水質級別：

    水(shui)質(zhi)級別(bie)(bie)，是依據地表(biao)水(shui)水(shui)域(yu)(yu)環境功(gong)(gong)(gong)能(neng)(neng)(neng)和保護目標(biao)(biao)(biao)，按功(gong)(gong)(gong)能(neng)(neng)(neng)高低依次劃分為五(wu)類(lei)(lei): Ⅰ-Ⅴ。對應地表(biao)水(shui)上述五(wu)類(lei)(lei)水(shui)域(yu)(yu)功(gong)(gong)(gong)能(neng)(neng)(neng)，將地表(biao)水(shui)環境質(zhi)量標(biao)(biao)(biao)準基本(ben)項目標(biao)(biao)(biao) 準值(zhi)分為五(wu)類(lei)(lei)，不同功(gong)(gong)(gong)能(neng)(neng)(neng)類(lei)(lei)別(bie)(bie)分別(bie)(bie)執行(xing)相(xiang)應類(lei)(lei)別(bie)(bie)的標(biao)(biao)(biao)準值(zhi)。水(shui)域(yu)(yu)功(gong)(gong)(gong)能(neng)(neng)(neng)類(lei)(lei)別(bie)(bie)高的標(biao)(biao)(biao)準值(zhi)嚴(yan)于水(shui)域(yu)(yu)功(gong)(gong)(gong)能(neng)(neng)(neng)類(lei)(lei)別(bie)(bie)低的標(biao)(biao)(biao)準值(zhi)。同一水(shui)域(yu)(yu)兼有多(duo)類(lei)(lei)使用功(gong)(gong)(gong)能(neng)(neng)(neng) 的，執行(xing)zui高功(gong)(gong)(gong)能(neng)(neng)(neng)類(lei)(lei)別(bie)(bie)對應的標(biao)(biao)(biao)準值(zhi)。實現水(shui)域(yu)(yu)功(gong)(gong)(gong)能(neng)(neng)(neng)與達功(gong)(gong)(gong)能(neng)(neng)(neng)類(lei)(lei)別(bie)(bie)標(biao)(biao)(biao)準為同一含義。

水質評價說明：

①按(an)評(ping)價目標分:為(wei)防治污(wu)染的水污(wu)染評(ping)價,如60年代以來廣泛進(jin)行的河流污(wu)染評(ping)價、湖(hu)泊富營養化(hua)評(ping)價等(deng);為(wei)合(he)理(li)開發利用水資源(yuan)的水資源(yuan)質量評(ping)價。

②按評(ping)(ping)價(jia)對象分(fen):地(di)(di)表水(shui)評(ping)(ping)價(jia)和(he)地(di)(di)下水(shui)評(ping)(ping)價(jia),前者(zhe)又分(fen)為河流(liu)、湖泊、水(shui)庫(ku)、沼澤、潮汐河口和(he)海洋等水(shui)質評(ping)(ping)價(jia)。

③按評(ping)價(jia)(jia)時段分:利用積累的(de)歷史水(shui)(shui)(shui)質(zhi)數(shu)據，揭示水(shui)(shui)(shui)質(zhi)發展過程(cheng)的(de)回顧(gu)評(ping)價(jia)(jia)，根據近期水(shui)(shui)(shui)質(zhi)監測數(shu)據，闡明水(shui)(shui)(shui)質(zhi)當前狀(zhuang)況的(de)現狀(zhuang)評(ping)價(jia)(jia)，和對擬建(jian)工(gong)程(cheng)作(zuo)水(shui)(shui)(shui)質(zhi)影響(xiang)分析的(de)影響(xiang)評(ping)價(jia)(jia)(又稱預斷評(ping)價(jia)(jia))。

④按水(shui)(shui)(shui)的(de)用(yong)途分(fen):飲用(yong)水(shui)(shui)(shui)水(shui)(shui)(shui)質評(ping)價，漁(yu)業用(yong)水(shui)(shui)(shui)水(shui)(shui)(shui)質評(ping)價，工業用(yong)水(shui)(shui)(shui)水(shui)(shui)(shui)質評(ping)價，農(nong)業用(yong)水(shui)(shui)(shui)水(shui)(shui)(shui)質評(ping)價，游泳(yong)和風景游覽水(shui)(shui)(shui)體的(de)水(shui)(shui)(shui)質評(ping)價等。

水質評價方法：

    評價方法有兩大類(lei)，一類(lei)是以(yi)水質的物(wu)理化(hua)學參數的實測值為(wei)依據的評價方法;另一類(lei)是以(yi)水生(sheng)物(wu)種群與水質的關(guan)系為(wei)依據的生(sheng)物(wu)學評價方法。

    較多(duo)采用(yong)(yong)的(de)(de)是物理化學參(can)(can)數(shu)(shu)(shu)(shu)(shu)評(ping)(ping)(ping)價(jia)(jia)(jia)方(fang)法(fa)(fa)，其中又分(fen):①單項參(can)(can)數(shu)(shu)(shu)(shu)(shu)評(ping)(ping)(ping)價(jia)(jia)(jia)法(fa)(fa)即(ji)用(yong)(yong)某一參(can)(can)數(shu)(shu)(shu)(shu)(shu)的(de)(de)實測濃(nong)(nong)度代表(biao)(biao)值(zhi)與(yu)水(shui)質(zhi)標準(zhun)對比，判斷水(shui)質(zhi)的(de)(de)優劣或適用(yong)(yong)程(cheng)度。②多(duo)項參(can)(can)數(shu)(shu)(shu)(shu)(shu)綜(zong)合(he)(he)評(ping)(ping)(ping)價(jia)(jia)(jia)法(fa)(fa)即(ji)把(ba)選(xuan)(xuan)用(yong)(yong)的(de)(de)若干參(can)(can)數(shu)(shu)(shu)(shu)(shu)綜(zong)合(he)(he)成(cheng)一個概(gai)括的(de)(de)指(zhi)(zhi)數(shu)(shu)(shu)(shu)(shu)來評(ping)(ping)(ping)價(jia)(jia)(jia)水(shui)質(zhi)，又稱指(zhi)(zhi)數(shu)(shu)(shu)(shu)(shu)評(ping)(ping)(ping)價(jia)(jia)(jia)法(fa)(fa)。指(zhi)(zhi)數(shu)(shu)(shu)(shu)(shu)評(ping)(ping)(ping)價(jia)(jia)(jia)法(fa)(fa)用(yong)(yong)兩種指(zhi)(zhi)數(shu)(shu)(shu)(shu)(shu)即(ji)參(can)(can)數(shu)(shu)(shu)(shu)(shu)權重評(ping)(ping)(ping)分(fen)疊(die)(die)加(jia)(jia)型(xing)指(zhi)(zhi)數(shu)(shu)(shu)(shu)(shu)和參(can)(can)數(shu)(shu)(shu)(shu)(shu)相(xiang)對質(zhi)量(liang)疊(die)(die)加(jia)(jia)型(xing)指(zhi)(zhi)數(shu)(shu)(shu)(shu)(shu)兩種。參(can)(can)數(shu)(shu)(shu)(shu)(shu)權重評(ping)(ping)(ping)分(fen)疊(die)(die)加(jia)(jia)型(xing)指(zhi)(zhi)數(shu)(shu)(shu)(shu)(shu)的(de)(de)計(ji)算(suan)方(fang)法(fa)(fa)是，選(xuan)(xuan)定(ding)若干評(ping)(ping)(ping)價(jia)(jia)(jia)參(can)(can)數(shu)(shu)(shu)(shu)(shu)，按各(ge)(ge)項參(can)(can)數(shu)(shu)(shu)(shu)(shu)對水(shui)質(zhi)影響的(de)(de)程(cheng)度定(ding)出權系數(shu)(shu)(shu)(shu)(shu)，然后將各(ge)(ge)參(can)(can)數(shu)(shu)(shu)(shu)(shu)分(fen)成(cheng)若干等級，按質(zhi)量(liang)優劣評(ping)(ping)(ping)分(fen)，zui后將各(ge)(ge)參(can)(can)數(shu)(shu)(shu)(shu)(shu)的(de)(de)評(ping)(ping)(ping)分(fen)相(xiang)加(jia)(jia)，求(qiu)出綜(zong)合(he)(he)水(shui)質(zhi)指(zhi)(zhi)數(shu)(shu)(shu)(shu)(shu)。數(shu)(shu)(shu)(shu)(shu)值(zhi)大表(biao)(biao)示(shi)水(shui)質(zhi)好，數(shu)(shu)(shu)(shu)(shu)值(zhi)小表(biao)(biao)示(shi)水(shui)質(zhi)差。用(yong)(yong)這(zhe)種指(zhi)(zhi)數(shu)(shu)(shu)(shu)(shu)表(biao)(biao)示(shi)水(shui)質(zhi)，方(fang)法(fa)(fa)簡明，計(ji)算(suan)方(fang)便。參(can)(can)數(shu)(shu)(shu)(shu)(shu)相(xiang)對質(zhi)量(liang)疊(die)(die)加(jia)(jia)型(xing)指(zhi)(zhi)數(shu)(shu)(shu)(shu)(shu)的(de)(de)計(ji)算(suan)方(fang)法(fa)(fa)是，選(xuan)(xuan)定(ding)若干評(ping)(ping)(ping)價(jia)(jia)(jia)參(can)(can)數(shu)(shu)(shu)(shu)(shu)，把(ba)各(ge)(ge)參(can)(can)數(shu)(shu)(shu)(shu)(shu)的(de)(de)實際濃(nong)(nong)度與(yu)其相(xiang)應的(de)(de)評(ping)(ping)(ping)價(jia)(jia)(jia)標準(zhun)濃(nong)(nong)度相(xiang)比，求(qiu)出各(ge)(ge)參(can)(can)數(shu)(shu)(shu)(shu)(shu)的(de)(de)相(xiang)對質(zhi)量(liang)指(zhi)(zhi)數(shu)(shu)(shu)(shu)(shu)，然后求(qiu)總(zong)和值(zhi)。

    根據生物(wu)與(yu)環(huan)境條件相適應的(de)原理(li)建(jian)立(li)起來的(de)生物(wu)學(xue)評(ping)價方(fang)法，通過(guo)觀測水(shui)生物(wu)的(de)受害癥狀(zhuang)或種群組(zu)成，可(ke)以反映出水(shui)環(huan)境質(zhi)(zhi)量(liang)的(de)綜(zong)合狀(zhuang)況，因而(er)既可(ke)對水(shui)環(huan)境質(zhi)(zhi)量(liang)作回顧評(ping)價，又可(ke)對擬建(jian)工(gong)程(cheng)的(de)生態效應作影響評(ping)價，是物(wu)理(li)化學(xue)參數(shu)評(ping)價方(fang)法的(de)補充。缺(que)點是難確定水(shui)污染(ran)物(wu)的(de)性質(zhi)(zhi)和含量(liang)。