Post-fire overland flow generation and inter-rill erosion under simulated rainfall in two eucalypt stands in north-central Portugal

2011 ◽  
Vol 111 (2) ◽  
pp. 222-236 ◽  
Author(s):  
M.C. Malvar ◽  
S.A. Prats ◽  
J.P. Nunes ◽  
J.J. Keizer
Keyword(s):  
Overland Flow ◽  
Simulated Rainfall ◽  
Rill Erosion ◽  
North Central ◽  
Flow Generation ◽  
Central Portugal

scholarly journals Runoff and inter-rill erosion in a Maritime Pine and a Eucalypt plantation following wildfire and terracing in north-central Portugal

2013 ◽  
Vol 61 (4) ◽  
pp. 261-268 ◽  
Author(s):  
Martinho A.S. Martins ◽  
Ana I. Machado ◽  
Dalila Serpa ◽  
Sergio A. Prats ◽  
Sílvia R. Faria ◽  
...  
Keyword(s):  
Overland Flow ◽  
Ground Cover ◽  
Maritime Pine ◽  
Rill Erosion ◽  
Forest Types ◽  
Key Factors ◽  
Study Region ◽  
North Central ◽  
Slope Engineering ◽  
Central Portugal

Abstract The purpose of this study was to assess how terracing affected overland flow and associated sediment losses, at the micro-plot scale (0.25 m2), in recently burnt stands of the two principal forest types in north-central Portugal, i.e. mono-specific stands of Maritime Pine and Eucalypt. Terracing is an increasingly common practice of slope engineering in the study region but its impacts on runoff and erosion are poorly studied. Non-terraced plots at the Eucalypt and the Pine site revealed similar median runoff coefficients (rc: 20-30%) as well as comparable median sediment losses (15-25 g m-2) during the first seven months following wildfire. During the ensuing, slightly wetter 18-month period, however, non-terraced plots at the Pine site lost noticeably more sediments (in median, 90 vs. 18 g m-2), in spite the runoff response had remained basically the same (median rc: 33 vs. 28%). By contrast, terraced plots at the same Pine site lost hugely more sediments (in median, 1,200 g m-2) during this 18-month period. Terraced plots at the Eucalypt site even lost three times more sediments (in median, 3,600 g m-2). Ground cover and resistance to shear stress seemed to be key factors in the observed/inferred impacts of terracing.

Post-fire mobilization of metals in a recently burnt area in North-Central Portugal: a contamination risk for waterbodies?

2021 ◽  
Author(s):  
Dalila Serpa ◽  
Ana Machado ◽  
Martha Santos ◽  
Isabel Campos ◽  
Fátima Jesus ◽  
...  
Keyword(s):  
Overland Flow ◽  
Fire Severity ◽  
Hazardous Substances ◽  
Burnt Area ◽  
North Central ◽  
Contamination Risk ◽  
Freshwater Bodies ◽  
Central Portugal ◽  
Study Sites

<p>Wildfires constitute a diffuse source of contamination to aquatic ecosystems. In burnt hillslopes, ash and sediments transported by overland flow are a source of potentially hazardous substances, like metals, posing a risk for downstream water bodies. In the present study, post-fire metal mobilization by overland flow was evaluated in 16 m<sup>2 </sup>bounded plots at a eucalypt stand in Albergaria-a-Velha (Aveiro district, North-Central Portugal) that burnt with moderate severity in September 2019. Overland flow samples were collected on a weekly to bi-weekly basis, depending on the occurrence of rain, during the first 6 months after fire. Aside from overland flow samples collected at slope scale, water and sediment samples were also collected in a fire-affected stream within the Albergaria burned catchment, to assess the contamination risk posed by the fire. Samples were collected at three sites along the stream: one upstream, one within and another downstream from the burnt area, after major rainfall events. The metals analysed in this study included, vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd) and lead (Pb). Results showed that most metals exhibited a peak in exports immediately after the first significant post-fire rainfall event likely due to the wash-off of the ash layer and high sediment losses, but for some elements like Zn and Cu, exports were more or less constant over time. The fire seems to have had a low impact on the water quality of the affected stream, since metal concentrations were similar between the three study sites. The quality of stream sediments, on the other hand, was clearly affected by the fire, especially after the rainy season. As fire severity and frequency is forecasted to increase in the near future due to climate changes, the results of this work reinforce the importance of water managers to define adaptative strategies to effectively protect freshwater bodies.</p>

Short-term nitrogen losses by overland flow in a recently burnt forest area in north-central Portugal: A study at micro-plot scale

2016 ◽  
Vol 572 ◽  
pp. 1281-1288 ◽  
Author(s):  
R.V. Ferreira ◽  
D. Serpa ◽  
A.I. Machado ◽  
M.L. Rodríguez-Blanco ◽  
L.F. Santos ◽  
...  
Keyword(s):  
Overland Flow ◽  
Forest Area ◽  
Nitrogen Losses ◽  
Short Term ◽  
North Central ◽  
Central Portugal

Effects of fire occurrence and recurrence on nitrogen and phosphorus losses by overland flow in maritime pine plantations in north-central Portugal

Geoderma ◽  
2017 ◽  
Vol 289 ◽  
pp. 97-106 ◽  
Author(s):  
Mohammadreza Hosseini ◽  
Violette Geissen ◽  
Oscar González-Pelayo ◽  
Dalila Serpa ◽  
Ana Isabel Machado ◽  
...  
Keyword(s):  
Overland Flow ◽  
Maritime Pine ◽  
Pine Plantations ◽  
Fire Occurrence ◽  
Nitrogen And Phosphorus ◽  
North Central ◽  
Central Portugal ◽  
Phosphorus Losses

Cation export by overland flow in a recently burnt forest area in north-central Portugal

2015 ◽  
Vol 524-525 ◽  
pp. 201-212 ◽  
Author(s):  
A.I. Machado ◽  
D. Serpa ◽  
R.V. Ferreira ◽  
M.L. Rodríguez-Blanco ◽  
R. Pinto ◽  
...  
Keyword(s):  
Overland Flow ◽  
Forest Area ◽  
North Central ◽  
Central Portugal

scholarly journals Erosion and Subsequent Transport State of Escherichia coli from Cowpats

2005 ◽  
Vol 71 (6) ◽  
pp. 2875-2879 ◽  
Author(s):  
Richard William Muirhead ◽  
Robert Peter Collins ◽  
Philip James Bremer
Keyword(s):  
Escherichia Coli ◽  
Surface Waters ◽  
Overland Flow ◽  
Single Cells ◽  
Rainfall Event ◽  
Buffer Strips ◽  
Simulated Rainfall ◽  
E Coli ◽  
Unattached Fraction ◽  
Over Time

ABSTRACT Processes by which fecal bacteria enter overland flow and their transportation state to surface waters are poorly understood, making the effectiveness of measures designed to intercept this pathway, such as vegetated buffer strips, difficult to predict. Freshly made and aged (up to 30 days) cowpats were exposed to simulated rainfall, and samples of the cowpat material and runoff were collected. Escherichia coli in the runoff samples were separated into attached (to particles) and unattached fractions, and the unattached fraction was analyzed to determine if the cells were clumped. Within cowpats, E. coli grew for 6 to 14 days, rather than following a typical logarithmic die-off curve. E. coli numbers in the runoff correlated with numbers inside the cowpat. Most of the E. coli organisms eroded from the cowpats were transported as single cells, and only a small percentage (about 8%) attached to particles. The erosion of E. coli from cowpats and the state in which the cells were transported did not vary with time within a single rainfall event or over time as the cowpats aged and dried out. These findings indicate that cowpats can remain a significant source of E. coli in overland flow for more than 30 days. As well, most of the E. coli organisms eroded from cowpats will occur as readily transportable single cells.

Sign in / Sign up

Export Citation Format

Share Document