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32(4), 365 373 Tap chi CAC KHOA HOC VE TRAI DAT 12 2010 PHAN LOAI TRUOT L 6 DAT DA VA DANH GIA NGUY CO TRUDT L 6 DOC TUYEN DUC)NG HO CHI MINH THUOC HA TINH NGUYEN TIEN HAI, BUI PHONG AN I MO DAU Dudng[.]
32(4), 365-373 Tap chi CAC KHOA HOC VE TRAI DAT 12-2010 PHAN LOAI TRUOT L DAT DA VA DANH GIA NGUY CO TRUDT L DOC TUYEN DUC)NG HO CHI MINH THUOC HA TINH NGUYEN TIEN HAI, BUI PHONG AN I MO DAU Dudng Hd Chf Minh (dudng HCM) la tuyen dudng quan trpng nha't dpc theo miln nui phfa tay Viet Nam Cung vdi Qud'c Ip 1A va cac dudng khac, dudng HCM gdp phin hinh mang ludi giao thdng kha hoin chinh d Viet Nam, tao dieu kien thuin Ipi cho sy phat triln kinh te - xa hpi va phue vu an ninh - qud'c phdng Tuy nhien, hieu qua su dung dudng HCM chua dupc phat huy hit bdi mpt nhung ly chfnh la tilm an nguy hilm tai biin trupt Id di't da (TLD) d nhilu nai dpe tuyen dudng dudi tic dpng cua nhieu yeu to Trong nhu'ng noi dudng HCM di qua, phfa tay Ha Tinh (khu vuc nghien cdu, vilt tat la KVNC) cd dja hinh ddi nui kha hilm trd, khf hau khic nghiet, lupng mua thudng ldn va tap trung chu yeu mua mua (lupng mua trung binh thing 13,6 -^ 352,9 mm, mua mua td thing den thing 10), cd nhilu nhilu dpng (ddng, bao, thudc hang thd hai so vdi cic tinh ven biin Viet Nam) Do vay, cac tai bie'n thien nhien (TBTN), nha't ia TL6(C'Q dieu kien phit triln Ddi vdi KVNC, da cd mpt sd nghien cdu vl TBTN ndi chung, tai bien TLD ndi rieng, dang ke nha't la cae cdng trinh cua [I, 3-6[ Tuy nhien, nhilu vin dl lien quan de'n TBTN va TLD khu vuc (hien trang, phan loai ) cdn bd ngd, nlu giai quyet dupc se cd gia tri thuc tiln cao, Ii ca sd cd thi dua nhung bien phip phdng chd'ng TBTN hay TLD, gdp phan ning cao hieu qua sd dung dudng HCM cung nhu nhu'ng tuyen dudng khac khu vyc II SO LUOC VE DIA HINH DUC5NG HCM KHU VUC HA TINH C3 Ha Tinh, dudng HCM chay qua eae thj Iran, huyen ly va nhilu xa thupe cac huyen Huang San, Vu Quang va Huo'ng Khe {hinh 7) Tu phfa bic (miln nui Tay Nghe An), dudng HCM chay qua khu vyc dap Ddi Nay (San Tien, Huang San) den ria bic thung lung sdng Ngan Phd Dja hinh ddi nui d day cd dp cao chu yeu td 80 den 200 m dupc tao bdi cac da phan tren ciia he tang Song Ca (0,-S, «) gdm da phien set xam den xen bpt ket, eat kit Vupt qua sPng Ngan Phd, dudng HCM eit dudng tai Phd Chiu Tiip tuc vl phfa nam den nga ba Khe Giao, dudng HCM (dudng 71 cu) chay dpc ria dja hinh ndi, doi thi'p - tao nen taluy duang chu yeu ben phai dudng ; cdn ben trii Ii taluy am (chi ddi noi hai ben dudng cd du taluy duang, nhung taluy trai thudng tha'p va dp dai nhd) Tao nen dja hinh ddi, ndi d doan Ii da phiin set, bpt kit, cat ket he ting Song Ca (doan Phd Chau - Huang Diln) va da vdi, vdi setsilic, cat ke't, bpt ket, da phien set he tang La Khe (C, Ik, doan Huang Diln - Khe Giao [9|) Sau vupt qua nhanh phu luu phfa tay cua song Ngin Sau (qua ciu Phdc Ddng), dudng HCM cit dudng 15 tai Khe Giao Td day den diu thj trin Huang Khe, dudng HCM phat triln tren nin dudng 15 chay tren dja hinh tao bdi cac tram tfch sdng thung lung sdng Ngan Sau, ddi nai cd mat cic ddi ndi thip tao bdi cac d i thupc he ting La Khe Thung lung sdng Ngan Siu phit trien keo dai theo phuang lay bic- ddng nam vdi chilu rpng thay doi 5-7,5 km, dp cao tuyet dpi bl mat dao dpng 10-15 m, tren dd cd mpt so ddi cao 20-90 m Tao nen dja hinh ddi nui la cac da thupc he ting La Khe, dPi chP la da vPi he ting Bic Son, Muc Bai, DPng Thp Theo mpt so tie gia [6, 7[ va kit qua nghien ciru cua ehung toi, vd phong hda phat triln tren cac he tang neu tren d khu vuc cd chilu day dao dpng 0,3-2 m (cd nai gin m [6|) chu yeu la san, cat, bpt, set bd rdi hoac gin kit yeu cd dp bin vUng ca hpc tha'p 365 V BAC BO