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1 Lj NHlGPCAC>QKHKTV rnam HOi MA LY V^T NAM OAJ MJC Qu3C «A 7PXCM TRUONG DAI HOC KHOA HOC XA H0I VA KHAN VAlt Vietnam geography science: toward green econom y and territorial security KY YEU HOI NGHI KHOA HOC DIA LY TOAN QUOC LAN THLf XII NHA XUAt BAN KHOA HQC TV NHl N VA CONG NGH$ Thanh pho Ho Chi Minh

2 M U C L U C DIA LY TU NHIEN, TAl NGUYEN VA MOI TR U IN G 1. VE XU AT XU DIA DANH DAY TRUUNG SU N VA CHAINE ANNAMITIQUE, VA VI TRI CUA NHUNG DAY NUI NAY TRONG MANG SUN VAN VIET NAM... 3 Le Dtfc An, Uong D'nh Khanh 2. XAY DUNG B0 TIEU CHI VA CHI TIEU PHAT TRIEN DU LICH BEN VUNG CHO VUNG VEN BIEN VA BIEN DAO VIET NAM BANG PHUUNG PHAP DELPHI...12 Trmyng Quang Hai, Nguyen An Thjnh, Giang Van Trong1, Bui Van Tuan1 3. NGHIEN CUU CAU TRUC VA DAC DIEM CANH QUAN DUI BU BIEN TINH PHU YEN...21 Nguyen Thai Hoa, Nguyen Cao Huan, Nguyen Thj Lan Phmyng, Tran Van Trtfffng2 4. NGHIEN CUU SINH KHI HAU - LY LUAN VA THUC TIEN UNG DUNG U VIET NAM...33 Nguyen Khanh Van, Hoang Ltfu Thu Thuy1, Hoang Bac1, Nguyen Manh Ha1 5. HE THONG PHAN CAP QUY HOACH KHONG GIAN BIEN U VIET NAM...40 Tran D f c Thanh, Dang Hoai Nhffn1, Nguyen Van Thao1 6. NHUNG VAN DE TAI NGUYEN VA MOI TRUUNG U BIEN DONG LIEN QUAN DEN PHAT TRIEN BEN VUNG HUYEN DAO TRUUNG SA, VIET NAM...49 Tran D'nh Lan, Nguyen Chu Hoi, Vu Manh Hung1 7. THE ECOLOGICAL SUCCESSION OF NATURAL - ANTHROPOGENIC LANDSCAPES IN KON KA KINH - KON CHU RANG CONSERVATION TERRITORY...65 Nguyen Dang Hoi, Ngo Trung Dung, Kuznetsov A.N. 8. DANH GIA DAO D0NG MUC NUUC, MUC NUUC BIEN DANG DO BAO VUNG BIEN VEN BU TINH NINH THUAN Dao D'nh Cham, Nguyen Quang M inh1, Ltfu Thj Thu Hien1 9. DANH GIA TAC D0NG CUA THOAI HOA DAT DEN HE SINH THAI TINH KON TUM...86 Lai V n h Cam, Vmyng Hong Nhat1, Nguyen Van Hong1, Le Ba Bien1, Ho Le Thu1 10. danh gia x o i MON dat ba n g mo hinh r u sl e s u dung he th o n g THONG TIN DIA LY VA v ien THAM U HUYEN A LUUI, TINH THUA THIEN HUE Ha Van Hanh, Nguyen Quang Viet1, Bui Thj Thu1, Nguyen Quang Tuan1 11. UNG DUNG GIS DE CHINH LY BAN DO DAT TINH AN GIANG DUA TREN CU SU PHAN LOAI DAT CUA FAO - UNESCO Tran The Djnh, Pham Hoang Hai, Hoang Bac2, Do Van Thanh, Nguyen Quyet Chien3, Lmyng Thj Thu Hien3 12. THEO DOI LUN DAT TAI VUNG DO THI TRUNG TAM THANH PHO HA N0I GIAI DOAN BANG DU LIEU SENTINEL Dang Vu Khac, Nguyen Cong Giang, Vu Anh Tuan i

3 TRUING DAI HOC KHXH&NV TPHCM 13. BA MUOI NAM BIEN B0NG RONG TO NHIEN DUOI TAC BONG NHAN SINH TAI RATANAKIRI (CAMPUCHIA), ATTAPEU (LAO) VA KON TUM (VIET NAM) Nguyen D'rnh Dmong1, Lai VTnh Cam1 14. TAI NGUYEN VI THE HE THONG COA SONG VEN BIEN BAC TRUNG B Uong D'rnh Khanh, Chu Anh Dung1, Tong Phuc Tuan1, Bui Quang Dung1 15. BE XUAT SO DUNG HOT LY TAl NGUYEN BAT GAN VOI CAC MO HINH KINH TE SINH THAI VUNG TAY THANH HOA, NGHE AN Nguyen Manh Ha 16. KINH TE BIEN XANH: BOI CANH VA KIEN NGHI CHO VIET NAM Tran Van Trtfffng, Nguyen Thj Ha Thanh1, Hoang Bac 17. BANH GIA MOC B 0 HAN KHI TUONG TINH QUANG NINH TRONG XU THE BIEN BOI KHI HAU Hoang Ltfu Thu Thuy, Vmong Van Vu, Tong Phuc Tuan, Pham Thj L y, Tran Thj Mui, Pham Thj Cuc 18. O NHIEM KHONG KHI VA BINH HUONG KHONG GIAN BAI CHON LAP, BOT RAC XUAN SON, BA VI, HA N 0I Pham Thj To Oanh 19. N0ISUY SO LIEU CHLOROPHYLL-A VUNG BIEN NAM TRUNG B 0 TO DO LIEU MODIS AQUA BANG PHUONG PHAP NGHICH b Ao KHOANG CACH CO TRONG SO Nguyen Trjnh Dtfc Hieu, Nguyen Htfu Huan 20. BANH GIA CHAt LUONG NUOC THAI TAI CAC cang CA TREN BIA BAN TINH QUANG BINH Nguyen Thj Hmong B'nh 21. PHAN TICH BAC BIEM TAI NGUYEN BAT LANH THO LUU VOC SONG MA TINH THANH HOA Vu Van Duan 22. Anh HUONG CUA NUOC THAI CONG NGHIEP BEN MOI TRUONG NUOC MAT TINH PHU THO Tran Thuy Linh, Nguyen Dieu Trinh 23. BANH GIA TINH TON THUONG CUA HE SINH THAI RONG O KHU VOC TAY NGUYEN DUOI ANH HUONG CUA TO NHIEN VA NHAN SINH Doan Ngoc Nguyen Phong,Nguyen Quang Viet1, Nguyen Phtf&c Gia Huy1, Le Duy Dat 24. SO DUNG PHUONG PHAP PHAN TICH BA BIEN BE XAC BINH MUA CHAY RONG O VUNG SINH THAI NUI CAO TINH QUANG BINH Nguyen Phtfong Van 25. NGHIEN COU TAI BIEN L0 QUET O HUYEN CHO BON, TINH BAC KAN Pham Hmong Giang, Nguyen Phmong Lien1, Than Thj Huyen, Nguyen Thanh M ai1, Vu Van Anh1 26. BANH GIA MOC B 0 KHO HAN TREN BIA BAN TINH VlNH PHUC BANG CHI SO CHUAn HOA LUONG MUA (SPI) Tran Thj Mui ii Hoi nghi Khoa hoc Bia ly toan quoc lan thu XII Khoa hoc dia ly Viet Nam vai pkat trien kinh te xanh va dam bao an ninh lank tho

4 27. TAC DONG CUA RAC THAI NHUA TOI CAC KHU DU LICH BIEN VIET NAM VA DE XUAt GlAl PHAP GlAM THIEU RAC THAI NHUA PHUC VU PHAT TRIEN BEN VUNG Dtf Van Toan, Nguyen Thuy Van, Nguyen Th j Thuy1, Bui Thj Thuy1, Le D fc Dat1, M ai Kien Djnh1' Nguyen Htfu Tung1, Vu Thj Hien1, Nguyen Thj Khang1, Do Quynh Nga1 28. DA DANG VA PHAN BO KHONG GIAN CAC LOAI HAT TRAN (GYMNOSPERM) V KHU VUC TAY NGUYEN: THUC TRANG, b Ao TON VA SU DUNG BEN VUNG Nguyen Dang Hoi1, Vu Dinh Duy, Le Xuan Dac1, Tran Thj Thanh Htfomg1, Pham M ai Phmyng1 29. ANH HUVNG CUA BIEN DOI KHI HAU DEN NUOI TRONG VA DANH BAT THUY SAN TINH PHU YEN Nguyen Thj Thu Ha 30. DANH GIA TAC DONG CAC YEU TO KHI TUUNG DEN NONG DO PM2.s TAI THANH PHO HA NOI Dao Ngoc Hung, Vu Thj Hanh, Dieu Thj Thuy Nguyen2, Phan Htfu Phuc, Vo Thj Be Tam 31. NGHIEN C^U HIEN TRANG TAl NGUYEN NUOC CAC HUYEN dao PHUC VU PHAT TRIEN BEN VUNG KINH TE BIEN (LAy VI DU LY SUN VA PHU QUY) Phan Thj Thanh Hang, D o Thj Van H^ffng, Nguyen Thj Bfch1, Nguyen Quang Thanh1, Ngo Thanh Nga1 32. UNG DUNG MO HINH RUSLE DANH GlA XOI MON DAT LUU VUC SONG TRA KHUC VOI SU HO TRU CUA GIS Dmyng Thj NghTa, Dtf Vu Viet Quan1, Pham Minh Tam1, Nguyen Cao Huan1 33. PHUUNG PHAP THANH LAP BAN DO DIA MAO - THO NHUUNG LAY V DU VUNG BAC TAY NGUYEN V TY LE 1 / Nguyen Van Dung 34. TONG QUAN VE DINH GIA DICH VU HE SINH THAI TAI CAC KHU BAo TON Le Hai Nguyen, Tran Thj Doan Trinh 35. DANH GIA DIEN BIEN CHAt LUUNG NUOC NGAm THEO KHONG GIAN VA THUI GIAN NAM 2019 TAI MOT SO HUYEN VA THANH PHO TREN DIA BAN TINH QUANG BINH Hoang Anh Vu 36. SU DUNG NGUON TAI NGUYEN NUOC LUU VUC SONG BANG GIANG - KY CUNG VI MUC DICH PHAT TRIEN KINH TE XANH VA BEN VUNG CAC TINH CAO BANG, LANG SUN Nguyen Thanh Hue, Vu Thj Thuy, Vu Nhtf Van 37. DANH GIA TAC DONG CUA BIEN DOI KHI HAU DEN TAI NGUYEN BIEN VA hai dao TINH QUANG BINH.304 Tran Hieu Quang 38. THUC TRANG MAN HOA, PHEN HOA VUNG DONG BANG BAC BO Nguyen Van Dung 39. HIEN TRANG CHAt LUUNG NUOC THAI CHAN NUOI LUN SAU BIOGAS TAI MOT SO KHU VUC NGHIEN CUU CUA TINH BAC NINH Ngo Van Gidi, Kieu Quoc Lap1, Nguyen Thj Nham Tuat1 iii

5 TRUING DAI HOC KHXH&NV TPHCM 40. QUAN LY RAC THAI HUUNG TUI MUC TIEU KHONG CHAT THAI" Nguyen Thj Cam Yen, Ho Dae Thai Hoang1 41. NGHIEN CUU DANH GlA ANH HUONG CUA MUC NUUC BIEN DANG DEN CAC CHI TIEU SU DUNG DAT NAM 2020 CUA TINH PHU YEN Nguyen D'rnh Huy, Le Van Thang 42. UNG DUNG PHAN TICH THONG KE DA BIEN TRONG DANH GlA KIM LOAI NANG TRONG DAT NONG NGHIEP TINH NAM DINH Nguyen Thj Thu Hien, Vmyng Hong Nhat1 43. NGHIEN CUU SU THAY DOI CANH QUAN KHU VUC DAI VEN BIEN TINH NAM DINH GIAI DOAN Vmyng Hong Nhat, Nguyen Hieu, Dang Xuan Phong 44. danh gia to n g h u p d ieu k ien t u n h ien ph u c vu phat t r ie n cay SAO DEN O' LUU VUC SONG BE Phan Van Trung, Nguyen Dang Do, Nguyen Tham2 45. DAC DIEM CAC NHAN TO THANH TAO CANH QUAN TINH CA MAU Tran Hoang Khiem, Nguyen Quyet Chien1, Phan Hoang Linh, Nguyen Hoang Duyen1 DIA LY KINH TE, XA HOI VA NHAN VAN 46. PHAT TRIEN DU LICH TINH LANG SUN THEO TUYEN HANH LANG KINH TE LANG SUN - HA NOl Nguyen Thj Ngoe Anh, Nguyen Phmyng Thao1, Chu Thj Hoang Khuyen 47. NHAN DIEN CU HOl, THACH THUC VA GIAI PHAP PHAT TRIEN BEN VUNG DAO CU LAO CHAM TRONG THUI KY HOI NHAP QUOC TE Tran Van Anh 48. cac nhan t o Anh h u o n g d e n h ieu qua quan l y nha n u u c v e d a t dai o h u yen su n ha, tin h QUANG NGAI D o Thj Viet Hmyng, Bui Thj Thu1, Huynh Quoe Tuan 49. dau TU XAY DUNG SAN PHAm DU LICH O' QUANG NAM NEN TANG CHO SU PHAT TRIEN NGANH DU LICH BEN VUNG Tran Van Anh 50. VAN DUNG MA TRAN SWOT TRONG DANH GlA TIEM NANG VA XAY DUNG MO HINH DU LICH SINH t h Ai t in h ha Tin h Nguyen Dlnh Tinh 51. QUY HOACH MO HINH DU LICH TINH NINH THUAN BANG UNG DUNG PHUUNG PHAP HO SU DIA LY ROSSMO" 415 Dinh Thien Phmyng 52. KHA NANG LIEN KET BAU BANG VUI CAC DIEM DU LICH O KHU VUC PHA DONG BAC HUYEN PHONG DIEN, TINH THUA THIEN HUE Bui Thj Thu, D o Thj Viet Hmyng1, Nguyen Minh Nguyet iv Hoi nghi Khoa hoc Dia ly toan quoc lan thu XII Khoa hoc dia ly Viet Nam vai phat trien kinh te xanh va dam bao an ninh lank tho

6 BANH GlA XOI MON BAT BANG MO HiNH RUSLE SU5DUNG HE THONG THONG TIN BjA LY VA VIEN THAM O HUYEN A LUOI, TiNH TH^A THIEN HUE H a V a n H a n h 1, Nguyen Q u an g V iet1, B u i Thi T h u 1, N guyen Q u an g T u an1 Abstract Assessment of soil erosion by R U S L E model using geographic inform ation system and remote sensing in A Lu o i District, T h ua Thien H ue Province Soil erosion is considered as the most popular soil degradation process and causes adverse impacts on agriculture and environment, especially in the humid tropical regions. This article paper employed the Revised Universal Soil Loss Equation (RUSLE) with the integration o f Remote Sensing and GIS (Geographic Infromation System) into predicting annual soil loss rate in A Luoi District, Thua Thien Hue province. The inputs o f this model include rainfall, erosivity, soil erodibility, slope length and stepness, cover management and conservation pratices. These parameters extracted from GIS data and satellite images were processed to obtain the potential amount of annual soil loss. Based on erosion estimation, the study area was divided into 5 different soil erosion severity classes: none-erosion, low, moderate, high and very high. The result predicted 9.68% as high and very high classes, 34.26% as moderate class and 56.06% as low and none-erosion classes. This study outcome provides a scientific basis for land use managers, planners in adjusting land use policy to maintain and conserve land resources for the study area. Key words: Potential soil erosion, RUSLE, GIS, Remote Sensing, A Luoi 1. DAT VAN DE Qua trinh thoai hoa dat do xoi mon dang dien ra ngay mot tram trong de doa den nen nong nghiep nhieu nudc tren the gidi cung nhu d Viet Nam. Dae biet, xoi mon do nude xay ra rat pho bien va dang la qua trinh chinh gay nen su thoai hoa dat, suy giam kha nang san xuat d cac nude nhiet ddi am. 0 Thai Lan, theo Virgo va Holmes (1977) da nghien cuu d vung Tarnto Settlement xoi mon khoang tan/ha/nam d vung trong cay ca phe vdi do doc 120. Partosedono (1974) quan trac xoi mon d luu vuc song Cimanuk, Indonesia udc tinh hang nam mat di ldp dat day 5,2 mm va d Philippines theo Mirranda (1978) udc tinh xoi mon 44,6 tan/ha/nam d luu vuc Agno [4]. 0 Viet Nam, luong dat xoi mon thuc te cung duoc do dac d mot so khu vuc, Le Huy Ba va cong su ( ) udc tinh toc do xoi mon dat tren phu sa co mdi khai hoang la 1,8 cm/nam; theo Bo Nong nghiep va Phat trien nong thon, dat doc mien Bac tang mat mat di khoang 1 cm/nam. Xoi mon la mot qua trinh bao gom tach va van chuyen cac vat lieu be mat dudi su tac dong cua nudc va gio tu noi nay den noi khac. De udc tinh xoi mon dat do nudc, nhieu mo hinh xoi mon nhu USLE (Universal Soil Loss Equation), WEPP (Water Erosion Prediction Project), SWAT (Soil and Water Assessment Tool), EUROSEM (European Soil Erosion Model),... da duoc phat trien va su dung rong rai trong nhieu nam qua. Trong do, mo hinh RUSLE (Revised Universal Soil Loss Equation) duoc cai tien tu mo hinh USLE van la mo hinh thuc nghiem duoc su dung rong rai nhat de udc t^nh xoi mon do nudc [4]. Day la mo hinh kinh nghiem duoc phat trien bdi Wischmeier va Smith, mo phong luong dat mat hang nam mot cach don gian, de hieu va khong doi hoi qua nhieu so lieu. Gan day, mo hinh xoi mon dat nham thanh 1 Truong D ai hoc Khoa hoc, D ai hoc Hue 96 Hoi nghi Khoa hoc Dia ly toan quoc lan thu XII Khoa hoc dia ly Viet Nam vai phat trien kinh te xanh va dam bao an ninh lanh tho

7 lap cac ban do nguy co xoi mon dudi su tro giup cua cong nghe GIS (Geographical Information System) da dugc thuc hien bdi nhieu tac gia va d nhieu khu vuc khac nhau tren the gidi [8], [11]. A Ludi la mot huyen mien nui nam ve pma Tay cua tinh Thua Thien Hue vdi dien tich dat tu nhien la 1.225,21 km2. Khu vuc co dia hinh doi nui chiem 89,3%, do doc ldn hon 250 chiem 72,5% dien tich, luong mua trung binh nhieu nam d A Ludi len den tren mm. 0 day co mot so dan toc chung song, trong do cac dan toc it ngudi nhu: Ta Oi, Co Tu, Bru - Van Kieu... vdi phuong thuc canh tac chu yeu la du canh, du cu dot rung md rong dat canh tac nen cang thuc day qua trinh xoi mon dien ra manh me [1]. Vi vay, ldp tho nhuong se co nguy co bi xoi mon do nudc cuon troi manh cac chat dinh duong, tang dat canh tac se bi bao mon va neu khong co bien phap can thiep se dan den be mat tro soi da khong con kha nang san xuat, moi trudng sinh thai se bi huy hoai nghiem trong. Bai bao nay tap trung danh gia xoi mon dat tiem nang d huyen A Ludi. Ket qua nghien cuu se giup cho cac nha quan ly, nhung nha quy hoach nhung co sd khoa hoc cho viec dinh hudng su dung dat nham duy tri va bao ton tai nguyen dat cho khu vuc nghien cuu. 2. D 0 LIEU VA PH tfong PHAP NGHIEN CU U 2.1. Du lieu Nguon du lieu bao gom: * Du lieu phi khong gian - Dac diem tu nhien (kh^ hau, thuy van, dia hinh, tho nhuong), dac diem kinh te - xa hoi (dan so; khai thac khoang san; phat trien nong, cong nghiep; xay dung co sd ha tang...) cua khu vuc nghien cuu; - Tai lieu lien quan den xoi mon do nudc tu cac nghien cuu trong va ngoai nudc... * Du lieu khong gian - Anh Landsat 8 (path 125, row 49) duoc tai tu ngay 25/04/2019; - Mo hinh so do cao SRTM 30 m duoc tai tu - Du lieu tham phu be mat duoc giai doan tu anh ve tinh Landsat 8; - Du lieu tho nhuong huyen A Ludi; - Du lieu cac tram do mua tinh Thua Thien Hue va vung phu can (tram Ta Rut tinh Quang Tri). - Ban do hanh ch^nh huyen A Ludi Phuong phap nghien cuu Phuong phap thu thap so lieu, du lieu thu cap Phuong phap nay duoc su dung de thu thap cac du lieu khong gian va phi khong gian de co nhung thong tin chung va khai quat ve lanh tho nghien cuu. Nguon du lieu nay duoc thu thap tu nhieu nguon khac nhau nhu: - UBND va Phong Tai nguyen va Moi trudng huyen A Ludi; - Sd Khoa hoc va Cong nghe, Cuc Thong ke, UBND tinh Thua Thien Hue; - Cac trang web cung cap nguon anh vien tham nhu - Dai Khi tuong Thuy van tinh Thua Thien Hue; - Cac thu vien va trung tam luu tru de tai nghien cuu khoa hoc cac cap Phuong phap GIS va vien tham Dua tren co sd tai lieu thu thap, phan mem Mapinfo duoc su dung de thong ke cac loai dat, chuyen doi du lieu ban do sang dinh dang ArcGIS; de t^nh toan cac cong thuc trong mo hinh, phan DIA LY TU NHIEN, TAI NGUYEN VA MOI TRUIN G 97

8 mem ArcGIS da dugc su dung de lugng hoa cac thong tin trong cac ban do don tinh thanh cac gia tri so. Moi ban do don tinh dugc xem nhu la mot thong so dau vao trong mo hinh; sau do dua vao cac cong cu tich hgp trong phan mem ArcGIS de tinh toan va danh gia lugng dat xoi mon. Ngoai ra, phan mem SAGA (System for Automated Geographic Analysis) cung dugc su dung de tinh toan chi so dia hinh LS. Phuong phap vien tham dugc su dung trong nghien cuu de thanh lap ban do tham phu va cac chi so thuc vat. Anh Landsat la nguon so lieu pho bien de thanh lap ban do tham phu voi do phan giai trung binh (30 m). Anh Landsat 8 dugc tai mien phi tu web nam 2019 dung de thanh lap ban do tham phu dat va tinh toan chi so NDVI (Normalized Difference Vegetation Index). Be tien xu ly va giai doan anh, nhom tac gia da su dung mot so phan mem lien quan nhu ENVI 5.3, ArcGIS va SAGA Phuongphap ung dung mo hinh RUSLE Bay la phuong phap rat quan trgng cho phep tinh toan mot cach nhanh chong, tiet kiem kinh phi va co do chinh xac cao. Can cu vao su phu hgp giua dac diem tu nhien cua dia phuong, nguon so lieu san co va yeu cau cua mo hinh, mo hinh RUSLE (Revised Universal Soil Loss Equation) da dugc lua chgn de t^nh toan lugng dat mat di hang nam cho toan lanh tho huyen A Luoi. Mo hinh doi hoi 05 thong so dau vao (input) bao gom mua, dia hinh (do doc va chieu dai suon), dat, tham phu va cac bien phap quan ly. Mo hinh RUSLE dugc Renard va cong su (1997) phat trien [9] dua tren mo hinh USLE - Universal Soil Loss Equation cua Wischmeier & Smith [10]. Nhung thong so dau vao can thiet cua mo hinh bao gom: nang lugng mua (R), chieu dai va do doc cua suon (LS), he so tham phu (C) va cac bien phap quan ly tham phu (P). Moi quan he giua cac thong so dugc the hien o cong thuc: A = R.L.S.K.C.P (1) Trong do: A: Lugng dat mat trung binh nam (tan/ha/nam) L: Chieu dai suon doc K: He so xoi mon cua dat (tan.ha.h/ha.mj.mm) P: Cac bien phap bao ve tham phu R: Nang lugng mua (MJ.mm/ha.h) S: Bo doc cua suon C: He so tham phu 3. K E T QUA NGHIEN CUU VA THAO LUAN 3.1. Cac thong so dau vao de tinh toan tiem nang xoi mon dat a. He so tham phu (C) Hien nay co nhieu phuong phap tiep can trong tinh toan chi so C dua vao vien tham, trong do chi so NDVI dugc su dung kha pho bien, ngoai ra cac chi so thuc vat nhu SAVI (Soil Ajusted Vegetation Index) cung dugc mot so tac gia su dung. He so C dugc tinh toan dua vao chi so thuc vat NDVI tu anh ve tinh Landsat8 sau khi da xu ly anh huong cua dia hinh nui bang thuat toan Minneart Correction. NDVI = (NIR - RED)/(NIR + RED) He so NDVI dao dong tu -1 den 1, tham phu tot thuong co gia tri NDVI cao va tham phu cang thua thot thi gia tri NDVI cang thap, dat trong thi NDVI gan bang 0 va ao ho, song suoi co gia tri am. He so nay ty le voi he so C thong qua do tuong quan de chuyen doi va dao dong tu 0 den 1. Trong nghien cuu, he so C su dung cong thuc dugc phat trien boi Van der K nifjff va cong su 1999 dua vao chi so NDVI [5]: 98 Hoi nghi Khoa hgc B ia ly toan quoc lan thu XII Khoa hoc dia ly Viet Nam voi phat trien kinh te xanh va dam bao an ninh lanh tho

9 C = exp[-2*ndvi/( 1 -NDVI)] Sau khi tinh toan chi so C dua vao chi so NDVI, chi so C trung binh duoc tinh toan cho cac loai tham phu tu do phuc vu tinh toan luong dat xoi mon hang nam. Ket qua tinh toan cho thay gia tri C dao dong tu 0 den 0,3365, gia tri trung binh la 0,020. Trong do, rung ram voi nhieu tang tan va lop phu be mat cao nen he so C co gia tri nho voi 0,0086, rung thua co he so C bang 0,0097. Rung ram chu yeu phan bo o nhung khu vuc co do cao tuyet doi lon, o cac dinh phan thuy tiep giap voi nuoc Lao, tinh Quang Nam, tinh Quang Tri va huyen Phong Bien. Khu vuc rung thua nam tiep giap ben duoi khu vuc rung ram, doc theo cac thung lung song co do cao va do doc nho hon nen chiu anh huong boi cac hoat dong khai thac cua con nguoi. Rung trong co gia tri C bang 0,0104, phan bo hau nhu doc cac tuyen duong va gan cac khu dan cu - noi thuan loi cho viec canh tac va khai thac. Boi voi cay lua, chu yeu phan bo o thung lung A Luoi bao gom cac xa xung quanh thi tran A Luoi, cac xa ph^a Nam nhu Bong Son, A Bot, A Roang voi chi so C bang 0,0586. Cay co va bui thap co gia tri C bang 0,1836 phan bo nhieu nhat o khu vuc phia Bac o xa Hong Thuy, Hong Thuong, Bong Son, con lai phan bo rai rac voi dien tich nho o cac xa con lai. Bat trong - day la loai dat bi cac hoat dong dot nuong lam ray, hoat moi bo hoang sau canh tac, khai thac khoang san hoac san ui xay dung cac cong trinh voi lop phu rat it, theo tinh toan he so C co gia tri 0,3365 (hinh 1). b. He so LS He so LS phan anh kha nang xoi mon do dia hinh, thong thuong dia hinh nhieu doi nui cao thi gia tri LS cang lon va nguoc lai. He so LS duoc tinh toan theo cong thuc cua Moore va nnk. (1991) cho phep mo phong he so LS o quy mo luu vuc va canh quan [6]: LS = (m+1).(as/22,13)m.(sinx/0,0896)n Trong do, m = 0,4 va n = 1,3; As la khu vuc thu nuoc tren suon so voi do dai duong dong muc o do cao ma dong chay suon chay vao cac dong suoi (specific catchment area) va x la do doc - tinh bang do. Cong thuc LS duoc phat trien boi Moore va nnk. duoc tich hop trong phan mem SAGA de dang uoc tinh LS tu mo hinh so do cao DEM. Theo ket qua tinh toan LS, gia tri LS o khu vuc nghien cuu dao dong tu 0 den 26,72, gia tri trung binh la 6,71. LS co gia tri lon chu yeu phan bo o nhung khu vuc nui cao tiep giap voi nuoc Lao, tinh Quang Tri va huyen Phong Bien (xa Hong Kim, Hong Ha) va tinh Quang Nam. Nhung khu vuc thung lung co gia tri LS nho (duoi 3) phan bo doc thung lung A Luoi, Hong Van, A Roang, Hong Ha va Huong Nguyen; con lai nhung khu vuc phia tren thung lung co gia tri LS tang dan tu 6 den khoang 12,7. Nhin chung, khu vuc nghien cuu co gia tri LS lon, chiem phan lon dien tich lanh tho nen co tiem nang xay ra xoi mon rat lon (hinh 2). Hinh 1. So do he so C tham phu thuc vat khu vuc nghien cuu Hinh 2. So do he so dia hinh LS d khu vuc nghien cuu BIA LY TH NHIEN, TAI NGUYEN VA MOI TRUIN G 99

10 c. He so xoi mon cua dat (K) He so khang xoi cua dat duoc tinh toan dua vao bang tra duoc phat trien boi Steward va nnk. (1975) [7] dua vao thanh phan co gioi va ham luong mun trung binh 2%. Trong nghien cuu nay da dua vao ban do tho nhuong tinh Thua Thien Hue sau do trich xuat thong tin thanh phan co gioi de xac dinh he so khang xoi K cua dat. Theo thong tin tu ban do dat, khu vuc nghien cuu co thanh phan co gioi dat gom cat pha, thit nhe, thit nang va thit trung binh. Khu vuc nghien cuu co he so khang xoi dat dao dong tu 0,013 den 0,055, trong do dat thit nang chiem phan lon dien tich voi 68,32% voi he so K kha lon 0,033. Thit trung co he so Bang 1. He so xoi mdn cua dat - K (tan.ha.h/ha.mj.mm) T T T h an h p h an c o gioi Ki' hien K D ien tich T i le % 1 Cat pha b 0, ,57 0,21 2 Thit nhe c 0, ,63 23,98 3 Thjl trung d 0, ,83 7,28 4 Thjt nang e 0, ,87 68,32 5 Song suoi, ao ho 0, ,10 0,21 T ong , Nguon: Tinh toan tu ban do khang xoi lon nhat voi K bang 0,055 nhung chi chiem 7,28% dien tich; dat cat pha co he so K nho nhat voi 0,013 va chiem dien tich khong dang ke voi 0,21%. Dat thit nhe co he so khang xoi K = 0,032 va chiem den 23,98%. Nhin chung, thanh phan co gioi o khu vuc chu yeu la dat thit nhe va thit nang, he so K dao dong tu 0,032-0,033. d. He so nang luong mua (R) Day duoc xem la thong so rat quan trong thuc day qua trinh xoi mon do nuoc dien ra. Luong mua va cuong do mua cang lon keo theo nguy co xoi mon cang manh. Trong nghien cuu, he so R su dung cong thuc ke thua tu nghien cuu cua Ho Kiet (1991) [3] de tinh toan nang luong tren co so noi suy 10 tram do mua o khu vuc nghien cuu. R = -25, ,49917*P (R2 = 0,989) Trong do: R - Nang luong mua (MJ.mm/ha.h) P - Luong mua trung binh nam (mm) Theo tinh toan he so R o khu vuc dao dong tu 1.123,04 den 1.788,32 voi gia tri trung binh 1.637,51. Trong do, khu vuc phia Nam do anh huong cua day Bach Ma nen luong mua o day co xu huong tang so voi khu vuc phia Bac nen he so R tang dan tu Nam len Bac. e. He so cac bien phap quan ly tham phu (P) He so nay the hien cac bien phap can thiep trong quan ly xoi mon thong qua ap dung cac ki thuat canh tac de ngan chan xung luc hat mua va dong chay mat. He so P duoc xac dinh dua tren tham khao cac cong trinh nghien cuu tuong ung voi cac bien phap canh tac ap dung de quan ly xoi mon. 0 khu vuc nghien cuu, rat it cac bien phap quan ly xoi mon duoc thuc hien trong canh tac nong nghiep. Cay lua nuoc la truong hop dac biet, duoc nguoi dan bao boc boi cac con muong xung quanh vua co chuc nang la he thong thuy loi nhung dong thoi lai ngan chan xoi mon, rua troi ra khoi khu vuc ruong. Doi chieu voi bang tra cua Wischmeier, W. H., and Smith, D.D [10], he so P cho cay lua bang 0,01 va cac cay trong khac bang 1 tuong ung voi khong co bien phap quan ly xoi mon. 100 Hoi nghi Khoa hoc Dia ly toan quoc lan thu XII Khoa hoc dia ly Viet Nam voi phat trien kinh te xanh va dam bao an ninh lanh tho

11 Hinh 3. He so khang xoi dat K a khu vuc nghien cuu Hinh 4. Sa do he so xoi mdn do mua R a khu vuc nghien cuu 3.2. Danh gia tiem nang xoi mon dat o' huyen A Luoi Sau khi thanh lap cac ban do don tinh ting voi cac thong so dau vao cua mo hinh RUSLE, luong dat xoi mon trung binh hang nam duoc tinh theo cong thtic A = K *R *L S*C *P duoi su tro giup cua phan mem ArcGIS bang cong cu Raster Calculator. Ket qua t^nh toan cho thay luong dat mat hang nam o lanh tho dao dong tn 0 den 644,73 tan/ha/nam, luong dat xoi mon trung binh la 6,33 tan/ha/nam va duoc phan thanh 05 cap xoi mon theo tieu chuan Viet Nam (TCVN) 5299: 2009 [2]. Qua bang 2 va hinh 5 cho thay, cap khong xoi mon chiem dien tich 20,61%, phan bo chu yeu o khu vuc thung lung A Luoi, A Roang, vung dat thap o xa Hong Ha, Huong Nguyen tiep giap voi Huong Tra... voi do doc nho va chu yeu canh tac lua, duoc bao ve boi he thong bo muong. Ngoai ra, dien tich rung ram bao phu o nhung khu vuc nui cao cung han che duoc su anh huong cua T T Bang 2. Phan cap luong dat xoi mdn a lanh tho nghien cuu (tan/ha/nam) theo TCVN 5299: 2009 L u tfn g d at xoi m on C ap xoi m on D ien tich (h a) % dien tich 1 < i Khong xoi mon ,21 20, Xoi mon yeu ,31 35, Xoi mon trung binh ,94 34, Xoi mon manh ,15 8,39 5 > 50 Xoi mon rat manh 1.583,39 1,29 T ong , Hinh 5. Sa do phan cap xoi mdn dat a khu vuc nghien cuu DIA LY TH NHIEN, TAI NGUYEN VA MOI TRUQNG 101

12 dia hinh, luong mua den xoi mon nen co luong dat xoi mon hau nhu khong dang ke. Cap xoi mon yeu chiem dien tich ion nhat voi 35,45% lanh tho, phan bo chu yeu o nhung khu vuc rung ram va rung thua o nhung khu vuc co dia hinh doc nhung do anh huong cua lop phu nen han che xoi mon. Ngoai ra, khu vuc co cap xoi mon nay con phan bo rai rac doc theo cac thung lung nho, cac chan subn nui noi co do doc nho hon so voi nhung khu vuc tren cac subn. Cap xoi mon trung binh cung chiem dien ion voi 34,26% dien tich phan bo chu yeu o khu vuc doi nui voi tham phu chu yeu la rung thua hoac rung trong va trang co, cay bui thap. Cap xoi mon manh va rat manh chiem phan nho voi 9,68 % dien tich lanh tho, phan bo kha nhieu o xa Hong Thuy, noi co dia hinh kha thuan loi nen bi con ngubi pha huy tham phu kha manh, chu yeu la trang co va dat trong. So dien tich con lai phan bo kha rai rac o tat ca cac xa nhu Hong Thai, Hong Thuong (chiu anh huong boi cong trinh Thuy Dien), Hong Ha De xuat hu dng su* dung va bao ve tai nguyen dat d lanh tho nghien cuu Can cu vao tinh hinh thuc te o lanh tho nghien cuu, mot so bien phap dinh huong su dung va bao ve tai nguyen dat nhu sau: - Su dung bien phap nong hoc nhu canh tac theo dubng dong muc theo cac dubng co do cao nhu nhau: cac loai thuc vat chinh se duoc trong giua cac bang cay; cac bang cay duoc trong o noi co kha nang xoi mon lon; han che lam dat de ngan chan su mat di cac vat lieu dat, co the hinh thanh dat tro soi da, hoac bi mang di boi nuoc; tao lop phu va tu goc de tang cubng cac vat lieu cay hoac chat huu co cho lop be mat dat nham giam luong dat mat mat di, tang tinh tham cho dat; trong cay ho dau, phu tren be mat dat giua khoang trong cua cac cay lau nam de bao ve dat hoac tang chat dinh duong cho dat. - Su dung cac bien phap cong trinh nhu nhung bien phap co ly ngan chan dong chay mat nham giam thieu dat va nuoc bi troi theo doc o khu vuc go doi va mien nui, noi co mua keo dai va tap trung, tham phu thuc vat dang co nguy co bi thu hep do hien tuong dot nuong lam ray va khai thac rung. - Xay dung cac mo hinh canh tac tren dat doc nhu canh tac theo bang trong nong lam ket hop, phat trien mo hinh ky thuat canh tac nong nghiep dat doc de trong co theo phuong thuc nong - suc ket hop; trong rung quy mo nho voi viec san xuat luong thuc, thuc pham, thuc hien mo hinh ky thuat san xuat nong nghiep voi cay an qua quy mo nho. 4. K E T LUAN Mo phong xoi mon voi su tich hop cua mo hinh RUSLE, cong cu vien tham va GIS da uoc tinh duoc luong dat mat tiem nang trung binh hang nam o huyen A Luoi. Trong nghien cuu, cac cong thuc thuc nghiem duoc phat trien cho nhieu khu vuc khac nhau dua lua chon de phu hop voi khu vuc nghien cuu, tu do mo phong cac he so duoi su tro giup cua cong nghe GIS va vien tham da cho phep uoc tinh xoi mon o quy mo canh quan. Ket qua mo phong da xac dinh va chia lanh tho thanh 05 cap do xoi mon theo TCVN; trong do 9,68% dien tich o muc xoi mon manh va rat manh, 34,26% o muc xoi mon trung binh va con lai phan lon dien tich (56,06%) la o muc xoi mon yeu va khong xoi mon. Do thieu so lieu thuc te ve xoi mon, ket qua nghien cuu chi xac dinh cac khu vuc co tiem nang xoi mon hang nam, tu do giup cac nha quan ly co dinh huong trong viec bao ve tai nguyen dat. Vi vay, mot so dinh huong su dung va bao ve tai nguyen dat o lanh tho nghien cuu duoc de xuat lien quan den viec su dung cac bien phap nong hoc trong canh tac, cac bien phap cong trinh ngan chan dong chay mat va xay dung cac mo hinh canh tac tren dat doc. Day la nhung co so khoa hoc giup cho cac nha quan ly, nhung nha quy hoach co giai phap dinh huong su dung tai nguyen dat hop ly va ben vung. 102 Hoi nghi Khoa hoc Dia ly toan quoc lan thu XII Khoa hoc dia ly Viet Nam vai phat trien kinh te xanh va dam bao an ninh lanh tho

13 Lfri cam un: Bai bao duac hoan thank nam trong khuon kho de tai VT-UD.09/17-20 (Chu nhiem: Nguyen Quang Tuan) thuoc Chuang trinh Khoa hoc va Cong nghe cap Quoc gia ve Cong nghe vu tru ( ). Nhom tac gia tran trong cam an Chuang trinh! TAI L IE U THAM KHAO 1. Ha Van Hanh va rmk. Dank gia canh quan chophat trim nong - lam ngfiep vaphong tranh thien tai, NXB Dai hoc Hue. 2. Tong cuc Tieu chuan Do luong Chat luong (2009), Tieu chuan quoc gia TCVN 5299:2009 ve Chat luang dat - Phuang phap xac dinh muc do xoi mdn dat do mua, Ha Noi. 3. Pham Hun Ty va Ho Kiet (2008). Mo phong rui ro xoi mon vung canh quan doi nui tren co sd ung dung so lieu vien tham va mo hinh mat dat pho quat hieu chinh RUSLE. Tap cm Dai hoc Hue, (48), Ashiagbor G., Forkuo E.K., Laari P. va cong su. (2012). Modeling soil erosion using RUSLE and GIS tools. International Journal o f Remote Sensing & Geoscience (IJRSG), Volume 2, Jamil A.A. Anache. Modeling of (R) USLE C-factor for pasture as a function of Normalized Difference Vegetation Index. Journal o f Science and Technology 3(9), Jose L. Garcia Rodriguez va Martin C. Gimenez Suarez (2010). Historical review of topographical factor, LS, of water erosion models. studylib.es, 2(2), Kenneth Espiritu (1997), Development o f a Computerized Version o f the Universal Soil Loss Equation and the USGS Pollutant Loading Functions, Master thesis, Virginia Polytechnic Institute and State University, USA. 8. Pradhan B. B., Chaudhari A., Jagarlapudi A. va cong su. (2011). Soil erosion assessment and its correlation with landslide events using remote sensing data and GIS: A case study at Penang Island, Malaysia. Environmental monitoring and assessment, 184, Renard K.G. et al. (1997), Predicting Soil Erosion by Water: A Guide to Conservation Planning with the Revised Universal Soil Loss Equation, U.S Government Printing Office, Washington DC. 10. Wischmeier, W.H. va Smith, D.D. (1978). Predicting Rainfall Erosion Losses: A Guide to Conservation Planning. accessed: 27/04/ Zandi J. J. va et al. (2015). An empirical approach to estimate soil erosion and its correlation with landslide events (a case study from Vazroud watershed, N Iran). International Journal of Forest, Soil and Erosion, 5(3), DIA LY TU NHIEN, TAI NGUYEN VA MOI TRUIN G 103