scholarly journals Modelling long-term alluvial-peatland dynamics in temperate river floodplains

2021 ◽  
Vol 18 (23) ◽  
pp. 6181-6212
Author(s):  
Ward Swinnen ◽  
Nils Broothaerts ◽  
Gert Verstraeten
Keyword(s):  
River Basin ◽  
River Channel ◽  
River Network ◽  
Management Options ◽  
Local Conditions ◽  
Channel Dynamics ◽  
River Floodplains ◽  
Modelling Framework ◽  
Peatland Development

Abstract. Peat growth is a frequent phenomenon in European river valleys. The presence of peat in the floodplain stratigraphy makes them hotspots of carbon storage. The long-term dynamics of alluvial peatlands are complex due to interactions between the peat and the local river network, and as a result, alluvial-peatland development in relation to both regional and local conditions is not well understood. In this study, a new modelling framework is presented to simulate long-term peatland development in river floodplains by coupling a river basin hydrology model (STREAM – Spatial Tools for River basins and Environment and Analysis of Management options) with a local peat growth model (modified version of DigiBog). The model is applied to two lowland rivers in northern Belgium, located in the European loess (Dijle (Dyle) River) and sand (Grote Nete River) belts. Parameter sensitivity analysis and scenario analysis are used to study the relative importance of internal processes and environmental conditions on peatland development. The simulation results demonstrate that the peat thickness is largely determined by the spacing and mobility of the local river channel(s) rather than by channel characteristics or peat properties. In contrast, changes in regional conditions such as climate and land cover across the upstream river basin have been shown to influence the river hydrograph but have a limited effect on peat growth. These results demonstrate that alluvial-peatland development is strongly determined by the geomorphic boundary conditions set by the river network and as such models must account for river channel dynamics to adequately simulate peatland development trajectories in valley environments.

scholarly journals Modelling long-term alluvial peatland dynamics in temperate river floodplains

2021 ◽  
Author(s):  
Ward Swinnen ◽  
Nils Broothaerts ◽  
Gert Verstraeten
Keyword(s):  
River Basin ◽  
River Channel ◽  
River Network ◽  
Local Conditions ◽  
Channel Dynamics ◽  
River Floodplains ◽  
Modelling Framework ◽  
Peatland Development ◽  
River Valleys

Abstract. Peat growth is a frequent phenomenon in European river valleys. The presence of peat in the floodplain stratigraphy makes them hotspots of carbon storage. The long-term dynamics of alluvial peatlands are complex due to interactions between the peat and the local river network, and as a result, alluvial peatland development in relation to both regional and local conditions is not well understood. In this study, a new modelling framework is presented to simulate long-term peatland development in river floodplains by coupling a river basin hydrology model (STREAM) with a local peat growth model (modified version of Digibog). The model is applied to two lowland rivers in northern Belgium, located in the European loess (Dijle river) and sand (Grote Nete river) belts. Parameter sensitivity analysis and scenario analysis are used to study the relative importance of internal processes and environmental conditions on peatland development. The simulation results demonstrate that the peat thickness is largely determined by the spacing and mobility of the local river channel(s) rather than by channel characteristics or peat properties. In contrast, changes in regional conditions such as climate and land cover across the upstream river basin showed to influence the river hydrograph, but have a limited effect on peat growth. These results demonstrate that alluvial peatland development is strongly determined by the geomorphic boundary conditions set by the river network and as such models must account for river channel dynamics to adequately simulate peatland development trajectories in valley environments.

Modelling peatland development in temperate alluvial environments

2021 ◽  
Author(s):  
Ward Swinnen ◽  
Nils Broothaerts ◽  
Gert Verstraeten
Keyword(s):  
Land Cover ◽  
River Channel ◽  
Carbon Accumulation ◽  
Management Options ◽  
River Floodplains ◽  
C Storage ◽  
Peatland Development ◽  
Sequestration Potential ◽  
Drainage Channels

<p>It is well known that C accumulation rates are much higher when focusing on short-term measurement periods in areas with active peat growth when compared to the net C storage at longer timescales as obtained from palaeo-studies. When selecting effective management options that aim to sustain or increase rates of peat development and, hence, C sequestration, a detailed insight into the factors controlling C storage in peatlands at longer timescales is therefore required. Several peatland models have been developed to simulate long-term peatland development and such models thus can be a useful tool to evaluate the effect of environmental changes and management on peatland dynamics at centennial to millennial scales. Many of these models assume the peat to form in a geomorphically stable environment. However, for river floodplains these assumptions cannot always be made. In temperate Europe for example, many river floodplains have known phases of active peat growth throughout the Holocene, influenced by the local geomorphic dynamics of the river channel(s) and associated sediment dynamics. In addition, many restoration efforts in floodplain environments are accompanied by allowing the river channel(s) to behave more freely, with increased meandering and more natural channel dynamics. As these dynamics are currently lacking in peatland models, a detailed assessment of the interactions between river channel(s) and the adjacent peatland in terms of long-term peat growth and carbon accumulation remains difficult.</p><p>Here, we developed a new peatland model, specifically designed for alluvial environments, by modifying an existing local peat growth model (1D version of Digibog), coupled with a raster-based river basin hydrology model (STREAM). This model allows to assess the effect of changes in both the river hydrology and local river channel properties on alluvial peatland development and the associated carbon dynamics. The model was applied at two contrasting lowland river basins in northern Belgium, located in the European loess (Dijle river) and sand (Grote Nete river) belts. Local peat growth was simulated at an annual resolution over a period of 10,000 years under a range of climate and land cover scenarios, as well as varying river channel characteristics (number of channels, channel dimensions, channel roughness and channel slope).</p><p>The results demonstrate that changes in river discharge through regional climate or land cover changes have a negligible effect on the floodplain peat growth as these changes mostly affect the magnitude of peak discharges. In contrast, the configuration of the local river network such as the number of river channels and their position relative to the peatland surface show to have a strong effect on the equilibrium peat thickness. Especially the number of drainage channels strongly affects the peat thickness with a fourfold reduction in number of channels leading to a threefold increase in simulated peat thickness. This demonstrates that limiting the number of drainage channels in a floodplain and raising the elevation of the channel bed can be effective strategies in stimulating floodplain peat formation and allow to quantify the long-term carbon sequestration potential of these different management practices.</p>

Linking long-term gully and river channel dynamics to environmental change using repeat photography (Northern Ethiopia)

Geomorphology ◽  
2011 ◽  
Vol 129 (3-4) ◽  
pp. 238-251 ◽  
Author(s):  
Amaury Frankl ◽  
Jan Nyssen ◽  
Morgan De Dapper ◽  
Mitiku Haile ◽  
Paolo Billi ◽  
...  
Keyword(s):  
Environmental Change ◽  
River Channel ◽  
Northern Ethiopia ◽  
Repeat Photography ◽  
Channel Dynamics

scholarly journals Long-term trends of rainfall and runoff regime in upper Otava River basin

2008 ◽  
Vol 3 (No. 3) ◽  
pp. 155-167 ◽  
Author(s):  
Z. Kliment ◽  
M. Matoušková
Keyword(s):  
River Basin ◽  
River Network ◽  
Statistical Testing ◽  
Trend Detection ◽  
Precipitation Regime ◽  
Paired Samples ◽  
Double Mass ◽  
Runoff Regime ◽  
Long Term Trends

The floods experienced recently in the Czech Republic gave rise to numerous discussions over the changed environment and related potential impacts on the rainfall and runoff processes. The main aim of our research project was to determine long term trends of rainfall and runoff regime in Otava River basin. The rainfall-runoff analyses using both the single and double mass curves over the period of the hydrologic observations were taken as a basic method. Beside mean discharge, precipitation, snow and air temperature trends, analysis of land cover change and human impact on the river network and drainage areas development were applied too. The greatest deviations were widely observed in the period between the 2<sup>nd</sup> half of the seventies and in the 1<sup>st</sup> half of the eighties. It has been related to the one of repeatedly coming rather humid episodes and correspond to major human influences on the river network. The whole system came slowly back to its initial condition in the early nineties. Standard statistical testing methods were applied to confirm the trends. The Wilcoxon single and paired samples test, and furthermore the Mann-Kendall non-parametric test were used. Trend detection using both tests also confirmed a different development of the discharges and precipitation regime in the Ostružn&aacute; and upper Blanice River basins in the period 1975&ndash;1982. The runoff trend deviation has been related to the nature and human factors, mainly to current climatic changes and changes of landscape retention potential.

scholarly journals The Panama Canal after a century of human impacts

2019 ◽  
Author(s):  
Jorge Salgado ◽  
María I. Vélez ◽  
Catalina González-Arango ◽  
Neil L. Rose ◽  
Handong Yang ◽  
...  
Keyword(s):  
Sustainable Management ◽  
Flood Control ◽  
Human Impacts ◽  
Panama Canal ◽  
Dam Construction ◽  
Clear Water ◽  
Management Options ◽  
Tropical River ◽  
River Floodplains

AbstractLarge tropical river dam projects are set to accelerate over the forthcoming decades to satisfy growing demand for energy, irrigation and flood control. When tropical rivers are dammed, the immediate impacts are well studied, but the long-term (decades-centuries) consequences of impoundment remain poorly known. Here, we gather historical and paleoecological data from Gatun Lake, formed by the building of the Gatun Dam (Panama Canal, Panamá) over 100 years ago, to reconstruct the limnological evolution of the system in response to individual and linked stressors (river damming, forest flooding, deforestation, invasive species, pollution and hydro-climate). We found that after a century of dam construction parallels associated with the natural hydrological functioning of river floodplains persist. Hence, hydrology remains the most important temporal structural factor positively stimulating primary productivity, deposition of new minerals, and reduction of water transparency during wet periods. During dry periods, clear water and aerobic conditions prevail and nutrients transform into available forms in the detrital-rich reductive sediments. We highlight the importance of climate change as an ultimate rather than proximate anthropogenic factor for sustainable management options of tropical dams.

Socioeconomic Challenges faced by Basin’s People in India

Think India ◽  
2019 ◽  
Vol 22 (2) ◽  
pp. 296-304
Author(s):  
Biplab Tripathy ◽  
Tanmoy Mondal
Keyword(s):  
River Basin ◽  
High Tide ◽  
North East ◽  
The People ◽  
Term Basis ◽  
Major River ◽  
River Ganga ◽  
Basin Region ◽  
Basin Area

India is a subcontinent, there huge no of people lived in river basin area. In India there more or less 80% of people directly or indirectly depend on River. Ganga, Brahamputra in North and North East and Mahanadi, Govabori, Krishna, Kaveri, Narmoda, Tapti, Mahi in South are the major river basin in India. There each year due to flood and high tide lots of people are suffered in river basin region in India. These problems destroy the socio economic peace and hope of the people in river basin. There peoples are continuously suffered by lots of difficulties in sort or in long term basis. Few basin regions are always in high alert at the time of monsoon seasons. Sometime due to over migration from basin area, it becomes empty and creates an ultimate loss of resources in India and causes a dis-balance situation in this area.

scholarly journals The Observatorio Astronómico Nacional - Tonantzintla: Site Evaluation

2009 ◽  
Vol 5 (S260) ◽  
Author(s):  
H.M. Hernández-Toledo ◽  
L.A. Martínez-Vázquez ◽  
A. Pani-Cielo
Keyword(s):  
Ccd Photometry ◽  
Local Conditions ◽  
Astronomy Education ◽  
Site Evaluation ◽  
New Instrumentation ◽  
Sky Conditions ◽  
Alternative Solutions ◽  
Term Monitoring

AbstractThe objective of this contribution is to present some results of an evaluation on the local conditions at the site that were considered in order to propose that the Observatorio Astronómico Nacional, Tonantzintla, (OAN-Tonantzintla) become a National Facility for Astronomy Education. The evaluation included a quantitative diagnostic (CCD photometry) on the quality of the local sky. The attributes of the 1-m telescope, the current instrumentation and a well planned upgrading that includes new instrumentation is considered at the basis for a successful transition maintaining the attractiveness of the site for astronomy education. A 3-year upgrading program actually in progress at UNAM is providing funding for that purpose. Physics and astronomy programs at college and graduated levels at UNAM will benefit from this, yielding clear connections among astronomy researchers and educators and students at various levels. Although the OAN-Tonantzintla faces the danger of deteriorating its sky conditions, we are maintaining awareness of the night sky characteristics in long-term monitoring campaigns and encouraging the local authorities to find alternative solutions to this problem.

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