| dc.description.abstract | In the foredunes at Zuid-Kennemerland national park, The Netherlands, five trenches were made to promote sediment transport from the beach to the dune valleys behind the foredune ridge. The man-made trenches bear a close resemblance to trough blowouts, a naturally-occuring aeolian feature common in coastal dune areas. In this study, I compared the trenches of Zuid-Kennemerland to natural trough blowouts in terms of morphology, evolution, flow dynamics and erosional/depositional patterns. A total of four digital elevation models, made between April 2014 and April 2015, were analyzed for this study. Both visual interpretations and quantitative data retrieved from the DEMs were combined with current knowledge of natural trough blowouts and up-to-date meteorological data. It appears that the man-made trenches are important pathways of sediment transport. Erosion is dominant within the deflation basin and especially on the sidewalls, whereas sediment is deposited closely behind the deflation basin area. Erosional and depositional patterns show a good correlation with dominant wind direction and speed. The morphology and evolution of the trenches are, however, different from natural trough blowouts. The trenches are relatively wide compared to their natural counterparts. In addition, the trenches do not have a clear transportational ramp, which means that the depositional lobe often lies downhill from the deflation basin. Hence, it is difficult to make an accurate model of flow dynamics within and around the trenches without conducting a field study. | |
