The whole amount of carbon, formed as dioxide in the buried soils in dry valleys of the Don River basin is 0.15 109 ton. Therefore, the mean carbon emission rate for the total period is 1.2 t km-2 a-1, it was 0.42 t km-2 a-1 before mid-19th century and 2.4 t km-2 a-1 after rapid increase of erosion volumes in mid-19th century.
- Добавил в систему: Сидорчук Алексей Юрьевич