Nitrogen retention in a river system and the effects of river morphology and lakes

2005 ◽  
Vol 51 (3-4) ◽  
pp. 19-29 ◽  
Author(s):  
M. Venohr ◽  
I. Donohue ◽  
S. Fogelberg ◽  
B. Arheimer ◽  
K. Irvine ◽  
...  
Keyword(s):  
Surface Area ◽  
Surface Waters ◽  
Water Surface ◽  
Nitrogen Retention ◽  
River System ◽  
Catchment Scale ◽  
Nitrogen Emissions ◽  
Water Surface Area ◽  
Nutrient Emissions ◽  
The Mean

The mean annual transfer (loss and retention) of nitrogen in a river system was estimated using a conceptual approach based on water surface area and runoff. Two different approaches for the calculation of water surface area were applied to determine riverine nitrogen retention in four European catchments, ranging between 860–14,000 km2 in area, and differing considerably in the proportion and distribution of surface waters, specific runoff and specific nutrient emissions. The transfer rate was estimated sequentially as either the mean value for the total catchment, on a sub-catchment scale, or considering the distribution of water surface area within a sub-catchment. For the latter measure, nitrogen retention in larger lakes was calculated separately. Nitrogen emissions modelled with MONERIS and HBV-N were used to calculate nitrogen river loads and compare those with observed loads. Inclusion of the proportion of water area within a sub-catchment improved modelled results in catchment with large lakes in sub-catchments, but not where there was a homogenous distribution of surface waters among sub-catchments.

Groundwater protection and diffuse nitrogen emissions to surface waters – which catchment areas have to be considered?

2007 ◽  
Vol 7 (3) ◽  
pp. 103-110
Author(s):  
C. Schilling ◽  
M. Zessner ◽  
A.P. Blaschke ◽  
D. Gutknecht ◽  
H. Kroiss
Keyword(s):  
Surface Water ◽  
Total Nitrogen ◽  
Surface Waters ◽  
Flow Path ◽  
Emission Model ◽  
Catchment Scale ◽  
Danube Basin ◽  
Nitrogen Emissions ◽  
Nitrogen Levels ◽  
Catchment Areas

Two Austrian case study regions within the Danube basin have been selected for detailed investigations of groundwater and surface water quality at the catchment scale. Water balance calculations have been performed using the conceptual continuous time SWAT 2000 model to characterise catchment hydrology and to identify individual runoff components contributing to river discharge. Nitrogen emission calculations have been performed using the empirical emission model MONERIS to relate individual runoff components to specific nitrogen emissions and for the quantification of total nitrogen emissions to surface waters. Calculated total nitrogen emissions to surface waters using the MONERIS model were significantly influenced by hydrological conditions. For both catchments the groundwater could be identified as major emission pathway of nitrogen emissions to the surface waters. Since most of the nitrogen is emitted by groundwater to the surface water, denitrification in groundwater is of considerable importance reducing nitrogen levels in groundwater along the flow path towards the surface water. An approach was adopted for the grid-oriented estimation of diffuse nitrogen emissions based on calculated groundwater residence time distributions. Denitrification in groundwater was considered using a half life time approach. It could be shown that more than 90% of the total diffuse nitrogen emissions were contributed by areas with low groundwater residence times and short distances to the surface water. Thus, managing diffuse nitrogen emissions the location of catchment areas has to be considered as well as hydrological and hydrogeological conditions, which significantly influence denitrification in the groundwater and reduce nitrogen levels in groundwater on the flow path towards the surface water.

scholarly journals Impacts of Rapid Changes of Land Cover and Intensive Human Activities on Avarga Toson Lake Area, Mongolia

2020 ◽  
Vol 12 (15) ◽  
pp. 6070
Author(s):  
Urtnasan Mandakh ◽  
Danzanchadav Ganbat ◽  
Bayartungalag Batsaikhan ◽  
Sainbayar Dalantai ◽  
Zolzaya Adiya ◽  
...  
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Surface Area ◽  
Human Activities ◽  
Water Surface ◽  
Land Development ◽  
Water Area ◽  
Lake Area ◽  
Surrounding Area ◽  
Water Surface Area

Avarga Toson Lake and its surrounding area are very important for people, wildlife, and animals in Delgerkhaan Soum of Khentii Province in Eastern Mongolia. Some research has been conducted so as to explore the medical nature and characteristics of the lake and its surrounding area. However, the adverse effects of land use have neither been studied nor reported. The fact that the water catchment area is shrinking evidences clearly that findings of various real-time studies must be used effectively in the long-term by the local government and relevant authorities in order to take immediate remedial measures. Our study focused on land cover changes occurring as a result of human activities in the area, using a Landsat imageries and water indices approach to estimate the changes of land use and land cover. The aims of this study were to assess the land use and cover change that occurred between 1989 and 2018 and to define the impacting factors on the changes of water surface area in Avarga Toson Lake area, Mongolia. Findings revealed that the water surface area has decreased by 34.1% in the past 30 years. The lake water area had the weakest, positive correlation with temperature and precipitation. We did not find any indicators suggesting a relationship between lake area and climate variables. In contrast, the area was slightly correlated with socio-economic variables, such as Toson Lake area with the number of visitors (R2 = 0.89) and Burd Lake area the with number of livestocks (R2 = 0.75), respectively. Therefore, the main conclusion of this paper is that socioeconomic factors driven by land use change, policy, and institutional failure together with the existing pressure on the lake may amplify their effect of the water surface area decreasing. Additionally, even if policy adoption is relatively sufficient in the country, the public institutional capacity to implement a successful sustainable land management model regarding land access, land development, land resources protection, land market, and investments in infrastructure remains very limited.

scholarly journals Changes in the surface area of lakes in the Gwda River basin

2015 ◽  
Vol 14 (3) ◽  
pp. 121-129
Author(s):  
Kubiak-Wójcicka Katarzyna ◽  
Izabela Lewandowska
Keyword(s):  
Twentieth Century ◽  
Surface Area ◽  
River Basin ◽  
Water Surface ◽  
General Trend ◽  
Topographic Maps ◽  
Lake Surface ◽  
Water Surface Area ◽  
Starting Point ◽  
Lake Surface Area

Abstract This paper presents lake surface area changes that have taken place in the Gwda River basin. The studies were conducted on the basis of the cartographic materials released since the beginning of the twentieth century until the present times. The starting point was the area of all lakes greater than 1 ha which are present on the MPHP map from 2010. The assessment of the changes in the surface area of lakes in the Gwda River basin during approximately the last 100 years was possible thanks to the use of German topographic maps, so called Messtischblatt, at a scale of 1: 25 000 released between 1919 and 1944. The area of all the studied lakes has decreased by 465.09 ha (from 12783.62 ha at the beginning of the twentieth century to 12318.53 ha at the present time). Despite the general trend of lake atrophy, in particular cases one may observe an increase in the water surface area. This is the result of hydrotechnical works leading to river and lake damming, which in turn hampers the pace of atrophy.

Sign in / Sign up

Export Citation Format

Share Document