中文摘要：

为给进一步实施滇池入湖污染控制及小流域污染治理提供依据,以滇池环湖28条河流入湖水量及水体中不同形态氮的质量浓度逐月调查数据为基础,研究了滇池河流不同形态氮的入湖浓度（ρ）和入湖负荷的时空变化,并探讨了不同形态氮的入湖负荷贡献.结果表明：1滇池河流入湖ρ（TN）在2.91-94.01 mg/L之间,以ρ（DIN）（DIN为溶解性无机氮）最高,而ρ（DON）（DON为溶解性有机氮）和ρ（PN）（PN为颗粒态氮）均较低.2滇池河流氮入湖负荷总量为6 908.47 t/a,绝大多数河流以DIN负荷为主,平均贡献为67.15%;DON和PN入湖负荷贡献相近,平均分别为17.86%和14.99%.3不同形态氮入湖负荷贡献的季节性差异明显,DIN入湖负荷较高值出现在春夏季（3—9月）,平均贡献达74.01%;DON入湖负荷较高值则出现在秋冬季（9月—翌年1月）,平均贡献达33.42%;PN入湖负荷贡献月份变化差异较小,最高值出现在2月,贡献为40.19%.4滇池河流氮入湖负荷不仅要考虑DIN的贡献,也应重视DON和PN负荷,控制滇池河流氮入湖负荷需要考虑不同河流不同形态氮负荷组成及其季节性差异,有针对性地采取相应措施.

英文摘要：

Based on monthly water input data from 28 rivers into Dianchi Lake and nitrogen concentrations,the spatial and temporal changes in nitrogen concentration and loading were revealed in this paper,along with a discussion of the loading contributions of different nitrogen fractions,with a goal of providing scientific support for further control over pollutant input as well as pollution treatment of the small watershed. The results showed： 1） the change in total nitrogen（ TN） concentration of the rivers running into Dianchi Lake ranged from 2. 91-94. 01 mg/L,with dissolved inorganic nitrogen（ DIN） concentration contributing the most,in contrast to a relatively low percentage of the concentration of dissolved organic nitrogen（ DON） and particulate nitrogen（ PN）. 2） The total volume of TN loading from the rivers into Dianchi Lake reached 6908. 47 t/a,with DIN loading contributing the most,averaging 67. 15%; the contributions of DON and PN loading were similar,averaging 17. 86% and 14. 99% respectively. 3） There was a significant difference in seasonal loading contributions of different nitrogen fractions. DIN peaked between March and September,its contribution averaging 74. 01%. DON peaked between September and January,its contribution averaging33. 42%. In contrast,there was little difference in monthly PN loading,peaking in February,contributing 40. 19%. 4） In terms of nitrogen loading of rivers into Dianchi Lake,not only shouldDIN contributions be considered,but also DIN and PN loading should be paid great attention to,and at the same time,the components and seasonal differences of the loading of different nitrogen fractions should also be taken into consideration in terms of control over pollution of rivers into Dianchi Lake,to take effective countermeasures.