Search results for "WATER"
showing 10 items of 9348 documents
Improvement of lateral connectivity in a sector of River Hârtibaciu (Olt/Danube Basin)
2017
Abstract The Hârtibaciu River in the Alţâna area has a disturbed lateral connectivity owing to its lateral embankments, as a result of which fish communities in this river sector are negatively influenced. The method of obtaining the water supply for a new proposed wetland is by gravitation, and any excessive water supply to the wetland will be controled and directed to the Hârtibaciu River in a natural manner. A state-of-the-art man-made wetland should increase the quality of the habitat for local fish communities, especially for the Rhodeus sericeus population, which is a species of conservation interest.
The role of urban growth, climate change, and their interplay in altering runoff extremes
2018
Changes in climate and urban growth are the most influential factors affecting hydrological characteristics in urban and extra-urban contexts. The assessment of the impacts of these changes on the extreme rainfall–runoff events may have important implications on urban and extra-urban management policies against severe events, such as floods, and on the design of hydraulic infrastructures. Understanding the effects of the interaction between climate change and urban growth on the generation of runoff extremes is the main aim of this paper. We carried out a synthetic experiment on a river catchment of 64 km2to generate hourly runoff time series under different hypothetical scenarios. We impos…
Analytical approach extending the Granier method to radial sap flow patterns
2020
Abstract The Granier thermal dissipation (TD) method is probably the most applied method to compute the transpiration flux of trees, due to its simplicity and effective compromise between theory and data availability. Starting from the heat transfer equations at the basis of Granier’s method, the objective of this paper is to derive an analytical solution for the transpiration flux to extend the sap flow equations to the radial domain. We adopted a flexible approach to cope with the differences in radial sapflow density (SFD) profile shapes that are known to occur in relation to wood anatomy (diffuse porous vs. ring- or non-porous xylem). With this purpose, we investigated the robustness of…
Soil conservation and sustainable development goals(SDGs) achievement in Europe and central Asia: Which role for the European soil partnership?
2021
Abstract Voluntary soil protection measures are not sufficient to achieve sustainable soil management at a global scale. Additionally, binding soil protection legislation at national and international levels has also proved to be insufficient for the effective protection of this non-renewable natural resource. In 2012, the FAO Members established the Global Soil Partnership (GSP) with the mission to facilitate and contribute exchange of knowledge and technologies related to soils, and develop dialogue and raise awareness for the need to establish a binding global agreement for sustainable soil management. Moreover, region-specific aspects of implementation are considered and strengthened th…
Determining hydraulic properties of a loam soil by alternative infiltrometer techniques
2015
Testing infiltrometer techniques to determine soil hydraulic properties is necessary for specific soils. For a loam soil, the water retention and hydraulic conductivity predicted by the BEST (Beerkan Estimation of Soil Transfer parameters) procedure of soil hydraulic characterization was compared with data collected by more standard laboratory and field techniques. Six infiltrometer techniques were also compared in terms of saturated soil hydraulic conductivity, Ks. BEST yielded water retention values statistically similar to those obtained in the laboratory and Ks values practically coinciding with those determined in the field with the pressure infiltrometer (PI). The unsaturated soil hyd…
Analysis of uncontrolled phosphorus precipitation in anaerobic digesters under thermophilic and mesophilic conditions.
2019
This study compares the operation of mesophilic and thermophilic anaerobic digestion of sewage sludge and their effects in uncontrolled phosphorus precipitation. The research has been carried out using a pilot plant consisting of two digesters of 1.6 m3 working volume, treating the mixed sludge of Alzira WWTP (Valencia, Spain). The digesters were operated in parallel, at different conditions: mesophilic (38 ± 2.0°C) and thermophilic (55 ± 2.5°C) temperatures and organic loading rates (OLR) ranging from 1.1 to 1.7 kg volatile solids (VS) m−3 d−1 and different hydraulic retention times (HRT) 20, 15 and 12 days. Uncontrolled precipitation was evaluated through P, Mg and Ca mass balances in bot…
Occurrence of antibiotics and antiretroviral drugs in source-separated urine, groundwater, surface water and wastewater in the peri-urban area of Chu…
2020
Recently, there has been an increased interest in bridging the knowledge gap in the occurrence and fate of pharmaceuticals in African urban water cycles. In this study, the occurrence of 7 antibiotics and 3 antiretrovirals in source-separated urine, groundwater, wastewater and surface water of the peri-urban area of Chunga in Lusaka, Zambia, was studied. In groundwater, the pharmaceuticals were only sporadically present with 4 antibiotics and 1 antiretroviral detected. The concentration of the antibiotics ranged from below limit of quantification (<LOQ) to 880 ng/L, with sulfamethoxazole having the highest detection frequency of 42.3%. In the surface water, a comparatively high concentrati…
Consistent Clustering of Elements in Large Pairwise Comparison Matrices
2018
[EN] In multi-attribute decision making the number of decision elements under consideration may be huge, especially for complex, real-world problems. Typically these elements are clustered and then the clusters organized hierarchically to reduce the number of elements to be simultaneously handled. These decomposition methodologies are intended to bring the problem within the cognitive ability of decision makers. However, such methodologies have disadvantages, and it may happen that such a priori clustering is not clear, and/or the problem has previously been addressed without any grouping action. This is the situation for the case study we address, in which a panel of experts gives opinions…
Underwater Wireless Communications for Cooperative Robotics with UWSim-NET
2019
The increasing number of autonomous underwater vehicles (AUVs) cooperating in underwater operations has motivated the use of wireless communications. Their modeling can minimize the impact of their limited performance in real-time robotic interventions. However, robotic frameworks hardly ever consider the communications, and network simulators are not suitable for HIL experiments. In this work, the UWSim-NET is presented, an open source tool to simulate the impact of communications in underwater robotics. It gathers the benefits of NS3 in modeling communication networks with those of the underwater robot simulator (UWSim) and the robot operating system (ROS) in modeling robotic systems. Thi…
Selective visual odometry for accurate AUV localization
2015
In this paper we present a stereo visual odometry system developed for autonomous underwater vehicle localization tasks. The main idea is to make use of only highly reliable data in the estimation process, employing a robust keypoint tracking approach and an effective keyframe selection strategy, so that camera movements are estimated with high accuracy even for long paths. Furthermore, in order to limit the drift error, camera pose estimation is referred to the last keyframe, selected by analyzing the feature temporal flow. The proposed system was tested on the KITTI evaluation framework and on the New Tsukuba stereo dataset to assess its effectiveness on long tracks and different illumina…