Task: Derive Topographic P arameters and Landforms, Analyze Time Ser ies o f DEMs

Approach

Co mpute s lope

asp ect and

curvatu re f ro m a

the given

e levat ion model

Res 10

MySlope

My asp ec

Curvature

3D el evat ion wi th curva ture overaly

Reso lu t ion cour sen ess =1

Zoo med in area SW o f Lake Johnson

Showin g concave and con vex area

MEA 582, Assignment9

Geomorphometry II: Spatial and Temporal Terrain Analysis

Due: Mar 22, 2011

Brenda McLuskie

Student ID: bhmclusk

bhmclusk@ncsu.edu

704 708-4880

Float and In teger s

ras te r have very

d i f fe ren t

h is tograms

Aspect h i s to grams

sho w the

inco mplet eness o f

in teger dat a

His to gram o f s lope in t erger ras t er

His to gram o f s lope f loat r as t er

His to gram o f asp ect in te ger r as te r

His to gram o f asp ect f loa t ras te r

S lope In t eger map , s lop e_in t

S lope F loat map

Zoo m o f the SW

of Johnson lake

are . At th is zoo m

level the l ines o f

e levat ion chan ge

can b e seen

cau sing a s t ep l i ke

chan ge in

e levat ion . Th e

flo at ras te r c lear ly

handles th is i s sue

bet te r .

Zoo m in o f S lope In teger map , s lope_in t_10 m

Zoo m in o f S lope floa t map ,

myslop e

Th e d i f ference b etween a f loat r as ter and an in teger r as t er i s th at f loat ras te rs h ave a l arger

ran ge o f valu es which i s b et t er su i ted to cont ious d a ta . In t eger r as t er s h ave a smal l ran ge o f

va lues contained in the a t t r ibu te t ab le . Th i s i s b et t e r fo r d iscret e da ta and wh ere addi t ional

data may b e n eed ed in the a t t r ibu te t ab le . In th e case abo ve , the d at a has too l arge o f a ran ge

for in teger ras te r fo rmat t o d isp lay th e dat a accurat ly and i s b es t su i t ed for f loat r as ter fo rmat .

Create S lope

Aspect and

curvatu res wi th

in terpo lat ion

f ro m BE poin ts a t

1M reso lu t ion

Eleva t ion fro m BE

poin ts a t 1 m reso lu t ion

Elev_l id_1 m

Output curvature r as t er f ro m

BE poin ts a t 1 m reso lu t ion

po in t Pc_ l id_1m

P rofcurvature1 fro m BE p oin t data

3D o f P rofcurva ture1 f ro m BE poin t d at a

Creat e S lope

Aspect and

curvatu res wi th

in terpo lat ion

f ro m Mul t ip le

re turn s dat a a t 1M

reso lu t ion

Eleva t ion fro m mul t ip le

re turn s dat a a t 1 m

reso lu t ion

Elev_l id mr_1 m

Output curvature r as t er f ro m

mul t ip l e r e turns d at a a t 1 m

reso lu t ion

Pc_ l idmr_1 m

P rofCurva ture1 f ro m mul t ip le r e turns

data

3D o fP rofCurvature1 f rom mul t ip le

re turn s dat a

Create S lope

Aspect and

curvatu res wi th

in terpo lat ion

f ro m BE poin ts a t

tension15 and

smooth in g 1 and

1M reso lu t ion

Eleva t ion fro m BE poin t s

wi th t ension = 15 and

smooth in g = 1 and r es=1 m

Elev_l id t15_1 m

Output curvature fro m BE

poin ts wi th t ens ion = 15 ,

smooth in g = 1 and r es=1 m

Pc_l id t15

Output tangential map from BE

poin ts wi th t ens ion = 15 and

smooth in g = 1 and r es=1 m

Tc_l id t15_1 m

P rofcurvature2 from BE po in ts

wi th t ension = 15 and

smooth in g = 1 and

res=1 m

3D o fP rofCu rvature2 f ro m BE poin t dat a

wi th t ension = 15 and smo oth ing = 1 and r es=1 m

Replace wi th the cor rect 3d map

Creat e S lope

Aspect and

curvatu res wi th

in terpo lat ion

f ro m Mul t ip le

re turn s dat a a t

tension15 and

smooth in g 1 and

1M reso lu t ion

Elev_l id mrt15_1 m

Pc_ l idmrt15_1 m

P rofCurva ture1 f ro m mul t ip le po in t dat a

3D o fP rofCu rvature2 f ro m mul t ip l e

po in t po in t data wi th t ension = 15

and smooth in g = 1 and res=1 m

Extracting landforms

at 9m and 45m

resloution

Featu res9c_1 m

Featu res9c_1 m wi th vecto r over l ay

Featu res45c_1 m

Featu res9c_1 m wi th vecto r over l ay

3D e l eva t ion wi th features 9c

3D e l eva t ion wi th features 45c

Raste r Time

Ser i es ana lysi s fo r

Nags Head b each

NH_2008_1 m

NH_9908_stddev

NH_9908_slope

NH_9908_ran ge

Nags head fro m

1999-2008 max

3D map

Or igina l Or tho_2001_t792_1m

data

Or igina l Or tho_2001_t792_1m d ata

With faci l i t y over l ay

Masked Or tho-2001_t792_1m

Univar o f e l eva t ion

Univar o f excavat ion

Apply Mask Excavat ion

Excavat ion o ver lay on or igina l o r tho map

Result s : Thi s p ro j ect h ad 6 majo r sec t ions:

1 ) Creat ion o f curva ture map sho win g con vex and con cave s lopes e f fect ing ero sio n .

2 ) Co mpar ing in teger and flo at r as ter fo rmat s . I have a lways under s tood the gu id el ine to use in teger fo rmat fo r

d iscret e da ta and flo at fo r cont inuous dat a and ho w the creat ion o f an a t t r ibu te tab le a l t ered th e or igina l d ata .

Th i s sect ion gave me th e o ppor tun i ty to d i r ect ly co mpare the two formats and see the s tep s add ed to the image

in the in t eger d at a .

3 ) Th e Slope in t erpo lat ion sect ion was s imi l ar to l a s t week in th at t ension and smooth ing mu st be consid ered to

accurate ly re f l ect the d ata .

4 ) Th e featu re sect ion was an oppor tun i ty so sho w ho w reso lu t ion fro m 9M to 45M wi l l d ras t ical l y a l t er resu l t s and

the ab i l i t y to use da ta may be d i r ect ly a f fect ed

5) Th e t ime ser i es sect ion o f th is a ss ign men t was a un iq ue oppor tun i ty to consid er the ch an ges in l andscap e over

t ime. I on ly wond er ho w usefu l i t cu rren t ly i s i f mo st locat ion s cur ren t ly don’ t have d igi t a l h i s to r i cal da ta .

6 ) Th e excavat ion sect ion was an oppor tun i ty to use masks to se l ect an area and d ete rmine vo lu me to b e r emoved

al lo win g fo r p roper p lanning o f t ru cks and equip men t to excavate .

Discussion and Conclusions: Each sect ion h ad oppor tun i t ie s to ad ju st var i ab l es and al te r r esu l t s to l ea rn new methods

to analys is d at a and vary o u tpu t to re fl ect th e desi r ed ou tco me.