Influence of climate,geology and humans on spatial and temporal nutrient geochemistry in the subtropical Richmond River catchment, Australia

2001 ◽  
Vol 52 (2) ◽  
pp. 235 ◽  
Author(s):  
Lester J. McKee ◽  
Bradley D. Eyre ◽  
Shahadat Hossain ◽  
Peter R. Pepperell
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Agricultural Land ◽  
Anthropogenic Impacts ◽  
Inorganic Nitrogen ◽  
Point Sources ◽  
Nutrient Concentrations ◽  
Wet Season ◽  
Nitrogen And Phosphorus ◽  
River Catchment

Water quality was monitored on a spatial and temporal basis in the subtropical Richmond River catchment over two years. Nutrient concentrations varied seasonally in a complex manner with highest concentrations (maximum =3110 µg N L – 1 and 572 µg P L –1 ) associated with floods. However, median (444 µg N L – 1 and 55 µg P L – 1 ) concentrations were relatively low compared with other parts of the world. The forms of nitrogen and phosphorus in streams varied seasonally, with greater proportions of inorganic nitrogen and phosphorus during the wet season. Minimum nutrient concentrations were found 2—3 months after flood discharge. With the onset of the dry season, concentration increases were attributed to point sources and low river discharge. There were statistically significant relationships between geology and water quality and nutrient concentrations increased downstream and were significantly related to population density and dairy farming. In spite of varying geology and naturally higher phosphorus in soils and rocks in parts of the catchment, anthropogenic impacts had the greatest effects on water quality in the Richmond River catchment. Rainfall quality also appeared to be related both spatially and seasonally to human activity. Although the responses of the subtropical Richmond River catchment to changes in land use are similar to those of temperate systems of North America and Europe, the seasonal patterns appear to be more complex and perhaps typical of subtropical catchments dominated by agricultural land use.

scholarly journals Effects of watershed and riparian zone characteristics on nutrient concentrations in the River Scheldt Basin

2006 ◽  
Vol 10 (6) ◽  
pp. 913-922 ◽  
Author(s):  
J. Meynendonckx ◽  
G. Heuvelmans ◽  
B. Muys ◽  
J. Feyen
Keyword(s):  
Land Use ◽  
Agricultural Land ◽  
Wastewater Treatment Plants ◽  
Morphological Characteristics ◽  
Drainage Density ◽  
Point Sources ◽  
Nutrient Concentrations ◽  
Buffer Strip ◽  
Additional Influence ◽  
Scheldt Basin

Abstract. The relative influence of a set of watershed characteristics on surface water nutrient concentrations was examined in 173 watersheds within two subcatchments (Upper-Scheldt and Nete) of the River Scheldt Basin (Flanders, Belgium). Each watershed was described by seasonal rainfall, discharge loading of point sources, morphological characteristics (area, average slope, drainage density, elongation), land use and soil properties (soil texture and drainage). Partial regression analysis revealed that soil drainage variables had the strongest influence on nutrient concentrations. Additional influence was exerted by land use and point source loading variables. Nitrate concentrations were positively correlated with effluent loadings coming from wastewater treatment plants and with the area of agricultural land. Phosphate concentrations were best explained by effluent loadings of industrial point sources and by the area of urban land. Land use close to the river was not a better predictor of nitrate and phosphate concentrations than land use away from the river. This suggests that the mediating impact of riparian zones is rather explained by the hydrologic pathways within the buffer strip.

scholarly journals Assessment of runoff nitrogen load reduction measures for agricultural catchments

2018 ◽  
Vol 10 (1) ◽  
pp. 403-412 ◽  
Author(s):  
Marta Martínková ◽  
Tomáš Hejduk ◽  
Petr Fučík ◽  
Jan Vymazal ◽  
Martin Hanel
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Land Use Change ◽  
Agricultural Land ◽  
Nitrate Nitrogen ◽  
Nitrogen Sources ◽  
Point Sources ◽  
Pollution Sources ◽  
Agricultural Land Use ◽  
Physical Factors

AbstractWater quality in rural catchments is influenced by many societal and bio-physical factors (e.g. different pollution sources, land use and land cover changes). Good ecological status and surface water quality are currently challenged mainly due to different poorly identified pollution sources. The main objective of this study is to estimate the potential of different measures (land use changes and/or reduction in point sources) and their combinations in decreasing the nitrate-nitrogen load from Jankovský stream catchment. The eco-hydrological model SWIM, which simulates dynamics of nutrients in a catchment was used in the study. The simulations for scenario measures showed that nitrate-nitrogen loads at the outlet can be decreased more by reduction of municipal nitrate-nitrogen sources rather than by agricultural land-use change. Overall, the modeling results demonstrated that the most effective scenario was the combination of total reduction of municipal nitrate-nitrogen sources and agricultural land-use change.

scholarly journals Spatial and Long-Term Temporal Changes in Water Quality Dynamics of the Tonle Sap Ecosystem

Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2059
Author(s):  
Savoeurn Soum ◽  
Peng Bun Ngor ◽  
Thomas E. Dilts ◽  
Sapana Lohani ◽  
Suzanne Kelson ◽  
...  
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Water Level ◽  
Inorganic Nitrogen ◽  
Flood Pulse ◽  
Nutrient Ratios ◽  
Nitrogen And Phosphorus ◽  
Watershed Land Use ◽  
Tonle Sap

Tonle Sap lake-river floodplain ecosystem (TSE) is one of the world’s most productive freshwater systems. Changes in hydrology, climate, population density, and land use influence water quality in this system. We investigated long term water quality dynamics (22 years) in space and time and identified potential changes in nutrient limitation based on nutrient ratios of inorganic nitrogen and phosphorus. Water quality was assessed at five sites highlighting the dynamics in wet and dry seasons. Predictors of water quality included watershed land use, climate, population, and water level. Most water quality parameters varied across TSE, except pH and nitrate that remained constant at all sites. In the last decade, there is a change in the chemical nutrient ratio suggesting that nitrogen may be the primary limiting nutrient across the system. Water quality was strongly affected by development in the watershed i.e., flooded forest loss, climatic variation, population growth, and change in water level. Seasonal variations of water quality constituents were driven by precipitation and hydrology, notably the Mekong’s distinct seasonal flood pulse.

scholarly journals Perception of tools for assessing on-farm nutrient losses and mitigation options

2021 ◽  
Author(s):  
◽  
Maggie Rogers
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Environmental Sustainability ◽  
Agricultural Land ◽  
Mitigation Measures ◽  
Nitrogen And Phosphorus ◽  
Land Use Models ◽  
On Farm ◽  
Degraded Water Quality

<p>This research focuses on the prominent issue of degraded water quality in New Zealand caused by the intensification of agricultural land use, resulting in increased levels of diffuse pollutants such as sediment, nitrogen and phosphorus in waterways (Duncan, 2017). Degraded water quality is a critical issue that needs to be addressed both socially and scientifically. It needs to be addressed socially as human behaviour is influencing this degradation, and the science is needed to further our understanding and implementation of the best mitigation solutions.  The aim of this study was to evaluate how information surrounding potential nutrient mitigation measures provided by decision support tools is understood and interpreted by farmers facing tightening environmental regulations and a changing social outlook on environmental sustainability. To achieve this aim, the following activities were conducted: (i) A review of current theories and tools available to understand and encourage pro-environmental behaviour. (ii) A case study using the Land Utilisation Capability Indicator (LUCI) model to determine stakeholder engagement was carried out through interviews with 6 farmers in the Mangatarere Catchment.  The review showed that while information alone does not drive behaviour change, it is an essential component that when used in collaboration with other methods and incentives, can be very successful (Kennedy, 2010; Mackenzie-Mohr, 2000; Stern, 2000). From this review a method that was identified as having huge potential in terms of managing water quality was the use of land use models alongside targeted on-farm advice (Bouraoui & Grizzetti, 2014).  To understand the stakeholder perception and uptake of the information this method provides a case study was carried out using the LUCI model with 6 farmers in the Mangatarere Catchment. The results showed that LUCI proved to be a valuable tool for both the case study farmers and the wider farming community. Farmer feedback highlighted the importance of ensuring that information provided by such tools is communicated in a consolidated manner. This thesis shows that land use models such as LUCI have the potential to be a beneficial method of engaging stakeholders in prominent issues such as degrading water quality.</p>

scholarly journals Perception of tools for assessing on-farm nutrient losses and mitigation options

2021 ◽  
Author(s):  
◽  
Maggie Rogers
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Environmental Sustainability ◽  
Agricultural Land ◽  
Mitigation Measures ◽  
Nitrogen And Phosphorus ◽  
Land Use Models ◽  
On Farm ◽  
Degraded Water Quality

<p>This research focuses on the prominent issue of degraded water quality in New Zealand caused by the intensification of agricultural land use, resulting in increased levels of diffuse pollutants such as sediment, nitrogen and phosphorus in waterways (Duncan, 2017). Degraded water quality is a critical issue that needs to be addressed both socially and scientifically. It needs to be addressed socially as human behaviour is influencing this degradation, and the science is needed to further our understanding and implementation of the best mitigation solutions.  The aim of this study was to evaluate how information surrounding potential nutrient mitigation measures provided by decision support tools is understood and interpreted by farmers facing tightening environmental regulations and a changing social outlook on environmental sustainability. To achieve this aim, the following activities were conducted: (i) A review of current theories and tools available to understand and encourage pro-environmental behaviour. (ii) A case study using the Land Utilisation Capability Indicator (LUCI) model to determine stakeholder engagement was carried out through interviews with 6 farmers in the Mangatarere Catchment.  The review showed that while information alone does not drive behaviour change, it is an essential component that when used in collaboration with other methods and incentives, can be very successful (Kennedy, 2010; Mackenzie-Mohr, 2000; Stern, 2000). From this review a method that was identified as having huge potential in terms of managing water quality was the use of land use models alongside targeted on-farm advice (Bouraoui & Grizzetti, 2014).  To understand the stakeholder perception and uptake of the information this method provides a case study was carried out using the LUCI model with 6 farmers in the Mangatarere Catchment. The results showed that LUCI proved to be a valuable tool for both the case study farmers and the wider farming community. Farmer feedback highlighted the importance of ensuring that information provided by such tools is communicated in a consolidated manner. This thesis shows that land use models such as LUCI have the potential to be a beneficial method of engaging stakeholders in prominent issues such as degrading water quality.</p>

scholarly journals Nitrogen and Phosphorus Loads in Greek Rivers: Implications for Management in Compliance with the Water Framework Directive

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1531
Author(s):  
Konstantinos Stefanidis ◽  
Aikaterini Christopoulou ◽  
Serafeim Poulos ◽  
Emmanouil Dassenakis ◽  
Elias Dimitriou
Keyword(s):  
Water Framework Directive ◽  
Inorganic Nitrogen ◽  
Inorganic Phosphorus ◽  
Point Sources ◽  
Nutrient Concentrations ◽  
Nutrient Loads ◽  
Land Uses ◽  
Nitrogen And Phosphorus ◽  
Nitrogen Loads ◽  
Phosphorus Loads

Reduction of nutrient loadings is often prioritized among other management measures for improving the water quality of freshwaters within the catchment. However, urban point sources and agriculture still thrive as the main drivers of nitrogen and phosphorus pollution in European rivers. With this article we present a nationwide assessment of nitrogen and phosphorus loads that 18 large rivers in Greece receive with the purpose to assess variability among seasons, catchments, and river types and distinguish relationships between loads and land uses of the catchment. We employed an extensive dataset of 636 field measurements of nutrient concentrations and river discharges to calculate nitrogen and phosphorus loads. Descriptive statistics and a cluster analysis were conducted to identify commonalties and differences among catchments and seasons. In addition a network analysis was conducted and its modularity feature was used to detect commonalities among rivers and sampling sites with regard to their nutrient loads. A correlation analysis was used to identify major possible connections between types of land uses and nutrient loads. The results indicated that the rivers Alfeios, Strymonas, and Aliakmonas receive the highest inorganic nitrogen loads while the highest inorganic phosphorus loads were calculated for the rivers Strymonas, Aliakmonas, and Axios. Concerning the temporal variation of loads, inorganic nitrogen presented a peak on March and gradually declined until October when the dry period typically ends for most regions of Greece. Inorganic phosphorus loads had the highest average value in August and the lowest in October. Thus, our findings confirmed the presence of a typical seasonal variation in nitrogen loads that follows the seasonality in hydrology where high surface runoff during the wet months contribute to higher river discharges and higher nitrogen loads from the catchment. On the contrary, high phosphorus loads persisted during dry months that could be attributed to a dilution effect. Furthermore, the results imply a clear connection between agriculture and both nitrogen and phosphorus. Overall, this work presents extensive information on the nitrogen and phosphorus loads that major rivers in Greece receive that can largely aid water managers to adapt and revise basin management plans in accordance with agricultural management (e.g., which months farmers should reduce the use of fertilizers) with the purpose of meeting the environmental targets defined by the Water Framework Directive (WFD).

scholarly journals ASSESSING THE EFFECTS OF LAND USE CONVERSION ON RUNOFF AND NUTRIENT LOAD

2018 ◽  
Vol 30 (3) ◽  
Author(s):  
Khairul Anuar Mohamad ◽  
Noorbaharim Hashim ◽  
Ilya Khairanis Othman ◽  
Mohd Syazwan Faisal Mohd
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Agricultural Land ◽  
Fold Increase ◽  
Base Flow ◽  
Point Sources ◽  
Plant Management ◽  
Water Quality And Quantity ◽  
Effects Of Land Use

An agricultural land with intensive cultivation, large catchments with extended rivers and agricultural population of high-density are the primary reasons for higher pollutant loads in freshwater. However, there are problems in pursuing nutrient losses since several parameters, such as variability in soils and climate are associated with heavy rainfall, especially in tropic regions; plant management, limited resources, and insufficient technical support are not consistent in every crop management. Changes in agricultural practices and unmonitored point sources discharge from watershed, have led to algal bloom in abundance, and thus generated eutrophication at the downstream. The complex watershed processes and forecasting the effects of land use change on water quality can be determined by using tools of watershed models. The Hydrological Simulation Programme-FORTRAN (HSPF) uses lumped parameters, continuous model to predict the long-term evaluation, and deterministic for simulating the water quality and quantity process that occur at the watershed. Pervious land segments (PERLND), impervious land segments (IMPLND), and channel reach (RCHRES) modules were used to determine the general water quality and quantity on Johor watershed. Based on calibration and validation, the HSPF model was capable of simulating different runoff seasons. An increment of 60% in agricultural land had increased the annual mean total phosphorus (TP) load and total nitrogen (TN) load by 3.82% and 5.34%, respectively. A 2-fold increase in agricultural land would result in an approximately 2-fold increase in the quantity of annual TN and TP loads. Between TN and TP loads, TP load has potentially increased more than TN load during the dry, wet, and base-flow years. Upon the long-term of water quality and quantity simulation, this study provides essential knowledge for a method-based runoff and nutrient management plan for the Johor watershed.

The Nutritional Status of Waters and Origin Analysis of the Xitiaoxi Tributaries

2014 ◽  
Vol 937 ◽  
pp. 669-675
Author(s):  
Huan Wang ◽  
Xu Yin Yuan ◽  
Zheng Yang Li ◽  
Hai Yan Xu ◽  
Hai Long Chen
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Nutritional Status ◽  
Chlorophyll A ◽  
Spatial Variations ◽  
Wet Season ◽  
Nitrogen And Phosphorus ◽  
Chl A ◽  
Seasonal And Spatial Variations ◽  
Origin Analysis

This paper investigates the seasonal and spatial variations of nutrients, permanganate index and chlorophyll-a of the Xitiaoxi tributaries. The results show that most of nutrients, CODMnand chlorophyll-a in dry season are higher than in wet season. The concentrations of TN and NO3--N show significant higher in the tributaries dominated by woodland. The contents of TP, TDP and chl-a in tributaries influenced by towns are higher than the tributaries located in farmland and woodland. CODMnin mixed-source lands of farmland and towns have the highest concentration, followed by towns and woodland dominated tributaries. The rates of TN/TP indicate that eutrophication in most of tributaries are limited by TP. The correlations between nutrients, CODMnand Chl-a indicate the concentrations of organics and microorganism are associated with nitrogen and phosphorus in waters. Land use is the most important factor affecting water quality in tributaries of Xitiaoxi watershed. The values of TDP/TP in towns dominated tributaries are higher than other tributaries. Mixed-source lands are the most important factor affecting NH4+-N values.

scholarly journals Effects of watershed and riparian zone characteristics on nutrient concentrations in the River Scheldt Basin

2006 ◽  
Vol 3 (3) ◽  
pp. 653-679 ◽  
Author(s):  
J. Meynendonckx ◽  
G. Heuvelmans ◽  
B. Muys ◽  
J. Feyen
Keyword(s):  
Land Use ◽  
Agricultural Land ◽  
Wastewater Treatment Plants ◽  
Morphological Characteristics ◽  
Drainage Density ◽  
Point Sources ◽  
Nutrient Concentrations ◽  
Buffer Strip ◽  
Additional Influence ◽  
Scheldt Basin

Abstract. The relative influence of a set of watershed characteristics on surface water nutrient concentrations was examined in 173 watersheds within two subcatchments (Upper-Scheldt and Nete) of the River Scheldt Basin (Flanders, Belgium). Each watershed was described by seasonal rainfall, discharge loading of point sources, morphological characteristics (area, average slope, drainage density, elongation), land use and soil properties (soil texture and drainage). Partial regression analysis revealed that soil drainage variables had the strongest influence on nutrient concentrations. Additional influence was exerted by land use and point source loading variables. Nitrate concentrations were positively correlated with effluent loadings coming from wastewater treatment plants and with the area of agricultural land. Phosphate concentrations were best explained by effluent loadings of industrial point sources and by the area of urban land. Land use close to the river was not a better predictor of nitrate and phosphate concentrations than land use away from the river. This suggests that the mediating impact of riparian zones is rather explained by the hydrologic pathways within the buffer strip.

scholarly journals Evidence of Phosphate Mining and Agriculture Influence on Concentrations, Forms, and Ratios of Nitrogen and Phosphorus in a Florida River

Water ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1064
Author(s):  
Shuiwang Duan ◽  
Kamaljit Banger ◽  
Gurpal S. Toor
Keyword(s):  
Agricultural Land ◽  
Water Discharge ◽  
Mining Area ◽  
Specific Conductance ◽  
Organic N ◽  
Wet Season ◽  
Nitrogen And Phosphorus ◽  
Total N ◽  
Phosphate Mining ◽  
Molar Ratios

Florida has a long history of phosphate-mining, but less is known about how mining affects nutrient exports to coastal waters. Here, we investigated the transport of inorganic and organic forms of nitrogen (N) and phosphorus (P) over 23 sampling events during a wet season (June–September) in primary tributaries and mainstem of Alafia River that drains into the Tampa Bay Estuary. Results showed that a tributary draining the largest phosphate-mining area (South Prong) had less flashy peaks, and nutrients were more evenly exported relative to an adjacent tributary (North Prong), highlighting the effectiveness of the mining reclamation on stream hydrology. Tributaries draining > 10% phosphate-mining area had significantly higher specific conductance (SC), pH, dissolved reactive P (DRP), and total P (TP) than tributaries without phosphate-mining. Further, mean SC, pH, and particulate reactive P were positively correlated with the percent phosphate-mining area. As phosphate-mining occurred in the upper part of the watershed, the SC, pH, DRP, and TP concentrations increased downstream along the mainstem. For example, the upper watershed contributed 91% of TP compared to 59% water discharge to the Alafia River. In contrast to P, the highest concentrations of total N (TN), especially nitrate + nitrite (NOx–N) occurred in agricultural tributaries, where the mean NOx–N was positively correlated with the percent agricultural land. Dissolved organic N was dominant in all streamwaters and showed minor variability across sites. As a result of N depletion and P enrichment, the phosphate-mining tributaries had significantly lower molar ratios of TN:TP and NOx–N:DRP than other tributaries. Bi-weekly monitoring data showed consistent increases in SC and DRP and a decrease in NOx–N at the South Prong tributary (highest phosphate-mining area) throughout the wet season, and different responses of dissolved inorganic nutrients (negative) and particulate nutrients (positive) to water discharge. We conclude that (1) watersheds with active and reclaimed phosphate-mining and agriculture lands are important sources of streamwater P and N, respectively, and (2) elevated P inputs from the phosphate-mining areas altered the N:P ratios in streamwaters of the Alafia River.

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