KY YEU "CAC DE TAl NGHIEN CUU KHOA HOC- CONG NGHE NGANH TAl NGUYEN VA MOl TRUONG GIAI BOAN 2002-2006"
DEAN: N G H I E N CLTU T H l f N G H I E M D U B A O K H I H A U 6 V I E T N A M
Co" quan chu tri: V7en A7u fawrag 77*Hy van
C h u n h i e m de an: TSKH. Nguyin Duy Chinh Ban dieu h a n h de an:
TSKH. Nguyin Duy Chinh Chu nhiem, Truong ban PGS. TS. Trdn VietLiin Phd chu nhiem, uy vien TS. Nguyin Van Thing Thuky, uy vien CN. Truong Due Tri Thudng true, uy vien Cac t h a n h vien:
PGS. TS. Phan Van Tin Dai hoc Khoa hoc Tu nhien, Dai hoc QGHN TS. Nguyin Ddc Hiu Trung tim KTTV Trung uong, TTKTTVQG TS. Hoang Ddc Cudng Trung tim NCKH, Vien KTTV
ThS. L6 Xuin Cau Trung tim Tulieu KTTVva Mdi trudng Muc tieu cua de an:
1- Xay dung qui trinh cong nghe du bao k h i hau nham phuc vu co hieu qua thong tin khi hau cho cac co quan quan ly va chi dao Nha nude, cac to chuc kinh te - xa hpi trong phong chdng thien tai va chi dao san xuat hang nam, ciing nhu lap k d hoach, quy hoach dai han;
2- Hien dai hoa va tang cuotig tiem luc nghidn cuu, ung dung cua nganh khi tuong
thuy van, nham sdm dua cdng tac du bao va ra thdng bao k h i hau dinh ky vao nghidp vu thudng xuyen.
Npi dung nghien cdu cua de an:
1- Td chdc ngan hang du lidu phuc vu cdng tac du bao va ra thdng bao k h i hau dinh ky;
2- Nghien cuu thd nghidm cac phuong phap du bao k h i hau: thang, mua nam bang cac md hinh thuc nghidm;
3- Ra thdng bao k h i hau;
4- Chuan bi kien thdc, thdng tin khoa hoc va luc lupng can bp cho du bao k h i hau;
5- T i m hidu cac m d hinh du bao ddng luc cho cac khu vuc nhd dd lua chon va nhap cdng nghe du bao loai nay.
Tom tat bao cao ket qua cua de an:
1- Kho du lieu k h i k h i hau dung dd thuc hidn du bao k h i hau va ra thdng bao k h i hau dinh ky.
2- Quy trinh cdng nghd du bao k h i hau bang md hinh thuc nghiem va ra thdng bao khi hau dinh ky theo mua, nam; Cac ket qua thd nghidm, cac bao chuyen dd khoa hoc cua dd an,...
3- Ngoai ldi ndi dau, kdt luan va kien nghi,
KY YEU 'CAC Pg TAI NGHIEN CUll KHOA HOC- CONG NGHE NGANH TAl NGUYEN VA MOl TRUONG GIAI DOAN 2002-2006' Bao cao tong ket de an gom 6 chuong sau day:
Chuong I : M o t sd phuong phap va mo hinh du bao k h i hau hien nay trdn the gidi Chuong I I : X a y dung co sd du lieu phuc vu du bao k h i hau va ra thong bao k h i hau;
Chuong I I I : Co sd khoa hoc va can cd thuc hien cua cac phuong phap du bao k h i hau da duoc trien khai nghien cdu;
Chuong I V : T h u nghiem va danh gia ket qua du bao k h i hau bang cac mo hinh toan thdng ke;
Chuong V : Nghien cuu xay dung quy trinh du bao k h i hau;
Chuong V I : Xay dung quy trinh ra thdng bao k h i hau.
KET QUA XAY DUNG MO HINH DU BAO KHI HAU BANG PHUONG PHAP T H O N G K E T H U C N G H I E M 6 V I E T N A M Thdng tin khi hau, nhat la thdng tin du bao khi hau (DBKH), rdt cdn cho cdng tac
quy hoach phat trien san xuat t d Trung uong den dia phuong. Theo su khuyd'n cao cua Td chdc K h i tuong thd gidi ( W M O ) va nhu cau phuc vu thdng tin k h i hau d nude ta trong giai doan cdng nghidp hoa, hidn dai hoa hidn nay viec nghidn cdu D B K H va ra Thdng bao k h i hau (TBKH) dinh k y da duoc Tdng cue K T T V (trudc day) va Bd Tai nguyen va M d i trudng (hidn nay) xem la mdt trong nhung ndi dung trong tam thudc linh vuc K T T V . Dd an "Nghien cuu thd nghidm du bao k h i hau d Viet N a m " (goi tat la " D d an D B K H " ) da duoc nghiem thu d H d i ddng cap Bd va da dupe dua vao du bao thd nghiem nghidp vu (d Trung tam Nghidn cdu K h i hau, Vidn K T T V ) cho thay ket qua dang khich le budc dau vd nghidn cuu D B K H d nude ta [ 3 ] .
T B K H la san phdm cua cdng tac D B K H ndi chung - do la loai san phdm vda mang thdng tin tdng ket didn bien k h i hau theo cac thdi han (thang, mua, nam,...) da qua, vda mang ket qua du bao dinh lucmg cho cac thdi doan sdp tdi tuong dng dudi dang bang bidu va ban do phan bd cu the. Hidn nay T B K H v d i nguon thdng t i n phong phu, da dang, kip thdi, vdi phuong tien tinh toan hien dai va m d hinh du bao cd dp chinh xac cao,.. .dang cd tac dung quan trpng trong viec cung cdp thdng t i n t i n cay cho viec quy hoach va phat trien kinh te - xa hdi d nhieu nude tren the gidi.
Trudc day cac nha khoa hoc trdn the gidi da cd nhung quan niem khac nhau vd thdi han D B K H : Cd ngudi cho rang D B K H phai la du bao nhung bien ddng k h i hau cd chu ky keo dai hang thap ky, the k y trd len, con nhung bien ddng cd chu k y dudi mdt nam dupe coi la du bao k h i tupng han vda - han dai (gdn ket nhieu hon v d i du bao thdi tiet). Ngupc lai, cac nha khoa hoc M y va mdt sd nude khac lai coi cac du bao t d 2 tudn trd len la D B K H . Trong mdt vai thap k y gan day cac nha nghien cuu k h i hau the gidi da cd y kidn thdng nhdt: D B K H la d u bao t d thang, mua trd len, trong dd d u bao mua (du bao 3 thang lien tiep) la ddi tupng trung tdm cua D B K H hidn nay.
De phan dinh cac loai hinh D B K H khac nhau ngudi ta dua vao dac didm bien ddng cua k h i hau. Trong ly thuye't phan tich chudi thoi gian ngudi ta coi didn bien cua k h i hau la su td hop cua nhidu dao ddng vdi nhung budc sdng khac nhau. Cdc bien ddng k h i hau dupe chia thanh 3 loai chinh:
KY ygu "CAC DE TAI NGHIEN CPU KHOA HOC- CONG NGHg NGANH TAl NGUYEN VA MOI TRUONG GIAI DOAN 2002-2006" ^ 1- Bien dong co budc song dudi 1 nam, co tinh chat mua (vi du: han han, hi, bao,...)
2 - Bien ddng co chu ky dao dong tu 1 nam tdi mot vai thap k y ( v i du: hien tupng ENSO,...)
3 - Bien dpng co budc sdng hang thap k y den the k y ( v i du: bien dpng cua buc xa mat trdi, hoan luu nude sau, k h i nha kinh,...).
D u bao k h i hau dua vao cac bien dpng k h i hau vda neu cung dupe chia thanh 3 thdi han tuong ung:
1 - D u bao k h i hau han ngan co thdi han du bao dudi 1 nam, ddi tupng du bao chinh la mua.
2 - D B K H han vda cd thdi han du bao co mpt nam trd len tdi vai thap ky.
3 - D u bao k h i hau han dai cd thdi han du bao td thap k y tdi hang the ky.
Cho den nay tren the gidi co 2 phuong phap xay dung m d hinh D B K H chinh - dd la phuong phap thdng ke thuc nghidm va phuang phap so tri ddng luc. M d hinh thdng kd thuc nghiem hidn dang dupe su dung cd hieu qua d cac nude, song m d hinh sd t r i dpng luc cung dang dupe trien khai nghien cdu, thu nghiem cd ket qua d mdt sd nude tien tien.
Tren co sd cac ngudn so lieu da thu thap va tich luy dupe cua cac nude (sd lieu quan trdc hoac sd lieu phan tich lai) ngudi ta tidn hanh phan tich didn bien dong thdi cua cac nhan to du bao (NTDB) vdi cac nhan td dupe du bao (ddi tupng du bao - D T D B ) , t d dd xdc lap nhung mo hinh du bao.
Tren the gidi ngudi ta da va dang ap dung mpt so mo hinh toan thdng ke chinh vao D B K H nhu tuong quan hoi quy, xac suat co dieu kien va ham phan biet, xich Makov, phan tich pho, "mang than kinh", v. v. Nhin chung nhung m d hinh du bao nay dd tiep can va dd su dung, dat hidu qua tuong ddi cao. D d i vdi cac nude chua cd kha nang su dung cac mo hinh dpng luc thi viec su dung cac mo hinh toan thdng ke de xay dung m d hinh D B K H la giai phap diing dan. Tuy nhien de su dung cd hidu qua cac m d hinh thdng ke thi so lieu qua khd, ke ca ciia N T D B va ciia D T D B , deu ddng vai trd dac biet quan trpng. Sau day chiing toi xin gidi thieu vdn tdt ket qua xay dung va kiem chung mo hinh D B K H bang phuang phap toan thdng ke.
1. XAY DUNG VA KIEM CHUNG MO HINH DUBAo
1.1. Lua chon phuong phap: Ci Viet Nam nghien cdu D B K H lan ddu tien trien khai thuc hien, do dd De an tap trung khai thac, dp dung cac mo hinh toan thdng ke nhu phan tich hdi quy bdi tuyen tinh, tuang quan canon, phan tich phan ldp, phan tich hdi quy tdng budc, phan tich "mang than k i n h " . . . . [ l , 2. 4, 5, 6, 8] de lua chon phuang phap phu hop cho viec xay dung md hinh D B K H . T u ket qua khao sat cac m d hinh neu tren De an da chon phuang phap hdi quy bdi tuyen tinh va hdi quy tdng budc ket hop phan tich phan ldp ("pha") de xay dung va kiem chung mo hinh D B K H [3].
1.2. Doi tuong du bao va nhan to du bao: Trong DBKH cd the chon nhieu DTDB
khac nhau, song phd bien nhat la nhiet dp va lupng mua. Dd an D B K H cung chon 2 D T D B nay. Cac chudi sd lieu quan trdc d nude ta vua ngdn, vua bi dan doan va khong ddng ddu do dieu kien ddt nude cd chien tranh. Dp dai cac chudi cd t u 20 den 120 nam sd lieu d 174 tram trong pham v i ca nude, nhung chi cd khoang 120 tram cd 40 nam sd lieu (1961-2000) cd thd sd dung dupe cho bai toan nay. Rieng d nua phdn phia nam Viet N a m
KY YEU "CAC BE TAI NGHIEN Cull KHOA HOC- CONG NGHE NGANH TAl NGUYEN VA MOl TRUONG GIAI BOAN 2002-2006"
De an phai sir dung mpt so tram co thdi gian quan trac ngan hon (1975-2000), do mat dp ludi tram thua hon. Cac N T D B chon vao khao sat mo hinh dupe xac lap tu trucmg dp cao dia the v i (AT500), nhiet dp mat nude bien (SST - tinh cho cac d ludi 5x5 dp cho khu vuc Bac Ban Cau, l x l dp cho vung Bien Dong), cac dac trung k h i quydn-hai duong khu vuc xich dao Thai Binh Duong (TBD), 12 thanh phan chinh cua trucmg SST toan cau,...[3]. Dp dai chudi sd lieu cua cac N T D B dupe la'y tuong dng dp dai cua D T D B .
1.3. Kiem chiing (verification) mo hinh: Viec kiem chdng danh gia mo hinh de td do chon ra mo hinh thich hop nhat cho mpt D T D B nao do la rat can thiet. Den nay da co 2 each kidm chdng dupe su dung ddi vdi phuong phap hoi quy, dd la:
a/ Chia bp sd lieu sd dung thanh 2 phan: phan chinh de xay dung m d hinh (bien phu thudc) va phan con lai dung de kiem chdng m d hinh (bien dpc lap - D L ) ;
b/ Su dung toan bp chudi so lieu de xay dung m d hinh. Vide kiem chung dupe thuc hidn tuong ung la "kiem chdng cheo" (cross validation). Day la phuong phap kidm chdng dupe dung kha nhidu trong viec xay dung cac m d hinh du bao bang phuong phap toan thd'ng ke hien dai, nhat la k h i chudi so lidu dua vao su dung khdng dai.
De an da sd dung ca 2 each kidm chung nay cho phuong phap lua chon neu d muc 1.1.
Ben canh viec lap mdu xay dung m d hinh du bao va kidm chdng ndu trdn, Dd an dua vao "Hudng d i n k y thuat cua W M O " va mdt so kd't qua nghien cuu gan day cua cac nude dd chon cac chi tieu k i e m chdng sau day:
- D d i vdi du bao chudn sai hay gia tri cua yeu to dung phuong sai thang du (RMSE) va mdt so thong so khac tuong tu nhu: sai so binh phuong trung binh (MSE), sai sd tuydt ddi trung binh ( M A E ) , phuong sai nit gon (RV),...;
- Ddi vdi dac trung xac suat (du bao cac pha) dung "chi so d u bao" hay "ty le thanh cdng (Hit Rate)"- F I va chi so Heidke (Heidke Skill Score - HSS) dupe phat tridn t d "bang lien kd't" (contigency table) lam cac chi tieu chinh;
- Ngoai ra, khi dung phuong phap "kidm chung cheo" cd thd dung he so tuong quan gitta gia tri quan trdc va hdi quy ddc lap ma nhieu cdng trinh thudng dung ( C V R ) [ 7 ] .
Vide kidm chung m d hinh chu yd'u thuc hidn vdi cac chudi so lieu sir dung. Ben canh dd d mdt so nude ngudi ta cung danh gia "ty Id thanh cdng" cua m d hinh du bao theo ludi tram tham gia dubao (Trung Qudc, Lidn X d (cu), Hoa K y ) . Day la dang kiem chdng md hinh du bao theo dien, mang y nghla true quan va cung da dupe D d an dp dung.
2. KET QUA XAY DUNG VA KIEM CHUNG MO HINH 2.1. Du bao cac dac trung vung:
V d i cac dac trung vung (tinh trung binh cho ca vung) ket qua d u bao cho thdy: M d hinh du bao nhiet dp cho tri so F I , HSS ddi v d i du bao 3 pha theo chudi phu thupc dat 60- 70% va 30-50%, con ddi vdi chudi ddc lap: 40-60% va 20-40%; M d hinh du bao lupng mua thudng cho dp chinh xac kem hon (40-50% va 10-30% ddi vdi chudi dpc lap). Sd dung phuong phap "kidm chdng cheo", C V R dat 0.1 dd'n 0.4. Bang 1 tdng hop mdt so kd't qua du bao va kidm chung cu thd:
KY YEU "CAC DE TAl NGHIEN COU HOC- CONG NGHE NGANH TAI NGUYEN VA MOl TRUONG GIAI BOAN 2002-2006' Bang 1: Cac thong so danh gia cac md hinh du bao cho vung Dong bdng Bde Bp Mua
DB*
So N T D B
RMSE M A E RV FISHER HSS F 3 p h a (%)
F3DL (%) Lupng mua (lay v i du 4 "mua d u bao")
1 12 100.77 1.799 0.362 2.483 0.34 56 80
4 12 200.11 1.685 0.688 5.462 0.50 67 60
7 12 371.26 42.022 0.504 4.348 0.58 72 40
10 9 114.63 3.629 0.532 5.729 0.42 62 40
Nhiet dp (lay v i du 4 "mua d u bao")
1 12 0.61 0.015 0.526 3.361 0.43 62 40
4 7 0.2 0.013 0.647 7.893 0.31 54 60
7 9 0.24 0.026 0.440 3.669 0.56 67 60
10 5 0.64 0.062 0.261 6.346 0.47 64 60
(* Chon 4 miia DB: mua 1 gdm cdc thdng I, II, III; mua 4 gom cdc thdng TV, V, VI;
mua 7 gdm cdc thdng VII, VIII, IX; miia 10 gdm cdc thdng X, XI, XII dng vdi 4 quy trong nam.)
2.2. D u bao cac dac trufng cho cac t r a m :
Day la hudng phat tridn chinh cho D B K H d Viet N a m . Chat luong cac mo hinh du bao cho cac tram thudng thap hon so vdi d u bao cac dac trung vung, bien ddng kha manh theo mua va theo tram. Bang 2(a,b) gidi thieu mot v i du ve ket qua d u bao va kiem chung ddi vdi cac tram:
Bang 2a: Cac thdng so danh gia cac md hinh du bao lupng mua Tram Lang (Ha Ndi) Miia
DB
Sd N T D B
R M S E (mm)
M A E (mm)
RV FISHER F 3 p h a (%)
HSS (%)
1 12 38.1 1.527 0.567 3.77 49 23
4 12 158.1 2.045 0.459 2.37 50 11
7 8 150.0 4.499 0.639 8.73 62 44
10 12 80.1 0.165 0.702 7.10 60 40
Bang 2b: Cac thdng so danh gia cac md hinh du bao luong mua Tram Tan Son Nhdt (TI Ho Chi Minh)
Mua DB So N T D B R M S E (mm)
M A E (mm)
RV FISHER F 3 p h a (%)
HSS (%)
1 10 18.9 0.451 0.722 9.57 49 23
4 12 67 1.776 0.646 5.26 62 44
7 12 107.8 0.033 0.589 4.28 58 37
10 10 56.1 1.875 0.768 12.53 78 67
KY YEU XAC BE TAI NGHIEN CUU KHOA HOC- CONG NGHE NGANH TAI NGUYEN VA MOI TRUONG GIAI BOAN 2002-2006"
Hinhl: Diin bien cua ty le tram du bao ddng luong mm cac quy (1961-2000) 100
2 0 0 ,
— v. r- 3- — <r. t-. — f- 3- — r<-, ir, o>
\c *c *c s c r - r - c ^ r - r - =c -x. x x x o. c-
• Mua DB 1 • M ua DB4 * M ua DB7 o MuaDBIO Danh gia cho toan mang ludi tram (tinh cho toan chudi su dung) co the nhan tha'y
tri so F I bien dong khd manh: d dai bo phan cac tram F I > 50%, d mot sd khu vuc FI
>70% va d mdt vai khu vuc khac chi so F I lai dat khdng cao ( < 50%). Cac mua chuydn tiep td gid miia miia ddng sang gid mua miia he thudng dat hidu qua thap hon cdc mua khac trong nam. K i e m tra bang C V R theo phuong phap " k i e m chdng cheo" ddi vdi cac tram thi phan ldn cung dat d khoang 0 , 1 - 0,4; neu dung chi so HSS thi dat 10-30%
(tuong tu kd't qua du bao ddi vdi vung dao tren T B D cua Hoa K y ) . Vide danh gia chdt luong du bao qua chi so F I tinh theo ludi tram cung duoc De an thuc hidn cho cac miia trong nam va cho tdng nam. So tram tham gia du bao thu nghidm vao khoang 70-120 tram thudc thdi ky 1961-2000. N d i chung m d hinh dat ty Id du bao diing khoang 55- 65% so tram tham gia du bao. Hinh 1 cho thay didn bien cua chi so F I d 4 mua du bao dng vdi 4 quy trong nam [ 3 ] :
Tdm lai, tuy cha't lupng ciia md hinh du bao chua that cao (nha't la ddi vdi lupng mua) va chua that deu cho cac miia va cac tram, song hieu qua du bao dat dupe cua De an cung xa'p x i ket qua du bao hien nay d nhieu nude tren the gidi. V i the cd the dua md hinh du bao nay vao thu nghiem du bao nghiep vu d nude ta.
T d nhan dinh nay De an da xay dung mdt phan mem phuc vu viec thu nghiem du bao nghiep vu. So lieu dau vao cho phan mem tren la cac dac trung k h i tupng - hai duong vung bidn xich dao T B D do Hoa K y va Australia phat hang thang tren Internet. San phdm du bao tu phan mdm nay gdm: chudn sai mua, xac sua't xuat hidn 3 pha (hut, can va vupt chuan) va chi so F I cho mua du bao. Hinh 2 (d trang cudi bai bao) bidu didn cac ket qua du bao bang ban do lupng mua cho miia du bao thd 4 (thang IV, V, VI) nam 2003.
KET LUAN VA KIEN NGHI
Qua ket qua nghien cdu cd thd nit ra mpt vai nhan xet sau day:
1. M d i quan he giua nhung nhidu dpng tren viing bien nhiet ddi T B D va didn bien khi hau d nude ta la kha chat che. Chinh v i the vide lua chon cac nhan to du bao (vua mang tinh dia phuong vda mang tinh khu vuc tac dpng) cua khu vuc nay la hop ly. T d kd't qua xdy dung phuong phap D B K H bang m d hinh toan thdng kd cho nhiet dp va lupng mua mua cac N T D B td cac dac trung sau day dupe xac lap:
- Chuan sai nhiet dp nude mat bidn (SSTA) d cdc vung N I N O (NTNOl+2, N I N 0 3 , N I N 0 3 . 4 , N I N 0 4 ) va cac viing thudc Bidn Hoa Ddng, Bidn Ddng vd vinh Belgan;
KY YEU -CAC PE TAl NGHIEN CUU KHOA HOC- C6NG NGHE NGANH TAl NGUYEN VA MOI TRUflNG GIAI BOAN 2002-2006' ^
- Chi sd dao dpng nam (SOI);
- Chuan sai k h i ap muc bien khu vuc Indonesia;
- Dp cao dia the v i muc 500 mb (ludi 5x5 dp kinh-vT).
2. T d ket qua khao sat cac m d hinh thdng ke thuc nghiem Dd an da chon dupe phuang phap hPi quy bpi tuyen tinh vdi su su dung toan bp chudi sd lieu de xay dung mo hinh D B K H . Hinh thdc tuyen chon N T D B bang hoi quy tung budc thong qua tieu chuan phuang sai thang du mang tinh thuyet phuc. V d i ca sd du lieu hien co d nude ta thi phuang phap hdi quy bpi tuyen tinh ket hop phuang phap " k i e m chdng cheo" dat hieu qua du bao tuong ddi cao (vdi ty le thanh cong ung vdi du bao 3 pha dat 50-70%, mpt sd trudng hop con dat cao hon), v i the dupe chon dd lap quy trinh D B K H nghiep vu. Mac dau vay mo hinh du bao nay cung cdn tiep tuc hoan thien theo hudng:
- Dua them cac NTDB moi co lien quan den hoat dpng cua gio mua Chau A va Chau Uc;
- De lap ban do du bao (pha hoac chudn sai) cho ca ludi tram cd the nghien cuu dp dung mo hinh tuang quan canon dd dam bao tinh tdi uu ve chat lupng;
- Nghien cuu them hinh thdc lien ket cac bien va true giao hoa cac bien cua trudng sd lieu sd dung de lam tang hieu qua du bao cua m d hinh.
3. Viec kidm chdng chat lupng mo hinh theo cac chi sd ma W M O da khuyd'n cao, trong dd hieu qua nhat la chi so F I , la cdng viec cdn thiet mang tinh quyet dinh trong vide lua chon mo hinh du bao tdi uu.
4. Trong khi chua cd m d hinh dpng luc D B K H cho khu vuc Ddng N a m A d nude ta cdn tidp tuc nghien cdu D B K H theo hudng su dung cac san phdm cua m d hinh dpng luc lam N T D B cho cac md hinh thdng ke thuc nghiem nhu each lam hidn nay cua mpt sd nude, hoac tiep tuc nghien cuu D B K H bang cac phuang phdp khdc dd nang cao chat lupng du bao.
KY YEU "CAC BE TAI NGHIEN CUU KHOA HOC- CONG NGHE NGANH TAI NGUYEN VA MOI TRI ftiNr. GIAI BOAN 2002-2006"
Hinh 2: BAN ¥)6 DIT BAO MUA MUA 4 (IV, V, VI) NAM 2003
TV L£ THANH CONG (%) CUA MO HiNH DU BAO LUONG MUA CAC THANG IV, V, VI Kfr QUA DU BAO CHUAN SAI LUONG MUA CAC THANG W, V. VI NAM 2003
XAC SUAT HUT CHUAN (DUOl 33 %) XAC SUAT VUOT CHUAN (TR£N 67 %)
0 11 33 55 100 nu.Vi i t;
