(dynamic) polygons (dynamic) polygons The geographical datum for the location data. Presently only WGS-1984, OS 1936 and LOCAL are recognised. LOCAL indicates a local grid. date/time of the first event date/time of the last event optional descriptive name ID of the upstream polygon. If no id is given, this catchment is either on its own or the topmost catchment in a series. ID of the downstream polygon. If no id is given, this polygon is either on its own or the last catchment in a series. use this field as a notebook to add comments, suggestions description of data entered etc. Optional mark identifying special points(i.e.): 1 = catchment outlet 2 = saddle 3 = high-point Areal weighted polygon centroid X coordinate of the point (Easting) Y coordinate of the point (Northing) Z coordinate of the point (altitude) Areal weighted polygon centroid Optional uniform value for the area covered by this polygon for this event optional polygon area