Abstract
The construction of terraces, in the Douro Region, with earthen embankments rises aset of problems related to the hydrological processes. The main objective of this study is the evaluation of the electrical resistivity spatial variation in agriculture terraces atDouro valley (Portugal).To achieve this objective two variables are analysed, the soil electrical resistivity andthe flow direction algorithms. In field survey, 13 electrical resistivity profiles wererecorded. The contributing area calculated with the algorithms D (DeterminiscInfinity Flow) and MFD (Multiple Flow Direction), are the base of the internal runoffmodelling, both supported by the digital elevation model with a special resolution of1m2.Was stablished a correlation between the spatial variation of the soil electrical resistivityrepresented by standard deviation electrical resistivity of each profile and the averagevalue of contributing area coincident with each profile.The electrical resistivity standard deviation seems to be moderately good correlated forthe D algorithm at about 1m of depth and has a good correlaon at 1,5m to 2m ofdepth with the MFD algorithm. The results analysis shows a significant positivestatistical correlation between electrical resistivity standard deviation and thecontributing areas (MFD and D) depending on the soil depths.

Abstract
device to increase energy autonomy of moored oceanographic monitoring stations. Oscillations and currents through the sea or river are used to produce energy when the whole system is submerged to a depth between 3 to 10 meters. In order to have an inexpensive system, a buoy containing a Linear Electromagnetic Generator (LEG), is fabricated in a 3D printer, using PLA (polylactic acid) filament. Inside of the buoy, one cylinder shaped LEG (98mm length and 25mm of diameter) produces a maximum output power of 20 mW with a 4 Hz movement. To increase power output in larger systems, more LEGs can be added.

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This paper describes the PISCES system, an integrated approach for fully autonomous mapping of large areas of the ocean in deep waters. A deep water AUV will use an acoustic navigation system to compute is position with bounded error. The range limitation will be overcome by a moving baseline scheme, with the acoustic sources installed in robotic surface vessels with previously combined trajectories. In order to save power, all systems will have synchronized clocks and implement the One Way Travel Time scheme. The mapping system will be a combination of an off-the-shelf MBES with a new long range bathymetry system, with a source on a moving surface vessel and the receivers on board the AUV. The system is being prepared to participate in round one of the XPRIZE challenge.