Topography
Surface: Select the surface the calculation will be based: Existing Surface or Proposed Surface
Calculation Grid: The cell spacing of the grid that the drainage analysis is calculated on. 10m or 30ft is a typical useful value.
Furrows or Beds
Furrow or Beds Restrict Water Flow Direction: If furrows or beds exist tick this ON.
Furrow/Beds Height (m): The height of the intended furrows in the field. The water will build up any depressions and then spill across the furrow. The Ponding Depth Map shows water depths in the furrows, not on the beds.
Furrow/Beds Bearing (deg): The direction of the furrows relative to North. Use the ‘Pick’ button to click two points to define the direction or type a number in. Currently, only straight furrows/beds are handled.
Cost Analysis
Typical Gross Income ($/ha/yr or $/ac/yr): Insert the gross income per hectare (or per acre) per year.
Loss in Ponded Areas (%): The loss of crop yield in the areas that pond water in an average year from water logging, weeds and disease.
Loss in Non-Ponded Areas (%): This is to account the losses in timeliness of operations; i.e. planting, spraying and harversting can be delayed waiting for ponded areas to dry out. That waiting reduced the yield for the rest of the field. This loss in production is often overlooked but it can be quite significant.
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