Morphometric analysis in Bangla

2. f~wgiƒcwgwZ we‡klb (Morphometric Analysis) m¤ú‡K© Professor of
Geography, Cambridge University Richard J. Chorley Gi e³e¨ n‡”Q- The
need for the precise description of the geometry of landforms,
particularly those of domnantly fluvial erosive origin, has been a
recurring theme in geomorphology.This topogrphic, hydraulic and
hydrological unity of the basin provieded the basis for the
Morphometric system of R.J. Horton(1954), as elaborated by
Strahler(1964), and it is now employed as a basic erosional landscape
element.
-Introduction to fluvial processes, 1977.
b`xgvjv AeevwnKvi Aa¨q‡bi KviY-
K) b`x wbqš¿‡bi Rb¨;
L) cvwb mieivn Ae¨vnZivLvi Rb¨ I
M) cvwb P‡µiAe¯’v Rvbvi Rb¨|

3. AeevwnKvi ‰ewkó¨ we‡klb-
wewfbœ b`x weÁvbx AeevwnKvi ‰ewkó¨‡K wewfbœ fv‡e we‡klb K‡i‡Qb|
Horton,(1932) Ges j¨vs‡eb(1947) AeewnKvMZ w`K †_‡K b`x‡K we‡klb
K‡i‡Qb|
Djg¨vb (1967)b`x Ges DcZ¨Kviw`K †_‡K b`x‡K we‡klb K‡i‡Qb|
Rb÷b, µm Ges †MÖ b`xgvjv AeevwnKvi cÖwµqv mg~‡ni we‡klb K‡i‡Qb|
÷ªjvi Ges †Pvwj© AeevwnKvi cÖwµqv I AvK…wZ‡K we‡klb K‡i‡Qb|
AeevwnKv b`x LvZ LÛvsk cÖ¯’
AvqZb AeevwnKvGjvKv b`x LvZmsjMœ
AvqZb
b`x LÛvs‡kiAvqZb cÖ¯’‡”Q`
AvqZb
ˆ`N©¨ AeevwnKvˆ`N©¨ b`x LvZˆ`N©¨,
b`xgvjv NbZ¡
b`x LÛvs‡ki‰`N©¨ cÖ‡¯’iˆ`N©¨
AvK…wZ AeevwnKvAvK…wZ RvwjKv AvK…wZ,
b`x AvK…wZ
eµZvb`x LvZ
AvK…wZ
cÖ‡¯’iAvK…wZ
eÜziZv| AeevwnKveÜziZvev
AeevwnKvXvj
RvwjKv eÜziZvev
RvwjKv Xvjev b`x
Xvj
b`x LvZeÜziZv,b`x
LvZXvj
eÜziZvicÖ¯’‡”Q`
MfxiZv
‡MÖMix I Iqvwjs b`xRf~wgiƒc we‡klb mviYx

4. b`xR f~wgiƒc we‡klb-
1964 mv‡j ÷ªjvi b`xR f~wgiƒc†K mvavibZ wbgœwjwLZ wZb fv‡e we‡klb K‡ib -
1| b`xAeevwnKvi mij ˆiwLK cÖK…wZ,
2| b`xAeevwnKvi AvqZwbK cÖK…wZ I
3| b`xgvjv AeevwnKv Ges b`x LvZ RvwjKv eÜziZv|
1| b`xAeevwnKvi mij ˆiwLK cÖK…wZt
A) U‡cvjwR‡Kj `„wó‡KvY--
b`x ch©vq µg (Order)
wØfvRb AbycvZ(bifurcation ratio)
Av) R¨vwgwZ¨K `„wó‡KvY
b`xi ˆ`N©¨ (Stream Length)
b`xi Mo ˆ`N©¨( Average Stream Length)
b`xi ‰`N¨©AbycvZ(Stream -Length Ratio)
AeevwnKvi AwfKl© †K›`ª †_‡K `yiZ¡ (The Distance to the centre of Gravity of the Drainage
Basin)
`xN©¨Zg AeevwnKvi e¨v‡mi ˆ`N©¨
b`xi ˆ`N©¨ I DcZ¨Kv ˆ`‡N©¨iAbycvZ

5. b`x AeevwnKvi AvqZwbK we‡klb (Areal aspects of the Basin)
K) b`x AeevwnKvi AvqZb (Area of the Basin)
L) AeevwnKvi b`x NbZ¡ (Drainage Density of the Basin)
M) AeevwnKv I AvqZ‡bi cvi¯úvwiK cv_©K¨ (Basin –Area Ratio)
N) AeevwnKvi AvK…wZ (Shape of the Basin)
b`x gvjv AeevwnKv Ges b`x LvZ RvwjKv eÜziZv(Relief aspects of the Basin)
K) b`x Lv‡Zi Xvj
L)AeevwnKvi Xvj
M) AeevwnKv eÜziZv
N) b`x ˆ`N©¨I Xv‡ji m¤úK©

7. K) b`x ch©vqµg (Order)
mvs¸ b ` x
e v›` i e vb
c Ö_ g c h ©vq
2 q c h ©vq
3 q c h ©vq
4 _ ©c h ©vq
nU©‡bi b`x ch©vq µg

8. mvs¸ b ` x
e v›` i e vb
c Ö_ g c h ©vq
2 q c h ©vq
3 q c h ©vq
4 _ ©c h ©vq
StrahlerGi b`x ch©vq µg

9. mvs¸ b ` x
e v›` i e vb
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1 1 1 1
1
1
1
1
12
2
2
2
2
2
2
2
5
14
18
28
19
5
9
‡kª‡fi b`x ch©vq µg

10. wØfvRbAbycvZ (bifurcation ratio)
Rb=
Nu
Nu+1GLv‡b,
Rb= wØ-fvRb AbycvZ,
Nu= †Kvb ch©v‡qi b`x Lv‡Zi †gvU msL¨v,
Nu+1= cieZx© ch©v‡qi b`x Lv‡Zi †gvU msL¨v|
(k-u)
Nu= Rb
†Kvbch©v‡qi b`x Lv‡Zi †gvU msL¨v(Nu) wbY©‡qi Rb¨ wb‡gœv³ myÎ e¨envi K‡ib -
GLv‡b,
k= AeevwnKvi D”PZg ch©vq msL¨
u = b`x avcevch©vq

11. K
L
ZvwRbWscvnvo
b`xiˆ`N©
DcZvKvˆ`N©
b`xi eµZv=
b`xi ˆ`N©¨
DcZ¨Kvi ˆ`N©¨

12. g‡nkLvjx†P‡bj
C
`
Mv
I
b
` x
A
e
e v
wn
K v
C` MvI b ` x
K · e v R v i ‡R j v
K · e vR vi Dc ‡R j v

13. L)AeevwnKvi b`x NbZ¡ (Drainage Density of the Basin)t †Kvb GjvKvi b`x
¸‡jvi †gvU ˆ`N©¨‡K H GjvKvi AvqZb Øviv fvM Ki‡j AeevwnKvib`x NbZ¡
cvIqv hvq|
GLv‡b,
D =AeevwnKvib`x NbZ¡,
∑Lk=†Kvb GjvKvi b`x ¸‡jvi †gvU ˆ`N©¨,
Ak =AeevwnKviAvqZb|
Dc‡ii wPÎ I mviYx †_‡K K·evRvi ‡Rjvi 35 wKwg ˆ`N©¨wewkóC`MvI b`x
AeevwnKviAvqZb 142 eM© wKwg I b`x ¸‡jvi †gvU ˆ`N©¨ 516.2 wKwg|
myZivs C`MvI AeevwnKvib`x NbZ¡ 3.6 wKwg/ eM© wKwg|
Ak
Lk
D


14. g‡nkLvjx†P‡bj
C
`
Mv
I
b
` x
A
e
e v
wn
K v
C` MvI b ` x
K · e v R v i ‡R j v
K · e vR vi Dc ‡R j v
198wg
28wKwg
b`xLv‡Zi Xvj t
b`xiDrmn‡Z †gvnbv ch©š— D”PZvI Abyf~wgK`~i‡Z¡iAbycvZ‡Kb`x Lv‡Zi Xvj ejv nq| b`xLv‡Zi Xvj †K
wgUvi/wK‡jvwgUv‡i cÖKvkKiv nq| f~`„‡k¨Xvj D‡jL †hvM¨ f~wgKv cvjb K‡i _v‡K| Xvj wb®‹vkbaiY wba©vibK‡i Ges
f~-c„‡ôi cwieZ©b NUvq| Xvj AeevwnKvi Dw™¢`,cÖvYx,emwZ , †mP,cwienb, AbycÖ‡ek,cvwb aviY, cvwb cÖevn
BZ¨vw` wbqš¿Y K‡i _v‡K| wewfbœ ch©v‡q b`xiXvj mgvb _v‡K bv| mvavibZt 1g ch©v‡q b`xiXvj †ekx _v‡K Ges b`xi
ch©vq I Xvj wecixZ fv‡e m¤úK©hy³| wP‡Î C`MvI AeevwnKvi b`xLv‡Zi Mo Xvj 5.65wg/wKwg|
Xvj (S) =
H = †gvnbv n‡Z Drmch©š— D”PZv(198wg)
L = b`xLv‡Zi Abyf~wgK`~iZ¡(38wKwg)| C`MvI b`xAeevwnKv,K·evRvi
L
H

15. K¨vwj‡dvwbq©v wek¦we`¨vj‡qi f~‡Mv‡ji mn‡hvMx Aa¨vcK Leal A. K. Mertes
b`xLvZ m¤ú‡K© e‡jb- “River, any body of fresh water flowing from an
upland source to a large lake or to the sea, fed by such sources as
springs and tributary streams. The main parts of a river include a
channel, in which the water flows, and a floodplain—a flat region of a
valley on either side of the channel”. - Microsoft ® Encarta ® 2008.
÷ªjvi(1964) Gi g‡Z b`xLvZ nj cÖevwnZ cvwbi kw³i d‡j MwVZ GKwU mi“ ev
PIov, Mfxi ev AMfxi, †mvRv ev evuKv, Lvov mylg Xvj wewkó GB c_ hvi
ga¨w`‡q axi ev cÖej †e‡M KL‡bv mweivg ev KL‡bv Aweivg fv‡e cvwb
cÖevwnZ nq| Bnv KL‡bv Ggb mi“ nq †h GK jv‡dB cvi nIqv hvq Avevi K‡qK
gvBj ch©š— cÖk¯’ n‡q _v‡K|

16. the River Severn

18. Meanders on the Severn
(middle course)

23. mvaviY fv‡e b`xi †h ¯’vbw`‡qcvwb cÖevwnZnq Zv‡K b`x LvZ e‡j|
AvK…wZ I ˆewk‡ó¨iDci wfwË K‡i b`x LvZ †K K‡qK fv‡efvM Kiv
hvq| George Harry Dury Introduction to Fluvial Processes cy¯—‡K
G‡K AvU †kªbx‡ZfvM K‡i‡Qb|
†hgb-
mwc©j (Meandering)
webywb (Braided)
mij (Straight)
Straight- simulating
Deltaic- distributary
Anabranching
Reticulate
Irregular.

24. Channel Length (ft.)
SINUOSITY = ------------------------------
Valley Length (ft.)

25. mwc©j b`xLvZ (Meandering channel) t
b`x Lv‡Z Pjvi c‡_ †h mvgÄm¨ c~Y© eµZvi m„wó K‡i Zv‡K mwc©j b`xLvZ (Meandering
channel) e‡j| Dbwesk kZvãxi ga¨fvM †_‡K mwc©j b`xLvZ(Meandering) Gi msL¨vZvwË¡K
w`K wb‡q cÖPzi M‡elYv n‡q‡Q| 1954 mv‡j cvwbweÁvbx iv‡gj b`xi mvgÄm¨ c~Y© eµZvi
†¶‡Î Meander kãwU cÖ_g e¨enviK‡ib

32. A Braided channel
is one that have
development into
sevsral channels
which successively
meet and redivided.
- Leopold Wolman
& Miller.