scholarly journals Assessing the stream water quality dynamics in connection with land use in agricultural catchments of different scales

2008 ◽  
Vol 3 (No. 3) ◽  
pp. 98-112 ◽  
Author(s):  
P. Fučík ◽  
T. Kvítek ◽  
M. Lexa ◽  
P. Novák ◽  
A. Bílková
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Surface Waters ◽  
Nitrate Concentration ◽  
Stream Water ◽  
Arable Land ◽  
Ecological Status ◽  
Simple Method ◽  
Agricultural Catchments ◽  
Nitrate Concentrations

The ecological status of many surface waters in the Czech Republic is poor, mainly due to still relatively high discharges of N substances especially from agriculture. High nitrate values in the streams situated particulary in basins of drinking water reservoirs invoke the neccesity for the precise detection of diffuse pollution areas to enable the setting of the appropriate land management strategies or relevant measures. We introduce a simple method for estimating the changes of nitrate concentrations in surface waters regarding the land use modification. Stream and drainage water nitrate concentrations in prevailingly agricultural catchments of three different scales located in the Crystalline complex of the Czech massif were included in this study. Water quality samples were collected through the years 1992–2006 at monthly and bi-monthly intervals. For the catchment land use analysis, the satellite images LANDSAT 7 (CORINE Land Cover) and digitised cadastre maps of the land register were processed using ESRI ArcMap GIS; both sources corrected by field survey. We demonstrate on three different basin – scale studies a strong relation between the arable land ratio within a catchment and the coherent stream water nitrate concentration. The results acquired from all the evaluated catchments showed that every 10% decrease of ploughed land proportion in a catchment lowers the nitrate concentration C90 value (90% probability of non-exceedance) in average by 6.38 mg/l.

scholarly journals Effect on nitrate concentration in stream water of agricultural practices in small catchments in Brittany: I. Annual nitrogen budgets

2002 ◽  
Vol 6 (3) ◽  
pp. 497-506 ◽  
Author(s):  
L. Ruiz ◽  
S. Abiven ◽  
P. Durand ◽  
C. Martin ◽  
F. Vertès ◽  
...  
Keyword(s):  
Land Use ◽  
Nitrate Concentration ◽  
Stream Water ◽  
Agricultural Practices ◽  
Climatic Conditions ◽  
Nitrogen Budgets ◽  
Annual Variations ◽  
Nitrate Concentrations ◽  
The Mean ◽  
Small Catchments

Abstract. The hydrological and biogeochemical monitoring of catchments has become a common approach for studying the effect of the evolution of agricultural practices on water resources. In numerous studies, the catchment is used as a "mega-lysimeter" to calculate annual input-output budgets. However, the literature reflects two opposite interpretations of the trends of nitrate concentration in streamwater. For some authors, essentially in applied studies, the mean residence time of leached nitrate in shallow groundwater systems is much less than one year and river loads reflect annual land use while for others, nitrate is essentially transport limited, independent of soil nitrate supply in the short term and annual variations reflect changes in climatic conditions. This study tests the effect of agricultural land-use changes on inter-annual nitrate trends on stream water of six small adjacent catchments from 0.10 to 0.57 km2 in area, on granite bedrock, at Kerbernez, in Western Brittany (France). Nitrate concentrations and loads in streamwater have been monitored for nine years (1992 to 2000) at the outlet of the catchments. An extensive survey of agricultural practices from 1993 to 1999 allowed assessment of the nitrogen available for leaching through nitrogen budgets. For such small catchments, year-to-year variations of nitrate leaching can be very important, even when considering the 'memory effect' of soil, while nitrate concentrations in streamwater appear relatively steady. No correlation was found between the calculated mean nitrate concentration of drainage water and the mean annual concentration in streams, which can even exhibit opposite trends in inter-annual variations. The climatic conditions do not affect the mean concentration in streamwater significantly. These results suggest that groundwater plays an important role in the control of streamwater nitrate concentration. Keywords: nitrate, diffuse pollution, agricultural catchment, nitrogen budget, leaching, Kerbernez catchments

scholarly journals Effect on nitrate concentration in stream water of agricultural practices in small catchments in Brittany: II. Temporal variations and mixing processes

2002 ◽  
Vol 6 (3) ◽  
pp. 507-514 ◽  
Author(s):  
L. Ruiz ◽  
S. Abiven ◽  
C. Martin ◽  
P. Durand ◽  
V. Beaujouan ◽  
...  
Keyword(s):  
Land Use ◽  
Nitrate Concentration ◽  
Stream Water ◽  
Agricultural Practices ◽  
Temporal Variations ◽  
Base Flow ◽  
Seasonal Patterns ◽  
Annual Variations ◽  
Nitrogen Inputs ◽  
Nitrate Concentrations

Abstract. In catchments with impervious bedrock, the nitrate concentrations in streamwater often show marked seasonal and small inter-annual variations. The inter-annual trends are usually attributed to changes in nitrogen inputs, due to changes in land use or in nitrogen deposition whereas seasonal patterns are explained in terms of availability of soil nitrate for leaching and of seasonality of nitrogen biotransformations. The companion paper showed that inter-annual variations of nitrogen in streamwater are not directly related to the variations of land use. The aim of this study is to describe nitrate concentration variations in a set of very small adjacent catchments, and to discuss the origin of the inter-annual and seasonal trends. Data from four catchments at the Kerbernez site (South Western Brittany, France) were used in this study. Nitrate concentrations in streamwater were monitored for eight years (1992 to 1999) at the outlet of the catchments. They exhibit contrasting inter-annual and seasonal patterns. An extensive survey of agricultural practices during this period allowed assessment of the amount of nitrogen available for leaching. The discharges measured since 1997 show similar specific fluxes but very different seasonal dynamics between the catchments. A simple, lumped linear store model is proposed as an initial explanation of the differences in discharge and nitrate concentration patterns between the catchments. The base flow at the outlet of each catchment is considered as a mixture of water from two linear reservoirs with different time constants. Each reservoir comprises two water stores, one mobile contributing to discharge, the other, immobile, where nitrate moves only by diffusion. The storm flow, which accounts for less than 10% of the annual flux, is not considered here. Six parameters were adjusted for each catchment to fit the observed data: the proportion of deep losses of water, the proportion of the two reservoirs and the size and initial concentration of the two immobile stores. The model simulates the discharge and nitrate concentration dynamics well. It suggests that the groundwater store plays a very important role in the control of nitrate concentration in streamwater, and that the pattern of the seasonal variation of nitrate concentration may result from the long term evolution of nitrogen losses by leaching. Keywords: nitrate, diffuse pollution, groundwater, seasonal variations, agricultural catchment, simulation model

scholarly journals Water quality improvements from afforestation in an agricultural catchment in Denmark illustrated with the INCA model

2004 ◽  
Vol 8 (4) ◽  
pp. 764-777 ◽  
Author(s):  
A. Bastrup-Birk ◽  
P. Gundersen
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Soil Water ◽  
Agricultural Land ◽  
Arable Land ◽  
N Deposition ◽  
Agricultural Land Use ◽  
Forest Land ◽  
N Dynamics ◽  
Nitrate Concentrations

Abstract. Intensive agricultural land use across Europe has altered nitrogen (N) budget of catchments substantially, causing widespread N pollution of freshwater. Although the N cycle in forests has changed due to increased N deposition, most forest soil waters in Europe have low nitrate concentrations. The protective function of forests on water quality has led to increasing interest in the planting of new forests on arable land as a measure to protect valuable or sensitive freshwater resources. The paper illustrates the effects of afforestation on water and N cycling using the Integrated Nitrogen Catchment (INCA) model. The model was calibrated on the Horndrup catchment in the eastern part of Jutland, Denmark, which is dominated by agricultural land use but also covered by 18% of forest land. The dynamics of nitrate concentrations in the stream water were simulated successfully by INCA over a three-year period. The simulation of the dynamics of nitrate concentrations in the soil water is closely linked to the simulation of the hydrological dynamics and especially to the rainfall. The best fit was achieved for both arable and forest land during the wettest year of the study period. The model was then used to simulate the effect of afforestation of a catchment dominated by agriculture on N fluxes with seepage and runoff. Scenarios of whole catchment conversion to forest were run, based on observations of evapotranspiration and N deposition from other Danish sites. The simulated conversion to mature forest reduced runoff by 30–45% and reduced the nitrate concentrations in the soil water by 50–70%. The simulated effect of afforestation on N leaching was an almost direct reflection of the change in the N input: substantial changes in the plant demand and soil N dynamics over the afforestation period were not simulated. To simulate the N dynamics over longer time-scales, appropriate for the study of afforestation, it is suggested that the INCA model be run with transient scenarios and linked to more detailed plant and soil models. Keywords: afforestation, arable land, forest hydrology, INCA, modelling, nitrogen, nitrate leaching

scholarly journals Mixtures of chemicals are important drivers of impacts on ecological status in European surface waters

2019 ◽  
Vol 31 (1) ◽  
Author(s):  
Leo Posthuma ◽  
Werner Brack ◽  
Jos van Gils ◽  
Andreas Focks ◽  
Christin Müller ◽  
...  
Keyword(s):  
Water Quality ◽  
Quality Management ◽  
Surface Waters ◽  
Water Quality Management ◽  
Ecological Status ◽  
Ecological Impacts ◽  
Chemical Pollution ◽  
Individual Species ◽  
Integrated Analysis ◽  
Chemical Mixtures

Abstract The ecological status of European surface waters may be affected by multiple stressors including exposure to chemical mixtures. Currently, two different approaches are used separately to inform water quality management: the diagnosis of the deterioration of aquatic ecosystems caused by nutrient loads and habitat quality, and assessment of chemical pollution based on a small set of chemicals. As integrated assessments would improve the basis for sound water quality management, it is recommended to apply a holistic approach to integrated water quality status assessment and management. This allows for estimating the relative contributions of exposure to mixtures of the chemicals present and of other stressors to impaired ecological status of European water bodies. Improved component- and effect-based methods for chemicals are available to support this. By applying those methods, it was shown that a holistic diagnostic approach is feasible, and that chemical pollution acts as a limiting factor for the ecological status of European surface waters. In a case study on Dutch surface waters, the impact on ecological status could be traced back to chemical pollution affecting individual species. The results are also useful as calibration of the outcomes of component-based mixture assessment (risk quotients or mixture toxic pressures) on ecological impacts. These novel findings provide a basis for a causal and integrated analysis of water quality and improved methods for the identification of the most important stressor groups, including chemical mixtures, to support integrated knowledge-guided management decisions on water quality.

scholarly journals The consequences for stream water quality of long-term changes in landscape patterns: Implications for land use management and policies

2021 ◽  
Vol 109 ◽  
pp. 105679
Author(s):  
António Carlos Pinheiro Fernandes ◽  
Lisa Maria de Oliveira Martins ◽  
Fernando António Leal Pacheco ◽  
Luís Filipe Sanches Fernandes
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Stream Water ◽  
Landscape Patterns ◽  
Land Use Management ◽  
Stream Water Quality ◽  
Long Term Changes

Integrative hydrogeo-ecological assessment of the quantitative and qualitative response of groundwater to hydrological extremes

2021 ◽  
Author(s):  
Steffen Birk ◽  
Johannes Haas ◽  
Alice Retter ◽  
Raoul Collenteur ◽  
Heike Brielmann ◽  
...  
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Ecological Status ◽  
Urban Land Use ◽  
In Situ Monitoring ◽  
Drought Indices ◽  
Groundwater Levels ◽  
Hydrological Conditions ◽  
Hydrological Extremes ◽  
Observation Wells

<p>An integrative interdisciplinary approach is currently developed to investigate groundwater systems in alpine and prealpine environments and how they respond to hydrological extremes such as droughts, heavy rain and floods in terms of water quantity, hydrochemical quality, and ecological status. The new approach is aimed at improving the understanding of the interaction between physical, chemical, and biological processes in groundwater responses to extreme events as well as developing indicators suitable for an integrative monitoring and management of the aquifers. For this purpose, observation wells of the existing state hydrographic monitoring net have been selected within the Austrian part of the Mur river basin, stretching from the alpine origin to the national border in the foreland. The investigation area thus comprises diverse hydrogeological settings and land-use types. The selected observation wells have long-term records of groundwater levels and are used for sampling campaigns under different hydrological conditions. Groundwater level fluctuations are evaluated using drought indices and statistical approaches, such as auto-correlation and cross-correlation with precipitation and stream stages. Our hydrochemical analyses of groundwater and surface waters also consider compounds indicative of agricultural sources (e.g., nitrate), wastewater-borne micro-pollutants, and stable isotopes of water. These indicators are used to identify different drivers controlling water origin and quality. The ecological status is characterized using microbiological measures, such as total number of bacteria and microbial activity, groundwater fauna, and the qualitative composition of dissolved organic matter (DOM). First results demonstrate a deterioration of water quality from groundwater to surface water and from the alpine region towards the foreland, corresponding to the more intense agricultural and urban land use in the foreland. Linkages between water quality and hydrological conditions are currently being evaluated and will be further examined using UV-Vis spectrometry for high-resolution in-situ monitoring of water quality changes (DOM and nitrate) at selected observation wells.</p>

Development of Chemical Index as a Measure of In-Stream Water Quality in Response to Land-Use and Land Cover Changes

2006 ◽  
Vol 174 (1-4) ◽  
pp. 161-179 ◽  
Author(s):  
T. Tsegaye ◽  
D. Sheppard ◽  
K. R. Islam ◽  
W. Tadesse ◽  
A. Atalay ◽  
...  
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Land Cover ◽  
Stream Water ◽  
Land Cover Changes ◽  
Stream Water Quality ◽  
Chemical Index

scholarly journals Evaluating Stream Water Quality through Land Use Analysis in Two Grassland Catchments

2006 ◽  
Vol 35 (2) ◽  
pp. 617-627 ◽  
Author(s):  
A. Hayakawa ◽  
M. Shimizu ◽  
K. P. Woli ◽  
K. Kuramochi ◽  
R. Hatano
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Stream Water ◽  
Stream Water Quality
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