洞庭湖,歷史上(shang)有(you)云夢、云夢澤、九江(jiang)、五渚、五湖、三湖、重湖、太湖之稱。
洞(dong)(dong)庭湖(hu)(hu)(hu)(hu)的(de)(de)名(ming)稱(cheng)的(de)(de)歷來,有許多的(de)(de)說法(fa)。在《史記》、《周禮》、《爾雅》等古書上都有"云(yun)(yun)夢(meng)(meng)"的(de)(de)記載(zai)。夢(meng)(meng),是當(dang)時楚(chu)國方(fang)(fang)言"湖(hu)(hu)(hu)(hu)澤(ze)"的(de)(de)意思,與"漭"字相(xiang)通。"春秋(qiu)昭元年(nian)(nian),楚(chu)子與鄭伯田(tian)于江(jiang)南之夢(meng)(meng)"。又云(yun)(yun):"定四年(nian)(nian)楚(chu)子涉濉濟江(jiang),入于云(yun)(yun)中(zhong)。"《漢(han)陽志》說:"云(yun)(yun)在江(jiang)之北(bei)(bei),夢(meng)(meng)在江(jiang)之南。"合起來統稱(cheng)云(yun)(yun)夢(meng)(meng)。當(dang)時的(de)(de)云(yun)(yun)夢(meng)(meng)澤(ze)面積曾達4萬平方(fang)(fang)公(gong)里,《地理(li)今釋》載(zai):"東抵蘄州,西抵枝江(jiang),京山(shan)(shan)(shan)以(yi)(yi)(yi)南,青草(cao)以(yi)(yi)(yi)北(bei)(bei),皆古之云(yun)(yun)夢(meng)(meng)。"司馬相(xiang)如的(de)(de)《子虛賦(fu)》說:"云(yun)(yun)夢(meng)(meng)者(zhe)方(fang)(fang)八、九百里。"到了戰國后(hou)期,由于泥沙(sha)的(de)(de)沉積,云(yun)(yun)夢(meng)(meng)澤(ze)分為(wei)南北(bei)(bei)兩部,長江(jiang)以(yi)(yi)(yi)北(bei)(bei)成為(wei)沼澤(ze)地帶,長江(jiang)以(yi)(yi)(yi)南還保持(chi)一片(pian)浩(hao)瀚的(de)(de)大湖(hu)(hu)(hu)(hu)。自此不(bu)再叫云(yun)(yun)夢(meng)(meng),而將這片(pian)大湖(hu)(hu)(hu)(hu)稱(cheng)之為(wei)洞(dong)(dong)庭湖(hu)(hu)(hu)(hu),因為(wei)湖(hu)(hu)(hu)(hu)中(zhong)有一君山(shan)(shan)(shan),原(yuan)名(ming)洞(dong)(dong)庭山(shan)(shan)(shan)。《湘妃廟記略》稱(cheng):"洞(dong)(dong)庭蓋神仙洞(dong)(dong)府之一也,以(yi)(yi)(yi)其為(wei)洞(dong)(dong)庭之庭,故(gu)曰(yue)洞(dong)(dong)庭。后(hou)世以(yi)(yi)(yi)其洪水滔(tao)天,無得而稱(cheng),遂指(zhi)洞(dong)(dong)庭之山(shan)(shan)(shan)以(yi)(yi)(yi)名(ming)湖(hu)(hu)(hu)(hu)曰(yue)洞(dong)(dong)庭湖(hu)(hu)(hu)(hu)。"這就是洞(dong)(dong)庭湖(hu)(hu)(hu)(hu)名(ming)稱(cheng)的(de)(de)由來。
洞(dong)庭(ting)湖(hu)(hu)(hu)(hu)(hu)(hu)屬揚子準(zhun)地(di)(di)(di)(di)臺江(jiang)南地(di)(di)(di)(di)軸上(shang)的(de)(de)斷陷(xian)(xian)(xian)(xian)(xian)盆(pen)(pen)(pen)(pen)地(di)(di)(di)(di),形(xing)成(cheng)(cheng)(cheng)于燕山運(yun)(yun)動(dong),延續(xu)至(zhi)(zhi)喜馬拉雅運(yun)(yun)動(dong)。白堊紀(ji)為(wei)(wei)盆(pen)(pen)(pen)(pen)地(di)(di)(di)(di)發展擴(kuo)大(da)(da)時期(qi),第(di)四紀(ji)以來,洞(dong)庭(ting)湖(hu)(hu)(hu)(hu)(hu)(hu)拗(ao)陷(xian)(xian)(xian)(xian)(xian)盆(pen)(pen)(pen)(pen)地(di)(di)(di)(di)在(zai)(zai)(zai)新(xin)構造運(yun)(yun)動(dong)作用(yong)下(xia),再次(ci)下(xia)沉,接受沉積,成(cheng)(cheng)(cheng)為(wei)(wei)湖(hu)(hu)(hu)(hu)(hu)(hu)南省(sheng)第(di)四紀(ji)分(fen)布廣、厚度大(da)(da)、沉積層序全的(de)(de)地(di)(di)(di)(di)區。存在(zai)(zai)(zai)4次(ci)以上(shang)凹(ao)陷(xian)(xian)(xian)(xian)(xian)成(cheng)(cheng)(cheng)湖(hu)(hu)(hu)(hu)(hu)(hu)、凸起成(cheng)(cheng)(cheng)陸的(de)(de)演化(hua)過程(cheng),相應拗(ao)陷(xian)(xian)(xian)(xian)(xian)盆(pen)(pen)(pen)(pen)地(di)(di)(di)(di)解體,形(xing)成(cheng)(cheng)(cheng)斷拗(ao)盆(pen)(pen)(pen)(pen)地(di)(di)(di)(di)。早(zao)更(geng)新(xin)世早(zao)期(qi),在(zai)(zai)(zai)目平(ping)湖(hu)(hu)(hu)(hu)(hu)(hu)、澧(li)縣、沅(yuan)江(jiang)等凹(ao)陷(xian)(xian)(xian)(xian)(xian)成(cheng)(cheng)(cheng)湖(hu)(hu)(hu)(hu)(hu)(hu),中期(qi)湖(hu)(hu)(hu)(hu)(hu)(hu)侵(qin)擴(kuo)大(da)(da)到漢壽(shou)、鼎城、安鄉(xiang)、湘(xiang)陰等地(di)(di)(di)(di),出流由(you)安鄉(xiang)經(jing)澧(li)縣凹(ao)陷(xian)(xian)(xian)(xian)(xian)排入(ru)長(chang)江(jiang),末期(qi)凹(ao)陷(xian)(xian)(xian)(xian)(xian)轉(zhuan)為(wei)(wei)緩(huan)慢上(shang)升(sheng),湖(hu)(hu)(hu)(hu)(hu)(hu)泊萎縮(suo)一部分(fen)成(cheng)(cheng)(cheng)陸。早(zao)更(geng)新(xin)世晚(wan)期(qi),目平(ping)湖(hu)(hu)(hu)(hu)(hu)(hu)與沅(yuan)江(jiang)兩(liang)凹(ao)陷(xian)(xian)(xian)(xian)(xian)相連(lian),湖(hu)(hu)(hu)(hu)(hu)(hu)盆(pen)(pen)(pen)(pen)擴(kuo)大(da)(da)。赤(chi)山凸起成(cheng)(cheng)(cheng)為(wei)(wei)兩(liang)湖(hu)(hu)(hu)(hu)(hu)(hu)間的(de)(de)孤島,湖(hu)(hu)(hu)(hu)(hu)(hu)水從(cong)南縣、鲇市、藕池口排入(ru)長(chang)江(jiang),為(wei)(wei)第(di)四紀(ji)湖(hu)(hu)(hu)(hu)(hu)(hu)面(mian)大(da)(da)的(de)(de)興盛時期(qi)。隨著(zhu)湖(hu)(hu)(hu)(hu)(hu)(hu)盆(pen)(pen)(pen)(pen)轉(zhuan)為(wei)(wei)上(shang)升(sheng)為(wei)(wei)主,湖(hu)(hu)(hu)(hu)(hu)(hu)水退卻,出現洞(dong)庭(ting)湖(hu)(hu)(hu)(hu)(hu)(hu)平(ping)原(yuan)地(di)(di)(di)(di)貌景觀。中更(geng)新(xin)世,洞(dong)庭(ting)湖(hu)(hu)(hu)(hu)(hu)(hu)盆(pen)(pen)(pen)(pen)地(di)(di)(di)(di)發育為(wei)(wei)河網交織(zhi)的(de)(de)湖(hu)(hu)(hu)(hu)(hu)(hu)沼盆(pen)(pen)(pen)(pen)地(di)(di)(di)(di),澧(li)縣、目平(ping)湖(hu)(hu)(hu)(hu)(hu)(hu)和沅(yuan)江(jiang)至(zhi)(zhi)湘(xiang)陰的(de)(de)沉積體系。此時,湖(hu)(hu)(hu)(hu)(hu)(hu)水有(you)兩(liang)處(chu)出口,一處(chu)由(you)岳陽(yang)君山經(jing)廣興洲(zhou)入(ru)長(chang)江(jiang),另一處(chu)由(you)安鄉(xiang)佘(she)家(jia)臺經(jing)澧(li)縣進入(ru)江(jiang)漢盆(pen)(pen)(pen)(pen)地(di)(di)(di)(di)。晚(wan)更(geng)新(xin)世,目平(ping)湖(hu)(hu)(hu)(hu)(hu)(hu)凹(ao)陷(xian)(xian)(xian)(xian)(xian)和沅(yuan)江(jiang)至(zhi)(zhi)湘(xiang)陰凹(ao)陷(xian)(xian)(xian)(xian)(xian)部分(fen)地(di)(di)(di)(di)區再次(ci)活化(hua)沉降,并在(zai)(zai)(zai)赤(chi)山西部形(xing)成(cheng)(cheng)(cheng)常德、安鄉(xiang)河湖(hu)(hu)(hu)(hu)(hu)(hu)盆(pen)(pen)(pen)(pen)地(di)(di)(di)(di)和東(dong)部臨資口、黃茅洲(zhou)和北(bei)大(da)(da)市河湖(hu)(hu)(hu)(hu)(hu)(hu)盆(pen)(pen)(pen)(pen)地(di)(di)(di)(di),但其它(ta)范圍已大(da)(da)為(wei)(wei)縮(suo)小(xiao),形(xing)狀復雜,湖(hu)(hu)(hu)(hu)(hu)(hu)水由(you)南向(xiang)北(bei)流,并在(zai)(zai)(zai)團山附近(jin)有(you)東(dong)、西水系匯合,在(zai)(zai)(zai)石(shi)首一帶(dai)注入(ru)長(chang)江(jiang)。發展到后期(qi),整個湖(hu)(hu)(hu)(hu)(hu)(hu)盆(pen)(pen)(pen)(pen)為(wei)(wei)河網交錯(cuo)的(de)(de)洞(dong)庭(ting)平(ping)原(yuan),當時在(zai)(zai)(zai)君山西南側有(you)一方(fang)圓130平(ping)方(fang)公里的(de)(de)小(xiao)湖(hu)(hu)(hu)(hu)(hu)(hu)。
先秦之后,云夢澤逐(zhu)漸解(jie)體,江(jiang)(jiang)(jiang)(jiang)(jiang)湖(hu)(hu)(hu)關系轉變(bian),直(zhi)接影響到洞庭湖(hu)(hu)(hu)的(de)(de)(de)(de)(de)演變(bian)。漢晉以(yi)(yi)來(lai),長(chang)(chang)江(jiang)(jiang)(jiang)(jiang)(jiang)流域(yu)人口(kou)(kou)逐(zhu)漸增(zeng)長(chang)(chang),墾殖(zhi)活動強度增(zeng)大(da)(da)(da)(da),自(zi)然植被受到破(po)壞,長(chang)(chang)江(jiang)(jiang)(jiang)(jiang)(jiang)的(de)(de)(de)(de)(de)含沙(sha)量(liang)開始增(zeng)高。隨著(zhu)荊(jing)(jing)(jing)北云夢澤的(de)(de)(de)(de)(de)逐(zhu)漸淤(yu)塞(sai),荊(jing)(jing)(jing)江(jiang)(jiang)(jiang)(jiang)(jiang)河床自(zi)動調節抬(tai)高,加上受西北—東南方向新構造掀(xian)斜運動的(de)(de)(de)(de)(de)影響,荊(jing)(jing)(jing)江(jiang)(jiang)(jiang)(jiang)(jiang)主泓(hong)道(dao)逐(zhu)漸向南擺(bai)動。東晉永和年間,荊(jing)(jing)(jing)江(jiang)(jiang)(jiang)(jiang)(jiang)南岸形成(cheng)景口(kou)(kou)、淪口(kou)(kou)二股分(fen)流匯合成(cheng)淪水(shui)(shui)進入洞庭湖(hu)(hu)(hu)。洞庭湖(hu)(hu)(hu)由(you)于承納兩(liang)口(kou)(kou)分(fen)泄之江(jiang)(jiang)(jiang)(jiang)(jiang)水(shui)(shui)江(jiang)(jiang)(jiang)(jiang)(jiang)沙(sha),湖(hu)(hu)(hu)泊的(de)(de)(de)(de)(de)淤(yu)積過(guo)程(cheng)開始加速,形成(cheng)大(da)(da)(da)(da)小(xiao)不(bu)一(yi)(yi)的(de)(de)(de)(de)(de)湖(hu)(hu)(hu)群(qun)。唐宋(song)(song)時(shi)期,荊(jing)(jing)(jing)江(jiang)(jiang)(jiang)(jiang)(jiang)統(tong)一(yi)(yi)河床的(de)(de)(de)(de)(de)形成(cheng),使(shi)邊界條件發(fa)生重(zhong)大(da)(da)(da)(da)變(bian)化(hua)(hua)。隨著(zhu)荊(jing)(jing)(jing)江(jiang)(jiang)(jiang)(jiang)(jiang)堤防不(bu)斷修(xiu)筑(zhu),江(jiang)(jiang)(jiang)(jiang)(jiang)面束(shu)狹、泄洪(hong)(hong)(hong)(hong)(hong)不(bu)暢,洪(hong)(hong)(hong)(hong)(hong)水(shui)(shui)位開始抬(tai)升(sheng),江(jiang)(jiang)(jiang)(jiang)(jiang)水(shui)(shui)頂(ding)托倒灌機率(lv)增(zeng)大(da)(da)(da)(da),每當大(da)(da)(da)(da)洪(hong)(hong)(hong)(hong)(hong)水(shui)(shui)通過(guo)荊(jing)(jing)(jing)江(jiang)(jiang)(jiang)(jiang)(jiang)段常形成(cheng)決口(kou)(kou),“九穴十三(san)口(kou)(kou)”形成(cheng)。穴口(kou)(kou)大(da)(da)(da)(da)量(liang)分(fen)流長(chang)(chang)江(jiang)(jiang)(jiang)(jiang)(jiang)洪(hong)(hong)(hong)(hong)(hong)水(shui)(shui),使(shi)洞庭湖(hu)(hu)(hu)呈現(xian)明顯擴漲(zhang)之勢,湖(hu)(hu)(hu)盆向西、向南伸展,南連青草(cao)、西吞赤沙(sha),水(shui)(shui)域(yu)面積擴大(da)(da)(da)(da)。形容湖(hu)(hu)(hu)水(shui)(shui)波瀾壯闊的(de)(de)(de)(de)(de)“八百里洞庭”一(yi)(yi)詞便(bian)開始在(zai)這一(yi)(yi)時(shi)期的(de)(de)(de)(de)(de)詩(shi)文典籍中(zhong)出現(xian)。隨著(zhu)水(shui)(shui)域(yu)擴展,使(shi)原來(lai)在(zai)漢晉時(shi)期彼此支離的(de)(de)(de)(de)(de)洞庭、青草(cao)、赤沙(sha)3個湖(hu)(hu)(hu)泊在(zai)高水(shui)(shui)位時(shi)得以(yi)(yi)連成(cheng)一(yi)(yi)片。由(you)于受長(chang)(chang)江(jiang)(jiang)(jiang)(jiang)(jiang)來(lai)水(shui)(shui)的(de)(de)(de)(de)(de)影響越(yue)來(lai)越(yue)大(da)(da)(da)(da),洞庭湖(hu)(hu)(hu)洪(hong)(hong)(hong)(hong)(hong)水(shui)(shui)過(guo)程(cheng)也相應發(fa)生顯著(zhu)變(bian)化(hua)(hua),由(you)唐宋(song)(song)以(yi)(yi)前以(yi)(yi)“春溜滿(man)漲(zhang)”為主逐(zhu)漸轉變(bian)為以(yi)(yi)“夏秋水(shui)(shui)漲(zhang)”為主,洪(hong)(hong)(hong)(hong)(hong)水(shui)(shui)特(te)征除由(you)四水(shui)(shui)注(zhu)入的(de)(de)(de)(de)(de)“桃(tao)花(hua)汛”之外,長(chang)(chang)江(jiang)(jiang)(jiang)(jiang)(jiang)夏秋水(shui)(shui)漲(zhang)的(de)(de)(de)(de)(de)洪(hong)(hong)(hong)(hong)(hong)水(shui)(shui)特(te)征已(yi)突現(xian)出來(lai),使(shi)湖(hu)(hu)(hu)泊的(de)(de)(de)(de)(de)洪(hong)(hong)(hong)(hong)(hong)水(shui)(shui)過(guo)程(cheng)在(zai)年內變(bian)化(hua)(hua)由(you)原來(lai)的(de)(de)(de)(de)(de)單(dan)峰(feng)型轉變(bian)為明顯的(de)(de)(de)(de)(de)雙峰(feng)型。
宋代以后,荊(jing)(jing)江(jiang)(jiang)河(he)床不斷為(wei)泥沙淤積,洪水(shui)位持續抬升,使魏晉時(shi)原“湖(hu)高江(jiang)(jiang)低、湖(hu)水(shui)入江(jiang)(jiang)”的(de)江(jiang)(jiang)湖(hu)關(guan)系(xi)逐漸演變(bian)為(wei)“江(jiang)(jiang)高湖(hu)低、江(jiang)(jiang)水(shui)入湖(hu)”的(de)格(ge)局,洞庭湖(hu)水(shui)浸日益嚴重(zhong)。元、明(ming)、清三(san)朝,隨(sui)著荊(jing)(jing)江(jiang)(jiang)堤防的(de)不斷修(xiu)筑和穴口的(de)時(shi)決時(shi)塞,江(jiang)(jiang)患加劇,荊(jing)(jing)江(jiang)(jiang)潰堤、湖(hu)區(qu)潰垸(huan)頻繁(fan)。江(jiang)(jiang)湖(hu)關(guan)系(xi)開始緊張起來,說(shuo)明(ming)從宋代開始,江(jiang)(jiang)湖(hu)關(guan)系(xi)開始發(fa)生(sheng)歷史(shi)性變(bian)化,人為(wei)因(yin)素成為(wei)江(jiang)(jiang)湖(hu)關(guan)系(xi)變(bian)異的(de)不可忽(hu)視的(de)因(yin)素。
明(ming)嘉靖之(zhi)(zhi)(zhi)后,中(zhong)央政府(fu)采(cai)取“舍南(nan)救北(bei)(bei)”的(de)(de)治水(shui)(shui)(shui)方(fang)針,荊江(jiang)(jiang)北(bei)(bei)岸穴口(kou)盡堵,南(nan)岸保留太平、調(diao)弦二口(kou)與洞(dong)(dong)(dong)庭(ting)湖(hu)(hu)勾通。清代仍繼續沿襲明(ming)朝(chao)的(de)(de)消極治水(shui)(shui)(shui)方(fang)針,在長江(jiang)(jiang)來(lai)水(shui)(shui)(shui)有增無減的(de)(de)情況下(xia),一(yi)遇洪水(shui)(shui)(shui)則(ze)湖(hu)(hu)水(shui)(shui)(shui)泛(fan)濫四(si)溢(yi)、向(xiang)外擴(kuo)展已成必然之(zhi)(zhi)(zhi)勢。西洞(dong)(dong)(dong)庭(ting)湖(hu)(hu)和南(nan)洞(dong)(dong)(dong)庭(ting)湖(hu)(hu)就是在這一(yi)背(bei)景下(xia)逐漸擴(kuo)大起(qi)來(lai)的(de)(de)。這一(yi)時(shi)期(qi)(qi)洞(dong)(dong)(dong)庭(ting)湖(hu)(hu)的(de)(de)范圍,“每歲夏(xia)秋之(zhi)(zhi)(zhi)交,湖(hu)(hu)水(shui)(shui)(shui)泛(fan)濫,方(fang)圓八(ba)九(jiu)百(bai)(bai)里(li)(li),龍陽(yang)、沅(yuan)江(jiang)(jiang)則(ze)西南(nan)之(zhi)(zhi)(zhi)一(yi)隅(yu)。”說明(ming)唐(tang)宋時(shi)期(qi)(qi)洞(dong)(dong)(dong)庭(ting)湖(hu)(hu)在西吞赤沙湖(hu)(hu)之(zhi)(zhi)(zhi)后,向(xiang)西南(nan)又有了迅(xun)速的(de)(de)發(fa)展。迄至清代中(zhong)期(qi)(qi)以(yi)前,洞(dong)(dong)(dong)庭(ting)湖(hu)(hu)仍繼續呈擴(kuo)漲之(zhi)(zhi)(zhi)勢,到(dao)道光年(nian)間,為洞(dong)(dong)(dong)庭(ting)湖(hu)(hu)自(zi)先秦(qin)以(yi)來(lai)擴(kuo)展至鼎(ding)盛時(shi)期(qi)(qi)。道光《洞(dong)(dong)(dong)庭(ting)湖(hu)(hu)志》記(ji)載它的(de)(de)范圍是:“東北(bei)(bei)屬巴陵,西北(bei)(bei)跨華(hua)容(rong)、石(shi)(shi)首、安鄉,西連武陵、龍陽(yang)、沅(yuan)江(jiang)(jiang),南(nan)帶益陽(yang)而(er)環湘陰(yin),凡四(si)府(fu)一(yi)州,界分九(jiu)邑,橫亙八(ba)九(jiu)百(bai)(bai)里(li)(li),日月若(ruo)出沒其(qi)中(zhong)。”可(ke)(ke)見(jian)洞(dong)(dong)(dong)庭(ting)湖(hu)(hu)自(zi)魏晉南(nan)北(bei)(bei)朝(chao)之(zhi)(zhi)(zhi)后是逐步(bu)“回春(chun)”的(de)(de)。由(you)魏晉時(shi)期(qi)(qi)的(de)(de)五百(bai)(bai)余里(li)(li)到(dao)唐(tang)宋之(zhi)(zhi)(zhi)際的(de)(de)七、八(ba)百(bai)(bai)里(li)(li),繼而(er)又發(fa)展到(dao)清中(zhong)葉的(de)(de)八(ba)九(jiu)百(bai)(bai)里(li)(li),湖(hu)(hu)水(shui)(shui)(shui)波濤可(ke)(ke)直拍岳(yue)陽(yang)、華(hua)容(rong)、漢壽(shou)、沅(yuan)江(jiang)(jiang)、湘陰(yin)等縣城,君山(shan)(shan)(shan)、艑(bian)山(shan)(shan)(shan)、層山(shan)(shan)(shan)、寄山(shan)(shan)(shan)、團山(shan)(shan)(shan)、磊石(shi)(shi)山(shan)(shan)(shan)、赤山(shan)(shan)(shan)、墨山(shan)(shan)(shan)等均(jun)成為兀立湖(hu)(hu)中(zhong)的(de)(de)島(dao)嶼。洪水(shui)(shui)(shui)時(shi)節,洞(dong)(dong)(dong)庭(ting)湖(hu)(hu)水(shui)(shui)(shui)域面積(ji)超過6000平方(fang)公里(li)(li)。
十九(jiu)世紀中葉,洞(dong)庭(ting)(ting)(ting)湖(hu)(hu)(hu)(hu)(hu)(hu)(hu)開(kai)(kai)(kai)始(shi)由(you)(you)(you)盛轉衰,進(jin)(jin)入(ru)(ru)有史記載(zai)以來(lai)演變(bian)(bian)為(wei)(wei)劇烈(lie)的(de)(de)(de)(de)(de)(de)(de)(de)階段(duan)。從6000平(ping)方(fang)(fang)公里(li)的(de)(de)(de)(de)(de)(de)(de)(de)浩瀚大(da)湖(hu)(hu)(hu)(hu)(hu)(hu)(hu),萎(wei)縮到目(mu)前2691平(ping)方(fang)(fang)公里(li)的(de)(de)(de)(de)(de)(de)(de)(de)湖(hu)(hu)(hu)(hu)(hu)(hu)(hu)面,就是(shi)(shi)在這一百多年(nian)時間內(nei)(nei)(nei)發生的(de)(de)(de)(de)(de)(de)(de)(de)。其主要原(yuan)因就是(shi)(shi)人為(wei)(wei)和(he)政策的(de)(de)(de)(de)(de)(de)(de)(de)因素,導致(zhi)咸豐(feng)、同治年(nian)間藕(ou)池(chi)(chi)、松滋(zi)(zi)相繼潰(kui)(kui)口(kou)(kou),荊(jing)江四(si)(si)口(kou)(kou)分(fen)(fen)流入(ru)(ru)洞(dong)庭(ting)(ting)(ting)湖(hu)(hu)(hu)(hu)(hu)(hu)(hu)局(ju)面的(de)(de)(de)(de)(de)(de)(de)(de)正(zheng)式(shi)形(xing)成(cheng)(cheng)。咸豐(feng)二年(nian),荊(jing)江藕(ou)池(chi)(chi)堤馬(ma)林工(gong)在小水(shui)(shui)年(nian)份潰(kui)(kui)決,清(qing)(qing)政府(fu)借口(kou)(kou)民力拮據未予堵筑(zhu),形(xing)成(cheng)(cheng)藕(ou)池(chi)(chi)口(kou)(kou)、至咸豐(feng)十年(nian)長江大(da)水(shui)(shui),在原(yuan)潰(kui)(kui)口(kou)(kou)沖刷成(cheng)(cheng)藕(ou)池(chi)(chi)口(kou)(kou)。同治九(jiu)年(nian)松滋(zi)(zi)潰(kui)(kui)口(kou)(kou),因堵筑(zhu)不(bu)堅(jian)固,同治十二年(nian)復潰(kui)(kui),形(xing)成(cheng)(cheng)松滋(zi)(zi)河。藕(ou)池(chi)(chi)口(kou)(kou),松滋(zi)(zi)口(kou)(kou)形(xing)成(cheng)(cheng)后,原(yuan)由(you)(you)(you)兩(liang)口(kou)(kou)分(fen)(fen)流轉變(bian)(bian)為(wei)(wei)四(si)(si)口(kou)(kou)分(fen)(fen)流,江湖(hu)(hu)(hu)(hu)(hu)(hu)(hu)關(guan)系(xi)巨變(bian)(bian),成(cheng)(cheng)為(wei)(wei)洞(dong)庭(ting)(ting)(ting)湖(hu)(hu)(hu)(hu)(hu)(hu)(hu)近(jin)一百多年(nian)來(lai)演變(bian)(bian)的(de)(de)(de)(de)(de)(de)(de)(de)重大(da)轉折點。由(you)(you)(you)于四(si)(si)口(kou)(kou)自(zi)北而南(nan)奔(ben)流,奪流改道(dao),不(bu)僅使(shi)(shi)四(si)(si)水(shui)(shui)三(san)角洲平(ping)原(yuan)被(bei)(bei)淹,而且(qie)還迫(po)使(shi)(shi)四(si)(si)水(shui)(shui)改變(bian)(bian)流向(xiang),徹(che)底(di)打亂了(le)原(yuan)有水(shui)(shui)系(xi)格(ge)局(ju)。沅水(shui)(shui)尾閭的(de)(de)(de)(de)(de)(de)(de)(de)主泓(hong)被(bei)(bei)迫(po)遺棄(qi)故(gu)道(dao),改由(you)(you)(you)大(da)圍(wei)堤西北方(fang)(fang)向(xiang)入(ru)(ru)湖(hu)(hu)(hu)(hu)(hu)(hu)(hu);資水(shui)(shui)尾閭的(de)(de)(de)(de)(de)(de)(de)(de)主泓(hong)也不(bu)再經(jing)由(you)(you)(you)沅江縣城側,而是(shi)(shi)改由(you)(you)(you)毛角口(kou)(kou)經(jing)楊柳潭入(ru)(ru)湖(hu)(hu)(hu)(hu)(hu)(hu)(hu)。四(si)(si)口(kou)(kou)和(he)四(si)(si)水(shui)(shui)在湖(hu)(hu)(hu)(hu)(hu)(hu)(hu)內(nei)(nei)(nei)相互頂托干(gan)擾,造(zao)成(cheng)(cheng)局(ju)部(bu)地區(qu)水(shui)(shui)位壅(yong)高。更為(wei)(wei)嚴重的(de)(de)(de)(de)(de)(de)(de)(de)是(shi)(shi)大(da)量(liang)泥沙傾積湖(hu)(hu)(hu)(hu)(hu)(hu)(hu)內(nei)(nei)(nei),成(cheng)(cheng)為(wei)(wei)制(zhi)(zhi)約洞(dong)庭(ting)(ting)(ting)湖(hu)(hu)(hu)(hu)(hu)(hu)(hu)演變(bian)(bian)的(de)(de)(de)(de)(de)(de)(de)(de)一個主要矛(mao)盾。四(si)(si)口(kou)(kou)入(ru)(ru)湖(hu)(hu)(hu)(hu)(hu)(hu)(hu)泥沙淤積形(xing)成(cheng)(cheng)的(de)(de)(de)(de)(de)(de)(de)(de)河口(kou)(kou)三(san)角洲自(zi)西北向(xiang)東南(nan)推進(jin)(jin),加速(su)了(le)洞(dong)庭(ting)(ting)(ting)湖(hu)(hu)(hu)(hu)(hu)(hu)(hu)洲灘的(de)(de)(de)(de)(de)(de)(de)(de)發育(yu)。隨(sui)著三(san)角洲在湖(hu)(hu)(hu)(hu)(hu)(hu)(hu)內(nei)(nei)(nei)不(bu)斷(duan)充填(tian)和(he)南(nan)移東進(jin)(jin),洞(dong)庭(ting)(ting)(ting)湖(hu)(hu)(hu)(hu)(hu)(hu)(hu)由(you)(you)(you)此進(jin)(jin)入(ru)(ru)了(le)迅速(su)縮小的(de)(de)(de)(de)(de)(de)(de)(de)過程。伴隨(sui)著泥沙淤積和(he)洲灘的(de)(de)(de)(de)(de)(de)(de)(de)迅速(su)擴展(zhan),湖(hu)(hu)(hu)(hu)(hu)(hu)(hu)區(qu)繼之開(kai)(kai)(kai)展(zhan)大(da)量(liang)的(de)(de)(de)(de)(de)(de)(de)(de)圍(wei)墾。湖(hu)(hu)(hu)(hu)(hu)(hu)(hu)泊(bo)變(bian)(bian)成(cheng)(cheng)洲灘,洲灘又成(cheng)(cheng)為(wei)(wei)垸(huan)(huan)土(tu)和(he)湖(hu)(hu)(hu)(hu)(hu)(hu)(hu)田(tian),洞(dong)庭(ting)(ting)(ting)湖(hu)(hu)(hu)(hu)(hu)(hu)(hu)人進(jin)(jin)水(shui)(shui)退的(de)(de)(de)(de)(de)(de)(de)(de)狀況開(kai)(kai)(kai)始(shi)出(chu)(chu)現。濱湖(hu)(hu)(hu)(hu)(hu)(hu)(hu)堤垸(huan)(huan)如鱗,彌望無際,已有與水(shui)(shui)爭地之勢(shi)。乾隆年(nian)開(kai)(kai)(kai)始(shi)到嘉(jia)慶年(nian)間,湖(hu)(hu)(hu)(hu)(hu)(hu)(hu)南(nan)的(de)(de)(de)(de)(de)(de)(de)(de)一些有識之士包(bao)括地方(fang)(fang)官開(kai)(kai)(kai)始(shi)呼吁限制(zhi)(zhi)圍(wei)湖(hu)(hu)(hu)(hu)(hu)(hu)(hu)造(zao)田(tian),并要求刨毀(hui)有礙行(xing)洪的(de)(de)(de)(de)(de)(de)(de)(de)私垸(huan)(huan)。二是(shi)(shi)清(qing)(qing)末光緒年(nian),在荊(jing)江來(lai)沙成(cheng)(cheng)倍增(zeng)長、洲灘迅速(su)擴展(zhan)的(de)(de)(de)(de)(de)(de)(de)(de)情況下(xia),再次出(chu)(chu)現筑(zhu)堤建垸(huan)(huan)的(de)(de)(de)(de)(de)(de)(de)(de)高潮(chao),挽垸(huan)(huan)呈惡性膨脹,至清(qing)(qing)末洞(dong)庭(ting)(ting)(ting)湖(hu)(hu)(hu)(hu)(hu)(hu)(hu)總計(ji)有堤垸(huan)(huan)1094座(zuo)。
民國時期(qi),圍(wei)墾沒(mei)有受(shou)到(dao)遏制(zhi),洞庭(ting)(ting)(ting)湖(hu)(hu)進一步(bu)萎縮(suo)。高(gao)位(wei)洲(zhou)灘(tan)因每年顯露期(qi)長(chang)(chang),相(xiang)繼挽成(cheng)(cheng)堤垸已(yi)成(cheng)(cheng)必然之勢(shi)。而中(zhong)位(wei)和低位(wei)洲(zhou)灘(tan),因地(di)(di)勢(shi)低下(xia),每年淹(yan)沒(mei)時間較(jiao)長(chang)(chang),修(xiu)垸工程(cheng)量大,且(qie)不適宜(yi)墾殖,這一類(lei)未經建垸的洲(zhou)灘(tan),當(dang)地(di)(di)俗(su)稱之為(wei)洲(zhou)土。據(ju)民國35年調查,已(yi)形成(cheng)(cheng)岳臨、蒼梧臺、注滋口、大通湖(hu)(hu)、飄尾五(wu)大區塊,總計(ji)在(zai)268萬畝。20世紀40年代(dai)中(zhong)期(qi)洞庭(ting)(ting)(ting)湖(hu)(hu)已(yi)是洲(zhou)灘(tan)廣袤(mao),湖(hu)(hu)體支離破(po)碎,港汊交織(zhi),灘(tan)地(di)(di)發(fa)育系數(shu)達(da)0.4左右。洞庭(ting)(ting)(ting)湖(hu)(hu)灘(tan)地(di)(di)發(fa)育程(cheng)度如此之高(gao),表明(ming)洞庭(ting)(ting)(ting)湖(hu)(hu)已(yi)進入它的衰(shuai)老(lao)階段。
此(ci)后由于分流入湖的(de)洪水夾(jia)帶大量泥沙,湖盆不斷淤積,1983年,這個長江水系(xi)重(zhong)要調(diao)節湖泊的(de)面積又縮小(xiao)到(dao)2691平方公里,并被(bei)分隔(ge)為幾個部(bu)分。
洞庭(ting)湖(hu)區位于長江(jiang)中游荊(jing)江(jiang)南(nan)岸,跨(kua)湘、鄂兩省。包括荊(jing)江(jiang)河段以南(nan),湘、資(zi)、沅、澧四(si)水(shui)控制站以下的(de)廣大(da)平(ping)原、湖(hu)泊水(shui)網區。洞庭(ting)湖(hu)南(nan)近湘陰(yin)縣、益(yi)陽(yang)市,北抵華容縣、安鄉縣、南(nan)縣,東(dong)濱岳陽(yang)市、汨(mi)羅市,西至澧縣。在(zai)北緯27°39′~29°51′;東(dong)經111°19′~113°34′之間(jian)。
洞庭(ting)湖大致可分為東(dong)洞庭(ting)湖、南洞庭(ting)湖和西洞庭(ting)湖三部(bu)分(另有(you)資(zi)料指(zhi)為四部(bu)分,還有(you)一部(bu)分為大通(tong)湖)。
東洞庭(ting)湖(hu)(hu)位于華容(rong)(rong)縣墨山鋪、注滋口,汨(mi)羅(luo)市磊山,益陽市大通湖(hu)(hu)農(nong)場之間。濱湖(hu)(hu)的有岳(yue)陽市區(qu)(qu)(岳(yue)陽樓區(qu)(qu)、君山區(qu)(qu))、華容(rong)(rong)縣、錢糧湖(hu)(hu)農(nong)場、君山農(nong)場、建新農(nong)場、岳(yue)陽縣,湖(hu)(hu)泊面積1327.8平(ping)方公里,(包括漉湖(hu)(hu)與(yu)湘(xiang)江洪道)。1988年,東洞庭(ting)湖(hu)(hu)被列入國家風景名勝區(qu)(qu)-“洞庭(ting)湖(hu)(hu)-岳(yue)陽樓風景名勝區(qu)(qu)”。
東(dong)洞(dong)(dong)庭湖(hu)(hu)(hu)城(cheng)陵磯七里山(shan)水文站前 南洞(dong)(dong)庭湖(hu)(hu)(hu)跨岳陽(yang)市境(jing)(jing)與益(yi)陽(yang)市之間(jian)(jian),指赤山(shan)與磊石山(shan)以南諸湖(hu)(hu)(hu)泊(bo),岳陽(yang)市境(jing)(jing)濱湖(hu)(hu)(hu)的有湘陰縣、屈原管理區,湖(hu)(hu)(hu)泊(bo)面積920平方公里,界于東(dong)、西洞(dong)(dong)庭湖(hu)(hu)(hu)之間(jian)(jian),主要有東(dong)南湖(hu)(hu)(hu)、萬子湖(hu)(hu)(hu)和橫嶺湖(hu)(hu)(hu)。橫嶺湖(hu)(hu)(hu)位于湖(hu)(hu)(hu)南湘陰縣北部,由大大小小24個常(chang)年性湖(hu)(hu)(hu)泊(bo)和3大片季節性洲土(tu)組成。
西洞庭湖(hu)(hu)(hu)(hu)(hu)(hu),在益陽(yang)市、常德市境,指赤(chi)(chi)山湖(hu)(hu)(hu)(hu)(hu)(hu)以西諸湖(hu)(hu)(hu)(hu)(hu)(hu)泊(bo),到20世(shi)紀僅存(cun)七(qi)(qi)里(li)湖(hu)(hu)(hu)(hu)(hu)(hu)和目(mu)平(ping)湖(hu)(hu)(hu)(hu)(hu)(hu)(有資料(liao)顯示(shi)還有半(ban)邊湖(hu)(hu)(hu)(hu)(hu)(hu)、大連湖(hu)(hu)(hu)(hu)(hu)(hu)),湖(hu)(hu)(hu)(hu)(hu)(hu)泊(bo)面積(ji)443.9平(ping)方公(gong)里(li)。有澧(li)水流經(jing)(jing)西北(bei),沅水流經(jing)(jing)西南,松滋河、虎(hu)渡河及藕(ou)池河西支諸水自北(bei)注入,現有通外江湖(hu)(hu)(hu)(hu)(hu)(hu)的(de)河湖(hu)(hu)(hu)(hu)(hu)(hu)面積(ji)約520平(ping)方公(gong)里(li),環湖(hu)(hu)(hu)(hu)(hu)(hu)的(de)漢壽縣(xian)、安鄉(xiang)縣(xian)、鼎城區(qu)(qu)、澧(li)縣(xian)、津(jin)市市、桃源縣(xian)、臨澧(li)縣(xian)、武陵區(qu)(qu)的(de)平(ping)原區(qu)(qu)稱為西洞庭湖(hu)(hu)(hu)(hu)(hu)(hu)區(qu)(qu),有吳淞高程51米以下的(de)平(ping)原河湖(hu)(hu)(hu)(hu)(hu)(hu)面積(ji)6285平(ping)方公(gong)里(li)。西洞庭湖(hu)(hu)(hu)(hu)(hu)(hu)早期系赤(chi)(chi)沙湖(hu)(hu)(hu)(hu)(hu)(hu)的(de)一(yi)部分(fen)。經(jing)(jing)歷(li)代治理,西洞庭湖(hu)(hu)(hu)(hu)(hu)(hu)區(qu)(qu)的(de)天然湖(hu)(hu)(hu)(hu)(hu)(hu)泊(bo)面積(ji)已縮減至520平(ping)方公(gong)里(li),能與東、南洞庭湖(hu)(hu)(hu)(hu)(hu)(hu)通流的(de)湖(hu)(hu)(hu)(hu)(hu)(hu)泊(bo),僅剩余目(mu)平(ping)湖(hu)(hu)(hu)(hu)(hu)(hu)、七(qi)(qi)里(li)湖(hu)(hu)(hu)(hu)(hu)(hu)。
目(mu)(mu)平湖 ,東(dong)臨赤山(shan),南(nan)抵漢壽、沅(yuan)江(jiang)山(shan)丘(qiu),北(bei)(bei)聯(lian)澧(li)水(shui)(shui)尾閭和松虎(hu)洪道尾閭,西達(da)西湖大堤。總(zong)(zong)面積(ji)(ji)(ji)350平方(fang)公(gong)里。目(mu)(mu)平湖因相傳范蠡曾隱居赤山(shan),曾稱(cheng)蠡湖。后人以其(qi)湖面廣闊,"舉目(mu)(mu)無(wu)際",改名目(mu)(mu)平湖,是(shi)西洞庭湖殘(can)存的(de)大湖泊,調(diao)蓄容積(ji)(ji)(ji)約21億(yi)立方(fang)米(mi)。總(zong)(zong)面積(ji)(ji)(ji)350平方(fang)公(gong)里,調(diao)蓄容積(ji)(ji)(ji)21億(yi)立方(fang)米(mi)。松滋、虎(hu)渡(du)河分(fen)泄(xie)江(jiang)水(shui)(shui)泥沙含(han)量(liang)大,北(bei)(bei)部淤積(ji)(ji)(ji)嚴重。1949~1988年,目(mu)(mu)平湖已(yi)平均淤高2米(mi)以上,32~33米(mi)高程的(de)淤洲已(yi)達(da)9萬畝左右。當水(shui)(shui)位下(xia)降至31米(mi)時,沅(yuan)澧(li)水(shui)(shui)已(yi)不能(neng)通流,行人可(ke)從西湖垸涉湖上赤山(shan)。
珊泊湖(hu),南靠省道1804線,西(xi)連澧水,距安(an)鄉縣城8公里,是(shi)屬(shu)半封閉型調蓄湖(hu)泊。面(mian)積約1700公頃,現有水面(mian)22300畝(mu),是(shi)湖(hu)南省第二大湖(hu)泊。湖(hu)面(mian)水域寬闊,碧波萬(wan)頃,水質清(qing)新,風景秀麗,且水位穩定(ding),光照充足,水質硬度、堿度適(shi)宜,底層有機物質豐(feng)富,有利(li)于氧化還原(yuan)和(he)物質循環,有利(li)于水中資源(yuan)生長(chang),宜養、宜捕(bu),為我國人工養殖高(gao)產(chan)(chan)天然湖(hu)泊之一。盛產(chan)(chan)青、草、鳊(bian)、鯽、鰱、鯉、鱖等(deng)(deng)優質魚(yu)類和(he)鱉、龜、鱔、珍珠等(deng)(deng)特種水產(chan)(chan),可年產(chan)(chan)鮮魚(yu)2000噸,魚(yu)苗80噸,珍珠1.2噸。
津(jin)市(shi)(shi)西湖(hu),位于津(jin)市(shi)(shi)市(shi)(shi)區以南約25公里(li)處,原是(shi)西洞庭湖(hu)的一(yi)部(bu)分,因(yin)筑堤分割而形(xing)成(cheng),包括彼此相連的毛(mao)里(li)湖(hu)、西湖(hu)、楊壩當、啞河(he)等,水(shui)(shui)(shui)(shui)(shui)(shui)面面積(ji)約40平方公里(li),5.71萬畝(mu),其中毛(mao)里(li)湖(hu)33000畝(mu),西湖(hu)17000畝(mu),楊壩當3000畝(mu),啞河(he)4000畝(mu),平均(jun)水(shui)(shui)(shui)(shui)(shui)(shui)深3.12米(mi),湖(hu)岸長約220公里(li),是(shi)省內(nei)第二大內(nei)陸淡(dan)水(shui)(shui)(shui)(shui)(shui)(shui)養殖(zhi)湖(hu)泊。該湖(hu)山水(shui)(shui)(shui)(shui)(shui)(shui)相連,風光秀麗(li),湖(hu)面大,附近無污染,水(shui)(shui)(shui)(shui)(shui)(shui)質清(qing)潔,深度適中,水(shui)(shui)(shui)(shui)(shui)(shui)位較穩定(ding),水(shui)(shui)(shui)(shui)(shui)(shui)草及(ji)餌料資(zi)源豐富(fu),屬半封(feng)閉型(xing)水(shui)(shui)(shui)(shui)(shui)(shui)體,有(you)一(yi)定(ding)的微流水(shui)(shui)(shui)(shui)(shui)(shui),自然(ran)產魚力(li)強,為典型(xing)的營養型(xing)湖(hu)泊,素(su)有(you)"黃金水(shui)(shui)(shui)(shui)(shui)(shui)面"之(zhi)美譽。湖(hu)內(nei)現(xian)有(you)上乘魚類(lei)品(pin)種(zhong)75種(zhong),以鰱、鳙(yong)、青、草、鯉、鳊魚為主(zhu),尤其是(shi)國內(nei)外市(shi)(shi)場緊(jin)俏的名貴水(shui)(shui)(shui)(shui)(shui)(shui)產如水(shui)(shui)(shui)(shui)(shui)(shui)魚、鱖魚、烏鱧、銀(yin)魚資(zi)源甚為豐富(fu),年產鮮(xian)魚600余(yu)噸。
七(qi)里湖,位于津市(shi)小渡口(kou)以下(xia)至石(shi)龜山,南抵(di)嘉山,北臨(lin)松(song)澧大垸。總面(mian)積94平(ping)方(fang)(fang)公里。七(qi)里湖承納澧水及松(song)滋河西支來水,泥沙含量(liang)較大,湖床淤(yu)積十分(fen)迅速。1952年實(shi)測(ce)(ce),湖底平(ping)均高程27.2米(mi)(mi);1983年實(shi)測(ce)(ce),平(ping)均淤(yu)高4.5米(mi)(mi),大淤(yu)高7.5米(mi)(mi)。調蓄(xu)容積由10億立方(fang)(fang)米(mi)(mi)減至不足3億立方(fang)(fang)米(mi)(mi)。為改善(shan)七(qi)里湖泄(xie)洪(hong)狀況,澧縣(xian)、津市(shi)曾(ceng)數次疏(shu)治,但仍難挽救七(qi)里湖的漸次消亡。
大(da)通湖(hu)在湖(hu)南省(sheng)南縣的(de)青(qing)樹(shu)嘴(zui)鎮東,接沅江市界,亦洞(dong)庭之一隅(yu)也。是組成洞(dong)庭湖(hu)的(de)四個較大(da)的(de)湖(hu)泊之一,其(qi)面積12.4萬畝(mu),是湖(hu)南省(sheng)大(da)的(de)內陸養殖湖(hu)泊。
洞庭(ting)湖(hu)(hu)自古為(wei)五湖(hu)(hu)之首,是中(zhong)(zhong)國水(shui)(shui)(shui)(shui)量(liang)大(da)的(de)通江(jiang)湖(hu)(hu)泊(bo),由于(yu)(yu)自然因素和(he)人(ren)為(wei)因素的(de)相(xiang)互(hu)(hu)作用、相(xiang)互(hu)(hu)制約(yue),洞庭(ting)湖(hu)(hu)經(jing)歷了由小(xiao)到(dao)大(da)、再由大(da)到(dao)小(xiao)的(de)演變過程。至(zhi)1949年(nian)(nian)(nian),減(jian)至(zhi)4350平(ping)(ping)(ping)方(fang)(fang)(fang)(fang)公(gong)里(li);至(zhi)1983年(nian)(nian)(nian),據(ju)湖(hu)(hu)南(nan)省水(shui)(shui)(shui)(shui)電(dian)勘測(ce)設計院量(liang)算(suan)測(ce)繪的(de)《洞庭(ting)湖(hu)(hu)高程、面(mian)(mian)(mian)積(ji)(ji)、容(rong)(rong)積(ji)(ji)曲線圖》計算(suan),已減(jian)至(zhi)2691平(ping)(ping)(ping)方(fang)(fang)(fang)(fang)公(gong)里(li)。20世紀90年(nian)(nian)(nian)代末,據(ju)水(shui)(shui)(shui)(shui)利(li)部門測(ce)算(suan),有(you)(you)面(mian)(mian)(mian)積(ji)(ji)2579.2平(ping)(ping)(ping)方(fang)(fang)(fang)(fang)公(gong)里(li)(一說(shuo)2740平(ping)(ping)(ping)方(fang)(fang)(fang)(fang)公(gong)里(li));但(dan)它(ta)還有(you)(you)湘、資、沅、澧四(si)水(shui)(shui)(shui)(shui)和(he)“長(chang)江(jiang)四(si)口”1300多(duo)平(ping)(ping)(ping)方(fang)(fang)(fang)(fang)公(gong)里(li)洪道(dao)面(mian)(mian)(mian)積(ji)(ji)(一說(shuo)1.878萬平(ping)(ping)(ping)方(fang)(fang)(fang)(fang)公(gong)里(li))。兩者合計,仍有(you)(you)3879.2平(ping)(ping)(ping)方(fang)(fang)(fang)(fang)公(gong)里(li),面(mian)(mian)(mian)積(ji)(ji)多(duo)于(yu)(yu)鄱(po)陽(yang)湖(hu)(hu)近400平(ping)(ping)(ping)方(fang)(fang)(fang)(fang)公(gong)里(li)。湖(hu)(hu)盆周長(chang)為(wei)803.2公(gong)里(li),總(zong)容(rong)(rong)積(ji)(ji)220億(yi)立(li)方(fang)(fang)(fang)(fang)米,其中(zhong)(zhong)天然湖(hu)(hu)泊(bo)容(rong)(rong)積(ji)(ji)178億(yi)立(li)方(fang)(fang)(fang)(fang)米,河道(dao)容(rong)(rong)積(ji)(ji)42億(yi)立(li)方(fang)(fang)(fang)(fang)米。1998年(nian)(nian)(nian)洪水(shui)(shui)(shui)(shui)期間,以城陵(ling)磯(蓮花塘)實(shi)際水(shui)(shui)(shui)(shui)位35米,洞庭(ting)湖(hu)(hu)容(rong)(rong)積(ji)(ji)則(ze)多(duo)達(da)228.77億(yi)立(li)方(fang)(fang)(fang)(fang)米,其中(zhong)(zhong)天然湖(hu)(hu)泊(bo)容(rong)(rong)積(ji)(ji)230億(yi)立(li)方(fang)(fang)(fang)(fang)米。河道(dao)容(rong)(rong)積(ji)(ji)50億(yi)立(li)方(fang)(fang)(fang)(fang)米;年(nian)(nian)(nian)均(jun)入湖(hu)(hu)徑流量(liang)3018億(yi)立(li)方(fang)(fang)(fang)(fang)米,是鄱(po)陽(yang)湖(hu)(hu)的(de)3倍(bei)、太(tai)湖(hu)(hu)的(de)10倍(bei)。(在岳陽(yang)水(shui)(shui)(shui)(shui)位(黃海基面(mian)(mian)(mian))33.50米時,湖(hu)(hu)泊(bo)容(rong)(rong)積(ji)(ji)167億(yi)立(li)方(fang)(fang)(fang)(fang)米,湖(hu)(hu)體水(shui)(shui)(shui)(shui)域(yu)面(mian)(mian)(mian)積(ji)(ji)2691平(ping)(ping)(ping)方(fang)(fang)(fang)(fang)公(gong)里(li),洪道(dao)面(mian)(mian)(mian)積(ji)(ji)1300平(ping)(ping)(ping)方(fang)(fang)(fang)(fang)公(gong)里(li),總(zong)計3991平(ping)(ping)(ping)方(fang)(fang)(fang)(fang)公(gong)里(li)。)。它(ta)的(de)具大(da)蓄(xu)洪能(neng)力,曾使(shi)長(chang)江(jiang)無數次的(de)洪患化險(xian)為(wei)夷,江(jiang)漢(han)平(ping)(ping)(ping)原和(he)武漢(han)三(san)鎮得以安全(quan)渡汛。無論是調(diao)蓄(xu)面(mian)(mian)(mian)積(ji)(ji)還是調(diao)蓄(xu)水(shui)(shui)(shui)(shui)量(liang),仍然為(wei)長(chang)江(jiang)流域(yu)大(da)的(de)調(diao)節湖(hu)(hu)泊(bo),是國內一大(da)淡水(shui)(shui)(shui)(shui)湖(hu)(hu)。1978年(nian)(nian)(nian)后,有(you)(you)人(ren)稱(cheng)它(ta)為(wei)國內第二大(da)淡水(shui)(shui)(shui)(shui)湖(hu)(hu),值得商榷。
湖(hu)(hu)(hu)(hu)底地面(mian)自西(xi)(xi)北(bei)向(xiang)東(dong)(dong)南微傾(qing)。湖(hu)(hu)(hu)(hu)區年(nian)(nian)(nian)均(jun)(jun)溫16.4~17℃,1月(yue)(yue)3.8~4.5℃,絕對低溫-18.1℃(臨(lin)湘(xiang)1969年(nian)(nian)(nian)1月(yue)(yue)31日(ri))。7月(yue)(yue)29℃左右,絕對高(gao)(gao)(gao)溫43.6℃(益陽(yang))。無(wu)霜期(qi)(qi)258~275天。年(nian)(nian)(nian)降(jiang)(jiang)水(shui)(shui)(shui)量(liang)(liang)(liang)(liang)1100~1400毫米(mi)(mi),由外圍山丘向(xiang)內部(bu)平(ping)(ping)原減少。4~6月(yue)(yue)降(jiang)(jiang)雨占(zhan)年(nian)(nian)(nian)總降(jiang)(jiang)水(shui)(shui)(shui)量(liang)(liang)(liang)(liang)50%以(yi)上(shang),多為(wei)大(da)雨和(he)暴雨;若遇(yu)各(ge)水(shui)(shui)(shui)洪峰齊(qi)集,易(yi)成(cheng)洪、澇、漬災。洞庭(ting)湖(hu)(hu)(hu)(hu)北(bei)有(you)分(fen)泄長江水(shui)(shui)(shui)流(liu)的(de)(de)松滋(zi)、太平(ping)(ping)、藕池、調(diao)弦(1958年(nian)(nian)(nian)堵口(kou))四口(kou);東(dong)(dong)、南、西(xi)(xi)三面(mian)有(you)湘(xiang)、資、沅、澧等水(shui)(shui)(shui)直接灌注(zhu)入(ru)(ru)湖(hu)(hu)(hu)(hu),形成(cheng)不(bu)對稱的(de)(de)向(xiang)心水(shui)(shui)(shui)系,水(shui)(shui)(shui)量(liang)(liang)(liang)(liang)充沛,年(nian)(nian)(nian)徑流(liu)變幅大(da),年(nian)(nian)(nian)內徑流(liu)分(fen)配不(bu)均(jun)(jun),汛(xun)期(qi)(qi)長而(er)洪澇頻(pin)繁。城(cheng)(cheng)陵(ling)磯(ji)(ji)多年(nian)(nian)(nian)平(ping)(ping)均(jun)(jun)徑流(liu)量(liang)(liang)(liang)(liang)3126億(yi)立(li)方(fang)米(mi)(mi),大(da)年(nian)(nian)(nian)徑流(liu)量(liang)(liang)(liang)(liang)(1945)5268億(yi)立(li)方(fang)米(mi)(mi),小年(nian)(nian)(nian)徑流(liu)量(liang)(liang)(liang)(liang)(1978)1990億(yi)立(li)方(fang)米(mi)(mi)。汛(xun)期(qi)(qi)(5~10月(yue)(yue))徑流(liu)量(liang)(liang)(liang)(liang)占(zhan)年(nian)(nian)(nian)均(jun)(jun)徑流(liu)量(liang)(liang)(liang)(liang)的(de)(de)75%;其(qi)中(zhong)四口(kou)1164億(yi)立(li)方(fang)米(mi)(mi),占(zhan)汛(xun)期(qi)(qi)徑流(liu)總量(liang)(liang)(liang)(liang)48.5%。洞庭(ting)湖(hu)(hu)(hu)(hu)水(shui)(shui)(shui)位始漲于4月(yue)(yue),7~8月(yue)(yue)高(gao)(gao)(gao),11月(yue)(yue)~翌年(nian)(nian)(nian)3月(yue)(yue)為(wei)枯水(shui)(shui)(shui)期(qi)(qi)。多年(nian)(nian)(nian)大(da)水(shui)(shui)(shui)位變幅,岳陽(yang)達(da)17.76米(mi)(mi)。素有(you)“洪水(shui)(shui)(shui)一(yi)大(da)片(pian),枯水(shui)(shui)(shui)幾條線”,“霜落洞庭(ting)干(gan)”之說。1954年(nian)(nian)(nian)長江中(zhong)游出現特大(da)洪水(shui)(shui)(shui),洞庭(ting)湖(hu)(hu)(hu)(hu)尚能(neng)削減洪峰,顯示(shi)湖(hu)(hu)(hu)(hu)泊調(diao)蓄(xu)功能(neng)。然(ran)(ran)而(er),眾水(shui)(shui)(shui)匯聚湖(hu)(hu)(hu)(hu)中(zhong),僅有(you)城(cheng)(cheng)陵(ling)磯(ji)(ji)一(yi)口(kou)流(liu)出,洪水(shui)(shui)(shui)停蓄(xu)時間長,泥(ni)沙大(da)量(liang)(liang)(liang)(liang)沉(chen)積(ji),多年(nian)(nian)(nian)平(ping)(ping)均(jun)(jun)入(ru)(ru)湖(hu)(hu)(hu)(hu)泥(ni)沙1.335億(yi)立(li)方(fang)米(mi)(mi),其(qi)中(zhong)來(lai)自長江的(de)(de)達(da)1.18億(yi)立(li)方(fang)米(mi)(mi),占(zhan)82.0%,來(lai)自四水(shui)(shui)(shui)的(de)(de)0.241億(yi)立(li)方(fang)米(mi)(mi),占(zhan)18%,而(er)城(cheng)(cheng)陵(ling)磯(ji)(ji)輸出量(liang)(liang)(liang)(liang)只占(zhan)入(ru)(ru)湖(hu)(hu)(hu)(hu)泥(ni)沙量(liang)(liang)(liang)(liang)的(de)(de)25.1%,淤(yu)積(ji)在洞庭(ting)湖(hu)(hu)(hu)(hu)的(de)(de)泥(ni)沙占(zhan)入(ru)(ru)湖(hu)(hu)(hu)(hu)泥(ni)沙總量(liang)(liang)(liang)(liang)的(de)(de)73.4%,達(da)0.984億(yi)立(li)方(fang)米(mi)(mi)。年(nian)(nian)(nian)均(jun)(jun)淤(yu)積(ji)量(liang)(liang)(liang)(liang)較鄱陽(yang)湖(hu)(hu)(hu)(hu)大(da)十(shi)幾倍。20世(shi)紀70年(nian)(nian)(nian)代以(yi)后,三口(kou)口(kou)門淤(yu)高(gao)(gao)(gao),入(ru)(ru)湖(hu)(hu)(hu)(hu)水(shui)(shui)(shui)量(liang)(liang)(liang)(liang)減少,但沅、澧洪道自然(ran)(ran)洲土增長殊巨,目平(ping)(ping)、七里湖(hu)(hu)(hu)(hu)淤(yu)高(gao)(gao)(gao)各(ge)達(da)2~4米(mi)(mi),南洞庭(ting)湖(hu)(hu)(hu)(hu)北(bei)部(bu)淤(yu)高(gao)(gao)(gao)2米(mi)(mi),東(dong)(dong)洞庭(ting)湖(hu)(hu)(hu)(hu)注(zhu)滋(zi)河口(kou)東(dong)(dong)伸(shen),飄尾廷(ting)伸(shen)至(zhi)君山。因此,西(xi)(xi)洞庭(ting)湖(hu)(hu)(hu)(hu)蓄(xu)洪能(neng)力(li)基本消失,南洞庭(ting)湖(hu)(hu)(hu)(hu)南移(yi),東(dong)(dong)洞庭(ting)湖(hu)(hu)(hu)(hu)東(dong)(dong)蝕,調(diao)蓄(xu)功能(neng)趨向(xiang)衰減。
洞(dong)庭湖(hu)(hu),水(shui)質清潔,富營養化不明顯(xian),主要(yao)污染物(wu)通過降水(shui)使(shi)大(da)氣層中的(de)有(you)(you)害物(wu)質隨雨水(shui)入(ru)湖(hu)(hu),是污染物(wu)質進入(ru)湖(hu)(hu)水(shui)的(de)途(tu)徑(jing)之一,隨雨水(shui)進入(ru)洞(dong)庭湖(hu)(hu)的(de)主要(yao)物(wu)質是SO、Co、NoX以及煙塵,有(you)(you)害有(you)(you)毒物(wu)質主要(yao)有(you)(you)汞、鎘、六價鉻(ge)、砷、鉛、酚、氰化物(wu)、硫化物(wu);洞(dong)庭湖(hu)(hu)是我國主要(yao)淡水(shui)商品魚(yu)基地(di),現有(you)(you)魚(yu)類113種(zhong),分(fen)屬11目22科(ke)(ke),其中102種(zhong)是與長江上游共有(you)(you)的(de),其中鯉(li)科(ke)(ke)魚(yu)類65種(zhong),鮠科(ke)(ke)10種(zhong),鰍(qiu)科(ke)(ke)9種(zhong),鰭科(ke)(ke)6種(zhong),銀(yin)科(ke)(ke)3種(zhong),鲇科(ke)(ke)、鮡科(ke)(ke)各為2種(zhong),其他16種(zhong)。漁獲量在15000到(dao)30500噸,主要(yao)經濟(ji)魚(yu)有(you)(you)青魚(yu)、草魚(yu)、鰱魚(yu)、鳙魚(yu)、鯉(li)、鯽、赤眼鱒。
洞(dong)(dong)庭(ting)(ting)湖(hu)的美(mei)景(jing)(jing)(jing),古人(ren)早有總結,清代《洞(dong)(dong)庭(ting)(ting)湖(hu)志》所載"瀟湘(xiang)八景(jing)(jing)(jing)"中的"洞(dong)(dong)庭(ting)(ting)秋月(yue)"、"遠浦歸帆(fan)"、"平沙落(luo)雁"、"漁(yu)村夕照(zhao)"、"江天幕雪(xue)"以及"日(ri)景(jing)(jing)(jing)"、"月(yue)影(ying)(ying)"、"云影(ying)(ying)"、"雪(xue)影(ying)(ying)"、"山影(ying)(ying)"、"塔影(ying)(ying)"、"帆(fan)影(ying)(ying)"、"漁(yu)影(ying)(ying)"、"鷗影(ying)(ying)"、"雁影(ying)(ying)"等洞(dong)(dong)庭(ting)(ting)湖(hu)"十影(ying)(ying)"。1988年8月(yue),“岳(yue)陽樓洞(dong)(dong)庭(ting)(ting)湖(hu)風景(jing)(jing)(jing)名勝區”被國(guo)務院確(que)定為國(guo)家風景(jing)(jing)(jing)名勝區。
封(feng)山(shan)(shan)(shan)(shan)印,臨(lin)湖(hu)(hu)石(shi)(shi)(shi)(shi)壁(bi)上仍可(ke)見一(yi)石(shi)(shi)(shi)(shi)印,長1米,寬0.8米,字(zi)跡依稀(xi)可(ke)辨,似是“永封(feng)”二(er)字(zi),俗稱為(wei)“封(feng)山(shan)(shan)(shan)(shan)印”。傳(chuan)(chuan)(chuan)說(shuo)(shuo)秦始皇當年(nian)巡狩天下(xia),船過君(jun)(jun)(jun)山(shan)(shan)(shan)(shan)時下(xia)令于(yu)(yu)石(shi)(shi)(shi)(shi)壁(bi)上刻封(feng)山(shan)(shan)(shan)(shan)令所留。柳(liu)毅井,是后人(ren)(ren)演(yan)繹唐(tang)人(ren)(ren)李朝(chao)威(wei)所寫(xie)《柳(liu)毅傳(chuan)(chuan)(chuan)》的(de)(de)故事開鑿的(de)(de)。君(jun)(jun)(jun)山(shan)(shan)(shan)(shan)上還(huan)(huan)有(you)一(yi)個群山(shan)(shan)(shan)(shan)懷抱的(de)(de)大坪,那(nei)便是宋(song)紹興元年(nian)鐘(zhong)相、楊么(me)率農民起義軍安(an)營扎寨(zhai)之(zhi)處。當年(nian)不堪官(guan)府壓迫的(de)(de)貧苦漁民,在(zai)(zai)此揭竿而(er)起,設水(shui)寨(zhai),造戰船,出(chu)沒(mei)于(yu)(yu)八百里(li)洞庭。君(jun)(jun)(jun)山(shan)(shan)(shan)(shan)上還(huan)(huan)留有(you)軍師洞、點將臺(tai)、萬人(ren)(ren)鍋(guo)等古跡。君(jun)(jun)(jun)山(shan)(shan)(shan)(shan)西南岸(an)還(huan)(huan)有(you)軒(xuan)轅(yuan)臺(tai)(鑄(zhu)鼎臺(tai)),傳(chuan)(chuan)(chuan)說(shuo)(shuo)為(wei)黃帝(di)鑄(zhu)鼎之(zhi)處;君(jun)(jun)(jun)山(shan)(shan)(shan)(shan)南岸(an)有(you)射蛟臺(tai),臨(lin)湖(hu)(hu)一(yi)突兀巨石(shi)(shi)(shi)(shi),相傳(chuan)(chuan)(chuan)漢武帝(di)在(zai)(zai)此射蛟,為(wei)民除害,又傳(chuan)(chuan)(chuan)為(wei)小后羿(yi)在(zai)(zai)此射蛟;酒香山(shan)(shan)(shan)(shan)傳(chuan)(chuan)(chuan)說(shuo)(shuo)盛產酒香藤,能釀長壽酒,漢代東方朔曾在(zai)(zai)此偷飲;朗(lang)吟(yin)亭(ting)則(ze)因呂洞賓在(zai)(zai)此吟(yin)詩(shi)而(er)得名(ming)。釣魚(yu)臺(tai),君(jun)(jun)(jun)山(shan)(shan)(shan)(shan)南岸(an),龍(long)口西側(ce),一(yi)巨石(shi)(shi)(shi)(shi)平臺(tai)突立湖(hu)(hu)邊(bian),并有(you)美麗(li)動人(ren)(ren)的(de)(de)傳(chuan)(chuan)(chuan)說(shuo)(shuo)。梳妝臺(tai),君(jun)(jun)(jun)山(shan)(shan)(shan)(shan)仙螺(luo)峰,幾(ji)塊巨石(shi)(shi)(shi)(shi)聳立峰巔(dian),相傳(chuan)(chuan)(chuan)君(jun)(jun)(jun)山(shan)(shan)(shan)(shan)青螺(luo)仙子在(zai)(zai)此梳妝。
擂(lei)(lei)(lei)(lei)鼓臺,在(zai)城(cheng)(cheng)陵磯,相傳為(wei)楚莊(zhuang)王(wang)(wang)擂(lei)(lei)(lei)(lei)鼓平叛之(zhi)(zhi)處(chu)。位于(yu)(yu)岳(yue)陽市(shi)云溪區永濟鄉擂(lei)(lei)(lei)(lei)鼓臺村(cun)、長江(jiang)中下(xia)游江(jiang)畔有座小山,巍峨挺立(li)、氣勢(shi)雄(xiong)(xiong)偉(wei),名曰擂(lei)(lei)(lei)(lei)鼓臺,源于(yu)(yu)東(dong)(dong)周列國時(shi)(shi)期(公元前606年(nian)),高(gao)35.2米(mi),南北長95米(mi),東(dong)(dong)南寬90米(mi),為(wei)楚莊(zhuang)王(wang)(wang)平定叛賊斗越椒(jiao)在(zai)此擂(lei)(lei)(lei)(lei)鼓督戰(zhan)而得名。該臺歷(li)代(dai)為(wei)兵(bing)家必爭之(zhi)(zhi)地,其相關傳奇(qi)故事至(zhi)今(jin)廣泛流傳,經(jing)久(jiu)不衰。岳(yue)陽樓,矗立(li)于(yu)(yu)岳(yue)陽市(shi)古(gu)西門城(cheng)(cheng)頭,臨洞庭,吞長江(jiang),氣勢(shi)雄(xiong)(xiong)偉(wei),其前身為(wei)三國時(shi)(shi)期東(dong)(dong)吳將領魯(lu)肅的閱(yue)兵(bing)樓,距(ju)今(jin)已有近(jin)1800年(nian)歷(li)史(shi)。它(ta)坐(zuo)東(dong)(dong)朝西,構(gou)(gou)造(zao)古(gu)樸端莊(zhuang),氣勢(shi)恢宏(hong)凝重(zhong),樓高(gao)19.42米(mi),為(wei)三層、四柱(zhu)(zhu)、飛(fei)檐、盔頂式純(chun)木結構(gou)(gou)。整座樓由四根(gen)直徑46厘米(mi)的楠木金柱(zhu)(zhu)、12根(gen)木廊柱(zhu)(zhu)和24根(gen)木檐柱(zhu)(zhu)支撐,柱(zhu)(zhu)上架(jia)梁(liang),梁(liang)上立(li)柱(zhu)(zhu),全(quan)部采用插榫法構(gou)(gou)造(zao)。三層樓中,設置、裝飾、圖案風(feng)格(ge)各異,特顯(xian)風(feng)姿。
樓的附近還(huan)有魯(lu)肅墓、小(xiao)喬(qiao)墓、岳陽文廟及慈氏塔(ta)等勝跡。