scholarly journals Conceptual Mini-Catchment Typologies for Testing Dominant Controls of Nutrient Dynamics in Three Nordic Countries

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1776 ◽  
Author(s):  
Fatemeh Hashemi ◽  
Ina Pohle ◽  
Johannes W.M. Pullens ◽  
Henrik Tornbjerg ◽  
Katarina Kyllmar ◽  
...  
Keyword(s):  
Land Use ◽  
Nutrient Dynamics ◽  
Pollution Monitoring ◽  
Organic N ◽  
Particulate Phosphorus ◽  
Nutrient Concentrations ◽  
Data Series ◽  
Nutrient Export ◽  
Small Streams ◽  
Export Behaviour

Optimal nutrient pollution monitoring and management in catchments requires an in-depth understanding of spatial and temporal factors controlling nutrient dynamics. Such an understanding can potentially be obtained by analysing stream concentration–discharge (C-Q) relationships for hysteresis behaviours and export regimes. Here, a classification scheme including nine different C-Q types was applied to a total of 87 Nordic streams draining mini-catchments (0.1–65 km2). The classification applied is based on a combination of stream export behaviour (dilution, constant, enrichment) and hysteresis rotational pattern (clock-wise, no rotation, anti-clockwise). The scheme has been applied to an 8-year data series (2010–2017) from small streams in Denmark, Sweden, and Finland on daily discharge and discrete nutrient concentrations, including nitrate (NO3−), total organic N (TON), dissolved reactive phosphorus (DRP), and particulate phosphorus (PP). The dominant nutrient export regimes were enrichment for NO3− and constant for TON, DRP, and PP. Nutrient hysteresis patterns were primarily clockwise or no hysteresis. Similarities in types of C-Q relationships were investigated using Principal Component Analysis (PCA) considering effects of catchment size, land use, climate, and dominant soil type. The PCA analysis revealed that land use and air temperature were the dominant factors controlling nutrient C-Q types. Therefore, the nutrient export behaviour in streams draining Nordic mini-catchments seems to be dominantly controlled by their land use characteristics and, to a lesser extent, their climate.

scholarly journals Biogeochemical and Hydrological Drivers of Heterogeneous Nutrient Exports From Subterranean Estuaries

2021 ◽  
Vol 8 ◽  
Author(s):  
Andrea J. Pain ◽  
Jonathan B. Martin ◽  
Caitlin R. Young
Keyword(s):  
Land Use ◽  
Chemical Composition ◽  
Groundwater Discharge ◽  
Nutrient Concentrations ◽  
Nutrient Export ◽  
Coastal Zones ◽  
Fresh Groundwater ◽  
Redfield Ratio ◽  
Subterranean Estuary ◽  
Subterranean Estuaries

Submarine groundwater discharge (SGD) to coastal zones contributes terrestrial freshwater and nutrients that may support harmful algal blooms (HABs). The magnitude of nutrient exports via SGD depends on volumes of fresh groundwater discharge, its chemical composition, and modifications by biogeochemical processing within subterranean estuaries. Thus, the ability to upscale SGD exports requires knowing the range of chemical composition of inland groundwater and how those compositions may be transformed as fresh and saltwater mix within subterranean estuaries. These processes may create heterogeneous magnitudes of solute exports, even at small spatial scales, and such heterogeneities have rarely been assessed for regional or global SGD nutrient export estimates. To evaluate heterogeneity in subterranean estuary processes and nutrient export, we collected seasonal pore water samples in 2015–2016 at three proximal (<20 km) subterranean estuary sites in Indian River Lagoon, FL. Sites have homogenous hydrogeological settings, but differ in land use and coastal features, and include a mangrove site, an urban site, and a site offshore of a natural wetland. All sites exhibit little variation through time in nutrient concentrations and modeled SGD rates. In contrast, each site exhibits significantly different nutrient concentrations of potential fresh groundwater sources, fresh groundwater discharge volumes, and nutrient transformations within subterranean estuaries. Groundwater specific discharge correlates with nutrient concentrations, suggesting that higher residence times in the subterranean estuary increase biogeochemical transformations that reduce anthropogenic nutrient loads but increase in situ nutrient sources derived from organic matter remineralization. The differences in transformations lead to SGD nutrient contributions that differ by orders of magnitude between sites and have N:P ratios that are greater than the Redfield ratio (15) for the mangrove (29) and urban sites (28), but less than the Redfield ratio for the wetland site (8). These results indicate that heterogeneity of both absolute and relative nutrient export via SGD complicates integration of nutrient fluxes across regional coastal zones and evaluations of its impacts to coastal ecosystems. A better understanding of the drivers of heterogeneity, including subterranean estuary processes, land use, coastal topography, and vegetation dynamics could improve assessments of regional nutrient loading and upscaling for estimates of global solute cycles.

scholarly journals Nutrient dynamics in tropical rivers, estuarine-lagoons, and coastal ecosystems along the eastern Hainan Island

2013 ◽  
Vol 10 (6) ◽  
pp. 9091-9147 ◽  
Author(s):  
R. H. Li ◽  
S. M. Liu ◽  
Y. W. Li ◽  
G. L. Zhang ◽  
J. L. Ren ◽  
...  
Keyword(s):  
Nutrient Dynamics ◽  
Sea Water ◽  
Inorganic Nitrogen ◽  
River Estuary ◽  
Hainan Island ◽  
Coastal Ecosystems ◽  
Particulate Phosphorus ◽  
Nutrient Concentrations ◽  
Tropical Region ◽  
Nutrient Inputs

Abstract. Nutrient dynamics were studied along the eastern Hainan Island based on field observations during 2006–2009, to understand nutrient biogeochemical processes and to have an overview of human perturbations on coastal ecosystems in this tropical region. The concentrations of nutrients in the rivers had seasonal variations enriched with dissolved inorganic nitrogen (DIN). High riverine concentrations of nitrate were mainly originated from agricultural fertilizer input. The ratios of DIN : PO43− ranged from 37 to 1063, suggesting preferential PO43− relative to nitrogen in the rivers. The areal yields of dissolved silicate (DSi) varied from 76 to 448 × 103 mol km−2 yr−1 due to erosion over the drainage area, inducing high levels of DSi among worldwide tropical systems. Aquaculture ponds contained high concentrations of NH4+ (up to 157 μM) and DON (up to 130 μM). Particulate phosphorus concentrations (0.5 ∼1.4 μM) were in lower level comparied with estuaries around the world. Particulate silicate levels in rivers and lagoons were lower than global average level. Nutrient biogeochemistry in coastal areas were affected by human activities (e.g. aquaculture, agriculture), as well as natural events such as typhoon. Nutrient concentrations were low because open sea water dispersed land-derived nutrients. Nutrient budgets were built based on a steady-state box model, which showed that riverine fluxes would be magnified by estuarine processes (e.g. regeneration, desorption) in the Wenchanghe/Wenjiaohe Estuary, Wanquan River estuary, and the Laoyehai Lagoon except in the Xiaohai Lagoon. Riverine and groundwater input were the major sources of nutrients to the Xiaohai Lagoon and the Laiyehai Lagoon, respectively. Riverine input and aquaculture effluent were the major sources of nutrients to the eastern coastal of Hainan Island. Nutrient inputs to the coastal ecosystem can be increased by typhoon-induced runoff of rainwater, and phytoplankton bloom in the sea would be caused.

scholarly journals Topography and Land Use Modulate Hydrological and Nutrient Export Dynamics in two Andean Streams

2019 ◽  
Author(s):  
Alejandro Sosnovsky ◽  
Mailén Elizabeth Lallement ◽  
Magalí Rechencq ◽  
Eduardo Enrique Zattara ◽  
María Valeria Fernández ◽  
...  
Keyword(s):  
Land Use ◽  
Nutrient Dynamics ◽  
Mountain Lake ◽  
Nutrient Export ◽  
Drainage Basins ◽  
Coarse Particulate Organic Matter ◽  
Annual Basis ◽  
Export Dynamics ◽  
Fluvial Dynamics ◽  
Limiting Nutrient

AbstractFluvial dynamics are driven by multiple environmental factors and scales. Studies coupling hydrological and nutrient dynamics of Andean streams are almost nonexistent. We characterized two adjacent streams with contrasting drainage basins: Casa de Piedra, originating in a small mountain lake and running through a pristine landscape, and Gutiérrez, originating in a large piedmont lake and running through an anthropized landscape. Despite both drainage basins sharing geology and climate, we found that the streams presented contrasting hydrological and nutrient dynamics. Casa de Piedra had higher discharge flashiness with shorter response delays to precipitation. Interestingly, Gutiérrez’s hydrology was buffered by the upstream lake, but its nutrient exports were not. Differences observed in quality and timing of coarse particulate organic matter export and basal export levels of phosphorus and nitrogen could be explained by human activities affecting Gutiérrez but not Casa de Piedra. Moreover, nitrogen:phosphorus ratio indicates a possible future shift to phosphorus as the limiting nutrient as Andean basins become more densely populated. In summary, our annual basis study shows that even under a common geology and climate, stream dynamics of adjacent basins can be starkly different due to differences in topography and land use.

scholarly journals Nutrient dynamics in tropical rivers, lagoons, and coastal ecosystems of eastern Hainan Island, South China Sea

2014 ◽  
Vol 11 (2) ◽  
pp. 481-506 ◽  
Author(s):  
R. H. Li ◽  
S. M. Liu ◽  
Y. W. Li ◽  
G. L. Zhang ◽  
J. L. Ren ◽  
...  
Keyword(s):  
Nutrient Dynamics ◽  
Inorganic Nitrogen ◽  
Hainan Island ◽  
Coastal Ecosystems ◽  
Eastern Coast ◽  
Particulate Phosphorus ◽  
Nutrient Concentrations ◽  
Tropical Rivers ◽  
Nutrient Inputs ◽  
Dissolved Silicate

Abstract. Nutrient dynamics based on field observations made along the eastern Hainan Island during the period 2006–2009 were investigated to understand nutrient biogeochemical processes, and to provide an overview of human perturbations of coastal ecosystems in this tropical region. The rivers showed seasonal variations in nutrient concentrations, with enrichment of dissolved inorganic nitrogen and dissolved silicate, and depletion of PO43−. High riverine concentrations of nitrate mainly originated from agricultural fertilizer inputs. The DIN : PO43− ratios ranged from 37 to 1063, suggesting preferential depletion of PO43− relative to nitrogen in rivers. Chemical weathering in the drainage area might explain the high levels of dissolved silicate. Aquaculture ponds contained high concentrations of NH4+ and dissolved organic nitrogen. The particulate phosphorus concentrations in the study area were lower than those reported for estuaries worldwide. The particulate silicate levels in rivers and lagoons were lower than the global average level. Nutrient biogeochemistry in coastal areas was affected by human activities (e.g., aquaculture, agriculture), and by natural phenomena including typhoons. The nutrient concentrations in coastal waters were low because of dispersion of land-derived nutrients in the sea. Nutrient budgets were built based on a steady-state box model, which showed that riverine fluxes are magnified by estuarine processes (e.g., regeneration, desorption) in estuaries and Laoyehai Lagoon, but not in Xiaohai Lagoon. Riverine and groundwater inputs were the major sources of nutrients to Xiaohai and Laoyehai lagoons, respectively, and riverine inputs and aquaculture effluents were the major sources for the eastern coast of Hainan Island. Nutrient inputs to the coastal ecosystem increased with typhoon-induced runoff of rainwater, elucidating the important influence of typhoons on small tropical rivers.

A Strategy for Estimating Nutrient Concentrations Using Remote Sensing Datasets and Hydrological Modeling

2012 ◽  
Vol 3 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Vladimir J. Alarcon ◽  
William H. McAnally
Keyword(s):  
Remote Sensing ◽  
Land Use ◽  
Total Nitrogen ◽  
Total Phosphorus ◽  
Hydrological Modeling ◽  
Northern Region ◽  
Nutrient Concentrations ◽  
Nutrient Export

This paper presents a methodology for estimating nutrient concentrations of total phosphorus (TP) and total nitrogen (TN) through the use of hydrological modeling, remote sensing datasets, and nutrient export coefficients. The strategy is applied to the Upper Tombigbee watershed, located in the northern region of the states of Mississippi and Alabama, USA. USGS GIRAS (1986), NASA MODIS MOD12Q1 (2001-2004) land use datasets, and USGS-DEM topographical datasets were used to characterize the physiography of the watershed. TN and TP concentration values estimated using the methodology were compared to values reported in the literature.

Biogeochemical Asynchrony: Ecosystem Drivers of Seasonal Concentration Regimes across the Great Lakes Basin

2020 ◽  
Author(s):  
Kimberly Van Meter ◽  
Nandita Basu ◽  
Danyka Byrnes
Keyword(s):  
Land Use ◽  
Phase Behavior ◽  
Nutrient Dynamics ◽  
Soluble Reactive Phosphorus ◽  
Low Flow ◽  
Nutrient Concentrations ◽  
Stream Metabolism ◽  
Great Lakes Basin ◽  
Discharge Data ◽  
Reactive Phosphorus

<p>Changes in seasonal climate regimes, and related changes in seasonal nutrient dynamics, are occurring across a range of climates and land use types. Although it is known that seasonal patterns in nutrient availability are key drivers of both stream metabolism and eutrophication, there has been little success in developing a comprehensive understanding of seasonal variations in nutrient export across watersheds or of the relationship between nutrient seasonality and watershed characteristics. In the present study, we have used concentration and discharge data from more than 200 stations across US and Canadian watersheds to identify (1) archetypal seasonal concentration regimes for nitrate, soluble reactive phosphorus, and total phosphorus, and (2) dominant watershed controls on these regimes across a gradient of climate, land use, and topography. Our analysis shows that less impacted watersheds, with more forested and wetland area, most commonly exhibit concentration regimes that are in phase with discharge, with concentration lows occurring during summer low-flow periods. Agricultural watersheds also commonly exhibit in-phase behavior, though the seasonality is usually muted compared to that seen in less impacted areas. With increasing urban area, however, nutrient concentrations frequently become essentially aseasonal or even exhibit clearly out-of-phase behavior. In addition, our data indicate that seasonal SRP concentration patterns may be strongly influenced by proximal controls such as the presence of dams and reservoirs. In all, these results suggest that human activity is significantly altering nutrient concentration regimes, with large potential consequences for both in-stream metabolism and eutrophication risk in downstream water bodies.</p>

Classification of Mini-catchment typologies for analyzing dominant controls of nutrient dynamic in three Nordic countries

2020 ◽  
Author(s):  
Fatemeh Hashemi ◽  
Ina Pohle ◽  
Henrik Tornbjerg ◽  
Katarina Kyllmar ◽  
Hannu Marttila ◽  
...  
Keyword(s):  
Nutrient Dynamics ◽  
Root Zone ◽  
Kendall Test ◽  
Organic N ◽  
Mitigation Options ◽  
Export Behavior ◽  
Optimal Dosing ◽  
Small Streams ◽  
Dissolved Reactive Phosphorus ◽  
Reactive Phosphorus

<p>Selection of non-point nutrient pollution management and mitigation options in catchments requires in-depth understanding of both spatial and temporal controlling aspects on nutrient dynamics for covering a diversity of factors controlling nutrient transfer to surface waters. Such an understanding can be obtained by analyzing the hysteresis behaviors and export regime in concentration-discharge (c-Q) relationships from the monitoring stations in smaller streams. <br>A classification scheme developed by Pohle et al. (2019), including nine different c-Q relationships classes were defined as a combination of export behavior (dilution, neutral, enrichment) and rotational pattern of the hysteresis (clock-wise, no rotation, anti-clockwise). To perform this, the export behavior was assessed based on the theoretical c-Q relationships by checking whether concentrations decrease, increase or do not change with discharge (Mann-Kendall test). The rotational pattern was also determined by comparing concentrations at the rising and the falling limb of the hydrograph (Kruskal-Wallis test).<br>The classification has been applied to a 8 years record (2010-2017) of daily discharge and discrete nutrient concentration  data from 88 small streams including forms such as - Nitrate, Organic N, Dissolved Reactive Phosphorus and Particulate P  from Denmark, Sweden and Finland. The streams drains catchments with a size ranging from 0.1 km² – 65 km². Additionally similarity in types of c-Q relationships were investigated by multivariate analysis for N and P forms  considering effects of land use, climate, soil type and the size of the catchments  . <br>The dilution behavior of the catchments might dominantly be related to arable catchments with low groundwater inputs and with a good direct contact from root zone to the stream (e.g. through tile drains for N) and macropore or surface runoff for P. The constant behavior of the catchments might dominantly be related to dominance of groundwater fed streams in arable or natural catchments and the enrichment behavior might dominantly be found in catchments influenced by point source discharges of nutrients.<br>This kind of catchments classification can be used for planning of optimal sampling frequencies in monitoring programs, cost-optimal dosing of mitigation options in catchments and inform about expected inertias in catchment responses to management. </p>

scholarly journals Influence of Ozone Treatment on Ultrafiltration Performance and Nutrient Flow in a Membrane Based Nutrient Recovery Process from Anaerobic Digestate

Membranes ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 64 ◽  
Author(s):  
Tobias Gienau ◽  
Artjom Ehrmanntraut ◽  
Matthias Kraume ◽  
Sandra Rosenberger
Keyword(s):  
Membrane Filtration ◽  
Recovery Process ◽  
Ozone Treatment ◽  
Organic N ◽  
Nutrient Concentrations ◽  
Particle Removal ◽  
Process Chain ◽  
K Fertilizer ◽  
P Fertilizer ◽  
Biogas Plants

Membrane filtration of biological suspensions is frequently limited by fouling. This mechanism is well understood for ultrafiltration of activated sludge in membrane bioreactors. A rather young application of ultrafiltration is the recovery of nutrients from anaerobic digestates, e.g., from agricultural biogas plants. A process chain of solid/liquid separation, ultrafiltration, and reverse osmoses separates the digestate into different products: an organic N-P-fertilizer (solid digestate), a recirculate (UF retentate), a liquid N-K-fertilizer (RO retentate) and water. Despite the preceding particle removal, high crossflow velocities are required in the ultrafiltration step to overcome fouling. This leads to high operation costs of the ultrafiltration step and often limits the economical application of the complete process chain. In this study, under-stoichiometric ozone treatment of the ultrafiltration feed stream is investigated. Ozone treatment reduced the biopolymer concentration and apparent viscosity of different digestate centrates. Permeabilities of centrate treated with ozone were higher than without ozone treatment. In a laboratory test rig and in a pilot plant operated at the site of two full scale biogas plants, ultrafiltration flux could be improved by 50–80% by ozonation. Nutrient concentrations in the fertilizer products were not affected by ozone treatment.

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