Nghien cQu - Trao doi
NiNutfc dUtfi dat dao Ly Sofn va dinh hUtfng khai thac sur dung
O PGS.TS. NGUYEN VAN DAN Hdi Dja chit Thuy vSn Viet Nam ThS. KIEU DANG TUYET, NGUYEN KHAC DOAN
M mrdc ta Cd tiem ning biin dao rat Idn, Ban chap hinh Trung Udng t\mDang khoi X da cd Nghj quyit sd09-CT/TWngiy 09/02/2007 ve chiin m mlupc bien dao din nam 2020. Chinh phu da cd Nghi quyit sd 27/2007/NQ-CP ngay 30/5/2007 ban hanh Chuang trinh hanh dpng cua Chfnh phu thi/c hipn Nghj quyit sd09-NQ/TW. Tuy nhien, si/phit triin kinh ti, bao vp QP-AN d diy dang ddi m$t vdi thich thUc Idn vi ngudn nudc nhpt cung cap cho an udng va sinh ho^t. Bai bio nay de c$p din tiem nang nUdc dUdi dat va de xuat giai phip hpp ly cung cap nudc cho huyen dao Ly Sdn, tlnh Quang NgaL
Khai quit vung nghien cUu Huyen d i o Ly Sdn cua tlnh Q u i n g Ngai dUde tach ra tU huyen Binh Sdn cua tlnh Quang Ngai vao nam 1993. Dao Ly Sdn cdn ed t&n la Cu Lao Re nam trdn vung b i l n Ddng Bac tlnh Q u i n g Ngai, trong pham vi 15o22'00"
d i n 15°23'00"vT dd Bac va 109''05'50" d i n 109''08'20" kinh dp Ddng, each dat lien ( C i n g Sa Ky) k h o i n g 24 km; each TP.
Q u i n g Ngai 44 km v l phia Ddng Bac va KCN Dung Q u i t 37 km v l phia Ddng Nam. Dien tich d i o vao khoang 10,7 km^ Dan s i khoing 20.000 ngudi.
Dao Ldn Ly Sdn ed hinh dang g i n giong nhu mot hinh thoi nam ngang theo hudng Tay Ddng, dja hinh tUdng doi bang phang, dp p h i n cat yeu, tren be mat cdn lai dau tich cua cac ngpn nui iLfa ed dp cao khac nhau tU 51 m (nui Hdn Sdi) d i n 169 m (nui
Thdi Ldi). P h i n Idn b l mat D i o Idn Ly Sdn va D i o Be dUdc d u tao bdi cac da tram tich phun trao t u l i Neogen, ed the la Miogen...
T i n g lUdng mUa trung binh nam khoing 2.400 mm nhung phan b l khdng dong deu giDfa cac t h i n g trong nam. Mua mua keo dai ty thang 9 den thang 2 nam sau, c h i l m khoing 80% lUdng mua c i nam. Mua khd keo dai ty t h i n g 3 d i n t h i n g 8.
Do dja hinh it phan eat, dien tich d i o nhd nen mang sud'i kem phat t r i i n , ehl cd mot so con s u l i nhd chay tam thdi vao mua mua d phia Nam d i o vdi luu lUdng rat nhd. D i o Ly Sdn, tlnh Q u i n g Ngai khdng cd nguon nUdc mat ty nhien tii sdng, sud'i. Nguon cung d p nude tren dao chu y l u dya vao nguon nude dudi d i t d l sinh hoat va san xuat. Sau khi cd dien ludi qud'c gia thi so lUdng g i i n g khoan, g i i n g dao tang vpt. Theo
thd'ng ke, nam 2014 toan Huyen d i o ehl cd 546 g i i n g nude thi den nay da ed g i n 1.300 g i i n g . Ben canh dd, t r i l u cUdng lien tyc xam thUc m^nh va sy phat trien kinh t l lam cho cac nguon nude dUdi dat bj n h i i m man va n h i i m ban.
Chinh vl vay viec nghien cufu, d i l u tra, danh gia nude dudi dat va d l xuat cac g i i i p h i p q u i n ly, khai thac suf dyng hdp ly l i cdng viec h i t syc quan trpng nham phat t r i i n b i n vufng TNN dUdi dit 6 day.
Dac diem dja c h i t thuy van Cac k i t q u i d i l u tra, danh gia nude dudi d i t cho thay, d i o Ly Sdn cd 3 t i n g chUa nude, bao gom: Tang chya nude Id hong Holoeen (qh) bao gom eac t r i m tfch gid (vQ2), b i l n (mQ2) vdi dien tich phan bo 3 km^ phan b l d phia Ddng, Ddng Nam xa An H i i , Ddng Nam xa An VTnh va 1 8 Tdi nguyen v d Mdi tru-dng | Ky 2 - Thing 12/2016
Nam, Tay Nam xa An Binh.
Thanh phan dat da chUa nude la eat hat mjn den thd cd c h i l u day 2 - 9 m.
Ket q u i bdm thi nghiem d cac g i i n g dao cho thay, mye nude ty 1,5 den 3,0 m each mat d i t , luu lUdng tU 0,3 den 2,3 l/s nen ed t h i x I p vao loai g i i u nude trung binh, tuy nhien d vung ven b i l n nude thudng bj man vdi dp tong khoang hda den 2,7 g/l. H i u h i t nude cua tang bj n h i i m ban vi sinh, mdt so ndi bj nhiim ban cac hdp chat nito.
Tang ehUa nude Id hong Pleistoeen (qp) Id thanh nhufng dai hep ven bd bien phia Bac va Nam xa An VTnh; phia Ddng Nam xa An H i i va phfa Nam xa An Binh vdi dien tich khoang 0,3 km^, p h i n cdn lai bi phii bdi tang chUa nude qh. Tong dien tich phan bo eiia tang ehUa nude qp khoang 3,4 km^. Thanh phan dat da chya nudc la cat thach anh l i n san day 3 - 8 m.
K i t qua bdm thi nghiem d cac gieng dao cho thay, myc nude tTnh khoing tii 2,0 den 6,0 m each mat dat, lUu lUdng dat 0,3 den 2,3 l/s, ed the xep tang vao loai giau nudc trung binh. Chat lUdng nadc eiia tang qp tUdng ty nha tang qh, tyc la bi man d vung ven bien vdi dp tong khoang hda dat den 1,6 g/l. NUdc bi n h i i m ban vi sinh va cac hdp cha't nito.
Tang chUa nude khe nUt eac thanh tao phun trao Pleistoeen (aqp) phan bo d khu vyc cac mieng niii lira Hdn Tien, Hdn Sol, nui Thdi Ldi vdi dien tich rdng ral d trung tam 2 dao khoang 12 km^- Thanh phan dat da chUa nUde la dam, san ket, tut mau nau vang, xen eac Idp mong bazan olivin, bazan olivin, bazan dolerit mau xam den, xam xanh vdi
chieu day ty 6,0 m d i n 70 m.
Nudc dudi dat xuat Id d mieng phieu nui iCfa G i i n g T i l n va Thdi Ldi ed lUu lUdng nhd c h i y kha thudng xuyen la nguon nUde quan trpng cho sinh hoat, chan nudi gia sue tren dao.
K i t q u i khao sat eac gieng dao cho thay, myc nyde tTnh thay doi phy thupc vao dia hinh ty 3,0 m d i n 30,0 m. Lyu lUdng bdm thi nghiem thay doi tU rat nhd den 6,25 l/s cd the x I p vao loai g i i u nude trung binh vdi mUc dp bat dong nhat cao. Nude dUdi dat d dai bd phan dien tich phan bo cd chat lUdng tot, rieng viing ven bien bj man vdi dp tong khoang hda len den 32 g/l.
TrOf lUdng nUdc dUdi dat TrO lUdng thac nude dUdi dat la lUdng nude cd the lay len bang cac cdng trinh khai thac dUde bo tri hdp ly ca ve mat kinh te va ky thuat ty tang chUa nude hay mdt cau true dja chat thiiy van gidi han cho phep trong khoang thdi gian nhat djnh ma khdng lam anh hudng den trQ lUdng, chat lUdng cung nha khdng tac ddng dang ke den mdi trudng. Can cU mUe dp tin cay, trO lUdng khai thac dUde xep vao cac d p A, B, C I va C2. TriJ lUdng d p A va B dUde dung de thiet ke khai thac tap trung, ca'p CI-khai thac ddn Ie, ca'p C2 khdng dUde diing de thiet ke kai thac.
Huyen dao Ly Sdn do ed y nghTa to Idn ve kinh te, QP-AN dUde dau ta nhieu cdng trinh dieu tra, danh gia nude dUdi dat vdi muc dich tim kiem, phat hien cac nguon nUdc dap Qng nhu cau cung cap nude d day.
Nam 1984, Doan 500 N da hoan thanh lap ban do dia chat thiiy van tren pham vi ca nude ti
Ie 1/500.000, trong dd ed d i o Ly Sdn. K i t q u i da xac djnh cac tang ehUa nude tren d i o va dac d i l m cua chung lam djnh hudng cho viec dieu tra t i l p theo.
Nam 1998, Lien doan DCTV mien Nam (nay la Lien doan QH&DT TNN mien Trung) thyc hien de an "Lap ban do DCTV DCCT va tim kiem nguon nyde dao Ly Sdn, tl Ie 1/25.000". Ket qua da xac dinh dUde 3 t i n g chya nude ed y nghTa: qh, qp va ^qp.
Tang chya nude ^ p trong cac thanh tao phun trao bazan phan bo phan Idn, c h i l m 70% dien tfch dao da dUde danh gia try lUdng nudc dudi dat xep d p C I la 1.121 mVng, tfnh theo luu lUdng thyc bdm on dinh 6 cac lo khoan.
Nam 2012, Lien doan QH&DT TNN mien Trung tiep tuc thuc hien de tai "Dieu tra, danh gia trO lUdng, hien trang sCf dung va de xuat giai phap quy hoach khai thac, sir dung hdp ly bao ve TNN tren dia ban huyen dao Ly Sdn". K i t qua nghien cUu da xac dinh trO lUdng cap C I la 2.749 m^/ng. Nam 2014, UBND huyen Ly Sdn thUe hien de an "Tham dd nude dudi dat khu vUe Trung tam huyen" K i t qua xac dinh trO lUdng nude dUdi dat xep d p C I d day la 1.192 m^/ng .
Nam 2016, Lien doan QH&DT TNN mien Trung thUe hien de an: "Dieu tra, danh gia ehi tiet tai nguyen nude phuc vu xay dung cdng trinh ca'p nude cho eac dao thupc lanh tho Viet Nam"
phan dao Ly Sdn. Sau khi da thi cdng hang loat cac cdng trinh khao sat trong dd cd khoan 7 lo khoan vdi chieu sau 30-45 m da danh gia, xac dinh trO lUdng nude dudi dat xep cap C I cho tang chUa nude qh la 769 va tang aqp la 2807, tong so la 3576 m^/ng.
Tdi nguyen vd Mdi tru-dng | Kif 2-Thing 12/2016 1 0
Tong hap kit qua danh gia tru luang nUdc dudi dat dao Ly San S6
TT 1 2 3 4
Nam hoan thanh 1998 2012 2014 2016
Trif iLfang cip 01, m^/ng Ting
qh
769 769
Tang 3qp 1121 2749 1192 2807 7869
Tdng s6 1121 2749 1192 3576 8638
Don v| thifc hien
Lien QH&DT TNN miln Taing Lien QH&DT TNN miln Tmng UBND huyen LySon Lien QH&DT TNN miln Trung
Ket qua danh gia trO lUdng nude dudi dat tren dao cac thdi ky dupe tap hdp d bang tren day cho thay, try lUdng nadc dudi dat d dao kha Idn cd the dii cung cap cho nhu cau hien tai va nhOng nam tiep theo.
PhUdng hUdng dieu tra, khai thac sir dung va b i o ve tai nguyen nUdc dUdi dat
Cd the thay, cac nguon nudc mat do con ngadi tao nen, mot mat mat nhieu dien tich dat, mat khac do anh hadng cua nhieu dieu kien nhat la sa bd'c hdi lam cho trO lUdng suy giam dang ke ve mua khd lam giam kha nang cung cap nude. Cac nguon nude dudi dat, tuy khdng idn, song on dinh theo thdi gian, khai thac thuan idi dang la nguon rat cd then vpng de cung cap nudc cho cac nhu cau ciia dao.
Kef qua dieu tra, danh gia den nay cho thay trO lUdng nudc dudi dat tUdng ddi phdng phu, Sdng dang dang trade nguy cd nhiim man va nhiim ban, dac biet trcng bdi canh bien doi khf hau se d i l n ra khcc liet vao the ky nay. Viec dieu tra danh gia tiep theo can dUdc thuc hien theo hudng chi tiet hda nham nang cao tra iUdng va nang cap dp tin cay ciia iUdng (tra lUdng hien nay chUa dii dieu kien xep cap A va B). Mat khac, can thL/c hien dieu tra vdi muc dich phcng ngaa.
giam thieu va chcng n h i i m ban, nhiim man, Ung phd vdi BDKH.
Can cU vao dac diem dja chat thiiy van eiia dao, viec khai thac nude dadi dat can thyc hien theo phUdng thUe tap trung: xay dung eac tram cap nude mini vdi cdng s u i t tii 500 den 2.000 m^/ng. Cae cdng trinh khai thac khdng qua sau, myc nude ha thap va luu IUdng khai thac d cac gieng khoan khdng qua Idn, ma d mUc hdp ly dUdc xac dinh tren cd sd dieu tra, danh gia nude dudi dat. Lam dUde nhu vay se d i dang quan ly va bao ve tang chUa nadc khoi bi can kiet va nhiim ban.
Van de BVMT ndi chung phai dUde quan tam thich dang. Neu mdi trudng dUde bao ve tot thi nadc dudi dat cung dUde bad ve td't. Cac giai phap BVMT cung dong thdi la cac giai phap bac ve nudc dudi dat. Mat khac, can dieu tra phan vung lanh tho theo mUc dp tu bao ve nudc dudi dat, tren cd s6 dd quy hoach lai viec phan bo nghTa trang, cac bai thai, diem xa thai... Bao ve nguon nudc dudi dat con dUdc dinh hudng thdng qua phong chong nhiim man trong dieu kien khai thac qua mac va nudc bien dang do bien doi khi hau.
Kit luan
Vung dao Ly Sdn rat nghed cac ngucn nadc tren mat. Viec xay dang cac he dap chaa nudc mat nhieu dien tich dat, gia thanh
cao va khdng hieu qua; trO IUdng nudc dudi dat xep C I da dUdc danh gia dat 8.638 mVng, dii de cung d p cho nhu cau hien tai ma ca trong nhOng nam tiep theo;
nudc dudi dat dUng trudc nguy cd n h i i m man, n h i i m ban, can co cae giai phap phai thac hdp ly va bao ve thi cae nguon nude mdi bao dam phat trien ben vOng.
Ldi cam an: Bai bao dUdc hoan thanh trong khudn kho thac hien De tai cap Nha nude: "Danh gia tiem nang, bien ddng tai nguyen nude mat, nude ngam va de xuat giai phap sir dung hdp ly tai nguyen nude phuc vu phat trien KT-XH 6 mdt so dao trpng diem" ma sd KC.09.04/16-20 thupc ChUdng trinh: "Nghien cUu khoa hoc va cdng nghe phuc vu quan ly bien, hai dao va phat trien kinh te bien". Ma so KC.09/16-20.
Tai lieu tham khao
1. N g u y i n Van Dan. Danh gia tai nguyen nUdc vung dao phuc vu quoc phong anh ninh va phat trien kinh ke. Tap chf Tai nguyen va Mdi trudng so 6 (164), trang 25-26. Ha Npi, 3/2013
2. Lien doan Quy hoach va Dieu tra tai nguyen nude mien Trung. Bao cao Dieu tra dia chat thuy van - Dia chat cong trinh va Tim kiem nguon nudc dao Ly San.
LUu trO Cue Quan ly tai nguyen nudc. Ha Npi 1998
3. Lien doan Quy hoach va Dieu tra tai nguyen nude mien Trung. Bao cao de tai "Dieu tra, danh gia trO luang, hien trang SLf dung va de xuat giai phap quy hoach khai thac. sCf dung hap ly bao ve tai nguyen nudc tren dia ban huyen dao Ly San, tlnh Quang Ngai". LUU trO Cue Quan ly tai nguyen nudc. Ha Npi 2012B 2 0 Tdi nguyen vd Moi tru-onq I Ky2-Thing 12/2016
