하천 퇴적토양의 이화학적 특성

Abstract

주요 하천 유역 퇴적토의 토양물리성과 화학성을 파악하여 농업적 활용에 있어서 토양환경적 안정성을 평가하기 위하여 2009년부터 2010년까지 한강 16개소, 금강 32개소, 영산강 27개소, 낙동강 144개소로 28개 시군의 219개소의 하천표토에서 50 cm까지 시료를 채취하였다. 하천토사의 입자밀도는 <TEX>$2.63Mg\;m^{-3}$</TEX> 이상으로 <TEX>$2.60{\sim}2.69Mg\;m^{-3}$</TEX>의 범위이었으며, 입경은 평균 0.7 mm로 0.075~0.85 mm 범위에 분포하고 있었다. 유역별 토사의 입경분포를 살펴보면, 한강과 금강에서는 0.075~0.85 mm 범위에 입자가 주로 분포하였으며, 금강과 영산강에서는 0.25~0.85 mm 범위에 입자로 입경이 큰 입자의 분포비율이 높았다. 하천 토사의 평균 화학성은 pH 6.3, EC <TEX>$0.16dS\;m^{-1}$</TEX>, 유기물 <TEX>$8g\;kg^{-1}$</TEX>, 유효인산 <TEX>$101mg\;kg^{-1}$</TEX>, 치환성 칼륨, 칼슘 및 마그네슘은 각각 0.39, 3.47, <TEX>$0.93cmol_c\;kg^{-1}$</TEX>이었으며, 유역별로는 한강유역에서 pH, 금강유역에서 염농도 (EC), 유효인산과 치환성 나트륨이, 영산강유역에서 유기물, 치환성 칼슘과 마그네슘이, 낙동강 유역에서는 치환성 칼륨이 각각 높았다. The river-bed sediments from the major river basins were analysed for the chemical and physical properties to evaluate environmental safety for the agricultural uses. The samples were taken from 16 sites of Han river, 36 of Geumgang river, 27 of Yeongsan river, and 140 of Nakdong river. The total of 219 samples from the 28 counties were taken from the surface of the sediments at the depth of 50 cm. The particle density of the sediments was greater than <TEX>$2.63Mg\;m^{-3}$</TEX> and the whole range of the density was <TEX>$2.60{\sim}2.69Mg\;m^{-3}$</TEX>, the average particle size was 0.7 mm whereas the size range was 0.075~0.85 mm. The analyses of the particle sizes by basins showed that Han and Geumgang river had particle sizes of 0.075~0.85 mm, while Geumgang and Yeongsan river had particle sizes of 0.25~0.85 mm. Geumgang and Yeongsan river tended to have greater particle sizes. The average values of the chemical properties were 6.3 for pH, <TEX>$0.16dS\;m^{-1}$</TEX> for EC, <TEX>$8g\;kg^{-1}$</TEX> for organic matter, <TEX>$101mg\;kg^{-1}$</TEX> for available phosphate, 0.39, 3.47, and <TEX>$0.93cmol_c\;kg^{-1}$</TEX> for exchangeable potassium, calcium, and magnesium respectively. The greatest property at each basin was pH for Han river, Ec, available phosphate and exchangeable sodium for Geumgang river, organic matter, exchangeable calcium and magnesium for Yeongsan river, and exchangeable potassium for Nakdong river.