KHOA HbC CbNG NGHfi DAIMH GIA BIEiXI DOIVG iVIOT SO Y E U TO IVIOI TRUOIVIi THLIY LY, THLIY HOA HO THAC BA YEIM B A I LAIVI CO SO DE DAIMH GIA TAC DOIMG CLIA VIEC D l IMHAP CA TIEU BAC Nguyin Hai SonS[.]
KHOA HbC CbNG NGHfi DAIMH GIA BIEiXI DOIVG iVIOT SO Y E U TO IVIOI T R U O I V I i THLIY LY, THLIY H O A HO T H A C B A - YEIM B A I LAIVI CO S O D E DAIMH G I A TAC DOIMG CLIA V I E C D l IMHAP CA T I E U BAC Nguyin Hai SonS Ddo Vdn PhiiS V6 Vdn Binh\ I ^ Minh Tudn^ T6MTAT Mdu nudc tai ho Thac Ba dupc thu tii 10 den 15 hang thang nam 2009 va 2010 de danh gid su bien ddng ciia mdt sd chi tieu mdi trudng nudc Ket qua phan tich cho thay nhidt dp nudc hd Thac Ba thdi gian nghien ciiu dao ddng tir 18,8 - 35,3°C, trung binh 27,9°C Dp dao ddng tir 26 - 350 cm, trung binh 153,0 cm Hd cd mat nudc rpng, dien tich thoang nen ham lupng oxy hda tan cao bien dpng tir 4.8 - 9.1 mg/l, tiling binh (7,2 mg/\) Dp ddn didn biln dpng tii 104.8 \iS/cm - 239.2 ^S/cm tiiy thudc vdo timg vi tri hd Ham lupng chat diep luc - a dao dpng tir 4,38 mg/1-8.55 m g / m l Ham lupng amoniac (0,02 mg/1-0,68 mg/l), trung binh (0,17 mg/\) Dinh dudng hd thdp dupc thi bidn qua ham lupng nitrit (NOj-N) va phdt (PO/-P) chi dat hrang iing tii 0,02 - 0,3 vd 0,01 mg/l - 0.3 mg/l, nguyen nhan la ngudn cung cap dinh dudng cho hd kem Hon ntra ho cd dp sdu tuang ddi cao nudc trung binh ca nam dao ddng tir m-10 m gdy anh hudng tdi qua trinh quang hpp, phan ung hda hpc mdi trudng nuac, dd la nhtrng nguyen nhan dan den lupng dinh dudng tai hd thap Nudc hd mang tinh kiem cd pH dao dpng tir 7.3 - 8.0 Nhin chung mdi trudng nudc hd Thac Ba sach chua bi d nhilm va phii hpp cho quan ddn cd Tieu bac phat trien Tir khda: Hd ThacBa, moi tru&ng nuoc, ca Tieu b^c L DAT VANDE Hd chiia Thdc Bd Id cdng trinh dau tidn cua nganh thuy dien Viet Nam Hd cd tdng dien tich mdt nudc la 19.050 vdi 1331 hdn dao ldn nhd chiem diln tich 4.350 ha, dung tich hd 2,9 ty m^ nudc, chu vi hd 629 km, chieu dai 80 km, chilu rdng tir 1-8 km miic nudc d cao trinh 58 m (Vu Tuan Canh va ctv, 1996) Cdng trinh thuy diln ndy dugc hodn vd di vao su dung tir ndm 1972 Tir di vdo boat ddng din dd gan 40 ndm, vi vdy hien trang mdi trudng nudc dd cd rat nhilu thay ddi Thim vdo dd, vile tha bd sung mdt sd loai cd nudi thdi gian vira qua vdi muc dich ndng cao san lirgng cd hd chiia cung cd thi dd tdc ddng true tiip hay gidn tiip din sir biln ddi cac yiu td mdi trudng hd Ddc biit, lodi cd Tieu bac dugc di nhdp vao hd chira Thdc Ba tir Trung Qudc ndm 2001 (Trung tdm Thiiy san Yin Bai 2005), hien dd phdt triln thdnh quan ddn vd cho san lugng ddng kl Do dd, mdi trudng nudc hd Thdc Bd cd till dd cd nhieu biln dpng so vdi trudc ddy Nhdm ndm dugc sir biln ddng vl mdt sd yl'u td mdi trudng nudc hd chira Thac Bd de cd hudng phdt trien tirong lai, ldm co sd cho vile ddnh gid tdc dpng cua vile di gidng thuan hda cd Tiiu bac, nin vile nghiin ciiu vd danh gid biln ddng mpt sd yiu td mdi trudng thuy ly, thuy hod hd Thac Bd - Yin Bai da dugc thuc hi|n tir ndm 2009 den ndm 2010 L PHUONG PHAP NGHEN CUU Phuong phdp thu vd bdo qudn mSu Mau nudc dugc thu tai 12 diim thudc viing (tiiugng luu: Ngdi Bile Phan Thanh, Tdn Lap, Xudn Long, Bao di; trung luu: Tdn Huong, Mdng Son Thugng Phuc Nuih, My Gia, Phuc An; luu: Cira Dpi 9, Cira dap Thac ba, Bdi sdi Yin Binh) tiieo mdt cdt ngang ti-ln hd Thdc Bd Thdi gian tiiu mau cd djnh tii ngdy 10-15 hang thdng Mau nudc dugc tiiu d tang mdt va dp sdu m Cdc yiu td ve: Nhiet dp, pH, dp trong, dp ddn diln, oxy hda tan (DO) dugc true tiep tai hien tiirdng Tiln hdnh tiiu mdi diem mgt mau Mau dugc chira h-ong chai nhua polyme vdi dung tich 1000 ml bao quan d 4°C, dua vl phdng tiii nghiim dl phdn tich: Ham lugng amon (NH4-N), ham lugng phdt (PO4-P), ham lugng nitiit (NO2-N), kiem tdng sd, ham lugng Clorophyll-a) Vi?n Nghien ciru Nudi Thiiy san I 78 NONG NGHIEP VA PHAT TRIEN NONG THON - KY - THANG 6/2011 KHOA HbC CbNG NGHfi (APHA, 1998) Phuong phdp phdn tich Trong nghiin cim nay, phuong phdp phdn tich Phuang phdp phdn tich dugc thi hidn cu thi nhu duac 5,u dung theo Tieu chuan Viet Nam vd SMEWW sau: Phuong phdp Thdng sd Mdtd Stt Do true tiip binh thu Nhiet kl Nhiit dp Do thi diing diln cue thuy tinh May pH pH Bdng dia Do dia cd chia vach cm secxi Dd Diln hda (von-ampe) Oxy hda tan (DO) Mdy DO May EC, Do dp ddn di|n Dd dan dien (EC) dd ddn didn Do quang tren Mau nudc: Ipc nudc qua giay Ipc dimg mdy hut chdn khdng Clorophyll-a may (SP 3000 - Ndng dp clorophyU-a dich chiit dupc xdc dinh bdng phuang phdp quang hpc d budc sdng 750 nm vd 663 plus) nm trudc axit hda vd 750 nm 665 nm sau axit hda Do quang tren PO4: Amoni molybdat vd kali antimonyl tactrat phan ung vdi Phdt mdy (SP 3000 - octo photphat tao thdnh axit di da pho^ho molybdic Axit di da bi khir bdng axit ascorbic tao san pham mdu xanh plus) Do dp hap thu quang d 880 nm Do quang tren Sir dung axit sunphanilic vd a-naptylamin d pH 2,0 din 2,5 dl Nitrit mdy (SP 3000 - tao san pham azo mdu tim dd vdi nitrit mau nudc; dp hdp thu quang d 543 nm plus) Amonia hypoelorit vd phenol phan ung vdi tao thdnh Do quang tren Amoniac mdy (SP 3000 - sdn pham indophenol mdu xanh; dp hap thu quang d ()63 nm plus) Diing H2SO4 chuan dd, bdi ehi thi mdu Methyl da cam Chuan dd 10 Dd kilm 3.Xiilysdlieu Hinh cho thay su biln ddng vl nhiet dp Sd lieu vd kit qua phan tich se dugc tdng hpp vd vimg id cd khde cu thi thirgng Itm (27,0"C), xir Iy theo phuong phdp thdng ke md td tren phdn tiling luu (28,2"C) vd luu (28,5''C) Nguyin nhdn Excel SPSS dl xdc dinh ty le % vd mdi tuong gdy hi|n tupng chinh l|ch nhiit dp gitra cdc viing quan Id viing thupng luu bj anh hudng ddng chay cua BL K!T QUA NGHEN CUU sdng Chay ndn nhi|t dp thudng thdp hon vimg luu Cdc yiu td thuy ly (nudc tinh) Nhidt dp ndm thdp nhat vdo T1-T3 a Nhiet nudc tiong hd (20 °C) cao nhdt vdo tiidng - tiidng (33.5''C) Vl Kit qua nghiin eiiu chi nhiet dd nudc hd Thdc tdng till, nhiet dd tii tiiang 12/2009 din tiidng Ba, Yen Bdi thdi gian nghien ciiu nhin chung Id 4/2010 Id thdp nhdtti-ongndm (20-22"C) bien dpng dd nhidt dp thap nhdt 20,2°C, cao b Do tiong nhat 34.1°C vd tiling binh 27,9°C Diln biln nhi|t dp Dp nirdc hd dao ddng tir 43.0 cm - 309,3 quatimgthdng giiia viing thupng luu trung luu vd cm vd phu thudc vdo timg miia ndm (miia mua luu dupc trinh bdy qua hinh vd miia khd) Dp trung binh thdi gian r" c nghiin ciiu tai viing hd dupc thi hi|n qua bang Bdng DQ (cm) trung binh vimg ciia hd '>^-t^^ •"^^^K,^^^Dp trung binh Giabi Thupngluu Trung luu Ha luu 43,0 Nho nhat 66,0 86,7 109,3 Ldn nh^t 213,6 309,3 71.1 ±19 Trung binh 125,7 ± 40,72 174,9 ± 66,27 Hinh Diln biln nhi|t dOti-ongtiidigian nghiin cuu —•—Thirong luu - • - ^ Trung \\j\i - * — H» Itfu 35.0 30.0 2S.0 20.0 is.o 10.0 A