[Objective] In order to provide fundamental data for a better understanding of the current pollution status and management for the malodorous black rivers

especially to prevent and control the eutrophication of Taihu lake

the spatial distribution and morphological characteristics of sediment nutrient in a rural malodorous black river were analyzed and evaluated.[Methods] Thirteen surface sediment samples along the Northern Branch of Zhangxia Stream in Zhoutie Town of Yixing City

Jiangsu Province were collected from the upstream to the downstream. The spatial distribution of total nitrogen concentration(TN)

total phosphorus(TP)

ammonia nitrogen(NH4+-N)

nitrate nitrogen(NO3--N)

organic nitrogen(Org-N) and total organic carbon(TOC) were investigated. The component distribution of carbon(C)

nitrogen(N)

phosphorus(P) in surface sediments were studied by coupling analysis for pollution assessment.[Results] Org-N was the main component of nitrogen in surface sediments with an average concentration of 2 193.69 mg/kg

accounted for 90.86% of TN. Concentrations of TN

Org-N

TP and TOC presented a fluctuant increasing trend from upstream to downstream

and the highest values were 2.98

3.46

6.29 and 1.59 folds of the minimum values

respectively. The concentration of NH4+-N increased slowly at the initial stage and then decreased rapidly

while the concentration of NO3--N showed an opposite trend. Mean ratio of C/N for the entire stream was 12.07

and the organic matter were mainly sourced from exogenous input. In addition

concentrations of TOC and TN showed an extremely significant positive correlation (p<0.01

n=13). Mean ratio of C/P was 2.04

and concentrations of TOC and TP showed a significant positive correlation (p<0.05

n=13). Mean ratio of N/P was 2.04

and concentrations of TN and TP showed an extremely significant positive correlation (p<0.01

n=13). As a result

the pollution of nitrogen and phosphorus was homogenous.[Conclusion] Organic pollution is the main pollution for rural malodorous black river in the Taihu lake watershed

where the nitrogen pollution is mainly Org-N pollution.