Topography

Topography is one of the major factors affecting yield and nutrition content in the soil. Thus slope can be a major yield-limiting factor, especially for undrained spots or eroded elevated spots; flow accumulation can impact yield significantly depending on dry or wet years. In some regions, topographical land features can explain even a mid-double-digit percentage of yield variability.

GeoPard solution has a built-in advanced topography analysis, so it automatically creates a Digital Elevation Model (DEM) for your field after you created (imported) a field boundary. Then it automatically creates Digital Elevation Model (DEM) for your field, and calculates the following topographic models and combined maps:

• Elevation – absolute numbers

• Slope – the measure of steepness or the degree of inclination of a feature relative to the horizontal plane

• Aspect – the compass direction that a slope faces

• Hillshade – a shaded relief effect for terrain visualization

• Elevation and hillshades

• Slope and Aspect

• Relief Position – defined as the difference between a central pixel and the mean of its surrounding cells.

• Ruggedness – defined as the mean difference between a central pixel and its surrounding cells.

• Roughness – the degree of irregularity of the surface. It’s calculated by the largest inter-cell difference between a central pixel and its surrounding cell.

See Chapter Zones Maps to find more details on how to create a zone map using topography.

GeoPard calculates these models since only DEM is not enough to accurately determine the field topography, for example, there may be a hilltop in the lowland that will differ in soil characteristics and productivity from other parts of the field with the same height in absolute values – e.g. slopy area, depression.

Using Compare Layers feature you can visually compare topography maps and how they correlate with other field maps such as multi-year crop development as shown in the screenshots below.

GeoPard incorporated various digital elevation datasets globally, from LIDAR with 2m spatial resolution in the UK to 30m SRTM, to provide the best possible topography analytics.