scholarly journals Monitoring the Snowpack Volume in a Sinkhole on Mount Lebanon using Time Lapse Photogrammetry

Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 3890 ◽  
Author(s):  
Charbel Chakra ◽  
Simon Gascoin ◽  
Janine Somma ◽  
Pascal Fanise ◽  
Laurent Drapeau
Keyword(s):  
Water Resources ◽  
Low Cost ◽  
Large Fraction ◽  
Hydrological Regime ◽  
Time Lapse ◽  
Daily Basis ◽  
Digital Elevation ◽  
Natural Snow ◽  
Remote Sensing Techniques ◽  
Topographic Surveys

Lebanon has experienced serious water scarcity issues recently, despite being one of the wealthiest countries in the Middle East for water resources. A large fraction of the water resources originates from the melting of the seasonal snow on Mount Lebanon. Therefore, continuous and systematic monitoring of the Lebanese snowpack is becoming crucial. The top of Mount Lebanon is punctuated by karstic hollows named sinkholes, which play a key role in the hydrological regime as natural snow reservoirs. However, monitoring these natural snow reservoirs remains challenging using traditional in situ and remote sensing techniques. Here, we present a new system in monitoring the evolution of the snowpack volume in a pilot sinkhole located in Mount Lebanon. The system uses three compact time-lapse cameras and photogrammetric software to reconstruct the elevation of the snow surface within the sinkhole. The approach is validated by standard topographic surveys. The results indicate that the snow height can be retrieved with an accuracy between 20 and 60 cm (residuals standard deviation) and a low bias of 50 cm after co-registration of the digital elevation models. This system can be used to derive the snowpack volume in the sinkhole on a daily basis at low cost.

scholarly journals Extracting High Resolution Snow Distribution Information with Inexpensive Autonomous Cameras

10.29007/93gh ◽  
2018 ◽  
Author(s):  
Pauline Millet ◽  
Hendrik Huwald ◽  
Steven V. Weijs
Keyword(s):  
High Resolution ◽  
Low Cost ◽  
Time Lapse ◽  
Distortion Correction ◽  
Snow Covered Area ◽  
Covered Area ◽  
Digital Elevation ◽  
Snow Distribution ◽  
Elevation Model ◽  
Time Lapse Photography

This study details a procedure to derive high resolution snow cover information using low-cost autonomous cameras. Images from time lapse photography of target areas are used to obtain temporally resolved binary snow-covered area information. Various image processing steps, such as distortion correction, alignment, projection using the Digital Elevation Model (DEM), and classification using clustering are described. Several innovations, such as matching the mountain silhouette with the DEM, and application of specific filters are described to make this terrestrial remote sensing method generally applicable to derive valuable snow information.

scholarly journals Development of single-cell-level microfluidic technology for long-term growth visualization of living cultures of Mycobacterium smegmatis

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Han Wang ◽  
Gloria M. Conover ◽  
Song-I Han ◽  
James C. Sacchettini ◽  
Arum Han
Keyword(s):  
Drug Treatment ◽  
Single Cell ◽  
Mycobacterium Smegmatis ◽  
Culture Media ◽  
Low Cost ◽  
Bacterial Pathogen ◽  
Growth Dynamics ◽  
Time Lapse ◽  
Cell Phenotype

AbstractAnalysis of growth and death kinetics at single-cell resolution is a key step in understanding the complexity of the nonreplicating growth phenotype of the bacterial pathogen Mycobacterium tuberculosis. Here, we developed a single-cell-resolution microfluidic mycobacterial culture device that allows time-lapse microscopy-based long-term phenotypic visualization of the live replication dynamics of mycobacteria. This technology was successfully applied to monitor the real-time growth dynamics of the fast-growing model strain Mycobacterium smegmatis (M. smegmatis) while subjected to drug treatment regimens during continuous culture for 48 h inside the microfluidic device. A clear morphological change leading to significant swelling at the poles of the bacterial membrane was observed during drug treatment. In addition, a small subpopulation of cells surviving treatment by frontline antibiotics was observed to recover and achieve robust replicative growth once regular culture media was provided, suggesting the possibility of identifying and isolating nonreplicative mycobacteria. This device is a simple, easy-to-use, and low-cost solution for studying the single-cell phenotype and growth dynamics of mycobacteria, especially during drug treatment.

scholarly journals Terrain Analysis of Biu Plateau, for Road Transport Development, Borno State, Nigeria

2014 ◽  
Vol 6 (2) ◽  
pp. 28
Author(s):  
Ikusemoran Mayomi ◽  
John Abdullahi ◽  
Anthony Dami
Keyword(s):  
Information Technologies ◽  
Low Cost ◽  
Road Transport ◽  
Accurate Information ◽  
Terrain Analysis ◽  
Road Transportation ◽  
Digital Elevation ◽  
Human Energy ◽  
Road Planning ◽  
Steep Slopes

Among all the means of transportation, road has been described as the most important, probably because of its flexibility and its low cost in terms of construction, maintenance and usage. However, in Nigeria, road is considered to be the most dangerous means of transportation because of their bad nature such as sharp bends, narrow bridges, steep slopes and other related problems which are associated with the terrain where these roads are constructed. Road transportation therefore needs proper planning and development through the use of geo-information technologies that would ease accessibility reduces human energy and yet brings reliable and accurate information on the terrain. In this paper, Ilwis 3.5 was used to create Digital Elevation Modelling (DEM), Shadowing, 3-Dimentional View, Slope maps and river direction maps of Biu plateau to analyze the use of GIS on road planning and development on the plateau. It was revealed that the technique has great capabilities of terrain analysis as features which are deemed humanly impossible to assess are viewed as if one is at the scene which may enhance quick analysis on road transportation. It was therefore, recommended that all the stake holders in road transportation should employ the use of this geo-information techniques in terrain analysis to ease transport planning and development in the area.

scholarly journals Accuracy of 3D Landscape Reconstruction without Ground Control Points Using Different UAS Platforms

Drones ◽  
2020 ◽  
Vol 4 (2) ◽  
pp. 13 ◽  
Author(s):  
Margaret Kalacska ◽  
Oliver Lucanus ◽  
J. Pablo Arroyo-Mora ◽  
Étienne Laliberté ◽  
Kathryn Elmer ◽  
...  
Keyword(s):  
Low Cost ◽  
Ground Control ◽  
Unmanned Aerial Systems ◽  
Control Points ◽  
Model Errors ◽  
Positional Accuracy ◽  
Ground Control Points ◽  
Digital Elevation ◽  
High Level ◽  
Aerial Systems

The rapid increase of low-cost consumer-grade to enterprise-level unmanned aerial systems (UASs) has resulted in the exponential use of these systems in many applications. Structure from motion with multiview stereo (SfM-MVS) photogrammetry is now the baseline for the development of orthoimages and 3D surfaces (e.g., digital elevation models). The horizontal and vertical positional accuracies (x, y and z) of these products in general, rely heavily on the use of ground control points (GCPs). However, for many applications, the use of GCPs is not possible. Here we tested 14 UASs to assess the positional and within-model accuracy of SfM-MVS reconstructions of low-relief landscapes without GCPs ranging from consumer to enterprise-grade vertical takeoff and landing (VTOL) platforms. We found that high positional accuracy is not necessarily related to the platform cost or grade, rather the most important aspect is the use of post-processing kinetic (PPK) or real-time kinetic (RTK) solutions for geotagging the photographs. SfM-MVS products generated from UAS with onboard geotagging, regardless of grade, results in greater positional accuracies and lower within-model errors. We conclude that where repeatability and adherence to a high level of accuracy are needed, only RTK and PPK systems should be used without GCPs.

scholarly journals Remote Sensing of Aerosols at Night with the CoSQM Sky Brightness Data

2021 ◽  
Author(s):  
Charles Marseille ◽  
Martin Aubé ◽  
Africa Barreto Velasco ◽  
Alexandre Simoneau
Keyword(s):  
Remote Sensing ◽  
Aerosol Optical Depth ◽  
Optical Depth ◽  
Low Cost ◽  
Empirical Relationship ◽  
Important Indicator ◽  
Sky Brightness ◽  
Night Sky ◽  
Remote Sensing Techniques ◽  
Night Sky Brightness

The aerosol optical depth is an important indicator of aerosol particle properties and associated radiative impacts. AOD determination is therefore very important to achieve relevant climate modeling. Most remote sensing techniques to retrieve aerosol optical depth are applicable to daytime given the high level of light available. The night represents half of the time but in such conditions only a few remote sensing techniques are available. Among these techniques, the most reliable are moon photometers and star photometers. In this paper, we attempt to fill gaps in the aerosol detection performed with the aforementioned techniques using night sky brightness measurements during moonless nights with the novel CoSQM: a portable, low cost and open-source multispectral photometer. In this paper, we present an innovative method for estimating the aerosol optical depth by using an empirical relationship between the zenith night sky brightness measured at night with the CoSQM and the aerosol optical depth retrieved at daytime from the AErosol Robotic NETwork. Such a method is especially suited to light-polluted regions with light pollution sources located within a few kilometers of the observation site. A coherent day-to-night aerosol optical depth and Ångström Exponent evolution in a set of 354 days and nights from August 2019 to February 2021 was verified at the location of Santa Cruz de Tenerife on the island of Tenerife, Spain. The preliminary uncertainty of this technique was evaluated using the variance under stable day-to-night conditions, set at 0.02 for aerosol optical depth and 0.75 for Ångström Exponent. These results indicate the set of CoSQM and the proposed methodology appear to be a promising tool to add new information on the aerosol optical properties at night, which could be of key importance to improve climate predictions.

scholarly journals Analysis of the Fee-to-Tax Reform on Water Resources in China

2021 ◽  
Vol 9 ◽  
Author(s):  
Zi-Rui Chen ◽  
Yuan Yuan ◽  
Xu Xiao
Keyword(s):  
Water Resources ◽  
Water Resource ◽  
Water Consumption ◽  
Tax Reform ◽  
Low Cost ◽  
Production Capacity ◽  
Cost Difference ◽  
Tax Rate ◽  
Leading Position ◽  
The Cost

The Resource Tax Law was officially implemented on September 1, 2020, in China. This law presents the “Fee-to-Tax” reform of water resources. This article compares the effects of the “Fee-to-Tax” reform under asymmetric duopoly conditions with perfect information. The mechanisms of the two policies are different when all firms simultaneously respond to water resources: the water resource fee affects output by reducing market size, while the water resource tax reduces output by amplifying the weighted cost difference effects between companies. Water resource taxes work better than fees for eliminating backward production capacity. A comparison of the situation when companies respond sequentially is also carried out. When a low-cost firm is in the leading position, the collection of fees actually reduces the output difference, whereas the tax improves it. When a high-cost firm acts as a leader, the effects depend on the cost difference. When the cost difference between firms is small, the first-move advantage of high-cost firms dominates the cost advantages of low-cost firms. Therefore, a higher tax rate yields a smaller output difference. When cost differences are relatively larger, the cost advantage of low-cost firms dominates the first-move advantage of high-cost firms. As the operational cost for reducing water consumption increases, the reduced water consumption first increases and then decreases.

scholarly journals Time-lapse cross-hole electrical resistivity tomography (CHERT) for monitoring seawater intrusion dynamics in a Mediterranean aquifer

2019 ◽  
Author(s):  
Andrea Palacios ◽  
Juan José Ledo ◽  
Niklas Linde ◽  
Linda Luquot ◽  
Fabian Bellmunt ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Electrical Resistivity ◽  
Seawater Intrusion ◽  
Electrical Resistivity Tomography ◽  
Low Cost ◽  
Heavy Rain ◽  
Time Lapse ◽  
Resistivity Tomography ◽  
Bulk Electrical Conductivity ◽  
Spatial Coverage

Abstract. Surface electrical resistivity tomography (ERT) is a widely used tool to study seawater intrusion (SWI). It is noninvasive and offers a high spatial coverage at a low cost, but it is strongly affected by decreasing resolution with depth. We conjecture that the use of CHERT (cross-hole ERT) can partly overcome these resolution limitations since the electrodes are placed at depth, which implies that the model resolution does not decrease in the zone of interest. The objective of this study is to evaluate the CHERT for imaging the SWI and monitoring its dynamics at the Argentona site, a well-instrumented field site of a coastal alluvial aquifer located 40 km NE of Barcelona. To do so, we installed permanent electrodes around boreholes attached to the PVC pipes to perform time-lapse monitoring of the SWI on a transect perpendicular to the coastline. After two years of monitoring, we observe variability of SWI at different time scales: (1) natural seasonal variations and aquifer salinization that we attribute to long-term drought and (2) short-term fluctuations due to sea storms or flooding in the nearby stream during heavy rain events. The spatial imaging of bulk electrical conductivity allows us to explain non-trivial salinity profiles in open boreholes (step-wise profiles really reflect the presence of fresh water at depth). By comparing CHERT results with traditional in situ measurements such as electrical conductivity of water samples and bulk electrical conductivity from induction logs, we conclude that CHERT is a reliable and cost-effective imaging tool for monitoring SWI dynamics.

scholarly journals Recent Approaches for the Production of High Value-Added Biofuels from Gelatinous Wastewater

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4936
Author(s):  
Ahmed Tawfik ◽  
Shou-Qing Ni ◽  
Hanem. M. Awad ◽  
Sherif Ismail ◽  
Vinay Kumar Tyagi ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Energy Recovery ◽  
Protein Concentration ◽  
Volatile Fatty Acids ◽  
Low Cost ◽  
Large Fraction ◽  
Value Added ◽  
Organic Loading Rate ◽  
Simultaneous Treatment ◽  
Factors Affecting

Gelatin production is the most industry polluting process where huge amounts of raw organic materials and chemicals (HCl, NaOH, Ca2+) are utilized in the manufacturing accompanied by voluminous quantities of end-pipe effluent. The gelatinous wastewater (GWW) contains a large fraction of protein and lipids with biodegradability (BOD/COD ratio) exceeding 0.6. Thus, it represents a promising low-cost substrate for the generation of biofuels, i.e., H2 and CH4, by the anaerobic digestion process. This review comprehensively describes the anaerobic technologies employed for simultaneous treatment and energy recovery from GWW. The emphasis was afforded on factors affecting the biofuels productivity from anaerobic digestion of GWW, i.e., protein concentration, organic loading rate (OLR), hydraulic retention time (HRT), the substrate to inoculum (S0/X0) ratio, type of mixed culture anaerobes, carbohydrates concentration, volatile fatty acids (VFAs), ammonia and alkalinity/VFA ratio, and reactor configurations. Economic values and future perspectives that require more attention are also outlined to facilitate further advancement and achieve practicality in this domain.

scholarly journals Analysis of the Fee-to-Tax Reform on Water Resources in China

2021 ◽  
Author(s):  
Zi-rui Chen ◽  
Pu-yan Nie
Keyword(s):  
Water Resources ◽  
Water Resource ◽  
Tax Reform ◽  
Low Cost ◽  
Production Capacity ◽  
Cost Difference ◽  
Tax Rate ◽  
Leading Position ◽  
Resource Policy ◽  
The Cost

Abstract Background: The Resource Tax Law has been officially implemented on September 1, 2020 in China. This law presents the “Fee-to-Tax” reform of water resources. Methods: This article compares the effects of the “Fee-to-Tax” reform under an asymmetric duopoly with perfect information. Results: First, an analysis when all firms simultaneously respond to the water resource policy is conducted. The mechanisms of the two policies are different: the water resource fee affects output by reducing market size, while the water resource tax reduces output by amplifying the weighted cost difference effects between companies. It is shown that the tax works better than the fee for eliminating backward production capacity. Then, a comparison of the situation when companies respond sequentially is carried out. When a low-cost firm is in the leading position, the collection of fees actually reduces the output difference, whereas the tax improves it. When a high-cost firm acts as a leader, the effects depend on the cost difference. When the cost difference between firms is small, the first-move advantage of high-cost firms dominates the cost advantages of low-cost firms. Therefore, a higher tax rate yields a smaller output difference. Conclusions: When cost differences are relatively larger, the cost advantage of low-cost firms dominates the first-move advantage of high-cost firms. Therefore, the “Fee-to-Tax” reform provides some benefits to maintain the environmental development of some water-mining or related industries.

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