Camacho inlet southern Brazil – Instability causes and user conflicts
Abstract Inlet stabilization is a common practice in Brazil, as it is worldwide. In this paper we present results of the analysis of the stabilization practices of the Camacho Inlet, located in Santa Catarina State, southern Brazil. This inlet is maintained intermittently, in accordance with a regime designed to benefit both local fishermen and rice farmers. Fishermen require this inlet to be open as a navigation channel during the fishing season; rice farmers needs it closed during the irrigation period to allow the pumping of fresh water from the Congonhas River which drains into the Camacho’s backbarrier lagoon. An additional complication arises from the tendency of this inlet to close naturally due to infilling by dune migration. Aerial images spanning a 65 year time period (1938–2003) were analyzed, demonstrating the variability in the inlet’s width between 0 (closed) and 360 m. The analysis of inlet stability and user needs indicate that an appropriate solution is the implementation of an annual inlet dredging program in the austral autumn. This would allow for the inlet to remain open from May to September and then close naturally for the rest of the year, providing for a backbarrier fresh water reservoir during the irrigation period.
Observations on the Stability St. Andrew Bay Inlets in Florida
Abstract The need for a cautious interpretation of results from an analytic method for an analysis of the stability of tidal inlets is illustrated by comparing theory with data from St. Andrew Bay in Florida's panhandle. Historically this bay was connected to the Gulf of Mexico by East Pass at the eastern end of the bay. However, following the opening of St. Andrew Bay Entrance in 1934 at the western end to serve Panama City, the flow cross-section of this channel increased while East Pass contracted gradually and eventually closed in 1998. In December 2001 East Pass was reopened by dredging a small flow-relief channel. These events provided the opportunity to apply the stability analysis to the newly-formed two-inlet one-bay system. Interpretation of the results in terms of observed inlet stability versus prediction is shown to be contingent upon knowledge of the history of channel maintenance and the morphodynamics of the bay. The illustration underscores the need to apply the method in pre-project engineering investigations of the long-term impact of opening a second inlet in a bay.
APPLICATION OF SATELLITE PHOTOGRAPHS IN A MORPHOTECTONIC STUDY OF THE CENTRAL ALBORZ, IRAN
This paper introduces a study of morphotectoni c structure in the Central Alborz Basin, Mazandaran province of Iran (about 1200 square kilometer), using Russian KFA-1000 satellite photography and sequential air photographs. The KFA-1000 metric camera has better ground resolution than SPOT and LANDSAT for the whole of the study area. Results are provided from one pair of 30×30 cm. photos, which provided easy interpretation and better results than other data. Areas identified from these images as being of significance were examined in greater detail through the use of aerial photographs (at scales of 1:5000, 1:10000 and 1:60000 were available).