scholarly journals Development of a Solar-Powered IoT-Based Instrument for Automatic Measurement of Water Clarity

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 2051 ◽  
Author(s):  
Tuan Ngoc Pham ◽  
Anh Pham Huy Ho ◽  
Tuong Van Nguyen ◽  
Ha Minh Nguyen ◽  
Nhu Huynh Truong ◽  
...  
Keyword(s):  
Light Intensity ◽  
Water Column ◽  
Secchi Depth ◽  
Measurement Data ◽  
Automatic Measurement ◽  
Regression Function ◽  
Weather Conditions ◽  
Water Clarity ◽  
Secchi Disk ◽  
Pass Through

Water clarity is the most common indicator of water quality. The purpose of the study was to develop an instrument which can automatically measure water clarity in place of manual measurement by Secchi disk. The instrument is suspended by buoys at the water surface and uses solar energy to measure the light intensity of LED bulbs after passing through a water column; the result is then converted to Secchi depth by using a regression function. Measurement data are stored in a cloud server so that mobile users can access via an Internet connection. Three experiments were conducted to examine the instrument performance: (i) to ensure light intensity of the LED bulbs is strong enough to pass through the water column; (ii) to determine the regression relationship between the measured light intensity of the instrument and Secchi depth; and (iii) to evaluate the coefficient of variation (CV) of the measured water clarity when using our instrument and a conventional Secchi disk. Experiment results show that the measured values of light intensity are stable with the average CV = 5.25%. Moreover, although there are slight differences between the Secchi depth measured by our instrument and those measured by Secchi disk, the measurements by our instrument can efficiently replace the measurements by conventional Secchi disk, which can be affected by weather conditions as well as by human subjectivity.

Water Quality Trends in Hamilton Harbour: 1987 to 1995

1996 ◽  
Vol 31 (3) ◽  
pp. 473-484 ◽  
Author(s):  
Murray N. Charlton ◽  
Robin Le Sage
Keyword(s):  
Algal Blooms ◽  
Action Plan ◽  
Secchi Depth ◽  
Water Clarity ◽  
Nutrient Loads ◽  
Hamilton Harbour ◽  
Near Shore ◽  
The Media ◽  
Park Area ◽  
Water Quality Trends

Abstract A series of water samples and Secchi depth measurements were conducted in Hamilton Harbour between 1987 and 1995. The data indicate little recent improvement in the harbour generally. Detection of real improvements may require high frequency sampling and a more extensive sample grid once a cause for improvement is in place. Some measures, such as chlorophyll and Secchi depth, approach RAP initial goals sometimes during recent years, but algal blooms still occur, which prevent attainment of satisfactory average conditions. The cause of aesthetic improvements in water clarity reported in the media was investigated with sampling along an inshore-offshore transect and intense Secchi measurements in the LaSalle Park area. The data are consistent with a transient clarifying effect of zebra mussels on structures near shore. The need to reduce nutrient loads as recommended in the Remedial Action Plan continues.

Water clarity modeling in Lake Tahoe: Linking suspended matter characteristics to Secchi depth

2006 ◽  
Vol 68 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Theodore J. Swift ◽  
Joaquim Perez-Losada ◽  
S. Geoffrey Schladow ◽  
John E. Reuter ◽  
Alan D. Jassby ◽  
...  
Keyword(s):  
Suspended Matter ◽  
Secchi Depth ◽  
Lake Tahoe ◽  
Water Clarity

scholarly journals Decoupling forest characteristics and background conditions to explain urban-rural variations of multiple microclimate regulation from urban trees

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5450 ◽  
Author(s):  
Wenjie Wang ◽  
Bo Zhang ◽  
Lu Xiao ◽  
Wei Zhou ◽  
Huimei Wang ◽  
...  
Keyword(s):  
Light Intensity ◽  
Explanatory Power ◽  
Weather Conditions ◽  
Tree Density ◽  
Urban Trees ◽  
Lower Percentage ◽  
Air Cooling ◽  
Rapid Urbanization ◽  
Unit Distance ◽  
Urban Rural

Background Rapid urbanization in semi-arid regions necessitates greater cooling, humidifying, and shading services from urban trees, but maximizing these services requires an exact understanding of their association with forest characteristics and background street and weather conditions. Methods Here, horizontal and vertical air cooling, soil cooling, shading, and humidifying effects were measured for 605 trees from 152 plots in Changchun. Additionally, weather conditions (Tair, relative humidity, and light intensity), forest characteristics (tree height, diameter at breast height (DBH), under-branch height, canopy size, tree density, and taxonomic family of trees) and background conditions (percentage of building, road, green space, water, and building height, building distance to measured trees) were determined for three urban-rural gradients for ring road development, urban settlement history, and forest types. Multiple analysis of variance and regression analysis were used to find the urban-rural changes, while redundancy ordination and variation partitioning were used for decoupling the complex associations among microclimate regulations, forest characteristics, background street and weather conditions. Results Our results show that horizontal cooling and humidifying differences between canopy shade and full sunshine were <4.5 °C and <9.4%, respectively; while vertical canopy cooling was 1.4 °C, and soil cooling was observed in most cases (peak at 1.4 °C). Pooled urban-rural data analysis showed non-monological changes in all microclimate-regulating parameters, except for a linear increase in light interception by the canopy (r2 = 0.45) from urban center to rural regions. Together with the microclimate regulating trends, linear increases were observed in tree density, Salicaceae percentage, Tair, light intensity outside forests, tree distance to surrounding buildings, and greenspace percentage. Redundancy ordination demonstrated that weather differences were mainly responsible for the microclimate regulation variation we observed (unique explanatory power, 65.4%), as well as background conditions (12.1%), and forest characteristics (7.7%). Discussion In general, horizontal cooling, shading, and humidifying effects were stronger in dry, hot, and sunny weather. The effects were stronger in areas with more buildings of relatively lower height, a higher abundance of Ulmaceae, and a lower percentage of Leguminosae and Betulaceae. Larger trees were usually associated with a larger cooling area (a smaller difference per one unit distance from the measured tree). Given uncontrollable weather conditions, our findings highlighted street canyon and forest characteristics that are important in urban microclimate regulation. This paper provides a management strategy for maximizing microclimate regulation using trees, and methodologically supports the uncoupling of the complex association of microclimate regulations in fast urbanization regions.

scholarly journals Fleshy Red Algae Mats Influence Their Environment in the Mediterranean Sea

2021 ◽  
Vol 8 ◽  
Author(s):  
Neele Schmidt ◽  
Yusuf C. El-Khaled ◽  
Felix I. Roßbach ◽  
Christian Wild
Keyword(s):  
Environmental Factors ◽  
Light Intensity ◽  
Water Temperature ◽  
Mediterranean Sea ◽  
Water Column ◽  
Red Algae ◽  
Water Movement ◽  
Ecosystem Engineer ◽  
Overlying Water ◽  
The Mediterranean

In the Mediterranean Sea, the fleshy red alga Phyllophora crispa forms dense mats of up to 15 cm thickness, mainly located on rocky substrates in water depths below 20 m. Because of the observed density of these mats and some first observations, we hypothesize that P. crispa is a yet undescribed ecosystem engineer that provides a multitude of ecological niches for associated organisms along small-scale environmental gradients. Therefore, we conducted an in-situ pilot study in the Western Mediterranean Sea to assess potential influence of the algae mats on the key environmental factors water movement, temperature and light intensity. We comparatively and simultaneously measured in P. crispa mats, in neighboring Posidonia oceanica seagrass meadows, on neighboring bare rocky substrates without algae mats, and in the directly overlying water column. We used several underwater logging sensors and gypsum clod cards. Findings revealed that P. crispa significantly reduced water movement by 41% compared to the overlying water column, whereas water movement was not affected by P. oceanica meadows and bare rocky substrates. Surprisingly, P. crispa increased the water temperature by 0.3°C relative to the water column, while the water temperature in P. oceanica and on bare rocky substrates was reduced by 0.5°C. Light intensity inside the red algae mats was reduced significantly by 69% compared to the water column. This was similar to measured light reduction of 77% by P. oceanica. These findings highlight the strong influence of the dense red algae mats on some key environmental factors. Their influence is obviously similar or even higher than for the well-known seagrass ecosystem engineer. This may be a factor that facilitates associated biodiversity similarly as described for P. oceanica.

scholarly journals Rancang Bangun Jemuran Otomatis Menggunakan Mikrokontroller WEMOS

CAHAYAtech ◽  
2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Adetya Windiarto Makhmud ◽  
Tutus Praningki ◽  
Ira Luvi Indah
Keyword(s):  
Internet Of Things ◽  
Solar Energy ◽  
Light Intensity ◽  
Weather Conditions ◽  
Daily Activities ◽  
The Internet ◽  
The Right ◽  
The Internet Of Things

Drying clothes is one of the daily activities of people who use solar energy. With these conditions, people are very dependent on weather conditions that are sometimes erratic. One of the right ways is by utilizing technology, namely using an automatic clothesline using a Wemos D1Mini microcontroller, equipped with an LDR sensor that will read light intensity and the DHT11 sensor will read humidity and temperature around the environment. This tool is also based on the Internet of Things which can be accessed from anywhere as long as it is connected to the internet. Keyword: Microcontroller, LDR sensor, DHT11 sensor, Internet of Things.

scholarly journals A Printable Device for Measuring Clarity and Colour in Lake and Nearshore Waters

Sensors ◽  
2019 ◽  
Vol 19 (4) ◽  
pp. 936 ◽  
Author(s):  
Robert Brewin ◽  
Thomas Brewin ◽  
Joseph Phillips ◽  
Sophie Rose ◽  
Anas Abdulaziz ◽  
...  
Keyword(s):  
3D Printing ◽  
Citizen Science ◽  
Scientific Discovery ◽  
Low Cost ◽  
Secchi Depth ◽  
Three Dimensional ◽  
Water Clarity ◽  
3D Printer ◽  
Satellite Validation ◽  
Wide Range

Two expanding areas of science and technology are citizen science and three-dimensional (3D) printing. Citizen science has a proven capability to generate reliable data and contribute to unexpected scientific discovery. It can put science into the hands of the citizens, increasing understanding, promoting environmental stewardship, and leading to the production of large databases for use in environmental monitoring. 3D printing has the potential to create cheap, bespoke scientific instruments that have formerly required dedicated facilities to assemble. It can put instrument manufacturing into the hands of any citizen who has access to a 3D printer. In this paper, we present a simple hand-held device designed to measure the Secchi depth and water colour (Forel Ule scale) of lake, estuarine and nearshore regions. The device is manufactured with marine resistant materials (mostly biodegradable) using a 3D printer and basic workshop tools. It is inexpensive to manufacture, lightweight, easy to use, and accessible to a wide range of users. It builds on a long tradition in optical limnology and oceanography, but is modified for ease of operation in smaller water bodies, and from small watercraft and platforms. We provide detailed instructions on how to build the device and highlight examples of its use for scientific education, citizen science, satellite validation of ocean colour data, and low-cost monitoring of water clarity, colour and temperature.

Some observations on the effects of accumulated benthic sludge on the behaviour of waste stabilisation ponds

2005 ◽  
Vol 51 (12) ◽  
pp. 217-226
Author(s):  
C.J. Banks ◽  
S. Heaven ◽  
E.A. Zotova
Keyword(s):  
Light Intensity ◽  
Dissolved Oxygen ◽  
Water Column ◽  
Suspended Solids ◽  
Biomass Concentration ◽  
Pilot Scale ◽  
Controlling Factor ◽  
Waste Stabilisation Ponds ◽  
Nutrient Levels ◽  
Complex Mechanisms

The effect of accumulated bottom sludge on water column characteristics was studied in two pilot-scale ponds. Parameters measured were ammonia, nitrate, phosphate, COD, suspended solids, dissolved oxygen (DO), temperature and light intensity. The de-sludged pond showed a stronger correlation between DO, light intensity, nutrients and suspended solids with the controlling factor being availability of nitrogen. This was less apparent in the pond with sludge where nutrient levels were higher and more complex mechanisms controlled biomass concentration. Water column characteristics in the two ponds converged rapidly in 7–10 weeks, however, due to accumulation of fresh sludge.

Reaction Behavior between Li and NiO Thin Film by EIS

2010 ◽  
Vol 150-151 ◽  
pp. 1603-1606
Author(s):  
Yu Cai ◽  
Zhao Yang Wu ◽  
Sheng Li Zhao ◽  
Ji Ne Zhu
Keyword(s):  
Electrochemical Impedance ◽  
Measurement Data ◽  
Lithium Ion ◽  
Open Circuit ◽  
Reaction Behavior ◽  
Polarization Voltage ◽  
Sei Film ◽  
Nio Thin Film ◽  
Pass Through ◽  
Impedance Property

The variation of impedance property during the 1st charge/discharge course was investigated by electrochemical impedance spectroscopy (EIS). The results show that the proposed equivalent circuit of RS(Qdl(RCtZW))(QSEIRSEI) perfectly simulating the EIS measurement data and all the errors less than 5% can reasonably explain the course of the reaction between Li and NiO electrode. The SEI film which distinctly influences the electrochemical performance of lithium ion battery is free at open circuit voltage. It begins to slowly grow at polarization voltage of 1.5V and completely forms at 0.3V in the 1st discharge. To react further with NiO, the Li+ must pass through SEI film and generate the fine grains Ni and amorphous Li2O matrix. SEI film partially decomposes and the NiO and Li are formed by reversible reaction of Ni and Li2O in the charge course.

Primary Productivity of Southern Indian Lake before, during, and after Impoundment and Churchill River Diversion

1984 ◽  
Vol 41 (4) ◽  
pp. 591-604 ◽  
Author(s):  
R. E. Hecky ◽  
S. J. Guildford
Keyword(s):  
Light Intensity ◽  
Primary Production ◽  
Water Column ◽  
Primary Productivity ◽  
Phosphorus Deficiency ◽  
Light Environment ◽  
Phytoplankton Production ◽  
Light Penetration ◽  
The Mean ◽  
Chlorophyll Concentrations

The primary productivity of seven regions of Southern Indian Lake and neighboring Wood Lake was measured during open-water seasons from 1974 to 1978. The lake had regional differences in chlorophyll concentrations and daily rates of integral primary production in 1974 and 1975 prior to impoundment of the lake. Regions receiving Churchill River flow tended to have higher chlorophyll concentrations and production rates than those regions marginal to the flow. Impoundment of the lake resulted in higher efficiencies of primary production in all regions, as indicated by higher light-saturated rates of carbon uptake per unit chlorophyll and by higher initial slopes of the hyperbolic light response relation of the phytoplankton. Many large basins of the lake had light penetration reduced by high concentrations of suspended sediment from eroding shorelines, while other areas had relatively unchanged light penetration. The increased efficiency of carbon fixation per unit chlorophyll resulted in higher rates of integral production in those regions where light penetration was not greatly affected. Daily rates of integral primary production in lake regions where light penetration had decreased markedly were not significantly different after impoundment because efficiencies of light utilization were higher. Comparison of the mean water column light intensities for those turbid regions with the values of Ik (light intensity at the onset of light saturation) for phytoplankton indicated that these turbid regions are now light deficient on average. Phosphorus deficiency, as indicated by alkaline phosphatase activity per unit ATP, which was present before impoundment, has been eliminated as the mean water column light intensity declined below 5 mEinsteins∙m−2∙min−1. The light environment of a new reservoir can be a significant determinant of integral production, and predicting the consequences of impoundment on phytoplankton production requires accurate prediction of the light environment.

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