Abstract
In this paper, the authors describe the realization and testing of a Wireless Sensor Network (WSN) framework aiming at measuring, remotely and in real time, the level variations of the sand layer of sandy beaches or dunes. The proposed framework is based on an innovative low cost sensing structure, able to measure the level variations with a 5-cm degree of precision and to locally transfer the acquired data through the ZigBee protocol. The described sensor is integrated in a wider ZigBee wireless sensor network architecture composed of an array of sensors that, arranged according to a grid layout, can acquire the same data at different points, allowing the definition of a dynamic map of the area under study. The WSN is connected to a local Global System for Mobile Communications (GSM) gateway that is in charge of data processing and transmission to a cloud infrastructure through a General Packet Radio Service (GPRS) connection. Data are then stored in a MySQL database and made available any time and anywhere through the Internet. The proposed architecture has been tested in a laboratory, to analyze data acquisition, processing timing and power consumption and then in situ to prove the effectiveness of the system. The described infrastructure is expected to be integrated in a wider IoT architecture including different typologies of sensors, in order to create a multi-purpose tool for the study of coastal erosive processes.
Highlights
Coastal erosion has been a worldwide issue since the early 1900s, and the risks and hazards related to its processes are increasing as the number of people living in coastal areas is impressive: about 86 million within 10 km from the coastline in Europe alone in accordance with the reports of European Topic Centre on Climate Change Adaptation (ETC-CCA) [1]
The idea at the base of the proposed monitoring architecture comes from the need for a tool capable of measuring the temporal variations of sandy beach and dune height variations at different points, in order to assess their progressive morphological modifications, possibly evaluating the sand volume variations
A simple sensor, opportunely installed, allows one to measure the height variation of a single dune in an easy way: presuming that the pole is inserted in the sand for half of its height and the other half is emerging from the sand, the 12 Light-Dependent Resistors (LDRs) resistors outside the dunes, being struck by the light, would provide a high output value, while the remaining 12 photo-resistors, covered by the sand, would provide a low value
Summary
Coastal erosion has been a worldwide issue since the early 1900s, and the risks and hazards related to its processes are increasing as the number of people living in coastal areas is impressive: about 86 million within 10 km from the coastline in Europe alone in accordance with the reports of European Topic Centre on Climate Change Adaptation (ETC-CCA) [1]. The downside of beach fills is the frequent (seasonal to annual) need to integrate the replenishment as waves and currents keep on moving and redistributing the sand, because they do not act to solve the main problem, which is river sediment load diminution. For all these reasons, increasing the knowledge about sediment transport is crucial to gain more information about particle redistribution along and across the beach. As a matter of fact, lately, dune restoration has been often utilized as an additional soft approach along with replenishment and sand redistribution [14,15]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
