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De Lima J.L.M.P.,Institute of Marine Research IMAR | De Lima J.L.M.P.,University of Coimbra | Silva V.P.,Federal University of Pernambuco | Abrantes J.R.C.B.,Institute of Marine Research IMAR | And 4 more authors.
Bodenkultur | Year: 2014

Soil macropores characterization improves the understanding of hydraulic behaviour and soil hydrological processes. This study presents an exploratory in situ assessment of soil surface macropores using an infrared thermography technique based on temperature gradients originating from soil surface heating with hot air. Although the presence of seeds, pebbles, stones and vegetation may create difficulty in the application of the technique, in particular because they might mask the presence of the macropores, the technique was successful in identifying surface macropores, providing a low cost and fast methodology to assess mapping soil surface macropores.


De Lima J.L.M.P.,University of Coimbra | De Lima J.L.M.P.,Institute of Marine Research IMAR | Dinis P.A.,University of Coimbra | Dinis P.A.,Institute of Marine Research IMAR | And 9 more authors.
Natural Hazards and Earth System Science | Year: 2011

This study describes and interprets the evolution of grain-size distribution of sediment yields generated in an experimental soil flume subjected to downstream and upstream moving rain storms. Results of laboratory experiments show that downstream moving storms cause more soil loss than do upstream moving storms. The pattern of sediment grain-size evolution in time during a runoff event exhibits a clear dependence on the direction of storm movement. A strong relationship between overland flow discharge and mean sediment size is found. Nevertheless, the mean grain-size of sediments transported during the rising limb of the hydrograph is coarser than during the recession limb of the hydrograph. This is more marked for downstream moving storms. © Author(s) 2011.


De Lima R.P.,Deltasync | De Lima R.P.,Institute of Marine Research IMAR | Cleveland T.G.,Texas Tech University | De Carvalho R.R.,University of Coimbra
Bodenkultur | Year: 2014

This work presents a technique that uses infrared thermography to estimate mean flow velocity, based on the time of travel of a heat tracer (hot water). A thermographic camera, installed above a flume, allows the visualization of the water surface temperature. When hot water is added to the flow, it appears in the footage as a bright mass moving downstream. This allows the quantification of its surface velocity, which corresponds to flow velocity (shallow flows). As a control, results were compared with the measurements obtained by an Acoustic Doppler Velocimeter. This technique is particularly suitable for measurements in shallow flows, where most common flow velocity equipment reveal some limitations due to incompatibilities with low water depths.

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