As the agricultural nfs is the most important factor for water environmental deterioration and lake eutrophication in china , more and more scientists and technologists focus on the control countermeasurc and pollution mechanism of agricultural non - point source ( nfs ) . based on the investigation of natural resource and agricultural distribution , the loss rule of nitrogen and phosphorus in the typical land of qiandao lake watershed and distribution rule of the phytoplankton and physico - chemical characteristic in the lake were studied , and the input loading of nitrogen and phosphorus was also calculated by the annagnps model in this thesis . according to the routine monitoring data of the water environment in qiandao lake from 1989 to 2001 , the concentrations of toxic substance and heavy metal were under the monitoring limit , but the total nitrogen ( tn ) and total phosphorus ( tp ) were much higher than the criterion for lake and reservoir 本文調(diào)查了千島湖流域的自然資源和農(nóng)業(yè)生產(chǎn)情況,研究了典型坡地降雨徑流中的氮、磷污染物的輸出規(guī)律,利用annagnps模型估算流域農(nóng)業(yè)非點(diǎn)源污染物輸入負(fù)荷,并在千島湖內(nèi)設(shè)點(diǎn)采樣,對水質(zhì)理化指標(biāo)和浮游植物群落進(jìn)行系統(tǒng)的研究,得出以下結(jié)論: 1989 2001年間的水環(huán)境常規(guī)監(jiān)測資料統(tǒng)計分析表明,有毒物質(zhì)和重金屬濃度長期在監(jiān)測下限內(nèi), no _ 2 - n 、 no _ 3 - n 、 nh _ 3 - n年平均濃度均符合類標(biāo)準(zhǔn),但湖泊水庫特定項(xiàng)目tn和tp濃度分別為超類和類,呈嚴(yán)重超標(biāo)狀況,湖區(qū)主要污染因子是將導(dǎo)致富營養(yǎng)化的物質(zhì)tn和tp 。