Investigating blue clay slopes : a study of gully frosion and slope system at Għajn Tuffieħa

Abstract

Mass movement shapes the land to form geomorphological features such as gullies and slopes. The main focus of this study was a thorough investigation of the gully erosion and the slope systems at Għajn Tuffieħa. The Blue Clay slope formations, inland from the beach, and its features were studied. This research focuses on the erosion occurring on a gully which was formed on the Blue Clay slope. This was done by producing a cross-sectional graph of each sampling point. Additionally photographic evidence of each transect were taken at two periods of time, at the beginning and end of winter. Another research method, using movement rods and a GPS, was utilised to calculate any mass movement on the clay slope. Readings showing the change in movement of the slope were collected in October and March. These research methods generated metamorphic data which was then analysed in detail. This metamorphic data was used to calculate the rate of erosion and a pattern was observed. The latter was generated due to a meander in the gully which adversely affected the end results. The erosion was much more severe on the right hand side of the gully walls. Statistical tests were also used to test if there was a relationship between certain variables, such as gully width, downhill slope distance and the average depth of the gully. This test showed that the width and depth increased at the end of the gully. The spearman rank coefficient and the chi-squared tests were used to provide statistical data. This research will contain information which will help others who are studying the soft slopes of the Maltese Islands or dealing with issues about these Blue Clay slopes. Gully erosion, which is analysed in detail, is also another factor which is really damaging and eroding the Blue Clay lay