Hgi Dia ly Vigt Nam Dai hoc Thai Nguyen GIO MUA TAY NAM v A V A N DE GIANG DAY KHI HAU VIET NAM
6 T R U d N G PHO T H 6 N G
Nguygn Thi Hong', Nguyen Phuang Lign' Abstract
Outhwest monsoon and problems of teaching climate Viet Nam in school
In the program geography in schools, knowledge areas geography naturally plays an important role, as one of the basis to explain the natural phenomena and economic - social. The knowledge geographic nature often difficult and abstract, especially knowledge about climate. Some of the contents on climate students find difficult is to find out the southwest monsoon in Vietnam. Within the scope of article authors would like to clarify' the cause of formation, performance characteristics, operation time of the southwest monsoon in Vietnam, based on climatology to explain, and identify system Ventilate the area. On that basis, proposed teaching content southwest monsoon while teaching about climate I 'lemam.
Trong chuang trinh Dja li d tmdng phd thdng, ming kien thiic Dja li tu nhien chiem vj tri quan trgng, la mpt trong nhiing ca sd de giii thich cac hien tupng ty nhien v i kinh t e - x a hgi. Cac kiin thire Dja li ty nhien thudng khd va trim tupng, dgc bigt l i kien thiic ve khi hau. Mpt tiong nhirng ndi dung vi khi ban hpc sinh thay khd Ii tim hieu vi gid mua Tay nam d Vigt Nam. Trong phgm vi bai bao tic gia mudn lim ro: nguyen nhan hinh thinh, die diim boat ddng, thdi gian hogt dpng cua gid mua Tay nam d Viet Nam, dua trgn co sd khi hgu hpc de giii thich, dong thdi xac djnh he thong gid toan khu vuc. Day la nhiing kien thiic can thiet khi giing day ndi dung cua bai khi hau VietNam.
I. Gl6 MUA TAY NAM 6 VIET NAM
Gid miia li loai gid xuat hign theo miia, hogt dpng theo chu ky nim. Gid xuat hien giiia hai miia cd hudng ngupc nhau, ddng thdi cd tinh chat rat khac nhau. Vi du: gid mua Tay nam vao miia ha va gid miia Ddng bac vio miia Ddng d Viet Nam lech nhau 180°, Gid miia Ddng bic v i gid miia Ddng Nam lech nhau 90°, gid miia Ddng Bac thudng rit lgnh va hoi khd, gid miia Tay Nam va Gong Nam thudng ndng am. Tgn goi ciia gid miia thudng can cii vio vj tri, lanh tho hoat dgng ciia gid nhu: gid miia chau A, chau Phi, chau Uc, chau My hoac gid mua ngi tuyin, gid mua ngoji tuyin [I].
Can cii vao nai xuit phat va hudng di chuyen eua khii khi m i ngudi ta thudng gpi tgn gio, nhu: gid miia Ddng Bac, gid mua Tay Nam, gid mua Ddng Nam. . Vi vay, gid mua Tay Nam thoi vao Viet Nam la cd hudng Tay Nam.
* Nguyen nhan hinh thdnh
Nguyen nhan sinh ra gid miia l i su xuit hign ciia cic trang tam ap hogt dpng thep mua d tren lyc dia. Miia ddng thudng joiat hien ap cao, miia he xuat hien ap t h ^ , vi dy gid mua Chau A cd hai trang tain ap ldn tien lyc dja chi phoi, dd la hg ap Iran xuat hien vao mua he, cao ip Xi bia xuat hign vao miia ddng. Ca hai tnmg tam ap nay chi phoi den khi hau toan khu vyc chau A, trong do c6 Viet Nam
Miia ha, gid miia Tay Nam thoi vao Vigt Nam cd hai nguon goc khac nhau, tinh chat gio va sy hoat ddng ciing khong hoin toan gi6ng nhau, bao gom hai loai gid sau:
+ Gid miia Tdy nam hogt ddng tu thdng IV din thdng V vd VI. vio dau miia he, tiling IV, V va VI, lyc,dja A_bit diu_ndng din len va xuit hi?n tmng tam hg ip, dgc biet la ap thap An Dp, Miama, miin tay ban dao ddng duong va Nam bp Vigt Nam Cic trung tam ap nay da hiit gio tir cao ip chi tuyen vjnh Bengan va thoi theo hudng tay nam, xuit hien gid miia Tay nam thoi vao Viet Nam rit manh vao diu miia hg [4],
' Khoa Dia li - Trudng Dgi hgc Suphgm - Dgi hgc Thdi Nguyin
Kp yiu Hpi nghi Khoa hgc Dia lp todn qudc ldnM7
Hoi Dia ly Viet Nam Dai hoc Thai Nguygn
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CD I
Hinh 1. Hoat ddng cua gid miia Tay nam vap thing V, VI
Thdi gian nay dai ap cao chi tuyen bin ciu nam chua manh, dong thdi dii hpi tu nhiet ddi va dai ip thap dn ddi bin cau bac chua hogt ddng manh nen gid Tay Nam cd nguon gdc ban cau Nam chua bieu hien rd Dong thdi ha ap Iran thupc Nam A cung chua hoat dpng manh nen gio co liudng chinh Ii hudng Tay Nam, nghia la chi chju sy chi ph6i ciia lyc Conolit nen co hudng ca ban ia hudng Tay Nam v i cd kha nang xam nhgp sau vio e i mign Bac v i mien Tmng Viet Nam (hinh 1)
+ Gid mita Tdy nam hogt dpng tie thdng 6, din thdng 7 vd 8: Vao giiia va cuoi miia hg thing 6, 7 va 8, gid miia Tay Nam cd ngudn g6c tin phong ban cau nam vuot qua-xich dgo tlii doi huoDg thinh gid Tay nam, Thdi gian nay dai ap cao chi myen ban can nam da manh, dong thdi dii hdi tii nhiet ddi va dii ip thip dn ddi bin cau bie ciing hoat ddng mgnh lgn nen gid Tay Nam cd ngudn goc ban cau nam da hogt dpng mgnh Liic nay cao ap chi tuyin tay Ben gan eiing da yiu dan [4j, Dong thdi ha ip Iran thupc Nam A ciing hpgt ddng mgnh nen gid cd hudng chinh la hudng tay nam, nhung khi Ien din miin Trung va mien Bic thi hit diu doi hudng thinh gid Ddng Nam tiic la cd hudng ngupc chieu kim d6ng ho dp Ha ip Iran hiit gid. Digu niy li giai tgi sao gid phan Tay Nam khdng hoat ddng manh va xam nhip sau vio miin bic, mien trang vao thing 7, 8 m i chi boat ddng manh vao thing 5 va 6, liic nay gid cd hudng Tay Nam chii yeu boat dpng d mien nam Mien Bac ehu yeu l i gid ddng nam ngn cdn goi la gid miia Ddng Nam. Nhu vgy neu khdng cd hg ap Iran hiit gid thi gid miia Tay Nam se cd hudng chinh l i Tay Nam va xam nhap sau vao Mien Bac v i mien Trung giong nhu gid mua Tay Nam xuat hien tir cao ip chi tuyin vmh Bengan vao thing 5 va 6 (hinh 2).
Nhu vgy ve nguyen nhan hinh thanh gid miia Tay Nam d Viet Nam cho thay cd hai ngu6n goc ro ret, mpt luong gid xuit phat tir vmh Ben gan vio diu mua Ha (Thg), mdt luong gid xuit phit '. Hogt dgng gid miia Tdy Nam
vdo thdng VTI.nil Kyyiu Hgi nghi Khoa hpcDia lp todn qudc ldn tha 7
Hpi Dia ly Viet Nam Dai hoc Thii Nguyen tir cao ap chi tuyin ban ciu nam vuot qua xich dgo doi hudng thinh gid Tay Nam goi la kh6i khi xich dao (Em).
* Ddc diim hogt dpng ciia gid mua Tdy nam & Viet Nam
Gid miia Tay Nam hoat dpng vao miia ha lai cd hudng Tay Nam xuat phat tir chi tuyen va khu vuc xich dgo nen cd tinh chit chung la ndng. Tuy nhien do hudng khac nhau, quang dudng di, va chiu su chi ph6i cua cac tnmg tam ap khic nhau nen sy hoat ddng cung nhu tinh chat nhiet am cd su khic nhau.
-I- Dgc diim cua gio mua Tdy Nam xudt phdt tu cao dp chi tuyin vmh Bengan (Tbg): Gid nay hogt ddng vao thing 4, 5 va 6, hudng chinh la Tay Nam hoat ddng manh k h ^ ca nude tir mign Nam ra mien Tmng va mien Bic, tuy nhien d mien Nam gid Tay Nam xuat phat tir bien th6i tryc tiep vao ngn day l i kh6i khi ndng am gay mua Idn, Cdn khi thoi vao mien Trang va miin Bic thi khii khi nay do phai vuat qua quang dudng rat dai hang nghin km qua Lao Igi phii vupt qua day Tmdng Son nen da gay ra hieu ling phan trd thinh gid phan Tay Nam, nen cd tinh chit rat ndng vi khd, Ngay tai H i Npi nhiet dp cd the lgn tdi 33-34°C; Bac tmng bd nhigt dp dat tdi 36-38''C, dp am tupng doi cd thi chi edn tir 30-50% [2].
+ Ddc diim cia gio miia Tdy Nam xudt phdt tir cao dp chi tuyin Bdn cdu nam (Em): Gio nay hoat ddng tir thing 6, 7 va 8, hudng chinh la hudng Tay Nam, nhung hudng Tay Nam chu yiu hogt ddng manh d mien nam Viet Nam. So vdi khoi khi chi tuyen Tbg thi khoi khi Em mit va am ban, do chu yeu di qua bien, nhiet dp trang binh l i 27°C-28''C, dp am tuang doi khoang 80-90%, Thdi tiit dae tnmg cho khdi khi nay la mua dai ding, trdi mit, am va cd gidng bao. Vio thing 6,7, dai hpi ty vit qua miin bic, hinh thanh bao d ngoii khai va dd bd vao mien bic Viet Nam, Dii hpi ty nhigt ddi l i sy gap gd cua tin phong ban ciu bic cd hudng ddng bic va tin phong bin ciu nam hudng dong nam vupt qua xich dao doi hudng thanh gid Tay Nam, tuy nhien dii hpi ty ehii yeu hogt ddng mgnh d ngoai khoi khu vyc bien Ddng. Nhu vay gid miia Tay Nam ciing tham gia vao su hinh thanh dai hdi tu v i bao d khu vuc bien Ddng, do bp vao bd biin Vigt Nam.
Gid miia Tay Nam vdi hai nguon goc khic nhau da chi phoi den khi hau Viet Nam trong miia hg. Dieu niy ciing Ii ca sd de giai thich gid mua Tay Nam da boat ddng mgnh va lan it gid tin. . phong ddng bic thoi vao Viet Nam vao giiia mua He, chi boat ddng mgnh via miia thu va miia Xuan. Day eung la ca sd de giai thich tgi sao Viet Nam khdng bj khd ndng nhu mpt s6 nude khac cd cung vT dp nhy Viet Nam.
2. VAN DE G I A N G D A Y VE GIO MUA T A Y NAM TRONG T R U O N G PHO T H 6 N G Gid mua Tay nam chi phoi rat Idn den khi hau Vigt Nam, hieu rd ve sy hinh thanh, dgc diem boat dpng cua gid miia Tay Nam d Vi^t Nam, cd thi giii thich dgc diem khi hgu Vigt Nam vio miia He. Khi giang day ve khi hgu Viet Nam, giao vien can hudng din cho hpc sinh tra Idi dupc eic cau hdi sau:
- Tai sao cimg Ii gid miia Tay Nam nhung Igi cd ngu6n goc v i tinh chat khic nhau?
- Tai sao gid phan Tay nam -gid Iao chi hogt dgng manh tiong thing 5 v i 6 sau do yeu dan di va dung lai'?
- Tai sao xuit hien gid mua Ddng nam hoat dpng manh d mien Bic Viet nam vip thing 7 v i 8 ? - ..
- Dai hpi ty v i gid mua tay nam cd m6i quan hg vdi nhau nhu the nao?
De tri Idi cic cau hdi niy, tmdc hit can hudng dan hpc sinh khai thic kien thirc tir hinh I va 2, sau dd xac dinh sy xuat hign cic tmng tam ap theo hai thdi gian khic nhau, cd the sir dyng Power Point vdi cic higu ling de bieu dien hudng gid, cae trung tam ip cao, ip thip.
- Hinh 1: gid mua Tay nam xuit phat tir cao ap chi tuyen vinh Bengan (Tbg) vao thing 4,5 v i 6 bao gom: scp ths^ An Dp, Miama, mien tay ban dio ddng duang v i Nam bd Vigt Nam. Cao jq) Tay Ben gan l i cao ap chi tuyen bin ciu bic, tir^dd xic djnh hudng gid thoi tii cao ixpykhzsp va Kyyiu Hpi nghi Khoa hgc Dia lp todn qudc ldn thu 7
Hoi Dia ly Vigt Nam Dgi hoc Thai Nguygn anh hudng den toan bd Viet Nam Can giii tiiich rd Ii thdi gian nay do Mat Trdi mdi chuyin ddng bieu kien Ien ban ciu bic nen dii ap t h ^ dn ddi va ha Iran chua hoat ddng manh.
- Hinh 2- gid miia Tay nam xuit phat tir chi tuyen bin cau nam hogt ddng vio thing 6, 7 va 8 bao gim ap cao Nam Thii Binh Duong Nam An Dp Duang, Cao ap Otiaylia, ha ap Iran, dai ap thap on ddi, ha ap bie bp. Dae biet c6 su chi ph6i manh cua ha ap Iran Xac dinh hudng gid thdi tii' cac cao ip ve ha ip, trang tam ip thip Iran hogt ddng mgnh hiit gid nguac chieu kim ddng hd lim gid Tiy Nam tid thinh gid Ddng nam d mien bac va mien trang. Cao ap Tay Ben gan va cac ha ap An Dp, Miama, ... bj suy yeu.
- Dya vio so do dii hdi ty vio thing 6, 7, 8, de giii thich gid tin phong bac ban cau dich ve bien Hoa Nam. Tin phong Nam bin cau boat ddng manh d Viet Nam va chinh l i gid mua Tay Nam va Ddng Nam lan at lam cho tin phong bac ban cau dich chuyen ve vT do cao. Tin phong Bac ban ciu vi Nam bin cau gap nhau tgo thanh dai hdi tu nhigt ddi va boat dpng manh d viing bien Ddng VietNam.
KET LUAN
Hogt dpng cua gid mua d Viet Nam rat phuc tgp, giing day vg khi hau ndi chung va gid miia d Vigt Nam ndi rigng Ii van de khd, vi vay de giai thich mdt cich logic khoa hpc cic hien tuong khi hiu d Viet Nam, dgc bigt ddi vdi gid mua Tay nam ddi hdi giio vien cin phai nim vung nhiing kien thiic co sd dia Ii ty nhign, higu ro ban chat ciia van de, van dung Iinh hoat eae phuang phap, phuang tign dgy hpc trong qua trinh dgy hpc thi mdi dem Igi hieu qua cao.
T A I LIEU THAM K H A O
[1]. Bp gido due vd Bdo tgo (2009) Sdch gido khoa Dia li 10 Nxb Giao due.
[2]. Bp gido due vd Ddo tgo (2009) Sdch gido khoa Dia li 12. Nxb Giio due [3]. Vu Ty Lap, (2010), Dia litu nhien Viit Nam, Nxb Dai hpc Su pham Hi Ngi, [4]. Le Ba Thio, (1983), CasdDia li tunhiin, tap I, Nxb Giao due H i Npi.
[5]. Pham Ngoc Toin, Phan Tit Die (1978), Khi hdu Viet Nam, Nxb Khoa hpc & Ky tiiugt Ha Npi.
Ky yeu Hgi nghi Khoa hgc Dia lp todn qudc ldn thu 7
