GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment1 Lecture 7. Terrain analysis 3: geomatics; geomorphometrics Andy Turner

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment2 Course component Lecture Workshop Practical Assignment Assessment

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment3 Outline Introduction Basic metrics Equidistant orthogonal comparisons Other geomorphometrics State of play

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment4 Assignment 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!

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment5 Definitions 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 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. geomorphometrics/

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment6 Idea for assignment 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

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment7 Last 2 Lectures Terrain analysis 1 –DEMs and DTMs –derived variables –example applications Terrain analysis 2 –access modelling –landscape evaluation –hazard mapping heightslopeaspect hillshading plan curvature Feature extraction

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment8 Origins Peter Fisher –Peakiness Development of a grids package –The SPIN!-project –MedAction, DesertLinks and tempQsim Desire for greater flexibility, capability and freedom than that offered by commercial proprietary GIS

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment9 Overview 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.

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment10 Raster Elevation Data based 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

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment11 Example DEM Red areas indicate high altitude, green low altitude

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment12 Future DEMs 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

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment13 Data pre-processing 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? How can we cope best with these

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment14 Data pre-processing contd. Define the river basins, catchments and HRUs for the DEM Develop land degradation risk indicators –Erosion –Salinity Develop a fully distributed hydrological model

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment15 Recap Geomorphometrics compare relative heights of cells Allowing comparison of terrain, topology Uncertainty is always present

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment16 Basic metrics Slopyness and Levelness calculated for the 2 cell neighborhood

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment17 Question Can any one suggest the name of a basic geomorphometric?

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment18 Slope and Aspect Slope is the gradient of an area and aspect is the angle to a particular orientation over a given region ography%29

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment19 Other metrics Slopyness Upness Downess Flatness Roughness Flatness calculated for the 2 cell neighbourhood

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment20 What region? How to calculate it? 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

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment21 Slope – 13 cell neighbourhood

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment22 Slope – 49 cell neighbourhood

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment23 Slope 8

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment24 Aspect 2

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment25 Aspect 4

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment26 Aspect 8

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment27 Scale and distance weighting 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?

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment28 Equidistant orthogonal comparisons Rotation invariant metrics B4 A4 E3 D4 C4 D3 B3 E4 A3E2 C3 * C1 A1B1 D1 C2 D2 E1 A2 B2.A.. BCB. AC X CA. BCB..A. For each metric, compare each orthoganal set within a region What is observed? hhhh, hhhl, hhll, llhl hlll, llll

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment29 Axis based metrics B4 A4 E3 D4 C4 D3 B3 E4 A3E2 C3 * C1 A1B1 D1 C2 D2 E1 A2 B2

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment30 H L r H L H L r L H HHLL / LHHL / HLLH HLHL / LHLH

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment31 HHHL - saddle

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment32 HHHH - crater

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment33 Geog 5060 GIS & Environment Lecture 7 HHLL - slope

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment34 LLLL - peak

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment35 Considerations 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?

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment36 Example 1: w_hhll

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment37 Example 4: sumd_abs_xlxh_ai_lllh

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment38 Axis based metrics Profile or Contour Concavity or Convexity Convergence or Divergence B4 A4 E3 D4 C4 D3 B3 E4 A3E2 C3 * C1 A1B1 D1 C2 D2 E1 A2 B2

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment39 Considerations 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!

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment40 Other geomorphometrics 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

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment41 Software used Proprietary or closed source –Commercial –Research LandSerf TauDEM Open source –GMT –Grids

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment42 Considerations 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?

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment43 Other geomorphometrics 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

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment44 Summary Basic metrics Equidistant orthogonal comparisons Scale and distance weighting Rotation invariant metrics Scale and distance weighting - uncertainty

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment45 Assignment 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.

GEOG5060 GIS & Environment Lecture 7 GEOG GIS and Environment46 Next week… Hydrological Modelling 1: –Catchment Models –With Katherine Arrell