After the October 2017 fires that affected almost 30% of the Mondego hydrographic basin in Central Portugal, a study has been conducted for two years in order to understand what are the most influencing factors of the water physical and chemical proprieties. Natural (geology, rainfall), anthropic (land use) and mixed (fires) factors were taken into account.

From the natural influencing parameters, rainfall seems, in short term, to increase the water’s aluminium, nitrate and turbidity, while in the long term reduces the concentrations of elements in surface water and approximates the water’s pH to rainfall features.

The igneous geology of a catchment does seem to have a great influence in the presence of arsenic in surface water, while the percentage of a catchment’s sedimentary carbonate geology influences the concentrations of calcium and bicarbonate, increasing the water’s alkalinity at the same time.

Agricultural land use seems to have a major influence in increasing the water’s chloride, potassium and sodium content, which lead to increases in electrical conductivity.

The fires had the biggest impact on surface water quality. Whether due to atmospheric deposition and surface runoff of combustion products, it increased the water’s concentrations of arsenic, potassium, calcium, magnesium, nitrate, sulfate and strontium, and consequently lead to increases in electrical conductivity.

You can read the full article here.

The article "Impacte dos incêndios florestais na qualidade das águas superficiais: um estudo na bacia hidrográfica do Mondego" (Impact forestall fires in the quality of surface water: a study in the Mondego hidrological basin) was published in the Livro de resumos XX Simpósio Luso-Brasileiro de Engenharia Sanitária e Ambiental and it can read here (in Portuguese)

In the upcoming July 1^st of 2022, the results from the PhD project “Surface water monitoring to assess forcers of land-use and occupation change” will be presented at the XX Simpósio Luso-Brasileiro de Engenharia Sanitária e Ambiental. With the title “Impacte dos incêndios florestais na qualidade das águas superficiais: um estudo na bacia hidrográfica do Mondego” (Impact forestall fires in the quality of surface water: a study in the Mondego hidrological basin), this presentation will reflect the results from a 2-year monitoring campaign on multiple sub-basins of the Mondego hydrological basin after the major Portuguese fires of 2017.

The presentation will have place in the Pedagogical Complex of the University of Aveiro, and will be conducted in Portuguese.

INTERREG Atlantic Area funding programme approved the extension of the Risk AquaSoil project until June of 2024.

RiskAquaSoil aims to develop a comprehensive management plan for risks in soil and in water to improve the resilience of the Atlantic rural areas. Through transnational cooperation, the project partners will combat the adverse effects of the climate change, especially on agricultural lands.

This time around one of the key studies during the Risk AquaSoil project will be understanding the impacts on water quality from severe draught.

The PhD project, Surface water monitoring to assess forcers of land-use and occupation change, was funded by the Fundação para a Ciência e Tecnologia (Portuguese national funding agency for science, research and technology). Under the research grant 2020.05101.BD, this project aims at:

1. Identify abiotic indicators of surface water associated with changes in land use for fire-affected areas, artificial areas and agricultural areas;

2. Quantify and determine the relationship/influence of the land-use and occupation changes, in alteration of abiotic water indicators;

3. Identify and determine the influence of forcers in the changes of land-use and determine their moderating/mediating role in the variation of abiotic indicators of water;

4. Define responses to problems related to changes of land-use, using as a basis the monitoring of surface water indicators.

After a series of devastating wildfires, a series of surface water monitoring campaigns were conducted. The results of these campaigns were contrasted with surface water geochemical backgrounds, determined using publicly available data. This methodology allowed to better identify which water parameters were most influenced by the fires.

Burnt plant material and organic matter partially account for the increases in Cl−, NO3−, SO42−, Al, As, Fe, and Mn content. High Al, Fe and Zn with low water conductivity suggests that these elements were associated with sediment loads after the removal of vegetation.

You can read the full article here.

A series of forest fires in Central Portugal in 2017 were responsible for a wide vegetation clearance leaving the weathering profiles more exposed to erosive action. Suspended loads from catchment areas affected by these fires were periodically sampled to evaluate spatial and seasonal variability in sediment production.

Bulk mineralogy reflected the geology of the source areas, but displayed high variability even for a single sampling site, which can be partially linked to the grain-size control on sediment composition. Clay mineralogy provided a better picture of the denudation at catchment scale. The predominance of detrital illite with low I5/I10, indicated very shallow weathering profiles. Chlorite was usually the second most common mineral, whilst kaolinite was detected only in less steep catchment areas with a predominance of granitic basement rocks or where previous-cycle depositional units are also present. Year-long shifts in clay assemblages were attributed to different spatial patterns of denudation.

You can read the full article here.

An article reflecting some of the findings of a study of surface water quality after intense forest fires was published on the Ecological Indicators Journal.

The article reflects the findings done on the first 8 months after the forest fires that affected Portugal on October of 2017, in relation with the surface water quality. After the 8 months of an almost monthly monitoring campaign, with focus on the water physical and chemical parameters, as well as a few compounds, it was noticed a considerable increase of turbidity, aluminium, iron and manganese. An increase in arsenic was also found on a smaller basin, however, it wasn’t possible to establish if the increase of this element was related to the forest fires, or the agricultural use of the basin. These changes were more obvious in the intense raining months of March and April. Interestingly, after this period, most of water parameters returned to normal levels, suggesting that precipitation must have played an important role as a depuration system.

These findings suggest that after a change of forest and natural areas to burnt areas, surface water should be the monitored for nitrate, aluminium, iron and manganese as to address what potential treatment the water should undergo prior to its usage.

You can read the full article here.