A model of long-term catchment-scale nitrate transport in a UK Chalk catchment

2019 ◽  
pp. 179-189
Author(s):  
N.J.K. Howden ◽  
S.A. Mathias ◽  
M.J. Whelan ◽  
T.P. Burt ◽  
F. Worrall
Keyword(s):  
Nitrate Transport ◽  
Catchment Scale

River Quality Models for Consent Setting in England and Wales

1989 ◽  
Vol 21 (8-9) ◽  
pp. 1015-1024 ◽  
Author(s):  
C. P. Crockett ◽  
R. W. Crabtree ◽  
I. D. Cluckie
Keyword(s):  
River System ◽  
Quality Model ◽  
Catchment Scale ◽  
Quality Models ◽  
England And Wales ◽  
Future Developments ◽  
Statistical Framework ◽  
River Quality ◽  
National Approach

In England and Wales the placing of effluent discharge consents within a statistical framework has led to the development of a new hybrid type of river quality model. Such catchment scale consent models have a stochastic component for the generation of model inputs and a deterministic component to route them through the river system. This paper reviews and compares the existing approaches for consent modelling used by various Water Authorities. A number of possible future developments are suggested including the potential need for a national approach to the review and setting of long term consents.

scholarly journals Integrated Impact Assessment for Sustainable Hydropower Planning in the Vjosa Catchment (Greece, Albania)

2021 ◽  
Vol 13 (3) ◽  
pp. 1514
Author(s):  
Rebecca Peters ◽  
Jürgen Berlekamp ◽  
Ana Lucía ◽  
Vittoria Stefani ◽  
Klement Tockner ◽  
...  
Keyword(s):  
Impact Assessment ◽  
Planning Process ◽  
Renewable Energy Sources ◽  
Decision Makers ◽  
Catchment Scale ◽  
Northern Greece ◽  
Hydropower Plants ◽  
Hydropower Planning

Mitigating climate change, while human population and economy are growing globally, requires a bold shift to renewable energy sources. Among renewables, hydropower is currently the most economic and efficient technique. However, due to a lack of impact assessments at the catchment scale in the planning process, the construction of hydropower plants (HPP) may have unexpected ecological, socioeconomic, and political ramifications in the short and in the long term. The Vjosa River, draining parts of Northern Greece and Albania, is one of the few predominantly free-flowing rivers left in Europe; at the same time its catchment is identified an important resource for future hydropower development. While current hydropower plants are located along tributaries, planned HPP would highly impact the free-flowing main stem. Taking the Vjosa catchment as a case study, the aim of this study was to develop a transferable impact assessment that ranks potential hydropower sites according to their projected impacts on a catchment scale. Therefore, we integrated established ecological, social, and economic indicators for all HPP planned in the river catchment, while considering their capacity, and developed a ranking method based on impact categories. For the Vjosa catchment, ten hydropower sites were ranked as very harmful to the environment as well as to society. A sensitivity analysis revealed that this ranking is dependent upon the selection of indicators. Small HPP showed higher cumulative impacts than large HPP, when normalized to capacity. This study empowers decision-makers to compare both the ranked impacts and the generated energy of planned dam projects at the catchment scale.

Modelling long-term diffuse nitrate pollution at the catchment-scale: Data, parameter and epistemic uncertainty

2011 ◽  
Vol 403 (3-4) ◽  
pp. 337-351 ◽  
Author(s):  
N.J.K. Howden ◽  
T.P. Burt ◽  
S.A. Mathias ◽  
F. Worrall ◽  
M.J. Whelan
Keyword(s):  
Epistemic Uncertainty ◽  
Nitrate Pollution ◽  
Catchment Scale ◽  
Scale Data

scholarly journals Assessment of catchment response and calibration of a hydrological model using high-frequency discharge–nitrate concentration data

2013 ◽  
Vol 44 (6) ◽  
pp. 995-1012 ◽  
Author(s):  
Rajesh R. Shrestha ◽  
Karsten Osenbrück ◽  
Michael Rode
Keyword(s):  
Surface Runoff ◽  
High Frequency ◽  
Hydrological Model ◽  
Nitrate Concentration ◽  
Subsurface Flow ◽  
Nitrate Transport ◽  
Response Analysis ◽  
Catchment Scale ◽  
Concentration Data ◽  
High Frequency Discharge

This study uses a high-frequency discharge and nitrate concentration dataset from the Weida catchment in Germany for the catchment scale hydrologic response analysis. Nitrate transport in the catchment is mostly conservative as indicated by the nitrate stable isotope (δ15N and δ18O) analysis. Discharge–nitrate concentration data from the catchment show distinctive patterns, suggesting flushing and dilution response. A self-organizing feature map-based methodology was employed to identify such patterns or cluster in the datasets. Based on knowledge of the catchment conditions and prevailing understanding of discharge–nitrate concentration relationship, the clusters were characterized into five qualitative flow responses: (1) baseflow; (2) subsurface flow increase; (3) surface runoff increase; (4) surface runoff recession; and (5) subsurface flow decrease. Such qualitative flowpaths were used as soft data for a multi-objective calibration of a hydrological model (WaSiM-ETH). The calibration led to a reasonable simulation of overall discharge (Nash–Sutcliffe coefficient: 0.84) and qualitative flowpaths (76% agreement). A prerequisite for using such methodology is limited biogeochemical transformation of nitrate (such as denitrification).

scholarly journals Long-term ecological observatories needed to understand ecohydrological systems in the Anthropocene: a catchment-scale case study in Brittany, France

2019 ◽  
Vol 19 (2) ◽  
pp. 363-377 ◽  
Author(s):  
Zahra Thomas ◽  
Pauline Rousseau-Gueutin ◽  
Benjamin W. Abbott ◽  
Tamara Kolbe ◽  
Hugo Le Lay ◽  
...  
Keyword(s):  
Catchment Scale

Evaluation and indirect estimation of nitrate losses from the agricultural microbasin Rybárik

Biologia ◽  
2007 ◽  
Vol 62 (5) ◽  
Author(s):  
Michal Sebíň ◽  
Pavla Pekárová ◽  
Pavol Miklánek
Keyword(s):  
Nitrate Concentration ◽  
Empirical Relation ◽  
Annual Runoff ◽  
Nitrogen Fertilizers ◽  
Nitrate Transport ◽  
Nitrate Losses ◽  
Long Term Trends ◽  
Academy Of Sciences ◽  
Annual Amount

AbstractThe long-term trends of mean monthly nitrate concentrations in stream and drainage runoff were evaluated in the experimental microbasin Rybárik (0.119 km2) at the Institute of Hydrology, Slovak Academy of Sciences, during the period 1987–2005. The results of analyses indicate a decreasing trend of nitrate concentration after the year 1989, but with relatively high losses in some years and relatively low losses in other years. This decreasing trend is mainly caused by a decrease in the use of nitrogen fertilizers. The nitrate concentration in surface runoff strongly correlates with runoff and fertilization. Based on measured data, an empirical relation was found describing the dependence of annual nitrate transport in the stream on annual runoff depth and on the annual amount of applied nitrogen fertilizers.

Modeling Nitrate Export at the Catchment Scale using StorAge Selection Functions

2020 ◽  
Author(s):  
Tam Nguyen ◽  
Rohini Kumar ◽  
Stefanie R. Lutz ◽  
Andreas Musolff ◽  
Jan H. Fleckenstein
Keyword(s):  
Time Distribution ◽  
Root Zone ◽  
Hydrologic Model ◽  
Distributed Model ◽  
Nitrate Transport ◽  
Catchment Scale ◽  
Near Surface ◽  
Soil Zone ◽  
Different Ages ◽  
Nitrate Export

<p>Catchments store and release water of different ages. The time of a water parcel remaining in contact with the catchment subsurface affects the solute dynamics in the catchment and ultimately in the stream. Catchment storage can be conceptualized as a collection of different water parcels with different ages, the so-called residence time distribution (RTD). Similarly, the distribution of water ages in streamflow at the catchment outlet, which is sampled from the RTD, is called the travel time distribution (TTD). The selection preferences for discharge can be characterized by StorAge selection (SAS) functions. In recent years, numerical experiments have shown that SAS functions are time-variant and can be approximated, for example, by the beta distribution function. SAS functions have been emerging as a promising tool for modeling catchment-scale solute export.</p><p>In this study, we aim to integrate the SAS-based description of nitrate transport with the mHM-Nitrate model (Yang et al., 2018) to simulate solute transport and turnover above and below the soil zone including legacy effects. The mHM-Nitrate is a grid based distributed model with the hydrological concept taken from the mesoscale Hydrologic Model (mHM) and the water quality concept taken from the HYdrological Predictions for the Environment (HYPE) model. Here, we replaced the description of nitrate transport in groundwater from the original mHM-Nitrate with time-variant SAS-based modeling, while we kept the detailed description of turnover of organic and inorganic nitrogen in the near-surface (root zone) from mHM-Nitrate. First-order decay was used to represent biogeochemical (denitrification) processes below the root zone and in the stream. The proposed model was tested in a mixed agricultural-forested headwater catchment in the Harz Mountains, Germany. Results show that the proposed SAS augmented nitrate model (with the time-variant beta function) is able to represent streamflow and catchment nitrate export with satisfactory results (NSE for streamflow = 0.83 and for nitrate = 0.5 at the daily time step). Overall, our combined model provides a new approach for a spatially distributed simulation of nitrogen reaction processes in the soil zone and a spatially implicit simulation of transport pathways of nitrate and denitrification in the entire catchment.</p><p><span>Yang, X.</span>, <span>Jomaa, S.</span>, <span>Zink, M.</span>, <span>Fleckenstein, J. H.</span>, <span>Borchardt, D.</span>, & <span>Rode, M.</span> ( <span>2018</span>). <span>A new fully distributed model of nitrate transport and removal at catchment scale</span>. <em>Water Resources Research</em>, <span>54</span>, <span>5856</span>– <span>5877</span>.</p>

scholarly journals Czasowa zmienność i przestrzenne zróżnicowanie ewapotranspiracji w zlewni nizinnej rzeki Łasicy

2021 ◽  
Vol 66 (3) ◽  
pp. 35-46
Author(s):  
Urszula Somorowska
Keyword(s):  
Surface Energy Balance ◽  
Water Cycle ◽  
Spatial Differentiation ◽  
Remote Sensing Data ◽  
Growing Season ◽  
Catchment Scale ◽  
Water Demands ◽  
Agricultural Areas ◽  
Accurate Quantification

Accurate quantification of evapotranspiration is necessary for understanding the water cycle at a local scale. At catchment scale, evapotranspiration might be approximated using remote sensing data useful in spatialtemporal analyses. In this study, the long-term and seasonal variability of evapotranspiration in the Łasica River catchment in the years 2003–2020 was assessed on the basis of data acquired from the SSEBop project (Operational Simplified Surface Energy Balance). Additionally, using the index of precipitation utilization (WWO), the degree of precipitation consumption for the water demands of plants was determined. The highest evapotranspiration occurs in forest areas, slightly lower in marshy belts covered with meadow vegetation, and the lowest in agricultural areas and anthropogenically transformed areas. The spatial differentiation of evapotranspiration is particularly marked during the growing season, from April to October. Mean annual evapotranspiration sum is 403 mm, of which 96% falls on the growing season. Extremely low annual ET sums occurred in 2015 (329 mm), 2019 (342 mm) and 2003 (384 mm), while particularly high – in 2010 (455 mm) and 2013 (447 mm). In dry years, WWO is even 71–77%, while in particularly wet years, WWO is much lower and amounts to 54–58%.

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