Estimation of particulate nutrient load usingturbidity meter

2006 ◽  
Vol 53 (2) ◽  
pp. 311-320 ◽  
Author(s):  
K. Yamamoto ◽  
T. Suetsugi
Keyword(s):  
Total Phosphorus ◽  
Flow Rate ◽  
Estimation Error ◽  
Nutrient Load ◽  
Nutrient Loads ◽  
Phosphorus Load ◽  
Regression Curve ◽  
Linear Relationships ◽  
Particulate Nutrients ◽  
Total Phosphorus Load

The “Nutrient Load Hysteresis Coefficient” was proposed to evaluate the hysteresis of the nutrient loads to flow rate quantitatively. This could classify the runoff patterns of nutrient load into 15 patterns. Linear relationships between the turbidity and the concentrations of particulate nutrients were observed. It was clarified that the linearity was caused by the influence of the particle size on turbidity output and accumulation of nutrients on smaller particles (diameter <23 μm). The L-Q-Turb method, which is a new method for the estimation of runoff loads of nutrients using a regression curve between the turbidity and the concentrations of particulate nutrients, was developed. This method could raise the precision of the estimation of nutrient loads even if they had strong hysteresis to flow rate. For example, as for the runoff load of total phosphorus load on flood events in a total of eight cases, the averaged error of estimation of total phosphorus load by the L-Q-Turb method was 11%, whereas the averaged estimation error by the regression curve between flow rate and nutrient load was 28%.

Factors affecting the efficiency of some estimators of fluvial total phosphorus load

1988 ◽  
Vol 24 (9) ◽  
pp. 1535-1540 ◽  
Author(s):  
Thomas C. Young ◽  
Joseph V. DePinto ◽  
Thomas M. Heidtke
Keyword(s):  
Total Phosphorus ◽  
Phosphorus Load ◽  
Factors Affecting ◽  
Total Phosphorus Load

Improving uncertain nutrient load estimates for Lake Balaton

2001 ◽  
Vol 43 (7) ◽  
pp. 279-286 ◽  
Author(s):  
A. Clement
Keyword(s):  
Water Quality Monitoring ◽  
Load Flow ◽  
Estimation Methods ◽  
Lake Balaton ◽  
Nutrient Loads ◽  
Total Load ◽  
Annual Total ◽  
Analytical Expressions ◽  
High Uncertainty ◽  
Total Phosphorus Load

Annual nutrient loads have been estimated for Lake Balaton over three decades. Tributaries may transport about half of the loads into the lake. The contribution of diffuse sources may reach two thirds of the total load. Biweekly/monthly water quality monitoring on small inflows (0.01 m3/s-0.3 m3/s range) results in a high uncertainty of load estimates. This paper evaluates the degree of uncertainties by using analytical expressions of sampling theory. Load-flow relationships were derived for five streams and annual total phosphorus load was predicted by four load estimation methods. A seasonal regression model, based upon the evaluation of historical set of observed phosphorus loads, appeared best to refine load estimates on small inflows. Correction frequently led to load estimates that exceeded uncorrected loads by a factor of two to three. Since the dynamics of the watercourses determined the errors of load estimates, stratified sampling is needed to decrease the uncertainties.

scholarly journals Atmospheric CO<sub>2</sub>, CH<sub>4</sub>, and CO with the CRDS technique at the Izaña Global GAW station: instrumental tests, developments, and first measurement results

2019 ◽  
Vol 12 (4) ◽  
pp. 2043-2066 ◽  
Author(s):  
Angel J. Gomez-Pelaez ◽  
Ramon Ramos ◽  
Emilio Cuevas ◽  
Vanessa Gomez-Trueba ◽  
Enrique Reyes
Keyword(s):  
Flow Rate ◽  
Random Noise ◽  
Least Square ◽  
Spatial Inhomogeneity ◽  
Inlet Pressure ◽  
Processing Scheme ◽  
Linear Relationships ◽  
Least Square Fit

Abstract. At the end of 2015, a CO2/CH4/CO cavity ring-down spectrometer (CRDS) was installed at the Izaña Global Atmosphere Watch (GAW) station (Tenerife, Spain) to improve the Izaña Greenhouse Gases GAW Measurement Programme, and to guarantee the renewal of the instrumentation and the long-term maintenance of this program. We present the results of the CRDS acceptance tests, the raw data processing scheme applied, and the response functions used. Also, the calibration results, the implemented water vapor correction, the target gas injection statistics, the ambient measurements performed from December 2015 to July 2017, and their comparison with other continuous in situ measurements are described. The agreement with other in situ continuous measurements is good most of the time for CO2 and CH4, but for CO it is just outside the GAW 2 ppb objective. It seems the disagreement is not produced by significant drifts in the CRDS CO World Meteorological Organization (WMO) tertiary standards. The more relevant contributions of the present article are (1) determination of linear relationships between flow rate, CRDS inlet pressure, and CRDS outlet valve aperture; (2) determination of a slight CO2 correction that takes into account changes in the inlet pressure/flow rate (as well as its stability over the years), and attributing it to the existence of a small spatial inhomogeneity in the pressure field inside the CRDS cavity due to the gas dynamics; (3) drift rate determination for the pressure and temperature sensors located inside the CRDS cavity from the CO2 and CH4 response function drift trends; (4) the determination of the H2O correction for CO has been performed using raw spectral peak data instead of the raw CO provided by the CRDS and using a running mean to smooth random noise in a long water-droplet test (12 h) before performing the least square fit; and (5) the existence of a small H2O dependence in the CRDS flow and of a small spatial inhomogeneity in the temperature field inside the CRDS cavity are pointed out and their origin discussed.

Runoff Nutrient Loads as Affected by Residue Cover, Manure Application Rate, and Flow Rate

2012 ◽  
Vol 55 (1) ◽  
pp. 249-258 ◽  
Author(s):  
C. A. Thayer ◽  
J. E. Gilley ◽  
L. M. Durso ◽  
D. B. Marx
Keyword(s):  
Flow Rate ◽  
Application Rate ◽  
Nutrient Loads ◽  
Manure Application

Nutrient pollution at the lower reaches of Mediterranean coastal rivers in Israel

2000 ◽  
Vol 42 (1-2) ◽  
pp. 147-152 ◽  
Author(s):  
B. Herut ◽  
N. Kress ◽  
H. Hornung
Keyword(s):  
Inorganic Nitrogen ◽  
Agricultural Runoff ◽  
Point Sources ◽  
Industrial Wastes ◽  
Nutrient Concentrations ◽  
Contamination Level ◽  
Nutrient Load ◽  
Nutrient Loads ◽  
Discharge Data ◽  
Coastal Rivers

This study represents the first attempt to evaluate the nutrient load introduced into the coastal waters by the rivers along the Mediterranean coast of Israel. Measurements of nutrient concentrations (phosphate, ammonium, nitrate, nitrite, silicic acid) at two or three stations along the lower river reaches (11 rivers) were carried out annually from 1990 up to 1998. Combining the nutrient concentrations with the monthly riverine discharges we assessed the nutrient load. In general, most of the coastal rivers contain high nutrient contamination level, compared to the criteria adopted by NOAA (USA) for coastal river estuaries. The high degree of contamination is attributed to extreme low natural flow combined with the discharge of domestic and industrial wastes, and with agriculture runoff. In terms of nutrient concentrations, the Kishon River is the most polluted, followed by the Soreq, Poleg and Alexander Rivers. The preliminary estimate is that the coastal rivers transport between ~2000 to 6000 tons of dissolved inorganic nitrogen (DIN) and between ~250–800 tons of dissolved inorganic phosphorus (DIP) to the sea. An additional 3500 and 3000 tons of DIN and DIP, respectively, are supplied through the Kishon River. The load of the Poleg River is unknown (no discharge data) but expected to be significant based on nutrient concentration measured. The total load of the coastal rivers constitutes a major component among the other land-base point sources such as the Gush Dan outfall. Our estimate probably represents minimal values, as it does not include diffused input of agricultural runoff nor the riverine particulate and dissolved organic nutrient loads (which are unknown).

scholarly journals Calibration of Stainless Steel-edged V-Notch Weir Stop Logs for Water Level Control Structures

2019 ◽  
Vol 35 (5) ◽  
pp. 745-749
Author(s):  
L. E. Christianson ◽  
R. D. Christianson ◽  
A. E. Lipka ◽  
S. Bailey ◽  
J. Chandrasoma ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Water Level ◽  
Flow Rate ◽  
Subsurface Drainage ◽  
Conservation Practices ◽  
Nutrient Loads ◽  
Level Control ◽  
Control Structures ◽  
Flow Monitoring ◽  
Flow Through

Abstract. Dependable flow rate measurements are necessary to calculate flow volumes and resulting nutrient loads from subsurface drainage systems and associated conservation practices. The objectives of this study were (1) to develop appropriate weir equations for a new stainless steel-edged 45° V-notch weir developed for AgriDrain inline water level control structures and (2) to determine if the equation was independent of flow depth in the structure. Weirs for 15 cm (6 in.) and 25 cm (10 in.) inline water level control structures were placed at three heights in each structure: at the base, 48 cm from the base, or 97 cm from the base, and the height of the nappe above the weir crest was recorded over a range of flow rates. The resulting data were fitted to equations of the form Q = aHb where Q is the flow rate, H is the height of the nappe above the weir crest, and a and b are fitted parameters. There were no significant differences in the fitted parameters across the two structure sizes or across the three weir placements. The fitted equation for these new stainless steel-edged V-notch weirs was Q = 0.011H2.28 with Q in liters per second and H in centimeters, and Q = 1.44H2.28, with Q in gallons per minute and H in inches. These equations can be used for measuring flow through AgriDrain in-line structures, although in-house weir calibration is highly recommended for specific applications, when possible. Keywords: Drainage, Flow monitoring, Subsurface drainage, V-notch weir, Weir calibration.

Variables Affecting the Use of Positive Displacement Pumps to Apply Herbicides in Ultralow Volume

1991 ◽  
Vol 5 (1) ◽  
pp. 111-116 ◽  
Author(s):  
James E. Hanks ◽  
Chester G. McWhorter
Keyword(s):  
Flow Rate ◽  
Liquid Flow ◽  
Field Application ◽  
Positive Displacement ◽  
Spray System ◽  
Linear Relationships ◽  
System Components ◽  
Spray Droplets ◽  
Median Diameter ◽  
Paraffinic Oil

Water and paraffinic oils were used to determine variables that affect positive displacement pumps used to meter liquid flow in an air-assist spray system. Components needed to construct an air-assist spray system were described for use in spray chambers and on a tractor for field application of herbicides in ultralow volume (ULV). The flow rate of the pump varied less than 2% for the water and oil as the pump setting was varied from 0 to 100% of the pump's capacity. Linear relationships were shown for both liquids as the voltage input varied from 4 to 13 volts. Air pressures to 100 kPa and liquid temperatures to 35 C did not affect flow rate of the pump. Volume median diameter of the spray droplets decreased from 295 μm to 77 μm and 159 μm to 85 μm for water and paraffinic oil, respectively, as the air pressure was adjusted from 14 to 110 kPa.

Impact of critical source area on AnnAGNPS simulation

2011 ◽  
Vol 64 (9) ◽  
pp. 1767-1773 ◽  
Author(s):  
Wang Xiaoyan ◽  
Lin Qinhui
Keyword(s):  
Source Area ◽  
Prediction Errors ◽  
Nutrient Loads ◽  
Watershed Scale ◽  
Point Source Pollution ◽  
Terrain Attributes ◽  
Average Slope ◽  
Nitrogen Yields ◽  
The Impact ◽  
Total Phosphorus Load

The objective of this paper is to study the impact of critical source area (CSA) within an Annualized AGricultural Non-Point Source pollution models (AnnAGNPS) simulation at medium- large watershed scale. The impact of CSA on terrain attributes is examined by comparing six sets of CSA (0.5, 1, 2, 4, 6 and 8 km2). The accuracy of AnnAGNPS stimulation on runoff, sediment and nutrient loads on these sets of CSA is further suggested in this paper. The results are as followed: (1) CSA has little effect on watershed area, and terrain altitude. The number of cell and reach decreases with the increase of CSA in power function regression curve. (2) The variation of CSA will lead to the uncertainty of average slope which increase the generalization of land characteristics. At the CSA range of 0.5–1 km2, there is little impact of CSA on slope. (3) Runoff amount does not vary so much with the variation of CSA whereas soil erosion and total nitrogen (TN) load change prominently. An increase of sediment yield is observed firstly then a decrease following later. There is evident decrease of TN load, especially when CSA is bigger than 6 km2. Total phosphorus load has little variation with the change of CSA. Results for Dage watershed show that CSA of 1 km2 is desired to avoid large underestimates of loads. Increasing the CSA beyond this threshold will affect the computed runoff flux but generate prediction errors for nitrogen yields. So the appropriate CSA will control error and make simulation at acceptable level.

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