I KHOA HOC j ^ E i S B I B i ^ B
PHAN TICH ANH HlTdNG CUA KHAI THAC CAT LONG SONG DEN Mirc DO HA T H A P Ml/C NlTdC MUA KIET TREN SONG HONG
PGS.TS. Pham Binh, ThS. H6 Viet Cuong Phong Thi nghiem Trpng diem quoc gia ve Dong luc hoc song bien Tom tSt: Bai bdo phan tich miic do dnh hirong cua viec khai Ihdc cdi trong long song den miic do hg thdp muc nuac miia kiet tren song Hong Tren dogn song Hong til Viet Tri den Hung Yen vd sdng Dudng giai dogn (1997*2012), khdi luang khai thdc cdt binh qudn mgt ndm it nhdt la 12.4 trieu m'. Niu tinh tdng cgng (gdm cd khdi lugng cdt do hien tugng xdi sdu hg du) khoi luang cdt bi l6y mdt khoi long song binh qudn mdi nam vdo khodng 16.2 trieu m ; Muc nuac mua kiet thai ky (2009^2012) da thdp han muc nu&c mim kiet thai ky (1993-1997), tgi San Tdy ciing luu luang 2750 m'/s, muc nu&c thdp han 2,27m, tgi Hd Noi cimg luu lugng 1497m /s mm nuac thdp han 1,80m vd tgi Thugng Cdt ciing luu lugng 1253m'/s, muc nu&c thdp han 4,46m;
Khai thdc cdt da dnh hu&ng den muc nu&c tuai: th&i ky (2009+2012) tgi San Tdy muc nuac 5,44m ung vdi muc nu&c tgi Hd Ngi 2,21m (~ muc nu&c thiet ke tuai), lim lugng tgi San Tdy la 2750m'/s: nhirng thai ky (1993+1997) liru lugng qua San Tdy chi cdn 1063m'/s.
Tii- khoa: khai thdc cdt. hg thdp muc nir&c. vai ciing luu luang.
Summary: This paper analyzes the impact of sand mining in the river bed to lower the water level in the dry season on the Red River, through the analysis found: - On the Red River section from Viettri to Hung Yen and on Duong river, period (1997 - 2012), the volume of sand mining and the annual average at least 12.4 million m3. If the total (including the volume of sand due lo downstream ero.'.ion) sand volume taken away from the river bed each year on average approximately 16.2 million m . - The water level in the dry season period (2009 + 2012) was lower than the water level in the dry season period (1993+1997), at Sontgy with the discharge 2750 m /s, wgter level lower than 2,27m, at Hanoi with the discharge 1497m'/s, water level lower thgn 1,80m and gt Thuongcat with same discharge 1253m'/s water level lower than 4,46m. - Sand mining affects water levels: time (2009 + 2012) in Sontay 5,44m level with the water level in Hanoi 2,21m (~ designed irrigation water level) discharge at Sontay is 2750m'/s;
but the period (1993^ 1997) discharge through Sontay just 1063m'/s.
Key words: sand mining, to lower the water level, with same discharge.
1. DAT VAN DE chinh tri song - bao ve va phong ch6ng sat Id bo Truoc nam 2000, su thay d6i muc nucic mua kiet """S. b6i ldp cua ldy nuac, lu6ng lach giao thong tren song H6ng anh huong din hoat dong cua *">'- Sau nam 2000, muc nuoc song H6ng lien cac cong trinh tren song chua ro rang, nhiing "^P ''* **P' ™ '^^i mot cap luu lupng miia cong trinh nghien ciiu trong thm gian nay chii '*,°' ™VC nuoc nam sau ha thdp hon nam mioc.
trpng den anh huong xoi sau ph6 biln long din ^*" "™ ^ ' " ' ' ™*"^ " " ^ thdp nhdt tai tram thuy ha du do tac dpng di6u tilt ciia h6 thuang luu, "^ ^^ ^ 9 ' l^ "''' ™^'' "^P ^^" "S^^ 21/2/2010
muc nucic thdp dat ky luc la 0,10m [3]. Ha thdp muc nuoc mua kiet tren song Hong anh hucing Nguoi phan bien: PGS.TSLe Manh Hiing •*'^" l*^' '^^ ^'^'^ % n"*<^ ^oi ven song.
Ngay nhan bai; 20/10/2014 Truoc cac hoat dpng khai thac cat (KTC) manh Ngay thong qua phan bien: 15/11/2014 me dien ra hang ngay da thu hiit sir quan tam cua Ngay duyet dang: 05/02/2015 cac nha khoa hpc va du luan bao chi.
36 TAP CHl KHOA HOC VA C O N G NGHE T H O Y LOI S<3 25 - 2015
Bai bao nay se danh gia mitc dp anh hucmg ciia KTC trong long song dfa h? thdp muc nuoc mua kiet tren song Hdng, song Du6ng tir nam 2000 din nay. Dong thai phan tich nguyen nhan lam bi6n doi mifc nuoc mua kiet song H6ng, song EhiSng nhu dieu kien thupng luu co them cac h6 chira nhu Scm La, Tuyen Quang, biSn dpng ve Icip phu thuc vjt, rimg phong hp... Nhung yia td tic dpng din dong song noi chuiig rdt phiic tap, kho co th6 tinh toan inch loi tiing ySu t6 rieng biet. De phan Uch ro hon anh huong do KTC la nguyen nhan dan ddn ha thap day song, ha thdp muc nuoc cdn chon thai ky KTC manh me nhdt.
Giai doai (2000-^2008), la giai doan co nhiiu dpt soi dpng cua thi truang bdt dpng san (2001+2002) va (2007+2008), cung la giai doan nhu cau vat Heu xay dung nha, ton ndn cac khu do thi mcii, mo them nhidu he thdng giao thong duong sa. Vi vay giai doai (2000+2008) la thai ky KTC manh me nhat, sau do co chiing lai. DS phan tich anh hucing cua KTC ddn dp ha thdp cao dp day song, ha thap muc nucic miia kiet cdn so sanh hai thoi ky truoc va sau giai doan nay:
-Thoi ky 1993+1997: la thoi kytmoc khi KTC manh - Thoi ky 200^2012: la Ihoi ky sau khi KTC manh Ve phuang phap phan tich, chiing toi su dung so lieu thuy van dong bp ve thai gian voi cac gia tri luu lupng Q, muc nuoc h, dp sau trung bmh dong chay h,b, dien tich mat cat ngang, dp rpng mat nuac... tai 3 tram thuy van Scm Tay, Ha Npi
I KHOA HOC ^ A I ; M ; M ! I ^ tren Song H6ng, Thuong Cat tren song Dudng, khep kin doan song Hong tir tram thuy van Son Tay den tram thuy van Ha Npi va doan song Du6ng din tram thuy van Thuong Cat.
2. HI?N TU'ONG HA THAP M^C NlT^C MUA KIET
2.1. Tai tram Son Tay:
So lieu a Bang I va Hinh 1 thi hien cung muc nuac tai tram thuy van Son Tay, luu luong dioi ky sau (2009-2012) cao hon thai ky truoc (1993- 1997), vi du vai muc rruac San Tdy 5,44m, luu luong thai ky truoc la 1063 m3/s, thoi ky sau len toi 2750m-^/s, nhu vay dS dat mgt muc nuac nhu nhau can bu them mot luu lugt^ la 1687 m^/s. Nlu chpn luu lugng nhu nhau, muc nuoc thai ky sau thap hon thai ky truac, s6 lieu thi hien a Bang 2, vai luu lugng San Toy la 2750m% muc nuoc thoi ky truoc la 7,7m, thoi ky sau ha xu6ng con 5,44m, ha thap 2,27m. Trung binh vai luu lupng Son Tay tu 2750 den 7750m /s muc nuoc thoi 1^ sau da ha thSp hon thoi ky truoc khoang 2,30m.
Muc nuoc ha thap do nguyen nhan day song bi ha ihap, mpt trong nhung nguyen nhan la do bi KTC.
Mpt nguyen nhan nua la do xoi sau ph6 biln long din ha du. Ket qua day song bi ha thSp do ylu t6 tong hpp the hien a Bang 3 va Hinh 2: Cimg voi cdp mice nuac 5,44m cao do day song trung binh nam 1997 la 0,38m, nam 2012, sau 15 nam, la - 2,28m thap hon truac la 2,66m. Trung binh, day song ha thap khoang 17,7cni/nam.
Bang Hst(m)
4.54 5.09 5.44 5.90 6.33 6.12 7.10 7.45 7.79 8.11 8.42 8.72 9.01
: So sanh Q Qst (m'/s) 2009-2012 1903 2403 2750 3250 3750 4250 4750 5250 5750 6250 6750 7250 7750
cung H tram Scrn Tay Qst(m'/s) 1993-1997
652 889 1063 1328 1606 1896 2199 2511 2834 3166 3507 3857 4214
J g (m3/s) 1251 1514 1687 1922 2144 2354 2551 2739 2916 3084 3243 3393 3536
Bang Qst (mVs)
1903 2403 2750 3250 3750 4250 4750 5250 5750- 6250 6750 7250 7750
1: So sanh H Hst(m) 2009-2012
4,54 5,09 5,44 5,90 6,33 6,72 7,10 7,45 7,79 8,11 8,42 8,72 9,01
:iing Q tram Sffn Tay Hst(m) 1993-1997
6,73 7,33 7,70 8,19 8,63 9,04 9,41 9,77 10,10 10,41 10,71 10,99 11,27
AHst (m) 2,19 2,24 2,27 2,29 2,31 2,31 2,32 2,31 2,31 2,30 2,29 2,27 2,26
TAP CHl KHOA HOC VA CONG N G H f T H C I Y t O I SO 25 - 2015 37
I KHOA HOC
Bang 3: So sanh cao flo day song trung binh T^^ ciing cap mirc nu*c H tram Sffn Tay
TT 1 2 3 4 5 6 7
H(m) 4,54 5,09 5,44 5,90 6,33 6,72 7,10
Zds(m) 2012 -3,27 -2,66 -2,28 -1,78 -1,33 -0,91 -0,53
Zds(m) 1997 -0,79 -0,06 0,38 0,91 1,37 1,77 2,12
AZds (m) 2,49 2,61 2,66 2,70 2,70 2,68 2,64
TT 8 9 10 11 12 13
H(m) 7,45 7,79 8,11 8,42 8,72 9,01
Zds(m) 2012 -0,16 0,17 0,49 0,79 1,08 1,35
Zds(m) 1997 2,42 2,68 2,91 3,12 3,29 3,45
AZds (m) 2,58 - 2,51 2,42 2,32 2,21 2,09
Zds-h tram Son Tay
1,671
« QST(m3/sl-H993-19971 • QSTim3/sH?009-2012)
— - Power |Q5T|m3/s|-(1993-I997»—• Power (QST|m3/sH2009-3012))
- ^ ^ ^ ^ r ^ " - ^ T " " " ' ^ - > ' . • - - - I -_ - ' J_— "
.
701 8,00 Mi;cmrdch(m) - P * |Zj!-ST|niH997| P * |Zls.STl»l-20ni
, him) Zfls-ST(mH997 - Zfls-ST(^1-2012
Hinh 1: So sdnh quan he Q-h trgm San Tdy ndm 1993-1997 vd nam 2009-2012
2.2. Tram thuy van Ha Noi:
The hien a Bang 4 va Hinh 3 vcii cimg muc nucic tai tram thuy van Ha Npi, luu luong thoi ky sau (2009-2012) cao ban then ky truoc (1993-1997), nhu voi cimg muc nuac Hd Ngi 2.21m, luu luong thoi ky truoc la 480 m3/s, thoi ky sau nay la 1497m'/s cao ban la 1017 m /s. Voi Itm lugng nhu nhau, mirc nucic thai ky sau thdp hon thoi ky truoc nhu the hien o Bang 5, cimg luu lugng Hd Ngi Id 1497 m'/s
Hinh 2: So sdnh cao do day song trgm San Tdy ndm 1997 vd ndm 2012
muc nucic thoi ky truac la 4,01m, thoi ky sau nay la 2,21m, ha thdp hon 1,80m. Tuong ling voi luu lupng Ha Npi tir 1497 ddn 4599 m'/s muc nuoc thai ky sau da ha thdp hon thoi ky truac trung binh la 1,70m.
Ve dp ha thdp cao dp day song thd hien o Bang 6 va Hinh 4, vai cap muc nuac 2,21m cao dp day song trung binh nam 1997 la 0,54m, sau 15 nam, nam 2012 la -1,13m thdp hon truac la 1,67m. Trung binh h? thdp la 11,1 cm/nam.
3 8 T * P C H l K H O A H O C V A C O N G N G H E T H O Y L O I SO 2 5 -
Bang 4: So sanh Q cung H tr?m Ha Npi Hhn
(m) 1,57 1,95 2,21 2,57 2,94 3,29 3,64 3,99 4,34 4,68 5,02 5,36 5,69
Qhn (m'/s) 2009- 1000 1292 1497 1796 2098 2404 2712 3022 3334 3648 3963 4280 4599
Qhn (m'/s)
1993- 251 379 480 644 827 1029 1248 1486 1740 2011 2298 2600 2918
AQ(m'/s) 749 913 1017 1152 1272 1375 1463 1536 1594 1637 1665 1680 1680
1 KHOA HOC ^ l i l ' l I l | 1 1 ^ Bang 5: So sanh H ciing Q tram Ha Npi
Qhn (m'/s)
1000 1292 1497 1796 2098 2404 2712 3022 3334 3648 3963 4280 4599
Hhn(m) 2009-2012
1,57 1,95 2,21 2,57 2,94 3,29 3,64 3,99 4,34 4,68 5,02 5,36 5,69
Hhn(m) 1993-1997
3,24 3,71 4,01 4,41 4,79 5,14 5,48 5,80 6,10 6,40 6,68 6,96 7,23
AHhn (m) 1,67 1,76 1,80 1,84 1,85 1,85 1,83 1,80 1,76 1,72 1,66 1,60 1,53 Bang 6: So sanh cao dp day song trung binh Zds cung cap muc nu'dc H tram Ha Npi TT
1 2 3 4 5 6 7
Hhn(m) 1,57 1,95 2,21 2,57 2,94 3,29 3,64
Zds(m)- 2012 -1,27 -1,19 -1,13 -1,06 -0,99 -0,93 -0,86
Zds(m)- 1997 0,514 0,527 0,542 0,569 0,605 0,648 0,698
AZds (m) 1,78 1,71 1,67 1,63 1.59 1,57 1,56
TT 8 9 10 11 12 13
Hhn(m) 3,99 4,34 4,68 5,02 5,36 5,69
Zds(m) -2012 -0,81 -0,75 -0,70 -0,66 -0,61 -0,57
Zds(m )-1997 0,755 0,819 0,890 0,967 1,051 1,141
AZds (m) 1,56 1,57 1,59 1,62 1,67 1,72
M V c n i r i t h l m l . QHN(m3/iH93-9'l • aHNlm3/i)-|03-121 -PoivM(QHN(nil/sl-(93-97|) Power (QHN (ni3/sH09-l 2)1
Zcts-htr^mH^N^i
Hinh 3: So sdnh quan he Q-h tram Hd Ndi Hinh 4 (phdi): So sdnh cao do ddy sdng tram ndm 1993-1997 vd ndm 2009-2012 Hd Ngi ndm 1997 vd ndm 2012
TAP CHfKHOAHOCVACONGNGHeTHUYLOl 5625-2015 39
I KHOA HOC 2.3. Tram Thupng Cat:
Tai tram thuy van Thupng Cat, kdt qua so sanh thd hien o Bang 7 va Hinh 5, voi ciing muc nude tai ttam thuy van Thupng Cat, luu lupng thai ky sau (2009+2012) cao hon thai ky truoc (1993-1997), vol muc nuoc la 2,08m, luu lupng thoi ky truoc la 83 m'/s, thcri ky sau nay la 1253 m'/s, nhu vay dd dat mot muc nuoc nhu nhau cdn mpt luu luong tang them la 1171 m'/s. Ndu cimg luu lupng, muc nuoc thai ky sau thdp hon thoi ky truac, thd hien a Bang 8, voi luu lupng Thupng Cat la 1253 m'/s muc
nuoc thai ky truac la 6,54m, thai ky sau nay ha xudng con 2,08m, ba thdp 4,46m. Trong Bang 8, voi luu lupng tit 1253 ddn 3151 m/s muc nuoc thai ky sau da ha thdp han thoi ky truoc trung binh la 4,40m.
Tai Thupng Cat, mure dp ha thdp cao d6 day song thd hien 6 Bang 9 va Hinh 6, voi cdp muc nudc 2,08m cao dp day song trung binh nam 1997 la 1,22m, sau 15 nam, nam 2012 la - 5,38m thdp han truac la 6,60m. Trung binh ha thdp la 44cm/lnam.
Bang 7: So sanh Q ciing H tram Thupng Cat Htc
(ra) 148 1.83 2.08 2.43 2.78 3.12 3.46 3.80 4.13 4.46 4.80 5.13 5.45
Qtc (raVs) 2009-2012 903 1111 1253 1454 1652 1846 2038 2228 2416 2602 2787 2970 3151
Qtc (m'/s) 1993-1997
37 61 S3 119 164 216 276 344 421 506 600 702 814
AQ(m'/s) 866 1050 1171 1335 1488 1630 1762 1884 1995 2096 2187 2267 2338
Bang 8: So sanh H ciing Q tram Thirffng Qtc (m7s)
903 1111 1253 1454 1652 1846 2038 2228 2416 2602 2787 2970 3151
Htc(m) 2009-2012
1.48 1.83 2.08 2.43 2.78 3.12 3.46 3.80 4.13 4.46 4.80 5.13 545
Htc(m) 1993-1997
5.70 6.22 6.54 6.97 7.35 7.71 8.03 8.34 8.63 8.90 9.17 9.41 9.65
Cat AHtc
(m) 4.22 4.39 4.46 4.54 458 4.59 4.58 4.54 4.50 4.44 4.37 4.29 4 20 Bang 9: So sanh cao do day song trung binh Zds cung cap mirc nu'dc H tram Thirong Cat
TT 1 2 3 4 5 6 7
Htc(m) 1.48 1.83 2.08 2.43 2.78 3.12 3.46
Zds(m)- 2012 -5.34 -5.37 -5.38 -5.38 -5.38 -5.36 -5.33
Zds(m)- 1997 1.49 1.32 1.22 1.09 0.97 0.88 0.80
AZds (m) 6.83 6.69 6.60 6.47 6.35 6.24 6.13
TT 8 9 10 11 12 13
Htc(m) 3.80 4.13 4.46 4.80 5.13 5.45
Zds(m) -2012
-5.30 -5.25 -5.19 -5.12 -5.05 -4.96
Zds(m )-1997 0.74 0.69 0.66 0.65 0.65 1.08
AZds (m) 6.03 5.94 5.85 5.77 5.70 6.04
TAP CHl KHOA HOC VA CONG NGHE T H O V LOI SO 25 - 2015
KHOA HOC B E ! ! H ! B ! I ^ B
Zas-hThuo-ng Cat 3.00 ^ y= 0 071x2-0.698X+2.361- 2.00 — R" = 0,904 1.00
0.00
4.00 M y e n
- y= 0,046x'- 0.222X-5.117 6.00 8 8o'°-!i^oo
Zds(mJ-1997 • Zds(m)2012 - Polv (Zds(mf-1997) — Polv. iZds(m) 2012)
Hinh 5: So sdnh quan he Q-h tram Thugng Hinh 6: So sdnh cao do ddy sdng trgm Thugng Cdt ndm 1993-1997 vd ndm 2009-2012 Cdt ndm 1997 vd nam 2012
3. PHAN TICH NGUYEN NHAN CUA VIEC H ^ THAP MU^C NU*dC
Nguyen nhan cua viec ha thap muc nuac mua kiet la do day song bi ha thap. Day song ha thap do 2 nguyen nhan, mot la hien tuong xoi sau pho bien ha du do biin cat bi giu tren cac ho, hai la do mot khoi luong Ion cat da bi khai thac khoi long song.
Ve anh huong cua cac ho thupng nguon den viec ha tiidp day song: Ho Hoa Binh van hanh nam 1990 CO dung tich hieu dung 5,65 trieu m^, ho chiia Tuyen Quang bat dau tich nuac nam 2006 CO dung tich hieu dung 1,70 trieu m^ h6 Son La tich nuoc nam 2010 co dung tich hieu dung dat d6n 6,50 trieu m^ co tac dpng lam giam lupng bun cat vung vh ha luu. Theo kit qua tinh xoi sau ph6 biln ha du do giii bim cat tren ho Hoa Binh cua Bang 10: So sanh miic do
va do xoi pho bien ha
nhieu tac gia [1],[2] cho thay sau khoang 50 nam, khi xoi sau dat gioi han on dinh [1],[2], long s6ng vung hpp luu Thao-Da xoi sau khoang 3,0m, viing Son Tay khoang 1,5m, viing Ha Npi khoang 0,50m. Ket qua tinh xoi sau sau ho Tuyen Quang cho thay hien tupng xoi sau chi xay ra tren song Lo, khong lan xuong song Hong. Ho Son La nam a thuang luu ho Hoa Binh nen khong lam thay doi nhieu den bim cat ha luu ho Hoa Binh. Nhu vay sau khi co them cac ho chua Scm La va Hoa Binh, hien tupng xoi pho bien tir hgp luu song Lo va song Hong ve ha luu khong thay doi nhieu.
Ket qua phan tich muc dp ha thap day song trung binh tai cac tram thiiy van thuc te Ion hon nhieu so voi xoi pho bien ha du ho thupng nguon Hoa Binh sau 50 nam the hien a Bang 10.
ha thap day song thuc te du ho thirong nguon
Tram thuy van Son Tay Ha Npi Thupng Cat
Dp ha thap cao dp day song Azds (m) Nam 1997
0,38 0,54 1,22
Nam 2012 -2,28 -1,13 -5,38
Zdsl997-Zds20l2
2,66 1,67 6,60
Trung binh 1 nam
0,18 0,11 0,44
Do xoi pho bien sau 50 nam
1,50 0,50
TAP CHl KHOA HOC VA CONG NGHE T H O V LOI sci 25 - 2015 41
KHOA HOC ~ ^ E 1 ! 3 ! B J I M
Bdn nay, hd Hoa Binh da van hanh dupc 24 nam, bdng 50% thoi gian dd long song dat xoi sau giai han dn dinh tai Son Tay khoang 1,50m, Ha Npi va Thupng Cat khoang 0,50m.
Nhung dd phan tich khdi lupng KTC toi thieu, chiing ta gia sit tai Son Tay, Ha Npi va Thuang Cat da dat tdi da bang 100% x6i sau gioi han dn dinh, vi vay dp ha thap dav song
do KTC tdi thidu uoc tinh t ^ Scm Tay khoang 1,16m va tai Ha Npi khoang 1,17m va Thupng Cat khoang 6,10m. Kdt qua phan tich tren duac thd hien o Bang 11. Voi each gia sir nay da phdn nao ly giai dupc vi sao hien nay miia k i a muc nuoc tren song H6ng tai Son Tay lai ha thdp nhidu hon muc nuoc a Ha Npi khi miic dp KTC gdn nhu nhau.
Bang H : l/dc tinh miic dp ha thdp day tdi thiju do khai thac cat Tram thiiy van
Do ha thap cao do day song Azas (m) Zdil997-^ds20I2
Son Tay 2,66
HaNoi Thuong Cat
1,67 6,60
Do x6i sau pho bien t o i *
1,50 0,50
Do KTC tdi thidu (m) 1,16 1,17 6,10 4 i r d C TINH LirONG KHAI THAC CAT cat bi ldy mdt trong 15 narn tten song Hong tir TOI THifiU TREN SONG ' - - ' " """ '^'^ ''^" " • " " ^ " " ' " ' "
Mirc dp ha thdp cao dp day song H6ng va song Dudng trong 15 nam (1997+ 2012), dupc tmh toan voi dp ha thdp day song toi thieu do KTC khi CO xoi sau phd bidn da dat gia tri Icin nhdt. Lupng
Bang 12: Khdi luong KTC tdi thidu tren song Hong vii song Dudng giai doan (1997 + 2012) hpp luu song tai Viet Tri den Hung Yen va tren song Dudng thd hien a Bang 12. Ket qua ttong vong 15 nam, long song H6ng, song Dudng da bi ldy mdt khoang 186,3 trieu m ' cat day, trung bulh mdi nam KTC khoang 12,4 ttieu m'.
Tren song (1) Song Hong
Song Duong
Dogn tit...den...
(2) Viet Tri den Ciia Duong Cira Duong den Hung Yen Toan bo song Duong
Chieu dai Ld&m)
(3) 53.2 65.3 62.1
Chieu rong B(m)
(4) 790 710 220
Dg hg thdp ddy song tsZds (m)
(5) 1.16 1.17 6.1 Tong
Binh quan 1 nam
Khoi lirang KTC (Itt mi)
(6) 48,752 54,244 83,338 186,335 12,422 Bang 13: U'o'c tinh tong khoi lutfng cat bi lay mat khoi long song Hong
va song Duong tfr 1997 den 2012 Tren song
(1) S. Hong S. H6ng Song Duong
Doan tir...den...
(2) Viet Tri den Cua Duons Cira Duong den Hirng Yen Toan bp song Dudng
Chieu dai L (10^ m)
(3) 53.2 65.3 62.1
Chieu rong B (m)
(4) 790 710 220
Dp ha thap day song AZds (m)
(5) 2.17 1.42 6.35 Tong
Binh quan 1 nam
T6ng khoi lucmg V (10' m')
(6) 90,990 65,835 86,754 243,580
16 ,239
42 TAP CHl KHOA HOC VA CONG NGHE THOY LOI SO 25 - 2015
KHOA HOC ^ ^ ^ s H a g s ^ B Khi tinh miic dp hsi thdp cao dp d^y song
Hong va song Dudng sau 15 nam (1997 - 2012), vai dp ha thap day song t6ng cpng do KTC cpng vai do xoi sau ph6 bidn ha du, lupng cat hi l^y mk khoi long song tren song H6ng til hap luu song tai Viet Tri dSn Hung Yen va song Du6ng thg hien a Bang 13. Long song Hong, song Du6ng da hi liy mk khoang 246,6 trieu m"^ cat day, trung binh m6i nam long song bi liy mk di khoang 16,2 trieu m^.
K8t qua tinh toan tren cho thiy mpt khdi lupng lan cat long da bi l4y khoi long song trong vong 15 nam ly giai cho nguyen nhan lam ha thap muc nuac miia kiet trong giai doan nhu'ng gan day. Dong thai bai bao ciing ly^ giai vi sao muc nuoc tai tram thuy van San Tay lai ha thap manh hon muc nuac tai tram thuy van Ha Npi, la do dp ha thip day song do xoi pho bien tai Son Tay Ion han nhieu so vai do ha thap day song tai Ha Npi, trong khi dp ha thap day song do KTC 6 hai vi tri gan nhu nhau.
5. KET LUAN
- Muc nuac mua kiet thai ky (2009^2012) da thdp han muc nuac miia kiet thai ky (1993^1997): Tai Son Tay cung luu luang
2750 m7s thdp hon 2,27m, tai Ha Npi cung luu lupng 1497mVs muc nuoc thdp han 1,80m va tai Thupng Cat ciing luu lupng 1253m^/s mirc nuac thap han 4,46m.
- Tren song Hong, cac tram phia thupng luu Ha Npi CO dp ha thap mirc nuac miia kiet Ion hon tram ha luu do chiu anh huong cua hien tupng xoi sau pho bien Ion ban.
Thdi ky (2009-2012) tai Son Tay muc nudc 5,44m, ung vdi muc nudc tai Ha Ndi 2,21m (~ muc nudc thiet ke tudi), luu lupng tai San Tay la 2750m^/s; nhung thdi ky (1993-^1997) lim lupng qua San Tay chi can 1063m^/s. Nhu vay can xa bii mpt luu lupng khoang tir 1687m /s tir cac ho thupng nguon de dam bao tudi.
Tren doan song Hdng tir Viet Tri den Hung Yen va song Dudng giai doan (1997-^2012), khdi luong KTC binh quan mdt nam it nh4t la 12,4 trieu m^. Neu tinh tdng cdng (gom ca khdi lupng cat do hien tupng xdi sau ha du) khdi lupng cat bi lay mat khoi long song binh quan mdi nam vao khoang 16,2 trieu tan.
Miic dp ha thap day sdng tren sdng Dudng manh ban nhieu muc dp ha thap day sdng Hong.
TAI LIEU THAM KHAO
[1] Vii Tk Uyen, Le Manh Hiing (2013), Cdnh bdo ve hgu qud khai thdc cdt sdng Hdng vugt lugng cdi vi hdng ndm. Tap chi Khoa hgc va Cdng nghe Thuy Ipi sd 3-2013, Vien Khoa hgc Thuy lpi Viet Nam.
[2] Nguyin Van Toan (1996), Nghien cuu dnh hudng cua cdng trinh thuy dien Hda Binh din biin ddi thuy vdn long ddn hg du vd gidi phdp chdng xoi bdi, bao ve cac cdng trinh va khu dan sinh kinh xk quan trpng, De tai KC-DL-94-15, Vien Khoa hpc Thiiy lpi VietNam.
[3] Le Manh Hiing (2013), Nghien cuu dnh huang hogt dong khai thdc cdt den thay ddi long ddn sdng Citu Long (sdng Tien, sdng Hdu) va de xudt gidi phdp qudn ly, quy hogch khai thdc hgp ly, Be tai ddc lap cap nha nudc Ma sd: DTDL.201 OT/29, Vien Khoa hpc Thuy loi Viet Nam.
[4] Pham Dinh (2014), Nghien citu dnh huang cua viec khai thdc cdt din chi do ddng chdy, diin biin long ddn va de xudt cdc gidi phdp khoa hgc cdng nghe phuc vu cdng tdc qudn ly, quy hogch khai thdc cdt hgp ly tren he thdng sdng Hdng vd sdng Thdi Binh, De tai ddc lap cip nha nuac Ma sd: DTDL.2012-T/27, Vien Khoa hpc Thiiy Ipi Viet Nam.
TAP C H l KHOA HOC VA C O N G N G H £ T H O Y LOI S(5 25 - 2015 43
