Changes in Agricultural Irrigation Water Quality in Nam River

남강 농업용수의 시기별 수질변화

To investigate chemical changes of agricultural water in Nam river used for the basic information. Samples were collected from seven sites along the Nam river and were analyzed for inorganic content from April to September in $1994{\sim}1995$. Average value of analyzed inorganic concentrations at seven sampling sites were pH 7.9, COD 7.3mg/l, $NO_3-N$ 1.2mg/l, $Na^+$ 6.2mg/l, $Cl^-$ 14.8mg/l, EC 0.13dS/m, $PO_4\;^{3-}$ 0.21mg/l, $K^+$ 2.6mg/l, $Ca^{2+}$ 10.8mg/l,$Mg^{2+}$ 2.9mg/l, $SO_4\;^{2-}$ 10.5mg/l, $Fe^{3+}$ and $Zn^{2+}$ 0.02mg/l. The monthly average value of COD, $NO_3-N$, $Na^+$ and $Cl^-$ showed highest peak in July $8.4{\sim}11.6$, $1.1{\sim}1.7$, $5.4{\sim}13.1$ $18.9{\sim}27.9mg/l$. The highest region of average COD, $NO_3-N$, $Na^+$ and $Cl^-$ were Weola pumping station, $8.8{\sim}11.3$, $1.6{\sim}2.4$, $9.0{\sim}10.2$ and $21.7{\sim}23.0mg/l.$ The ionic $copmposition({\Sigma}A/{\Sigma}C)$ : ratio between total equivalant of anions and canon) of Nam river was higher at Weola pumping station than other topography. The EC was positively correlated with $K^+$, $Ca^{2+}$, $Mg^{2+}$, $Na^+$, $Cl^-$ and $SO_4\;^{2-}$.

남강수계 농업용수의 수질변화를 구명하기 위하여 1994년에서 1995년까지 매년 4월부터 9월까지 남강수계 7개 지점을 조사한 결과는 다음과 같다. 무기성분 평균치는 pH 7.9, COD 7.3mg/l, $NO_3-N$ 1.2mg/l, $Na^+$ 6.2mg/l, $Cl^-$ 14.8mg/l, EC 0.13dS/m, $PO_4\;^{3-}$ 0.21㎎/l, $K^+$ 2.6mg/l, $Ca^{2+}$ 10.8mg/l,$Mg^{2+}$ 2.9mg/l, $SO_4\;^{2-}$ 10.5mg/l, $Fe^{3+}$ 0.03mg/l and Zn 0.02mg/l였다. 월별 무기성분 평균치는 7월에 COD $8.4{\sim}11.6mg/l$, $NO_3-N$ $1.1{\sim}1.7mg/l$, $Na^+$ $5.4{\sim}13.1$, $Cl^-$ $18.9{\sim}27.9mg/l$로 가장 높게 나타났으며, 조사지역별로는 월아양수장 지점이 COD $8.8{\sim}11.3mg/l$, $NO_3-N$ $1.6{\sim}2.4mg/l$, $Na^+$ $9.0{\sim}10.2mg/l$, $Cl^-$ $21.7{\sim}23.0mg/l$로 가장 높게 나타났다. 무기성분간의 음이온당량과 양이온당량 비율은 월아양수장 지점이 다른 지점보다 높게 나타났다. 주요성분중 EC는 $K^+$, $Ca^{2+}$, $Mg^{2+}$, $Na^+$, $Cl^-$과 $SO_4\;^{2-}$ 함량과 고도의 정의상관이 있었다.