洞庭湖流域区域生态风险评价

and w est par ts o f Dong ting Lake. Ba sed on the histo rical info rma tio n, floo d disaster , industrial po llutio n, ag ricultural pollution and anti-schistso me infectio n po llutio n a re selected as risk so urces, and ex po sur e assessment as w ell a s ha zard assessment has also been conducted. In the pro cess o f eco lo gica l risk assessment, tox icity pollution index es ( aim s a t N , P, heav y metals and so on) , w hich cha racterize effect o f toxic contamina tio n o n no rmal life of recepto r , ar e defined by the r atio s of no rmal concentration to Lethal Co ncent ratio n 50～ 48 ho urs ( L C50 -48) . For h eav y metals, owing to a lo t o f r esea rch o n th em, w e can g et tox icity po llutio n index v alues easily. Ho w ev er , it is ha rd fo r T N ( to tal Nitr og en) , T P ( to tal pho spho rus) to g et their v alues due to the lack of r esea rch o n L C50 -48 of TN and T P a broad and at home. As a r esult we pro po se an ex t rapolatio n me tho d to calculate the toxicity co efficient and acquire th eir va lues o f 1. 4 a nd 27, a nd thus estima te tox icity pollutio n index of T N and T P acco rding to th e co mpariso n betw een tox icity co efficient and L C50-48 of h eav y metals. In view o f the uncertainty o f risk, the unce rtainty coefficient is cho sen in the pr ocess o f our regio na l ecolog ical risk assessment. Specifically , w e consider the natur al a nd sample uncertainty w hen deter mining flo od disa ster index , ecolog y index es ( including biological index , div ersity index , impor tance index , and so on ) and f ragility index , a nd the model unce rtainty w hen dete rmining to xicity po llutio n index (including T N , T P a nd heav y metal to xicity pollution index ). After the nor malized and w eigh ted dispo sa l, the final results o f eco lo gica l risk assessment in Do ng ting Lake ar e o btained.
摘要: 对于生态系统 ,灾害性事件的产生 多为外界胁迫因素与 系统内部生态结构 不稳定性因素共同 作用的 结果 ,因此对流域生态风险进行评价时应充分考虑系统内部的生态结构与外界的胁迫性因素 。目前国内外 对 于外界胁迫 性因素的研 究多集 中在自 然灾害 (如 洪涝灾害 )以 及外界 污染物 主要集 中在重 金属类的 排 入 ,而事实上 ,其他类型的 污染物 ,如氮、磷等也将 对生态系统 产生一定的 危害 ,由于这些污 染物浓度 在个 别地区超 标程度较高并可能 对受体产生 巨大的影 响 ,因此 将该类污 染物作为一 类重要因素 纳入生态 风险 评价体系中是非常必要的 ,而由此得出的评价结果也更为系统和全面。
Universi ty , Ch angsha 410082, China ) . Acta E cologica Sinica , 2003, 23( 12): 2520～ 2530. Abstract: In eco system, th e g enera tio n o f ca ta stro phic ev ents a rises fr om the coo perativ e im pact o f the ex ter nal stressing facto rs a nd the inter na l unsteady facto rs ex isting in a n ecolog ical st ructure, w hich should be fully ta ke n into account for r egional eco log ical risk assessment. At present, resear ch o n ex ternal str essing facto rs is much focused o n the na tural disa sters ( such as sto rm flood disaster s) and resear ch o n ex ter nal contamina nts is in la rg e pa r t co nce nt rated on discha rg ed heav y m etals. But in fact, other contamina nts such a s nitro gen and phospho r us can also lead to ha rmfulness to eco sy stem. Due to the hig h lev el of the co ncentra tio n of these co ntaminants in ex cess of standa rd and their g r eat effec t o n r ecepto rs, it is necessar y to r eg ar d them as impo r ta nt fac tor s a nd to intro duce them into ecolog ical risk a ssessment
基金项目: 国家自然科学基金资助项目 ( 70171055、 50179011) ; 国家杰出青年科学基金资点专项科研基金资助项目 ( 20020532017) ; 2000年教育部高等学校优秀青年教师教学科研奖励计划资助项目 收稿日期: 2003-02-23; 修订日期: 2003-09-10 作者简介: 卢宏玮 ( 1980～ ) ,女 ,吉林延边人 ,硕士生 ,主要从事水域生态学研究。 E-mail: hong wei_ lu@ h otmail. com Foundation item: t he N ati onal Nat ural Sci ence Foundation of Chi na ( N o. 70171055, 50179011 ) , th e N atu ral Sci ence Foundation of Chi na f or Ex cellent Y outh ( N o. 50225926) , th e D oct oral Foundati on of M inis t ry of Educat ion of Chi na ( N o. 20020532017) and the Teaching and Research Aw ard Program f or O uts t andi ng Y oung Teach ers i n High er Education Inst it ut es in 2000 Received date: 2003-02-23; Accepted date: 2003-09-10 Biography: LU Hong-W ei, M as ter candi date, main res earch f ield: w ater regional ecol ogy.
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卢宏玮等: 洞庭湖流 域区域生态风险评价
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system. Such a choice is to ensure the assessment results being mo r e sy stematic and co mprehensiv e. Daphnia, a s a receptor in this pa per , is emplo yed for a naly sis o f th e eco log ical risk o f th e east , so uth
The regional ecological risk assessment of the Dongting Lake watershed
L U Ho ng-W ei, Z ENG Guang -Mi ng , X IE Geng-Xi n, ZHAN G Shuo-Fu, HU AN G GuoHe, JIN Xi ang -Ca n, L IU Hong -Lia ng ( Department of S cience an d Environment Engineerin g , Hu 'nan