Download or read book Monitoring of Suspended Sediment Concentration Using Optical Methods and Remote Sensing written by K. S. Albanakis and published by . This book was released on 1985 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Optical Sensor for In stream Monitoring of Suspended Sediment Concentration written by Yali Zhang and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Suspended sediment concentration (SSC) in water is one of the most important parameters to evaluate water quality. Monitoring SSC provides important information on determining sediment transport for soil erosion research and soil/water conservation practices. Sediment mass transported at a given time can be assessed by simultaneous SSC and water flow velocity measurements. Fouling, including bio-fouling, has damaging impact on optical SSC measurements over the long term. In this study, an inexpensive, real-time, self-cleaning, optical sediment and flow velocity sensor was developed. Laboratory experiments were conducted on a previously designed SSC sensor. A light modulation algorithm was designed to reduce the influence of ambient light, especially sunlight, on measurement accuracy. Statistical models to predict SSC based on measured light intensities were established and compared with neural network models. The statistical analysis showed that soil texture played an important role in SSC measurement accuracy while the designed sensor was capable of reducing the effect of water color on sensor performance. Neural-network models can further remove the influence of soil texture type on SSC measurement. The sensor design was simplified based on a stepwise selection analysis. Long-term field experiments were conducted in Kansas and Georgia to evaluate the sensor performance, the effect of fouling, including bio-fouling, on sensor lenses, and the effect of temperature on the measurement. Methods of removing the fouling effect through data correction were developed. Results indicated that the designed optical SSC sensor was capable of providing rapid response to SSC fluctuations in water flow. Temperature of the water body has an insignificant impact on SSC measurement. In order to reduce fouling, an air-blast cleaning mechanism was integrated into the optical sediment sensor. Laboratory experiments in a manually created fouling environment were conducted to observe the fouling process on sensor cases made of different materials, and to verify the effectiveness of air-blast cleaning in reducing fouling. Results indicated that air-blast cleaning mechanism was capable of reducing clay/silt fouling on sensor signals. The duration and frequency of air-blast cleaning can be determined and adjusted depending on actual field conditions. An air pressure drop test was conducted on the hose carrying pressurized air. Results showed negligible pressure drop. A flow velocity measurement function based on the cross-correlation principle was integrated into the optical sediment sensor. An experiment was conducted in laboratory to examine the sensor performance on velocity measurement using a closed circulation system. A solution of blue colorant, Brilliant Blue FCF, was used as an artificial source to absorb light emitted by LEDs in the sensor and the signal variation patterns were measured. The results indicated that the cross-correlation-based velocity sensor was capable of measuring water flow velocity within in a certain velocity range using the dye injection method.
Download or read book Optical Remote Sensing of Suspended Sediment Concentration in Coastal Water written by Zhimin Chen and published by . This book was released on 1992 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bio optical Modeling and Remote Sensing of Inland Waters written by Deepak R. Mishra and published by Elsevier. This book was released on 2017-04-28 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bio-optical Modeling and Remote Sensing of Inland Waters presents the latest developments, state-of-the-art, and future perspectives of bio-optical modeling for each optically active component of inland waters, providing a broad range of applications of water quality monitoring using remote sensing. Rather than discussing optical radiometry theories, the authors explore the applications of these theories to inland aquatic environments. The book not only covers applications, but also discusses new possibilities, making the bio-optical theories operational, a concept that is of great interest to both government and private sector organizations. In addition, it addresses not only the physical theory that makes bio-optical modeling possible, but also the implementation and applications of bio-optical modeling in inland waters. Early chapters introduce the concepts of bio-optical modeling and the classification of bio-optical models and satellite capabilities both in existence and in development. Later chapters target specific optically active components (OACs) for inland waters and present the current status and future direction of bio-optical modeling for the OACs. Concluding sections provide an overview of a governance strategy for global monitoring of inland waters based on earth observation and bio-optical modeling. Presents comprehensive chapters that each target a different optically active component of inland waters Contains contributions from respected and active professionals in the field Presents applications of bio-optical modeling theories that are applicable to researchers, professionals, and government agencies
Download or read book Remote Sensing Suspended Sediment Concentration in the Yellow River written by Liqin Qu and published by . This book was released on 2014 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hydrological Drought written by Lena M. Tallaksen and published by Gulf Professional Publishing. This book was released on 2004 with total page 634 pages. Available in PDF, EPUB and Kindle. Book excerpt: The majority of the examples are taken from regions where the rivers run most of the year.
Download or read book The Use of Multispectral Video Remote Sensing to Monitor Suspended Sediment Concentrations PHD written by Christopher Tom Lee and published by . This book was released on 1990 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Remote Sensing of Suspended Sediment in San Francisco Bay Using Satellite and Drone Imagery written by Joseph Henry Adelson and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Suspended sediment in San Francisco Bay affects the economic and ecological health of the estuary and its surrounding region by limiting light availability for photosynthesis, transporting contaminants, nourishing marsh restoration projects, infilling shipping channels, and providing protection to the shoreline from sea level rise via accretion on mudflats. Traditional efforts to study sediment transport phenomena have relied upon in situ measurements and numerical modeling, but these approaches have limitations. In situ measurement techniques rely on point measurements with high temporal resolution, yet they are difficult to deploy over large spatial areas. Models provide useful insight into the spatial heterogeneity of sediment processes. However, they rely on initial and boundary conditions and parameterizations that are based on observations, therefore the accuracy of models is also constrained in part by the limitations of in situ measurements. This dissertation presents remote sensing measurements from satellites and unmanned aerial vehicles (UAVs) to understand suspended sediment transport processes in estuaries like San Francisco Bay. Twelve methods for inferring suspended sediment concentration (SSC) from Landsat 7 imagery were compared using k-folds validation and assessed based on their abilities to recreate in situ SSC measurements from one meter below the surface. The best performer was the model of Nechad et al. (2010) using the red wavelength band with coefficients determined via Huber regression, with mean absolute error of 5.94 mg L-1 and bias of 0.15 mg L-1. Satellite-derived SSC observations compare well with USGS transects indicating that the method is well-suited to supplement cruise data that is costly to acquire and therefore limited in its frequency. Remote sensing measurements were aggregated by location, season, or tidal phase to understand the variability of SSC and to compare probability densities with in situ measurements. These results show that surface SSC is heightened in the shoals during summer months and has trended downward in Suisun and Grizzly Bays since 1999. Using satellite imagery from 2014-2017, remotely sensed surface SSC derived from the Nechad method was paired with bottom stress estimates based on two-dimensional hydrodynamic and fetch-limited wave models to investigate the relationship between surface SSC and flow. Observations of SSC closely fit a lognormal distribution though the shape, characterized by the modal value, depend on binning criteria including embayment, depth, and wave height. When binned by model-derived bottom shear stress, the modal value of the SSC distribution exhibited an inflection point at the critical shear stress for erosion. This suggests that remote sensing can be used to derive critical stresses that are otherwise difficult to measure. To account for the limitations of satellite imagery such as low spatial resolution and low temporal resolution (Landsat 7 overpasses occurred roughly once every 16 days), a method was developed to infer surface SSC from UAV-based imagery. While traditional remote sensing platforms take imagery at approximately a nadir viewing angle and provide multispectral images that are aligned with one another, an off-the-shelf camera aboard a UAV may not adhere to those qualities. Low cost multi-spectral cameras often include individual sensors for each band. The slight misalignment between images violates assumptions in two-band glint correction algorithms. Additionally, UAVs must tilt to fly and compensate for wind requiring images to occasionally be taken at angles more oblique than most satellite imagery. The method developed in this dissertation adapts previous techniques for sun glint correction for misaligned multispectral images and offers a novel approach to reduce the effects of camera orientation for oblique angles. During a field campaign, the UAV-based method to capture remote sensing reflectance was validated via comparison with in situ measurements made with a hyperspectral radiometer, and its ability to accurately infer SSC was verified based on in situ water samples. It was found that a polarizing filter is necessary to mitigate much of the glare on the water surface. A series of test flights were conducted to measure the surface SSC along a transect parallel to the Dumbarton Bridge during different phases of the tidal cycle. To reduce the impact of variability of incoming light, the flights were conducted over a period of 12 days at the same solar zenith angle during each day. Because the tide arrives later by roughly 50 minutes each day, consecutive daily transects over 12 days provided the variability over a tidal cycle. Cross-sectional sediment flux was computed from the remotely sensed surface SSC measurements and compared well to flux values estimated from in situ USGS observations.
Download or read book Hyperspectral Remote Sensing of Nearshore Water Quality written by Sima Bagheri and published by Springer. This book was released on 2016-11-11 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides details on of the utility of hyperspectral remote sensing – NASA/AVIRIS in nearshore water quality issues of NY/NJ. It demonstrates the use of bio optical modeling and retrieval techniques to derive the concentrations of important water quality parameters (chlorophyll, color dissolved organic matter and suspended sediments) in the study area. The case study focuses on the nearshore waters of NY/NJ considered as a valued ecological, economic and recreational resource within the New York metropolitan area. During field campaigns (1998-2001) measurements were made to establish hydrological optical properties of the NY/NJ nearshore waters with concurrent NASA/AVIRIS overflights. The field measurements included: 1) concurrent above and below surface spectral reflectance; 2) shipboard sampling for determination of inherent optical properties (IOP); and 3) concentrations of optically important water quality parameters. Understanding the relationship between reflectance, absorption and scattering is essential for developing the analytical algorithm necessary to use remote sensing as a monitoring /management tool in the nearshore environment.
Download or read book Monitoring Multi Depth Suspended Sediment Loads in Lake Erie s Maumee River Using Landsat 8 and Unmanned Aerial Vehicle UAV Imagery written by Matthew David Larson and published by . This book was released on 2017 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: Suspended sediment in water bodies is a considerable environmental concern. Traditional sampling methods for suspended sediment are time-consuming as they involve vertical and spatial point-sampling. Remote sensing (RS) is an alternative to in-situ measurements and it is capable of monitoring suspended sediments in shallow waters spatially at large scales. Use of RS technology to map suspended sediment concentrations (SSC) depends on sensor type and its capability `to see through' the water column at given surface and water column conditions. This study examined the capabilities of RS technology to spatially quantify SSC at multi-depth intervals within the Maumee River, Ohio. Water samples were collected and analyzed for SSC in May, June, and October at depths of 0.5 ft., 2 ft., 3 ft., and 6 ft. Landsat 8, surface hyperspectral measurements (aggregated to simulate sensors), and MicaSense Sequoia camera onboard an unmanned aerial vehicle (UAV) were used. Single spectral bands, ratios, and multiple bands/ratios were examined in developing algorithms relating RS and field measurements. Linear regression models provided the best relationship for surface, Landsat 8, and UAV data throughout all depths. A 6 ft. depth had the highest correlation for surface (R2adj=0.93) and Landsat 8 (R2adj=0.79) data. For UAV a 3 ft. depth provided the best relationship (R2adj=0.52). Band ratios using nonlinear fitting provided good relationships (surface R2adj=0.72 and Landsat 8 R2adj=0.54) at 6 ft. as well. Results showed Landsat 8 more accurately measured suspended solids at 6 ft. than shallower depths. Regression equations and band ratios showed increasing relationships with SSC with increasing depth for Landsat 8 with an exception for 3 ft., which can occur due to stratification. UAV measurements produced best results for 3 ft. Algorithms with best results included ultra blue, blue, and green bands which are not typically used for quantifying SSC. Shorter wavelength bands (400 nm-550 nm) should be considered in waters with small suspended sediments as those found in the Maumee River. Equations were not transferable from one day to another. It is surmised that concentration thresholds of 40-60 mg/L play a role in equation derivation, as well as meteorological factors.
Download or read book Rational Method for Correcting Sea Truth of Suspended Sediment Concentration Related to Remote Sensing written by Chin Y. Kuo and published by . This book was released on 1976 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Calibration and Testing of a Wireless Suspended Sediment Sensor written by Daniel Bigham and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A real time wireless, optical sensor network was tested for long-term, remote monitoring of suspended sediment concentrations (SSC) in streams. The sensor and control board assembly was calibrated using a two-stage calibration procedure, including a pre-calibration conducted in the laboratory to adjust the sensitivity of the sensor and a field calibration using grab samples to establish an effective statistical model to predict SSC from the sensor signals. The assembly was installed in three military bases around the United States. These bases were Fort Riley, Kansas; Fort Benning, GA; and Aberdeen Proving Ground, MD. The types of water bodies and watersheds varied greatly among the sites, which allowed the sensor to be tested under versatile conditions for potential widespread use. The results show that the sensor was capable of measuring SSC at each watershed independently. The calibration model developed for each sensor can be used to predict SSC from real-time sensor data. A data processing algorithm was developed to lessen the effect of fouling and clogging on sensor signals, along with eliminating anomalies in the data gathered. The results of this study displayed meaningful prediction data that can be used to estimate SSC in a stream over a long period of time. Information obtained in this study can be used as a launching point for future work and understanding of stream processes.
Download or read book Discrimination of Suspended Sediment Concentrations Using Multispectral Remote Sensing Techniques microform written by Liedtke, Jeffrey Lee and published by National Library of Canada. This book was released on 1987 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Verification of a Rational Method for Correcting the in Situ Data of Suspended Sediment Concentration Related to Remote Sensing Data Process written by Chin Y. Kuo and published by . This book was released on 1978 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Erosion and Sediment Transport Measurement in Rivers written by Jim Bogen and published by . This book was released on 2003 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Monitoring of Marine Pollution written by Houma Bachari Fouzia and published by BoD – Books on Demand. This book was released on 2019-06-05 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many of the pollutants discharged into the sea are directly or indirectly the result of human activities. Some of these substances are biodegradable, while others are not. This study is devoted to monitoring areas of the environment. Methods assessment is based on monitoring data and an evaluation of the impact of pollution.Surveillance provides a scientific basis for standards development and application. The methodology of marine pollution control is governed by algorithms and models. A monitoring strategy should be put in place, coupled with an environmental assessment concept, through targeted research activities in areas identified at local and regional levels. This concept will make it possible to diagnose the state of "health" of these zones and consequently to correct any anomalies. Monitoring of the marine and coastal environment is based on recent methods and validated after experiments in the field of marine pollution.
Download or read book Analysis of Suspended Sediment Distributions in the Surface Waters of Delaware Bay Using Remote Sensing of Optical Properties written by Richard Paul Stumpf and published by . This book was released on 1984 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt:
