GEOG 5060 GIS Environment Lecture 7 Terrain analysis

GEOG 5060 GIS & Environment Lecture 7. Terrain analysis 3: geomatics; geomorphometrics Andy Turner Lecture 7 GEOG 5060 - GIS and Environment 1

Course component • • • GEOG 5060 GIS & Environment Lecture 7 Lecture Workshop Practical Assignment Assessment Lecture 7 GEOG 5060 - GIS and Environment 2

Outline • • • GEOG 5060 GIS & Environment Lecture 7 Introduction Basic metrics Equidistant orthogonal comparisons Other geomorphometrics State of play Lecture 7 GEOG 5060 - GIS and Environment 3

Assignment GEOG 5060 GIS & Environment Lecture 7 • This part of the course is about working together to improve our teaching and research on geomorphometrics • During the lecture consider areas in which you could adress some of the gaps I will mention – it really could be anything! Lecture 7 GEOG 5060 - GIS and Environment 4

Definitions GEOG 5060 GIS & Environment Lecture 7 • Geomatics – Geomatics is a modern discipline, which integrates acquisition, modelling, analysis, and management of spatially referenced data, i. e. data identified according to their locations http: //en. wikipedia. org/wiki/Geomatics • Geomorphometrics – Geomorphometrics are measures of the state and change in surface geometry of the Earth's physical horizons. They are topographic measures that can be used in terrain analysis and geographical modelling. http: //www. geog. leeds. ac. uk/people/a. turner/research/interests/ geomorphometrics/ Lecture 7 GEOG 5060 - GIS and Environment 5

Idea for assignment GEOG 5060 GIS & Environment Lecture 7 • Develop wikipedia pages on geomorphometrics and link it to the geomatics wikipedia page – What other things are related? • Hydrology – Hydroinformatics – Surface water hydrology • • Landform identification Geomorphology - What combination of metrics can be used to identify different landforms? – What other than the standard offering would be useful? – You can even base your project on previous years work – ask me Lecture 7 GEOG 5060 - GIS and Environment 6

Last 2 Lectures height aspect hillshading plan curvature GEOG 5060 GIS & Environment Lecture 7 slope • Terrain analysis 1 – DEMs and DTMs – derived variables – example applications Feature extraction • Terrain analysis 2 – access modelling – landscape evaluation – hazard mapping Lecture 7 GEOG 5060 - GIS and Environment 7

Origins GEOG 5060 GIS & Environment Lecture 7 • Peter Fisher – Peakiness • Development of a grids package – The SPIN!-project – Med. Action, Desert. Links and temp. Qsim • Desire for greater flexibility, capability and freedom than that offered by commercial proprietary GIS Lecture 7 GEOG 5060 - GIS and Environment 8

Overview GEOG 5060 GIS & Environment Lecture 7 • So what are geomorphometrics? – Measures of the relative heights of the land of the earth’s surface to allow comparison of: – Topography – Terrain analysis e. g. how peaky is an area? – Surface geometry of the earth. Lecture 7 GEOG 5060 - GIS and Environment 9

Raster Elevation Data based GEOG 5060 GIS & Environment Lecture 7 • Raster Elevation Data – DEM data interpolated from vector data – Widely available – SRTM 3 arc secs • Publicly available – OS 10 metre • Available via chest – LIDAR 2 meter • Available but unlicensed • Getting better all the time • Uncertainties abound Lecture 7 GEOG 5060 - GIS and Environment 10

Example DEM GEOG 5060 GIS & Environment Lecture 7 Red areas indicate high altitude, green low altitude Lecture 7 GEOG 5060 - GIS and Environment 11

Future DEMs GEOG 5060 GIS & Environment Lecture 7 • SRTM DEM data is being produced at a 1 arc second resolution – America is available • Soon after we will have higher resolution… • We have 10 meter resolution DEM for the UK… – Again hundreds of thousands of rows and columns – How was it produced? – Is it any good? • Soon we will have more higher spatial resolution Lecture 7 GEOG 5060 - GIS and Environment 12

Data pre-processing GEOG 5060 GIS & Environment Lecture 7 • One of the first things to do is to be able to process all this data – Grids 1. 0 beta • Clean the data – Mask – Are there any holes? • Lecture 7 How can we cope best with these GEOG 5060 - GIS and Environment 13

Data pre-processing contd. GEOG 5060 GIS & Environment Lecture 7 • Define the river basins, catchments and HRUs for the DEM • Develop land degradation risk indicators – Erosion – Salinity • Develop a fully distributed hydrological model Lecture 7 GEOG 5060 - GIS and Environment 14

Recap GEOG 5060 GIS & Environment Lecture 7 • Geomorphometrics compare relative heights of cells • Allowing comparison of terrain, topology • Uncertainty is always present Lecture 7 GEOG 5060 - GIS and Environment 15

Basic metrics GEOG 5060 GIS & Environment Lecture 7 Slopyness and Levelness calculated for the 2 cell neighborhood Lecture 7 GEOG 5060 - GIS and Environment 16

Question GEOG 5060 GIS & Environment Lecture 7 • Can any one suggest the name of a basic geomorphometric? Lecture 7 GEOG 5060 - GIS and Environment 17

Slope and Aspect GEOG 5060 GIS & Environment Lecture 7 • Slope is the gradient of an area http: //en. wikipedia. org/wiki/Slope • and aspect is the angle to a particular orientation over a given region http: //en. wikipedia. org/wiki/Aspect_%28 ge ography%29 Lecture 7 GEOG 5060 - GIS and Environment 18

Other metrics • • • GEOG 5060 GIS & Environment Lecture 7 Slopyness Upness Downess Flatness Roughness Flatness calculated for the 2 cell neighbourhood Lecture 7 GEOG 5060 - GIS and Environment 19

What region? How to calculate it? GEOG 5060 GIS & Environment Lecture 7 • Circular region using equidistant orthoganal comparisons • Vector addition • Distance weighting • Scale NB From the model output white regions indicate areas of high values for that metric Lecture 7 GEOG 5060 - GIS and Environment 20

Slope – 13 cell neighbourhood Lecture 7 GEOG 5060 - GIS and Environment GEOG 5060 GIS & Environment Lecture 7 21

Slope – 49 cell neighbourhood Lecture 7 GEOG 5060 - GIS and Environment GEOG 5060 GIS & Environment Lecture 7 22

Slope 8 Lecture 7 GEOG 5060 - GIS and Environment GEOG 5060 GIS & Environment Lecture 7 23

Aspect 2 Lecture 7 GEOG 5060 - GIS and Environment GEOG 5060 GIS & Environment Lecture 7 24

Aspect 4 Lecture 7 GEOG 5060 - GIS and Environment GEOG 5060 GIS & Environment Lecture 7 25

Aspect 8 Lecture 7 GEOG 5060 - GIS and Environment GEOG 5060 GIS & Environment Lecture 7 26

Scale and distance weighting GEOG 5060 GIS & Environment Lecture 7 • Distance weighting • Differencing to focus on nid-scales can be done directly by applying a more complex spatial weighting scheme • Only relevant for some measures – Not aspect – What about upness and downness? Lecture 7 GEOG 5060 - GIS and Environment 27

Equidistant orthogonal comparisons GEOG 5060 GIS & Environment Lecture 7 • Rotation invariant metrics E 4 A 1 B 4 D 4 C 1 D 1 E 1 A 4 C 4 * C 2 A 2 E 3 D 3 C 3 D 2 B 3 A 3 E 2 Lecture 7 • For each metric, compare each orthoganal set within a region. A . . B C B . A C X C A . B C B . . A . • What is observed? • hhhh, hhhl, hhll, llhl hlll, llll GEOG 5060 - GIS and Environment 28

GEOG 5060 GIS & Environment Lecture 7 • Axis based metrics Lecture 7 E 4 A 1 B 4 D 4 C 1 D 1 E 1 A 4 C 4 * C 2 A 2 E 3 D 3 C 3 D 2 B 3 A 3 E 2 GEOG 5060 - GIS and Environment 29

GEOG 5060 GIS & Environment Lecture 7 HHLL / LHHL / HLLH HLHL / LHLH H H L r H L Lecture 7 r GEOG 5060 - GIS and Environment 30

HHHL - saddle Lecture 7 GEOG 5060 - GIS and Environment GEOG 5060 GIS & Environment Lecture 7 31

HHHH - crater Lecture 7 GEOG 5060 - GIS and Environment GEOG 5060 GIS & Environment Lecture 7 32

HHLL - slope Lecture 7 GEOG 5060 - GIS and Environment Geog 5060 GEOG 5060 GISGIS & & Environment Lecture 7 7 33

LLLL - peak Lecture 7 GEOG 5060 - GIS and Environment GEOG 5060 GIS & Environment Lecture 7 34

Considerations • • GEOG 5060 GIS & Environment Lecture 7 How to treat cells with the same height? How to treat cells with no data value? What conditioners are appropriate? Two types of weight – Distance weighting – Difference in elevation weighting • What is best? Lecture 7 GEOG 5060 - GIS and Environment 35

Example 1: w_hhll Lecture 7 GEOG 5060 - GIS and Environment GEOG 5060 GIS & Environment Lecture 7 36

Example 4: sumd_abs_xlxh_ai_lllh Lecture 7 GEOG 5060 - GIS and Environment GEOG 5060 GIS & Environment Lecture 7 37

Axis based metrics GEOG 5060 GIS & Environment Lecture 7 • Profile or Contour • Concavity or Convexity • Convergence or Divergence Lecture 7 E 4 A 1 B 4 D 4 C 1 D 1 E 1 A 4 C 4 * C 2 A 2 E 3 D 3 C 3 D 2 B 3 A 3 E 2 GEOG 5060 - GIS and Environment 38

Considerations GEOG 5060 GIS & Environment Lecture 7 • What other interesting metrics? – minimum type profile concavity – maximum type profile convexity • Better for identifying features? – Probably best in combination with the other metrics • Sorry, no examples! Lecture 7 GEOG 5060 - GIS and Environment 39

Other geomorphometrics GEOG 5060 GIS & Environment Lecture 7 • Up and down slope type geomorphometrics – Upslope area • Complex distance weighting – More hydrological type metrics • Flow accumulation • Visibility based metrics • Monte Carlo type uncertainty of all Lecture 7 GEOG 5060 - GIS and Environment 40

Software used GEOG 5060 GIS & Environment Lecture 7 • Proprietary or closed source – Commercial – Research Land. Serf • Tau. DEM • • Open source – GMT – Grids Lecture 7 GEOG 5060 - GIS and Environment 41

Considerations • • GEOG 5060 GIS & Environment Lecture 7 How to treat cells with the same height? How to treat cells with no data value? What conditioners are appropriate? Two types of weight – Distance weighting – Difference in elevation weighting • What is best? Lecture 7 GEOG 5060 - GIS and Environment 42

Other geomorphometrics GEOG 5060 GIS & Environment Lecture 7 • Up & down slope type geomorphometrics – Upslope area • Complex distance weighting – More hydrological type metrics • Flow accumulation • Visibility based metrics • Time and dynamics • Sensitivity & Monte Carlo type uncertainty of all Lecture 7 GEOG 5060 - GIS and Environment 43

Summary • • • GEOG 5060 GIS & Environment Lecture 7 Basic metrics Equidistant orthogonal comparisons Scale and distance weighting Rotation invariant metrics Scale and distance weighting - uncertainty Lecture 7 GEOG 5060 - GIS and Environment 44

Assignment GEOG 5060 GIS & Environment Lecture 7 • Show understanding of geomorphometrics • Experiment with the program in teams. Friday 2 -4. • Develop an output of some sort and explain the processes you went through to produce it. Lecture 7 GEOG 5060 - GIS and Environment 45

Next week… GEOG 5060 GIS & Environment Lecture 7 • Hydrological Modelling 1: – Catchment Models – With Katherine Arrell Lecture 7 GEOG 5060 - GIS and Environment 46