The microtopography of the Cape Sable seaside sparrow habitat is extremely important for determining whether or not a breeding season will be successful. Water flows from the main Shark River Slough drainage through the East Slough which is located in the center the Western sub-population's habitat. The direction of flow is indicated by the blue arrow in the figure at left. In extremely wet years, the flow of water instead of following the microtopography of the area becomes a sheet flow across most of the habitat. The flow of this water degrades the breeding sites that occurs at lower elevations. Thus, the only breeding habitat available is located in high elevation refugia. In dry years, all habitat becomes available for breeding.
The topographic layer for SIMSPAR was generated from a series of 284 sites surveyed on 1 km grid during a extremely wet year when the entire site was flooded. The water level at each site was measured to the nearest centimeter at six randomly chosen points. To increase the resolution of the layer to 500m, the intervening areas between survey sites were interpolated by taking the average height of the nearest survey sites.
The daily water height for each cell was calculated as a function of water level measured at gauging station NP205. A more detailed explanation of the hydrological portion of the model can be found in the modelling water flow and hydrology section of the website.