Source apportionment of riverine nitrogen transport based on catchment modelling

1996 ◽  
Vol 33 (4-5) ◽  
pp. 109-115 ◽  
Author(s):  
Hans B. Wittgren ◽  
Berit Arheimer

Source apportionment of river substance transport, i.e. estimation of how much each source in each subbasin contributes to the river-mouth transport, is a vital step in achieving the most efficient management practices to reduce pollutant loads to the sea. In this study, the spatially lumped (at sub-catchment level), semi-empirical PULSE hydrological model, with a nitrogen routine coupled to it, was used to perform source apportionment of nitrogen transport in the Söderköpingsån river basin (882 km2) in south-eastern Sweden, for the period 1991–93. The river basin was divided into 28 subbasins and the following sources were considered: land leakage from the categories forest, arable and ley/pasture; point sources, and; atmospheric deposition on lake surfaces. The calibrated model yielded an explained variance of 60%, based on comparison of measured and modelled river nitrogen (Total N) concentrations. Eight subbasins, with net contributions to the river-mouth transport exceeding 3 kg ha−1 yr−1, were identified as the most promising candidates for cost efficient nitrogen management. The other 20 subbasins all had net contributions below 3 kg ha−1 yr−1. Arable land contributed 63% of the nitrogen transport at the river mouth and would thus be in focus for management measures. However, point sources (18% contribution to net transport) should also be considered due to their relatively high accessibility for removal measures (high concentrations). E.g., the most downstream subbasin, with the largest wastewater treatment plant in the whole river basin, had a net contribution of 16 kg ha−1 yr−1. This method for source apportionment may provide authorities with quantitative information about where in a river basin, and at which sources, they should focus their attention. However, once this is done, an analysis with higher resolution has to be performed in each of the interesting subbasins, before decisions on actual management measures can be taken.

2012 ◽  
Vol 9 (1) ◽  
pp. 57-70 ◽  
Author(s):  
L. Lassaletta ◽  
E. Romero ◽  
G. Billen ◽  
J. Garnier ◽  
H. García-Gómez ◽  
...  

Abstract. Despite the particular management practices and climate characteristics of the Mediterranean regions, the literature dealing with N budgets in large catchments subjected to Mediterranean conditions is scarce. The present study aims to deepen our knowledge on the N cycle within the Ebro River Basin (NE Spain) by means of two different approaches: (1) calculating a global N budget in the Ebro River Basin and (2) calculating a series of detailed regional budgets at higher geographical resolution. N inputs and outputs were spatialized by creating a map based on the most detailed information available. Fluvial and atmospheric N export was estimated together with N retention. The Ebro River Basin annually receives a relatively high amount of new N (5118 kg N km−2 yr−1), mostly in the form of synthetic fertilizers (50%). Although it is a highly productive catchment, the net N input as food and feed import is also high (33%). Only 8% of this N is finally exported to the delta zone. Several territorial units characterized by different predominant uses (rainfed agriculture, irrigated agriculture and pastures) have differentiated N dynamics. However, due to the high density of irrigation channels and reservoirs that characterize Mediterranean catchments, N retention is very high in all of them (median value, 91%). These results indicate that problems of eutrophication due to N delivery in the coastal area may not be too severe but that high N retention values may instead lead to problems within the catchment, such as pollution of aquifers and rivers, as well as high atmospheric emissions. The most promising management measures are those devoted to reducing agricultural surpluses through a better balanced N fertilization.


2012 ◽  
Vol 599 ◽  
pp. 237-240 ◽  
Author(s):  
Faridah Othman ◽  
Mohamed Elamin Alaa Eldin

The Klang river basin is located within the state of Selangor and Kuala Lumpur, Malaysia. The Klang River drains an area of 1,288 km2 from the steep mountain rain forests of the main Central Range along Peninsular Malaysia to the river mouth in Port Klang, covering a distance of 120 km. It originates from the northern part of Selangor, drains the Klang Valley, and finally discharges itself into the Straits of Malacca. The pollution discharges for various locations along the river basin was obtained from the Water Quality and GIS group. The pollutants can come from point sources (PS) such as industrial wastewater, municipal sewers, wet market, sand mining and landfill. Pollutants can also come from non-point sources (NPS) such as agricultural or urban runoff, and commercial activity such as forestry, and construction due to rainfall event. Mathematical–computational modeling of river water quality is possible but requires an extensive validation. Besides it requires previous knowledge of hydraulics and hydrodynamics. To overcome these difficulties, a water quality index (WQI) was developed. The water quality index (WQI) is a mathematical instrument used to transform large quantities of water quality data into a single number. The purpose of this research is to classify the upstream and downstream of the Klang main river based on WQI value.


2015 ◽  
Vol 12 (14) ◽  
pp. 4275-4289 ◽  
Author(s):  
W. S. Zhang ◽  
D. P. Swaney ◽  
X. Y. Li ◽  
B. Hong ◽  
R. W. Howarth ◽  
...  

Abstract. This study provides a new approach to estimate both anthropogenic non-point-source and point-source nitrogen (N) inputs to the landscape, and determines their impacts on riverine ammonia–nitrogen (AN) flux, providing a foundation for further exploration of anthropogenic effects on N pollution. Our study site is Huai River basin of China, a water–shed with one of the highest levels of N input in the world. Multi-year average (2003–2010) inputs of N to the watershed are 27 200 ± 1100 kg N km−2 yr−1. Non-point sources comprised about 98 % of total N input, and only 2 % of inputs are directly added to the aquatic ecosystem as point sources. Fertilizer application was the largest non-point source of new N to the Huai River basin (69 % of net anthropogenic N inputs), followed by atmospheric deposition (20 %), N fixation in croplands (7 %), and N content of imported food and feed (2 %). High N inputs showed impacts on riverine AN flux: fertilizer application, point-source N input, and atmospheric N deposition were proved as more direct sources to riverine AN flux. Modes of N delivery and losses associated with biological denitrification in rivers, water consumption, interception by dams may influence the extent of export of riverine AN flux from N sources. Our findings highlight the importance of anthropogenic N inputs from both point sources and non-point sources in heavily polluted watersheds, and provide some implications for AN prediction and management.


2011 ◽  
Vol 8 (4) ◽  
pp. 8723-8759 ◽  
Author(s):  
L. Lassaletta ◽  
E. Romero ◽  
G. Billen ◽  
J. Garnier ◽  
H. García-Gómez ◽  
...  

Abstract. Despite the particular management practices and climate characteristics of the Mediterranean regions, the literature dealing with N budgets in large catchments subjected to Mediterranean conditions is scarce. The present study aims to deepen our knowledge on the N cycle within the Ebro River Basin (NE Spain) by means of two different approaches: (1) calculating a global N budget in the Ebro River Basin and (2) calculating a series of detailed regional budgets at higher geographical resolution. N inputs and outputs were spatialized by creating a map based on the most detailed information available. Fluvial and atmospheric N export was estimated together with N retention. The Ebro River Basin annually receives a relatively high amount of new N (5118 kg N km−2 yr−1), mostly in the form of synthetic fertilizers (50 %). Although it is a highly productive catchment, the net N input as food and feed import is also high (33 %). Only 8 % of this N is finally exported to the delta zone. Several territorial units characterized by different predominant uses (rainfed agriculture, irrigated agriculture and pastures) have differentiated N dynamics. However, due to the high density of irrigation channels and reservoirs that characterize Mediterranean basins, N retention is very high in all of them (median value, 92 %). These results indicate that problems of eutrophication due to N delivery in the coastal area may not be too severe but that high N retention values may instead lead to problems within the catchment, such as pollution of aquifers and rivers, as well as high atmospheric emissions. The most promising management measures are those devoted to reducing agricultural surpluses such as balanced N fertilization and low N livestock feeding.


2017 ◽  
Vol 19 (1) ◽  
pp. 51-64 ◽  
Author(s):  
Arturs Veinbergs ◽  
Ainis Lagzdins ◽  
Viesturs Jansons ◽  
Kaspars Abramenko ◽  
Ritvars Sudars

Abstract This study is focused on water quality and quantity modelling in the Berze River basin located in the Zemgale region of Latvia. The contributing basin area of 872 km2 is furthermore divided into 15 sub-basins designated according to the characteristics of hydrological network and water sampling programme. The river basin of interest is a spatially complex system with agricultural land and forests as two predominant land use types. Complexity of the system reflects in the discharge intensity and diffuse pollution of nitrogen compounds into the water bodies of the river basin. The presence of urban area has an impact as the load from the existing wastewater treatment plants consist up to 76 % of the total nitrogen load in the Berze River basin. Representative data sets of land cover, agricultural field data base for crop distribution analysis, estimation of crop management, soil type map, digital elevation model, drainage conditions, network of water bodies and point sources were used for the modelling procedures. The semi-distributed hydro chemical model HYPE has a setup to simulate discharge and nitrogen transfer. In order to make the model more robust and appropriate for the current study the data sets previously stated were classified by unifying similar spatially located polygons. The data layers were overlaid and 53 hydrological response units (SLCs) were created. Agricultural land consists of 48 SLCs with the details of soils, drainage conditions, crop types, and land management practices. Manual calibration procedure was applied to improve the performance of discharge simulation. Simulated discharge values showed good agreement with the observed values with the Nash-Sutcliffe efficiency of 0.82 and bias of −6.6 %. Manual calibration of parameters related to nitrogen leakage simulation was applied to test the most sensitive parameters.


2015 ◽  
Vol 12 (4) ◽  
pp. 3577-3615 ◽  
Author(s):  
W. S. Zhang ◽  
D. P. Swaney ◽  
X. Y. Li ◽  
B. Hong ◽  
R. W. Howarth ◽  
...  

Abstract. This study provides a new approach to estimate both anthropogenic non-point and point nitrogen (N) inputs to the landscape, and determines their impacts on riverine ammonia-nitrogen (AN) flux, providing a foundation for further exploration of anthropogenic effects on N pollution. Our study site is Huai River Basin of China, a watershed with one of the highest levels of N input in the world. Multi-year average (2003–2010) inputs of N to the watershed are 27 200 ± 1100 kg N km−2 yr−1. Non-point sources comprised about 98% of total N input and only 2% of inputs are directly added to the aquatic ecosystem as point sources. Fertilizer application was the largest non-point source of new N to the Huai River Basin (69% of net anthropogenic N inputs), followed by atmospheric deposition (20%), N fixation in croplands (7%), and N content of imported food and feed (2%). High N inputs showed impacts on riverine AN flux: fertilizer application, point N input and atmospheric N deposition were proved as more direct sources to riverine AN flux. Modes of N delivery and losses associated with biological denitrification in rivers, water consumption, interception by dams influenced the extent of export of riverine AN flux from N sources. Our findings highlight the importance of anthropogenic N inputs from point and non-point sources in heavily polluted watersheds, and provide some implications for AN prediction and management.


2017 ◽  
Vol 47 (2) ◽  
pp. 95-112 ◽  
Author(s):  
Peter Rončák ◽  
Evelin Lisovszki ◽  
Ján Szolgay ◽  
Kamila Hlavčová ◽  
Silvia Kohnová ◽  
...  

AbstractThe effects of land use management practices on surface runoff are evident on a local scale, but evidence of their impact on the scale of a watershed is limited. This study focuses on an analysis of the impact of land use changes on the flood regime in the Myjava River basin, which is located in Western Slovakia. The Myjava River basin has an area of 641.32 km2and is typified by the formation of fast runoff processes, intensive soil erosion, and muddy floods. The main factors responsible for these problems with flooding and soil erosion are the basin’s location, geology, pedology, agricultural land use, and cropping practices. The GIS-based, spatially distributed WetSpa rainfall-runoff model was used to simulate mean daily discharges in the outlet of the basin as well as the individual components of the water balance. The model was calibrated based on the period between 1997 and 2012 with outstanding results (an NS coefficient of 0.702). Various components of runoff (e.g., surface, interflow and groundwater) and several elements of the hydrological balance (evapotranspiration and soil moisture) were simulated under various land use scenarios. Six land use scenarios (‘crop’, ‘grass’, ‘forest’, ‘slope’, ‘elevation’ and ‘optimal’) were developed. The first three scenarios exhibited the ability of the WetSpa model to simulate runoff under changed land use conditions and enabled a better adjustment of the land use parameters of the model. Three other “more realistic” land use scenarios, which were based on the distribution of land use classes (arable land, grass and forest) regarding permissible slopes in the catchment, confirmed the possibility of reducing surface runoff and maximum discharges with applicable changes in land use and land management. These scenarios represent practical, realistic and realizable land use management solutions and they could be economically implemented to mitigate soil erosion processes and enhance the flood protection measures in the Myjava River basin.


2019 ◽  
Vol 11 (10) ◽  
pp. 2955 ◽  
Author(s):  
Adriana da Costa ◽  
Hugo de Salis ◽  
João Viana ◽  
Fernando Leal Pacheco

The zoning of groundwater recharge potential would be attractive for water managers, but is lacking in many regions around the planet, including in the Jequitiba River basin, Minas Gerais, Brazil. In this study, a physically based spatially distributed method to evaluate groundwater recharge potential at catchment scale was developed and tested in the aforementioned Jequitiba River basin. The data for the test was compiled from institutional sources and implemented in a Geographic Information System. It comprised meteorological, hydrometric, relief, land use, and soil data. The average results resembled the annual recharge calculated by a hydrograph method, which worked as validation method. The spatial variation of recharge highlighted the predominant contribution of flat areas, porous aquifers, and forested regions to groundwater recharge. They also exposed the negative effect of urbanization. In combination, these factors elected the following sectors of the Jequitiba River basin as regions of high recharge potential: the south-southeast part of the headwaters in Prudente de Morais; Sete Lagoas towards the central part of the basin; and the region between Funilândia and Jequitiba, near the Jequitiba river mouth. Some management practices were suggested to improve groundwater recharge. The map of groundwater recharge potential produced in this study is valuable and is therefore proposed as tool for planners in the sustainable use of groundwater and protection of recharge areas.


1993 ◽  
Vol 28 (3-5) ◽  
pp. 79-90 ◽  
Author(s):  
Z. Žáková ◽  
D. Beránková ◽  
E. Kocková ◽  
P. Kríž

Diffuse (nonpoint) pollution from the river basin is responsible for a substantial part of Czech reservoirs' deterioration caused by eutrophication and water pollution. The research results of two model drinking water supply reservoirs (different area and depth) in the Morava river basin showed that the main nutrient sources in the period 1960-1991 were: agricultural land use (overland and subsurface transport of nutrients, effects of drainage and erosion), point sources (urban activities, agricultural farms) and atmospheric depositions of N and P compounds. The accelerated eutrophication was manifested by the increasing development of phytoplankton. The main problems entail occurrence of toxic species of Cyanophyta/Cyanobacteria (blue-green algae) Aphanizomenon flos-aquae, Microcystis aeruginosa and some other species (e.g. Pseudanabaena limnetica). In the small and shallow drinking water reservoir of Ludkovice the living algae penetrated drinking water. In the deep reservoir of Vír the situation was more favourable. The increase of nutrient input (N,P) during the period 1969-1992 was highly significant Various measures have been proposed to slow the reservoir eutrophication (sustainable use of land, best management practices - soil retention, buffer strips, constructed wetlands etc.).


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 498e-498
Author(s):  
S. Paramasivam ◽  
A.K. Alva

For perennial crop production conditions, major portion of nutrient removal from the soil-tree system is that in harvested fruits. Nitrogen in the fruits was calculated for 22-year-old `Hamlin' orange (Citrus sinensis) trees on Cleopatra mandarin (Citrus reticulata) rootstock, grown in a Tavares fine sand (hyperthermic, uncoated, Typic Quartzipsamments) that received various N rates (112, 168, 224, and 280 kg N/ha per year) as either i) broadcast of dry granular form (DGF; four applications/year), or ii) fertigation (FRT; 15 applications/year). Total N in the fruits (mean across 4 years) varied from 82 to 110 and 89 to 111 kg N/ha per year for the DGF and FRT sources, respectively. Proportion of N in the fruits in relation to N applied decreased from 74% to 39% for the DGF and from 80% to 40% for the FRT treatments. High percentage of N removal in the fruits in relation to total N applied at low N rates indicate that trees may be depleting the tree reserve for maintaining fruit production. This was evident, to some extent, by the low leaf N concentration at the low N treatments. Furthermore, canopy density was also lower in the low N trees compared to those that received higher N rates.


Sign in / Sign up

Export Citation Format

Share Document