开都河水理化性质的空间分布特征

Spatial Distributions of Water Physicochemical Properties in the Kaidu River

为了解开都河水理化性质的空间分布特征,沿河选取了15个采样点,对各采样点的水温、pH、电导率(EC)、溶解氧(DO)、氧化还原电位(ORP)、硝态氮(NO_3^--N)、铵态氮(NH_4^+-N)、氯离子(Cl-)和五日生化需氧量(BOD5)等9项河水理化指标进行了测定,并运用主成分分析和聚类分析对测定结果进行了评估。结果表明:开都河水体整体水质较佳,自净能力较强,但仍有一定的差异;空间上,中上游水理化性质较好,但上游水体活力较差,因此,应加强上游水源的保护;黄水沟水文站与其他观测点相比水质较差,可能是因为汇入此处的各支流水质较差。主成分分析表明,pH、EC、DO、ORP、Cl-、NH_4^+-N和BOD5主要影响中上游河水理化性质,下游水质则主要受NO_3^--N的影响。聚类分析将河流分为中上游与下游2类,下游的高人口密度及污染物的不断积累,是造成下游水质差的主要原因。

In this study,15 sampling sites were selected along the Kaidu River to explore the spatial distribution of water physicochemical properties including water temperature,pH value,electrical conductivity（ EC）,dissolved oxygen（ DO）,oxidation reduction potential（ ORP）,nitrate nitrogen（ NO3^--N）,ammonium nitrogen（ NH4^＋-N）,chloridion（ Cl^-） and five-day biochemical oxygen demand（ BOD5）. The measured indicators were analyzed by principal component analysis and cluster analysis. The results showed that water quality in the Kaidu River was generally good and had strong self-purification capability,but the properties were different among different reaches. In general,water quality was good in the midstream and upstream,but the self-purification capability was poor in the upstream. Therefore,attentions should be paid to protect the water quality in the upstream where distributaries with poor water quality converge. Water quality at Huangshuigou Hydrologic Station was worse than those at other sampling sites,possibly caused by poor water quality from other distributaries near the station. Principal component analysis showed that pH,EC,DO and ORP,Cl-,NH4^＋-N and BOD5 were the main factors which influenced the water quality in the upstream and midstream,while NO3^--N was the main factor in the downstream.The results of clustering analysis indicated that the river could be divided into two sections（ upstream-midstream and downstream）. The spatial distribution characteristics may be as a result of the high population density in the downstream and the pollutant accumulation.