Modelling Runoff and Sediment Loads in a Developing Coastal Watershed of the US-Mexico Border

Urbanization can increase sheet, rill, gully, and channel erosion. We quantified the sediment budget of the Los Laureles Canyon watershed (LLCW), which is a mixed rural-urbanizing catchment in Northwestern Mexico, using the AnnAGNPS model and field measurements of channel geometry. The model was calibrated with five years of observed runoff and sediment loads and used to evaluate sediment reduction under a mitigation scenario involving paving roads in hotspots of erosion. Calibrated runoff and sediment load had a mean-percent-bias of 28.4 and − 8.1, and root-mean-square errors of 85% and 41% of the mean, respectively. Suspended sediment concentration (SSC) collected at different locations during one storm-event correlated with modeled SSC at those locations, which suggests that the model represented spatial variation in sediment production. Simulated gully erosion represents 16%–37% of hillslope sediment production, and 50% of the hillslope sediment load is produced by only 23% of the watershed area. The model identifies priority locations for sediment control measures, and can be used to identify tradeoffs between sediment control and runoff production. Paving roads in priority areas would reduce total sediment yield by 30%, but may increase peak discharge moderately (1.6%–21%) at the outlet.

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The changing sediment loads of the world's rivers

Annals of Warsaw University of Life Sciences – SGGW Land Reclamation ◽

10.2478/v10060-008-0001-x ◽

2008 ◽

Vol 39 (1) ◽

pp. 3-20 ◽

Cited By ~ 14

Author(s):

Des Walling

Keyword(s):

Soil Conservation ◽

Sediment Load ◽

Dam Construction ◽

Sediment Control ◽

Sediment Loads ◽

Catchment Disturbance ◽

Control Programmes ◽

Key Drivers ◽

World Rivers ◽

And Storage

The changing sediment loads of the world's rivers This contribution reviews available evidence of recent changes in the sediment loads of the world's rivers and identifies the key drivers of such change. Land clearance, land use change and other facets of catchment disturbance, soil conservation and sediment control programmes and dam construction are shown to have resulted in significant recent changes in the sediment loads of many world rivers. Some rivers have been characterized by significant increases in sediment load, whereas others show significant decreases. Interpretation of the resulting trends requires consideration of aggregation and storage and buffering effects within a river basin, such that the downstream response of a river may not clearly reflect the changes occurring in the upstream basin and in the loads of tributary rivers.

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Road runoff and sediment sampling for determining road sediment yield at the watershed scale

Canadian Journal of Forest Research ◽

10.1139/x11-104 ◽

2011 ◽

Vol 41 (10) ◽

pp. 1970-1980 ◽

Cited By ~ 8

Author(s):

Christopher G. Surfleet ◽

Arne E. Skaugset ◽

Matthew W. Meadows

Keyword(s):

Sediment Yield ◽

Road Network ◽

Field Measurements ◽

Storm Event ◽

Watershed Scale ◽

Road Runoff ◽

The Road ◽

Sediment Production ◽

Erosion Models ◽

Commercial Forest

In this study, we demonstrate that watershed-scale estimates of road sediment production are improved if field measurements of road runoff and sediment production are used in the analysis. We used several techniques to spatially extrapolate measurements of road runoff and sampled sediment: comprehensive road runoff measurements, runoff estimates derived from the Distributed Hydrology Soil Vegetation Model (DHSVM), and adjustment of the road erosion models WARSEM and SEDMODL2.The sediment yield for the Oak Creek, Oregon, road network based on measured road runoff and sediment was 6.5 tons/year. When DHSVM was used to simulate road runoff, the estimated sediment from roads was similar, 6.9 tons/years. The road sediment production estimated by SEDMODL2 and WARSEM, adjusted with field-measured road runoff and sediment, was 28% and 34% less, respectively, than using the models with the default parameters. When applied to a road network in commercial forest land with frequent road use, the sediment yield estimated by SEDMODL2 and WARSEM without adjustment from field measurements was 480% and 610% higher, respectively, than with adjustments. We found that measuring runoff and sediment from one large storm event (≥1 year recurrence) provided a statistically significant relationship with the annual sediment yield.

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Hydrologic Modelling of Construction Site Sediment Control Pond Using SWMM

10.32920/ryerson.14654439.v1 ◽

2021 ◽

Author(s):

Renata Krasnova

Keyword(s):

Stormwater Management ◽

Current Control ◽

Control Measures ◽

Background Information ◽

Construction Site ◽

Stormwater Treatment ◽

Hydrologic Modelling ◽

Sediment Control ◽

Sources Of Pollution ◽

Receiving Waters

Construction activities have been identified as one of the major sources of pollution to receiving waters. Although Erosion and Sediment Control (ESC) measures reduce the amount of sediment exported from construction sites, there are still significant concerns regarding the sufficiency of current control measures to protect receiving waters. This study documents the work completed to monitor and model the performance of a typical stormwater management facility used for erosion and sediment control in suburban construction site. The main objective of this study is to provide background information regarding the performance of stormwater management facilities for treating urban construction runoff prior to discharging to receiving water bodies. The RUNOFF and STORAGE TREATMENT blocks of EPA's stormwater management model (PCSWMM4.4) were used to simulate the quantity and quality of stormwater run-off from the area under construction and assess the performance of stormwater treatment facility (Ballymore Pond) located in Richmond Hill, Ontario. The performance of the construction site sediment control pond was found to be unsatisfactory due to the high outflow concentration of suspended solids. Some specific recommendations to improve its effectiveness have been made.

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Hydrologic Modelling of Construction Site Sediment Control Pond Using SWMM

10.32920/ryerson.14654439 ◽

2021 ◽

Author(s):

Renata Krasnova

Keyword(s):

Stormwater Management ◽

Current Control ◽

Control Measures ◽

Background Information ◽

Construction Site ◽

Stormwater Treatment ◽

Hydrologic Modelling ◽

Sediment Control ◽

Sources Of Pollution ◽

Receiving Waters

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Data Assimilation for Ionospheric Space-Weather Forecasting in the Presence of Model Bias

Frontiers in Applied Mathematics and Statistics ◽

10.3389/fams.2021.679477 ◽

2021 ◽

Vol 7 ◽

Author(s):

Juan Durazo ◽

Eric J. Kostelich ◽

Alex Mahalov

Keyword(s):

Data Assimilation ◽

Space Weather ◽

Bias Correction ◽

Geomagnetic Storms ◽

Circulation Model ◽

Storm Event ◽

Electron Content ◽

Systematic Bias ◽

Total Electron ◽

Mean Square Errors

The dynamics of many models of physical systems depend on the choices of key parameters. This paper describes the results of some observing system simulation experiments using a first-principles model of the Earth’s ionosphere, the Thermosphere Ionosphere Electrodynamics Global Circulation Model (TIEGCM), which is driven by parameters that describe solar activity, geomagnetic conditions, and the state of the thermosphere. Of particular interest is the response of the ionosphere (and predictions of space weather generally) during geomagnetic storms. Errors in the overall specification of driving parameters for the TIEGCM (and similar dynamical models) may be especially large during geomagnetic storms, because they represent significant perturbations away from more typical interactions of the earth-sun system. Such errors can induce systematic biases in model predictions of the ionospheric state and pose difficulties for data assimilation methods, which attempt to infer the model state vector from a collection of sparse and/or noisy measurements. Typical data assimilation schemes assume that the model produces an unbiased estimate of the truth. This paper tests one potential approach to handle the case where there is some systematic bias in the model outputs. Our focus is on the TIEGCM when it is driven with solar and magnetospheric inputs that are systematically misspecified. We report results from observing system experiments in which synthetic electron density vertical profiles are generated at locations representative of the operational FormoSat-3/COSMIC satellite observing platforms during a moderate (G2, Kp = 6) geomagnetic storm event on September 26–27, 2011. The synthetic data are assimilated into the TIEGCM using the Local Ensemble Transform Kalman Filter with a state-augmentation approach to estimate a small set of bias-correction factors. Two representative processes for the time evolution of the bias in the TIEGCM are tested: one in which the bias is constant and another in which the bias has an exponential growth and decay phase in response to strong geomagnetic forcing. We show that even simple approximations of the TIEGCM bias can reduce root-mean-square errors in 1-h forecasts of total electron content (a key ionospheric variable) by 20–45%, compared to no bias correction. These results suggest that our approach is computationally efficient and can be further refined to improve short-term predictions (∼1-h) of ionospheric dynamics during geomagnetic storms.

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China’s emission control strategies have suppressed unfavorable influences of climate on wintertime PM2.5 concentrations in Beijing since 2002

10.5194/egusphere-egu2020-6424 ◽

2020 ◽

Author(s):

Meng Gao ◽

Kaili Lin ◽

Shiqing Zhang ◽

Ken kin lam Yung

Keyword(s):

Control Strategies ◽

Emission Control ◽

Field Measurements ◽

Meteorological Conditions ◽

Control Measures ◽

Anthropogenic Emissions ◽

Recent Climate ◽

Decadal Variations ◽

Haze Days ◽

Emission Control Measures

Severe wintertime PM2.5 pollution in Beijing has been receiving increasing worldwide attention, yet the decadal variations remain relatively unexplored. Combining field measurements and model simulations, we quantified the relative influences of anthropogenic emissions and meteorological conditions on PM2.5 concentrations in Beijing overwinters of 2002-2016. Between the winters of 2011 and 2016, stringent emission control measures resulted in a 21% decrease in mean mass concentrations of PM2.5 in Beijing, with 7 fewer haze days per winter on average. Given the overestimation of PM2.5 by model, the effectiveness of stringent emission control measures might have been slightly overstated. With fixed emissions, meteorological conditions over the study period would have led to an increase of haze in Beijing, but the strict emission control measures have suppressed the unfavorable influences of recent climate. The unfavorable meteorological conditions are attributed to the weakening of the East Asia Winter Monsoon associated particularly with an increase in pressure associated with the Aleutian low.

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Evaluation of Recommended Water Sample Collection Methods and the Impact of Holding Time on Legionella Recovery and Variability from Healthcare Building Water Systems

Microorganisms ◽

10.3390/microorganisms8111770 ◽

2020 ◽

Vol 8 (11) ◽

pp. 1770

Author(s):

Marisa B. Hirsh ◽

Julianne L. Baron ◽

Sue M. Mietzner ◽

John D. Rihs ◽

Mohamed H. Yassin ◽

...

Keyword(s):

Hold Time ◽

Field Measurements ◽

Quality Parameters ◽

Hot Water ◽

Control Measures ◽

Sampling Location ◽

Sample Collection ◽

Water Safety ◽

Processing Methods ◽

The Impact

Water safety and management programs (WSMP) utilize field measurements to evaluate control limits and monitor water quality parameters including Legionella presence. This monitoring is important to verify that the plan is being implemented properly. However, once it has been determined when and how to sample for Legionella, it is important to choose appropriate collection and processing methods. We sought to compare processing immediate and flushed samples, filtration of different volumes collected, and sample hold times. Hot water samples were collected immediately and after a 2-min flush. These samples were plated directly and after filtration of either 100 mL, 200 mL, or 1 L. Additionally, unflushed samples were collected and processed immediately and after 1, 24, and 48 h of hold time. We found that flushed samples had significant reductions in Legionella counts compared to immediate samples. Processing 100 mL of that immediate sample both directly and after filter concentration yielded the highest concentration and percent sample positivity, respectively. We also show that there was no difference in culture values from time 0 compared to hold times of 1 h and 24 h. At 48 h, there were slightly fewer Legionella recovered than at time 0. However, Legionella counts were so variable based on sampling location and date that this hold time effect was minimal. The interpretation of Legionella culture results depends on the sample collection and processing methods used, as these can have a huge impact on the success of sampling and the validation of control measures.

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Erosion and Sediment Control At Road-Stream Crossings

The Forestry Chronicle ◽

10.5558/tfc59062-2 ◽

1983 ◽

Vol 59 (2) ◽

pp. 62-66 ◽

Cited By ~ 9

Author(s):

R. L. Rothwell

Keyword(s):

Suspended Sediment ◽

Overland Flow ◽

Bare Soil ◽

High Variability ◽

Final Conclusion ◽

Sediment Control ◽

Sediment Production ◽

Control Erosion

The effectiveness of a "brush mulch" to control erosion and sediment at road-stream crossings was evaluated by measurement and comparison of upstream and downstream suspended sediment. The brush mulch consisted of logging debris, such as branches, tree tops and logs 2-15 cm in diameter, laid on the ground to intercept and to slow overland flow and to trap sediment. Two treatments were defined and tested. Treatment no. 1 was a brush mulch and grass-fertilizer mixture applied by hydroseeding to three bare soil road-stream crossings. Treatment no. 2 was a grass-fertilizer mixture applied by hydroseeding to another three road-stream crossings.Total seasonal and storm sediment production for mulched and unmulched crossings averaged 31 and 37, and 566 and 2297 kg/day/ha, respectively. Tests showed significant differences between treatments for both seasonal and storm sediment production. The levels of significance were low because of high variability in sediment production among treatments and road crossings. Frequent onsite inspections during storm and nonstorm conditions, however, identified sources of variability and supported a final conclusion that the brush mulch was effective for erosion and sediment control at road-stream crossings.

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Application of Soft Computing Models with Input Vectors of Snow Cover Area in Addition to Hydro-Climatic Data to Predict the Sediment Loads

Water ◽

10.3390/w12051481 ◽

2020 ◽

Vol 12 (5) ◽

pp. 1481 ◽

Cited By ~ 1

Author(s):

Waqas Hussan ◽

Muhammad Khurram Shahzad ◽

Frank Seidel ◽

Franz Nestmann

Keyword(s):

Fuzzy Logic ◽

Snow Cover ◽

Sediment Load ◽

Snow Cover Area ◽

Inference System ◽

Sediment Yields ◽

Fuzzy Logic Inference ◽

Sediment Loads ◽

Neuro Fuzzy ◽

Logic Inference

The accurate estimate of sediment load is important for management of the river ecosystem, designing of water infrastructures, and planning of reservoir operations. The direct measurement of sediment is the most credible method to estimate the sediments. However, this requires a lot of time and resources. Because of these two constraints, most often, it is not possible to continuously measure the daily sediments for most of the gauging sites. Nowadays, data-based sediment prediction models are famous for bridging the data gaps in the estimation of sediment loads. In data-driven sediment predictions models, the selection of input vectors is critical in determining the best structure of models for the accurate estimation of sediment yields. In this study, time series inputs of snow cover area, basin effective rainfall, mean basin average temperature, and mean basin evapotranspiration in addition to the flows were assessed for the prediction of sediment loads. The input vectors were assessed with artificial neural network (ANN), adaptive neuro-fuzzy logic inference system with grid partition (ANFIS-GP), adaptive neuro-fuzzy logic inference system with subtractive clustering (ANFIS-SC), adaptive neuro-fuzzy logic inference system with fuzzy c-means clustering (ANFIS-FCM), multiple adaptive regression splines (MARS), and sediment rating curve (SRC) models for the Gilgit River, the tributary of the Indus River in Pakistan. The comparison of different input vectors showed improvements in the prediction of sediments by using the snow cover area in addition to flows, effective rainfall, temperature, and evapotranspiration. Overall, the ANN model performed better than all other models. However, as regards sediment load peak time series, the sediment loads predicted using the ANN, ANFIS-FCM, and MARS models were found to be closer to the measured sediment loads. The ANFIS-FCM performed better in the estimation of peak sediment yields with a relative accuracy of 81.31% in comparison to the ANN and MARS models with 80.17% and 80.16% of relative accuracies, respectively. The developed multiple linear regression equation of all models show an R2 value of 0.85 and 0.74 during the training and testing period, respectively.

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Is more better? Sediment production, weathering, and erosion inferred from multiple geochemical proxies and comprehensive field measurements in mountain catchments

10.5194/egusphere-egu2020-13564 ◽

2020 ◽

Author(s):

Clifford S. Riebe ◽

Leonard S. Sklar ◽

Claire E. Lukens

Keyword(s):

Field Measurements ◽

Cosmogenic Nuclides ◽

Spatial Variations ◽

Residence Times ◽

Size Distributions ◽

Erosion Rates ◽

Cosmogenic Nuclide ◽

Sediment Production ◽

Sediment Size ◽

Geochemical Proxies

Weathering in mountain landscapes produces sediment with size distributions that evolve as particles are transported down hillslopes, delivered to channels, and carried downstream. The evolving sizes influence rates of river incision into bedrock, which in turn set sediment residence times on hillslopes, with implications for the sizes of sediment produced by weathering. Hence, variations in sediment size are central to feedbacks that link climate, tectonics, and erosion in mountain landscape evolution. However, few studies have quantified how sediment sizes evolve during transport across catchments, focusing instead on rates of erosion and weathering. Yet recent modeling suggests that spatial variations in sediment size can lead to bias in erosion rates from conventional techniques, further highlighting the importance of understanding how sediment size evolves across landscapes.Here we show how a more complete and unbiased picture of sediment production, weathering, and erosion can be obtained by combining field measurements of sediment size together with conventional geochemical proxies in an integrative model that accounts for spatial variations in erosion, weathering, and sediment mixing, while incorporating effects of both abrasion and fragmentation during transport in channels. Our measurements, from a catchment draining the steep eastern Sierra Nevada, California, include particle size distributions of sediment from widely distributed locations. These measurements represent sediment that is produced on hillslopes and delivered to channels, reflecting the combined effects of the initial sediment size distribution (set by bedrock fracture spacing) and subsequent weathering on slopes. Our measurements also include cosmogenic nuclide concentrations and apatite-helium ages in 11 size classes, from sand to boulders, sampled from the creek. The cosmogenic nuclides reveal residence times of sediment in the catchment, while the apatite-helium ages reveal source elevations of sediment eroded into the stream. When combined together, the cosmogenic nuclide and apatite-helium data can be used to quantify altitudinal variations in erosion rates and sediment size distributions.Our measurements from catchment slopes indicate that hillslope sediment size decreases with decreasing elevation, reflecting altitudinal trends in physical, chemical, and biological weathering and producing downvalley fining in hillslope sediment supply. Cosmogenic nuclides in stream sediment decrease by two-fold with increasing particle size, indicating that erosion rates calculated using traditional techniques are sensitive to the size sampled from the creek. Apatite-helium ages suggest that the smallest and largest sizes sediment sizes in the stream originate from lower elevations, where slopes are gentler and soil-mantled. In contrast, coarse gravel and cobbles appear to originate from higher in the catchment, where slopes are steeper and bare bedrock is exposed. The differences in altitudinal trends in sediment size implied by the apatite-helium data and the direct observations from catchment slopes can be reconciled by accounting for particle fragmentation and abrasion during transport from hillslope sources to the sampling point in the creek. Our analysis indicates that each of the unique sources of information in our study are necessary for a complete and unbiased understanding of spatial variations in the production of sediment across the full range of sizes and their evolution during transport across the catchment.

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