Tiiu ban Cdc Khoa hoc vi Trdi ddt ISBN 978 604 913 016 8 NGHIEN ClTU DANH GIA THOAI HOA DAT lASV \\SC SONG CHAY RESEARCH ASSESSMENT SOIL DEGRADATION OF CHAY RIVER BASIN Nguven Manh Ha Vien Dja ly 18 H[.]
Tiiu ban: Cdc Khoa hoc vi Trdi ddt ISBN: 978-604-913-016-8 NGHIEN ClTU DANH GIA THOAI HOA DAT lASV \\SC SONG CHAY RESEARCH ASSESSMENT SOIL DEGRADATION OF CHAY RIVER BASIN Nguven Manh Ha Vien Dja ly 18 - Hoang Qude Viet, Ciu Giiy, H i Ndi Email: manbha ig(a)vahoo.com.vn Tdm tat: Thodi hod ddt vd hoang mgc hod khdng chi Idm biin ddi hdu, Idm mat di ndng sudt sinh hgc nudi sdng ngirdi md cdn ddn din ddi khdt, di cu bdt dn djnh xd hdi trin nhiiu quoc gia vd lanh thd Nghiin cim ngdn ngira thodi hod ddt vd hoang mgc hod da tra thdnh nhiim vu cdp bdch a mdi quoc gia vd trin phgm vi todn thi giai Sdng Chdy la sdng lan thir hai cua hi thdng sdng Ld Bdt ngudn tir sudm phia tdy bdc ddy Tdy Cdn Linh cd dinh cao 2,419m thugc tinh Hd Giang Sdng Chdy theo hirang phia tdy viing thugng km, tdi phia ddng nam ciia trung km vd kit thiic dd vdo sdng Ld a Doan Hiing Lim vuc sdng Chdy ndm giira cdc ddy mii: Phia bdc Id ddy niu cao 1,500-2000m, phia tdy Id ddy Con Voi vd phia ddng vd ddng nam Id ddy Tdy Cdn Linh (ddy nid cao nhdt a ddng bdc Viet Nam) Lim vuc sdng Chdy cd phgm vi rdng a viing thugng lim vd nhd ddn vi phia trung lim vd hg lim Lim vuc sdng thdp ddn tir phia bdc vd tdy bdc din ddng nam Han 60% diin tich lim vuc ndm a cao trin 400m Tdng diin tich lim vuc sdng Chdy vdo khodng 6500km Qua qud trinh nghiin cim cho thdy mirc thodi hda ddt nhu sau: Ddt luu vuc sdng Chdy thodi hda yiu (SCI) cd 64827,2ha chiim I5,82yo diin tich luu vuc; Ddt lim vuc sdng Chdy thodi hda trung binh (SC2) cd I07.634,2ha chiim 26,26%o diin tich hm vuc; Ddt lim vuc sdng Chdy thodi hda ndng (SC3) cd 203.858,8ha chiim 49,75% diin tich luu vuc Abstract: Soil degradation and desertification not only cause climate change, loss of biological productivity but also leads to hunger, migration and social instability in many countries and territories Prevention of soil degradation and desertification have become urgent tasks in each country and throughout the world The Chay river is the second largest tributary of the Lo river It originates from the western slope of the Tay Con Linh mountain range that has a peak height of 2,419m in Ha Giang province The river flows towards to the west in the upstream, to the southeast in the middle and lower reaches an finally enters the Lo river at Doan Hung The Chay river basin lies between high mountain ranges: in the north is a range of l,500-2000m height, on the west is the Con Voi mountain range and on the east and south east is the Tay Con Linh range (the highest range in the northeast of Vietnam) The Chay river basin is wider in the upstream reaches and tapers to an elongated shape in the middle and lower reaches The basin falls from the north and northwest to southeast More than 60% of the basin is higher 246 Hdi nghi Khoa hgc ky' niem 35 ndm Vien Khoa hgc vd Cdng nghe Viet Nam - Hd Ndi 10 2010 than 400m The Chay river basin area is 6,500bn^ (l,920km^ of this is located in China); river The results of comprehensive studies of soil degradation and potential desertification show that the areas affected by intensive potential soil degradation (SC3) make up 49.7 5yo, the areas of medium sod degradation (SC2) make up 26.26%, and the areas of weak soil degradation (SCI) make up 15,82%) I MODAU Dien tieh luu vyc sdng Chiy li 408.729,6 ha; phin thudc linh thi Viet Nam nim ranh gidi hanh ehinh eiia huyen thugc tinh: Ha Giang, Lio Cai, Yen Bii, Phu Thg Do phin bd treri lanh thd rdng ldn, chiy dai tir viing niii vi cao nguyen den viing ddi nui thip nen die diem dieu kien ty nhien luu vyc nghien cim phin hoi da dang va phire tap Tir liu cie dan tdc mien nui sdng luu vyc sdng Chiy da xiy dyng nen cie dien hinh rudng bic thang, trdng ngd theo hde di, dip dip khoi muong din mang tudi tieu, sin xuit thim eanh eho ning suit eao Ben eanh dd, tinh trang du canh, du cu, phat nuong lim riy theo kieu eanh tie lac hiu, ed xua bdc lot dat li chinh, khai thie rirng bira bai (tham chi ei rirng diu ngudn) di giy nen nhiing tai boa, nhieu noi dit bi bio mdn, rira trdi lim eho dit bac miu, ngheo miin, mit ein bing dinh dudng Cie tai bien thien nhien (nhu lii quet, lii bim di, trugt Id dit) eiing thudng xuyen xiy ra, lim cho dit ngiy eing thoii hoi vi mit ning sin xuit Dien tich dit xdi mdn tro sdi di vi ddi nui trgc ngiy eing gia ting Tinh trang d nhiem dit khai thie khoing sin, sir dung nhieu phin bdn hoi bge vi thude bio ve thyc vit eiing di xuit hien nhieu noi Thoii hoi d nhiem tii nguyen mdi trudng dit tren luu vyc di trd thinh vin de eip thiet can giii quyet II KET QUA VA THAO LUAN 2.1 Vi tri dja ly: Luu vyc sdng Chiy (LVSC) thudc dja phan Viet Nam nim toin bd ve phia Tiy ciia viing Ddng Bic Bic Bd Ranh gidi phia Bic cua he thdng luu vyc li dudng bien gidi Viet Trung, phia Tiy Nam li day mii Con Voi, phia Ddng li dudng phin thuy vdi luu vyc sdng Ld, phia Nam chay tren viing ddi cua huyen Doan Hiing tinh Phii Thg trudc dd vio sdng Ld Gidi ban toa dja ly: 21°34' va 22^51' VB ; 104*^10' vi 105^12' KD Phin dien tieh luu vyc thude nude ta nim d vj tri eye Bie eiia dit nude, noi duge eoi li viing siu, viing xa, kinh te - xi hdi chim phit trien Dudng bien gidi phin djnh hai qude gia khdng phii li dudng phin thiiy ty nhien eiia cac luu vyc sdng, sudi Phin ldn dien tieh luu vyc thugng luu diu nim d linh thd Trung C^ude, dd ddng ehinh eua he thdng luu vyc tdng the nude ban quan ly Dieu niy ein luu y td ehiic quin ly ting hgp luu vyc sdng Die biet tren LVSC ed dap thuy dien Thie Bi duge hoin thinh vi dua vao sir dung tir nim 1972 BA.-) DO u r VTC SO.N't C H A V TvrfH >-^t' i \:^r'-}7ri-'r"Vri-i-'-' Hinh 1: Sa dd hdnh chinh LVSC 247 ISBN: 978-604-913-016-8 Tiiu ban: Cdc Khoa hgc ve Trdi ddi Vj tri dja ly ciia LVSC cho thiy diy li mdt viing kinh tl cham phit triln so vdi nhieu vimg kinh te khie ci nude Hon 60% dien tich luu vyc nim d cao > 400m, giao thdng kem phat triln lim cho sy giao luu kinh te, du Ijch eua viing chua phit trien duge [1] 2.2 Dieu kien phat sinh va thoai hda dat luu vuc sdng Chay Dja hinh ed vai trd quan trgng viee phin bd eic loai dit d LVSC Tir dja hinh eao din dja hinh thip ed eic loai dit die trung tuong irng nhu: Dit miin Alit niii cao, dit miin ving dd tren nui, dit dd ving, dit den, dit xim bac miu, dit phii sa, dde tu Mdi kieu kien tnic hinh thii dja hinh thi hien nhirng qui luat thoii hoi dit rieng biet Cie loai dit hinh thinh d khu vyc nui vi cao nguyen noi ed qua trinh ngoai sinh dien manh me thi cd qua trinh thoii hoi dit xdi mdn, nia trdi li ehu ylu Cie loai dit hinh thinh d khu vyc ven sdng, sudi, qui trinh thoii hoi theo hudng giay hoi, sat Id, d nhieni li chii yeu Cac loai dit hinh thinh khu vyc trung qui trinh thoai hoa bj lay hoa vi viii lip li chu yeu Do die diem cua dja hinh LVSC chu ylu li nui cao, die, chia eit manh da tao nen sdng ngdi ciia LVSC rit die trung: ddng sdng cd dang hem vyc, tic ddng chiy ldn, hudng chiy bit diu tir ddng sang tay (tir Hoing Su Phi din Mudng Khuong) sau dd chuyin ddng dot nggt vi chiy tir bie xudng nam Luu lugng nude thay ddi thit thudng, die biet vio miia mua ed the tao nen lii quet giy xdi mdn, sat Id, viii lip dat li nguyen nhin din den thoii hoi dit Dilu kien hinh thinh va thoii hda dit d LVSC duge trinh biy d tren the hien tinh da dang, phire tap eua ldp phii thd nhudng thdng qua eic qui trinh thinh tao Dudi gdc qui luat dja ly ehung cho thiy ciy tnic ldp phu thd nhudng eiia LVSC li ket qui tie ddng giao thoa tuong tie cua qui luat dja ddi vi qui luat phi dja ddi, giiia qui luat ty nhien vi nhin tie Ket qui da hinh thinh nen dit dai cua LVSC gdm cd nhdm vi 16 loai [2,4] Qua bing Icho thiy nhdm dat xim cd dien tieh ldn nhit 293175,7ha chiem 71,7% dien tich luu vyc, tiep den la nhdm dit dd ving 75129,4ha chiem 18,23%) Nhd nhit la dit xdi mdn tro sdi di 484,6 chiem 0,12% dien tich luu vyc Bdng Phdn logi theo nhdm ddt luu vuc sdng Chdy TT I II III IV V VII Ten dit Nhdm dit phii sa Dit giiy Dit den Dit xim Dat dd ving Dit xdi mdn tro sdi di Tdng ddt Nui di Sdng sudi Tdng dien tich ty nhien Ky hieu P GL R X F E Dien tieh (ha) 2369.3 2918.9 1497.5 293175.7 75141.4 484.6 376320.1 14804.3 18689.2 409813.6 % DTTN 0.58 0.72 0.37 71.55 18,23 0,12 91,83 3,61 4,56 100,0 2,3 Thue trang thoai hoa dat luu vuc song Chay 2.3.1 Cdc qud trinh thodi hod ddt Nguyen nhin dan den cac qui trinh thoii hoi dat cd the la hi nhien (nhu sy gii hoa dit, trugt sat Id lii quet, xdi mdn mua ) hoac nhin tie (eanh tic ndng - lim nghiep, dit nuong, lam riy, phi rirng, khai thae khoang sin, xiy dyng Xdi mdn dit xiy d viing ddi nui ddc va nia trdi dit d vimg bing lugn sdng luu vyc sdng Chiy the hien rd San phim eiia cac qui trinh niy la cie don vi dit xdi mdn tro sdi di (E) vi dit xim bac miu (X) 248 Hgi nghi Khoa hgc ky' niem 35 ndm Vien Khoa hgc vd Cdng nghe Viet Nam - Hd Ndi 10'2010 Hoat ddng cua ngudi di thiie diy qui trinh xdi mdn nude, duge the hien dang: bao mon be mat d eic dinh it dde vi xdi mdn khe rinh tren eic sudn xdi mdn; xdi mdn d viing nui ed the dat tdi hang trim tin/ha/nim Thoii hoi nhin tie edn thi hien tren cic viing dit chuyen canh lim dit bac mau, ngheo kiet dinh dudng hoac phi vd ciu true dit mat chin thi dai gia sue qui mire vi lim dit khdng hgp ly Cic viing khai thie khoing san ha>- \ i t lieu xiy dyng, dit bj xio trgn vi bj mit ting mat Cic viing dd thj hoi vi khu edng nghiep, tinh trang thoii hoi yi d nhiem dit di xuit hien He qui li biln dii dit rirng phi nhieu thinh cie dang dit trdng ddi nui trgc cd phi thip vi hoang hoi 2.3.2 Time trgng thodi hod Dinh gii tdng hgp thyc trang thoii hda dit luu vyc sdng Chiy Mill'H 500 m) vi huyen Bie Ha (tinh Lao Cai) thudc thugng luu sdng Chiy (> 1000 m) Ngoai ra, cdn mdt phin dien tich nam rii ric d huyen Hoing Su Phi (tinh Ha Giang) - Ddt liru virc sdng Chdy thodi hod nhe vd trung binh (SC2): dit ed eic tinh chit vi die dilm suy giim nhe vi trung binh vl phi so vdi dit phit sinh Mdt vii die diem thoii boa xuit hien cd ning khie phuc dii vdi sin xuit \ i bio ve Nhirng die diem giim siit phi nhieu eiia dit ed thi la kit qui ciia qui trinh gii boa dit dudi rung, hoac nhii:ng bieu hien ciu tnic bj phi vd, nin dinh dudng bj giim siit boat ddng sin xuit eua eon ngudi Tren bin dl ty le 1/250.000 luu vyc sdng Chiy, SC2 chilm d i p tich 106.550,3 (tuong duong vdi 26,1% dien tich dit luu vyc) [4] Mdt dien tich ding ke SC2 d dde - 8'^ va 15*^ cd y nghia khai thie ndng, lim nghiep - Ddt liru virc sdng Chdy thodi hod ndng (SC3) dit suy giim phi den mue kiet que, nang phuc hdi ehiing rat khd khan vi phai diu tu tdn kem Dit ngheo kiet ve dinh dudng, ddng thdi cau tnic ciing bj pha buy, hoac bj xdi mdn manh, tro sdi san, tro ket vdn laterit Dit bj khd ban khdng thuin lgi cho sin xuat Dit luu \are sdng Chiy thoai hoa nang (SC3) thudng tip trung thinh dii ldn dgc theo song Chiy tir thugng luu thugc huyen Mudng Khuong (Lao Cai) den trung luu thudc huyen Bao Yen (Yen Bii) tip trung d dit ddi mii chua su dung, dd diy se li khu vyc cd tiem nang sat Id, xdi mdn, nia trdi rit ldn Phau dien thoai hoi nang (SC3) ting dit ngheo kiet den cic mat chin vat ly Cic mat chin vit ly la nhiing ting dit mit ciu tnic, chit ly ngin cin qui trinh luu thdng nhiet am cua dat Bdi vay tang dit hiru hieu ddi vdi canh tic trd nen ndng can Mdi lien he vdi ting dit ben dudi vi vd phong hoi gin nhu bj giin doan Tang miin hiu nhu vang mat, him lugng xuong dat bao gdm cic ket vdn, sdi san ting len Khd tim thiy eic hang hdc cua ddng vit dit phiu dien Cic ket vdn gii dang se ting len Thanh phan co gidi ciia dat ting ngudn vat lieu thd hay cd tang phin dj tich dgng set chit ly (mat chin vat ly) Dit bj pha vd eiu tnic hoan toan Ting dat mat ehuyen sang dang bdt hay dang limon rit thuin tien cho van chuyen eiia gid va nude Dit luu vyc sdng Chiy thoai hoi nang (SC3) chiem dien tieh ldn nhit luu virc sdng Chiy (khoang 203.945,1 ha; tuong duong 49,9% ting dien tieh dit luu vorc) Vi viy cin phai bio ve va phuc hdi rirng tren nhirng dien tieh nay, die biet ddi vdi dit trdng ddi mii trgc 2.4 Giai phap va md hinh su dung dat ben virng eho luu vyc sdng Chay Su dung dit ben viing theo luu vorc la sir dung cd hieu qui dit dai tren co sd quy hoach quin ly tdng hgp vi thdng nhat tren toin luu NTIC Tuy thude die diem dja mao thd nhudng timg luu vyc cu the de xic djnh co ciu sir dung dit cho lim nghiep, ndng nghiep, quin eu thi Thyc te cho thiy khai thie qui mirc dit rirng d thugng luu vao muc dich chinh ndng nghiep da lam tang cudng lii lut d luu va trung luu 250 Hdi nghi Khoa hgc ky' niem 35 ndm Vien Khoa hgc vd Cdng nghe Viet Nam - Hd Ngi 10 2010 Phin chia eiu tnic ldp phii thi nhudng theo eic don vj eiu thinh cua luu vyc nhu viing thugng luu-trung luu-ha luu va phu luu Tilp din chia ldp phii dit thinh cic tieu viing ti ngan, bun ng^n Dinh gii phi dit tren moi tieu vimg dya vio yeu td loai dat, ting diy, ddc, thinh phin co gidi vi eac qui trinh thoii hoi dit chu dao 2.4.1 Viing thuong luu sdng Chay: ve phia Viet Nam bao gdm cae huyen Hoing Su Phi, Xin Min tinh Hi Giang, huyen Mudng Khuong, Bie Hi, Bio Thing tinh Lio Cai, dugc gidi ban tga dja ly: 22*'i9' VB vi 22^51' VB ; 104°10' KD vi 104^49' KD Dien tieh viing thugng luu li 189.644,5ha, dd: dien tieh SCI li 2477,7ha; SC2 li 52479,4ha vi SC3 li 129448,Iha Dat dai d diy thuin lgi de phit trien cic ciy nhu ehe san, ngd, dd tuong, my, mach vi ciy in qui, chin nudi triu, bd, ngua Nhung da sd dit cua tieu viing niy ein duge sir dung de phit trien lim nghiep Md hinh RVAC, ciy in qui dn ddi, chin nudi bd siia 2.4.2 Viing Trung luu va luu sdng Chay: ve phia Viet Nam bao gdm eic huyen: Bie Quang (Hi Giang); Bio Yen, Luc Yen, Yen Binh, Yen Son (Yen Bii) ; Him Yen (Tuyen Quang); Doan Hiing, Ha Hda (Phu Thg) Gidi ban bdi toa dja ly: 21°34' VB vi 22°30' VB ; 104*'20'KD vi 105'^12'KD Dien tieh 201.480,0ha Trong dd, SCI li 62349,4ha chilm 30,9% dien tieh ty nhien trung vi luu; SC2 li 55154,9ha chilm 27,38% vi SC3 li 74410,7ha chiem 36,97%) Md hinh trang trai liy chin nudi lam eo sd, ket hgp vdi mdt sd ciy in qua cd lgi the Chin nudi gia sue cd simg vi nudi trdng thuy sin rat thich hgp vdi viing niy Ciy trdng ehu yeu: mang, tre viu, trim, siu, che Long [5] Viec nghien cim de xuit mdt md hinh quan ly luu vyc sdng (LVS) phii hgp vdi die dilm, tinh hinh LVSC ed the ddng gdp thiet thyc cho cdng tic quan ly vi bio ve tai nguyen mdi trudng mdt each hieu qui tren LVSC Md hinh niy hudng tdi viee thinh lip mdt tl chirc quin ly LVS vdi chuc ning, nhiem vu diy du de quin ly tdng hgp tii nguyen luu vyc sdng He thdng LVSC cd lien quan den tinh nude ta vi nim d pham vi cua 02 qude gia (Viet Nam, Trung Qude), dd ein ed td chirc quin ly LVS cip lien tinh cd sy hgp tie vdi tinh nude ban Ban quin ly (BQL) LVSC dugc lip de quin ly tdng hgp LVS Chirc ning eua BQL LVS la phdi hgp cic ben lien quan de thyc hien nhiem vy dd BQL LVS dai dien eho quyen lgi va trich nhiem ciia ngudi dan sinh sdng vi lim viec tren LVS quan he vdi chinh quyen Trung Uong vi cie LVS lin can BQL khuyen nghj cic quy hoach luu vyc sdng len cap Trung Uong vi thdng nhit cic hinh ddng se duge khuyen nghj len UBND cie tinh ve quy hoach vi quin ly tii nguyen ben virng LVSC III KET LUAN Ldp phu thd nhudng he thdng LVSC da dang, phire tap li ket qui tuong tie cua qui luat dja ddi (nhiet ddi gid miia) vdi qui luit dai cao vi dja mao - kien tao Ket qui tren luu vyc cd nhdm dit va 16 loai dit khie Dit he thdng lun vyc phin ldn li dit ddi niii, ddc xdi mdn tiem nang ldn Dinh gii thyc trang thoii hoi dit LVSC eho thiy: Dit thoii boa manh (SC3) 49,9% ting dien tieh; Dit thoii hoi trung binh (SC2): 26,1% tdng dien tich va dit thoii hoi ylu vi nhe (SCI): 15,8% tdng dien tich Be nghj khai thie dit tren luu vyc theo eiu tnic dja mao thd nhudng tir cao den thip li rirng bio ve, rimg phdng hd - rimg kinh doanh (R) - rimg + vudn (RV) - Rirng + vudn + ao + ehuing (RVAC) vi VAC d viing thip Cie md hinh kinh tl sinh thii cu thi ein xiy dyng cho moi vj tri luu vyc: Thugng - trung - Sy cin thiet thinh lip BAL luu vyc de hi vin qui hoach phit trien ben vUng 251 Tiiu ban: Cdc Khoa hgc ve Trdi ddt ISBN: 978-604-913-016-8 TAI LIEU THAM KHAO La Thanh Hi va nnk (2005) - Bio cio ting kit dk tii eip Nhi nude KC-08-27."Nghiin ciru gidi phdp khai thdc sir dung hgp ly tdi nguyin, bdo vi mdi trudmg vd phdng trdnh thiin tai km vuc sdng Ld - sdng Chdy " Nguyen Manh Hi (2005), '"Nghiin cim qud trinh hinh thdnh vd thodi hda ddt viing thugng lim sdng Chdy cho muc dich sir dung bin virng", Luin van thac sT khoa hgc Trudng Dai hgc KHTN - Dai hgc Qude gia Hi Ndi Nguyen Dinh Ky vi nnk (1998), ""Phuangphdp nghiin cihi thodi hod ddt" Tuyen tap cae edng trinh nghien cuu dja ly, Vien Dja ly Hi Ndi Nguyen Dinh Ky vi nnk (2005) - Bdo cdo thirc hiin di muc: "Nghiin cim dja ly phdt sinh vd thodi hod ddt, nhdm di xudt gidi phdp khai thdc hgp ly tdi nguyin vd bdo vi mdi tnrdmg trin hm vuc sdng Ld - sdng Chdy", thudc de tii: Nghien cim giii phap khai thie sir dung hgp ly tii nguyen, bio ve mdi trudng vi phdng trinh thien tai luu vyc sdng Ld - sdng Chiy Pham The VTnh (2005), Di xudt cdc md hinh sir dung ddt - nuac diin hinh cd hiiu qud kinh ti cao vd cd tdc dung bdo vi mdi truang hm vuc sdng Chdy, sdng Gdm Vien 252