Csilla Farkas

Senior Research Scientist

(+47) 948 14 727
csilla.farkas@nibio.no

Place
Ås O43

Visiting address
Oluf Thesens vei 43, 1433 Ås

Biography

Csilla Farkas was graduated as a hydrologist and holds a Ph.D. in earth sciences. She has worked in the fields of soil hydrology, soil erosion, catchment hydrology and water quality. She has experience i) in mathematical modeling of land use, management, and climate change indicated changes in water, particle and nutrient transport in the soil and within the landscape and ii) in studying the spatio-temporal variability of soil properties and water balance elements. 

Read more
To document

Abstract

Recent studies on using soil enhancer material, such as biochar, provide varying results from a soil hydrological and chemical perspective. Therefore, research focusing on soil-biochar-plant interactions is still necessary to enhance our knowledge on complex effects of biochar on soil characteristics. The present study investigated the changes in soil water content (SWC) and soil respiration (belowground CO2 production) over time during the growth of Capsicum annuum (pepper) in pot experiments. Concurrently, we investigated the influence of grain husk biochar with the amount of 0, 0.5%, 2.5%, and 5.0% (by weight) added to silt loam soil. Pepper plants were grown under natural environmental conditions to better represent field conditions, and additional irrigation was applied. SWC among treatments showed minor changes to precipitation during the beginning of the study while plants were in the growing phase. The highest water holding throughout the experiment was observed in the case of BC5.0. CO2 production increased in biochar amended soils during the first few days of the experiments; while the overall cumulative CO2 production was the highest in control and the lowest in BC2.5 treatments. We used the HYDRUS 1D soil hydrological model to simulate changes in SWC, using the control treatment without biochar as a reference data source for model calibration. The simulated SWC dynamics fitted well the measured ones in all treatments. Therefore, the HYDRUS 1D can be an exceptionally valuable tool to predict the hydrological response of different amount of biochar addition to silt loam soil including plant growth.

To document

Abstract

The aim of this work was to investigate whether the agronomic traits of vermicompost prepared from partially stabilised sewage sludge digestate after thermophilic composting were more favourable than those of conventional compost. The effects of various additives (green waste, spent mushroom compost, wheat straw, biochar) were also tested after 1.5 months precomposting followed by 3 months vermicomposting with Eisenia fetida or by compost maturing. Vermicomposting did not result in significantly more intensive mineralisation than composting; the average organic carbon contents were 21.2 and 22.2% in vermicomposts and composts, respectively. Hence, the average total (N: 2.4%; P: 1.9%; K: 0.9%) and available (N: 160 mg/kg; P: 161 mg/kg; K: 0.8%) macronutrient concentrations were the same in both treatments. The processing method did not influence the organic matter quality (E4/E6) either. However, on average the concentration of the plant growth regulator kinetin was more than twice as high in vermicomposts.

Abstract

The Balaton lake is the focal area of implementing the WFD in Hungary. At present, nutrient loads are primary threat to surface and subsurface water quality in the Balaton watershed. With increasing anthropogenic pressure and increased occurrence of extreme precipitation events in the future the nitrate loads might increase. The goal of this study was to evaluate the combined effect of climate, land use and soil management changes on nitrogen loads in Tetves Creek, which is the tributary of the Balaton lake. We applied the INCA-N (INtegrated CAtchment Model) water quality model to simulate the hydrological processes and nitrate transport for two periods: the current situation (baseline, 2006 to 2015) and for a future period (2046-2055). We calibrated the model against measured discharge and nitrate concentration data. The inorganic nitrogen sub-model was further validated using data of an independent period. The modelling chain was able to reproduce 59% of the variability of average nitrate concentrations in the Tetves Creek for the validation period. After validation, we examined several climate change, land use and nitrogen supply scenarios and their combined effects on runoff and nitrogen loads. Our main conclusions are summarised below.

Abstract

A negative impact of multiple anthropogenic stressors on surface waters can be observed worldwide threatening fresh- and marine water ecosystem functioning, integrity and services. Water pollution may result from point or diffuse sources. An important difference between a point and a diffuse source is that a point source may be collected, treated or controlled. Agricultural activities related to crop production are considered as diffuse sources and are among the main contributors of nutrient loads to open water courses, being to a large degree responsible for the eutrophication of inland and coastal waters. Knowledge of hydrological and biogeochemical processes are needed for climate adaptive water management as well as for introducing mitigation measures aiming to improve surface water quality. Mathematical models have the potential to estimate changes in hydrological and biogeochemical processes under changing climatic or land use conditions. These models, indeed, need careful calibration and testing before being applied in decision making. The aim of this study was to evaluate the efficiency of various water protective adaptation strategies and mitigation measures in reducing the soil particle and nutrient losses towards surface water courses from agricultural dominated catchments. We applied the INCA-N and INCA-P models to a well-studied Norwegian watershed belonging to the Norwegian Agricultural Environmental Monitoring Program. Available measurements on water discharge, TN and TP concentration of stream water and local expert knowledge were used as reference data on land-use specific sediment, N and P losses. The calibration and the validation of both the models was successful; the Nash-Sutcliffe statistics indicated good agreement between the measured and simulated discharge and nutrient loads data. Further, we created a scenario matrix consisting of land use and soil management scenarios combined with different climate change scenarios. Our results indicate that land use change can lead to more significant reduction in particle and nutrient losses than changes in agricultural practices. The most favourable scenario for freshwater ecosystems would be afforestation: changing half of the agricultural areas to forest would reduce sediment, total N and total P losses by approximately 44, 35 and 40%, respectively. Changes in agricultural practices could also improve the situation, especially by reducing areas with autumn tillage to a minimum. We concluded, that the implementation of realistic land use and soil management scenarios still would not lead to satisfactory reduction in freshwater pollution. Hence, mitigation measures, enhancing water and particle retention in the landscape – as sedimentation ponds, constructed wetlands etc. – are important in facing the upcoming pressures on water quality in the future.

Abstract

Soil moisture is an important but often undervalued element of the water cycle. Compared to other components, the volume of soil moisture is small; nonetheless, it is of fundamental importance to many hydrological, biological and biogeochemical processes. Through processes like evaporation and plant transpiration, soil moisture is a key variable in controlling the water and energy exchange between the land surface and the atmosphere, hence, it plays an important role in the development of weather patterns and the precipitation formation. It also strongly effects surface and subsurface runoff, soil erosion, food production, greenhouse gas emission, the buffer capacity of the soil, the soil biota and many other processes and sectors. It is deducable today that short-sighted mismanagement of soil or soil water strongly contributed to the collapse of large, powerful historic civilazations. Soil degradation is a global problem that is of strong concern for European countries as well. Yet, while much focus is given to open surface water recources - the EU Water Framework Directive is in place since 2000 - the Soil Framework Directive is still to be adopted. It is important to improve the global understanding of the importance of soil as a natural resource, and its hydraulic functioning, including its global change context. The presentation aims at taking a deeper insight into the “butterfly effect” of soil status and moisture dynamics by highlighting how small-scale management decisions and processes might influences large-scale processes and our life.

To document

Abstract

The saturated hydraulic conductivity of soil, Ks, is a critical parameter in hydrological models that remains notoriously difficult to predict. In this study, we test the capability of a model based on percolation theory and critical path analysis to estimate Ks measured on 95 undisturbed soil cores collected from contrasting soil types. One parameter (the pore geometry factor) was derived by model fitting, while the remaining two parameters (the critical pore diameter, dc, and the effective porosity) were derived from X‐ray computed tomography measurements. The model gave a highly significant fit to the Ks measurements (p < 0.0001) although only ~47% of the variation was explained and the fitted pore geometry factor was approximately 1 to 2 orders of magnitude larger than various theoretical values obtained for idealized porous media and pore network models. Apart from assumptions in the model that might not hold in reality, this could also be attributed to experimental error induced by, for example, air entrapment and changes in the soil pore structure occurring during sample presaturation and the measurement of Ks. Variation in the critical pore diameter, dc, was the dominant source of variation in Ks, which suggests that dc is a suitable length scale for predicting soil permeability. Thus, from the point of view of pedotransfer functions, it could be worthwhile to direct future research toward exploring the correlations of dc with basic soil properties and site attributes.

To document

Abstract

Climate change is expected to have a vigorous impact on soils and ecosystems due to elevated temperature and changes in precipitation (amount and frequency), thereby altering biogeochemical and hydrological cycles. Several phenomena associated with climate change and anthropogenic activity affect soils indirectly via ecosystem functioning (such as higher atmospheric CO2 concentration and N deposition). Continuous interactions between climate and soils determine the transformation and transport processes. Long-term gradual changes in abiotic environmental factors alter naturally occurring soil forming processes by modifying the soil water regime, mineral composition evolution, and the rate of organic matter formation and degradation. The resulting physical and chemical soil properties play a fundamental role in the productivity and environmental quality of cultivated land, so it is crucial to evaluate the potential outcomes of climate change and soil interactions. This paper attempts to review the underlying long-term processes influenced by different aspects of climate change. When considering major soil forming factors (climate, parent material, living organisms, topography), especially climate, we put special attention to soil physical properties (soil structure and texture, and consequential changes in soil hydrothermal regime), soil chemical properties (e.g. cation exchange capacity, soil organic matter content as influenced by changes in environmental conditions) and soil degradation as a result of longterm soil physicochemical transformations. The temperate region, specifically the Carpathian Basin as a heterogeneous territory consisting of different climatic and soil zones from continental to mountainous, is used as an example to present potential changes and to assess the effect of climate change on soils. The altered physicochemical and biological properties of soils require accentuated scientific attention, particularly with respect to significant feedback processes to climate and soil services such as food security.

Abstract

The determination of environmentally minimum water level in lakes is essential for the protection of their ecosystems. The assessment of minimum water level depends on a number of biotic and abiotic factors of the lake ecosystem; however, in many cases these factors are not easy to collect and assess in their entirety. At the same time, the lakes in many cases consist an important water reserve to meet the requirements arising from economic activities, e.g. industry, agriculture. In this paper, the morphological features in four lakes – Vegoritida, Petron, Cheimaditida and Zazari – of Northern Greece are analysed in order to assess their environmentally minimum water level. The morphological analysis is based on the relationship of the lake surface area and volume with the water level. An optimization method is applied taking into account that the biodiversity is favoured as the surface area covered by the lake is increased and the human water requirements are satisfied to the greatest possible extent by the available water volume of the lake. The environmentally minimum water level determined by the morphological analysis in the four lakes is compared with the minimum water level based on the analysis of the requirements of fish fauna and macrophytes.

To document

Abstract

Catchment scale hydrological models are promising tools for simulating the effect of catchment-specific processes and management on soil and water resources. Here, we present a model intercomparison study of runoff simulations using three different semi-distributed rainfall-runoff catchment models. The objective of this study was to demonstrate the applicability of the Hydrologiska Byrans Vattenavdelning (HBV-Light); Precipitation, Evapotranspiration and Runoff Simulator for Solute Transport (PERSiST); and INtegrated CAtchment (INCA) models on Somogybabod Catchment, near Lake Balaton, Hungary. The models were calibrated and validated against observed discharge data at the outlet of the catchment for the period of January 1, 2006 –July 12, 2015. Model performance was evaluated using graphical representations, e.g. daily and monthly hydrographs and Flow Duration Curves (FDC) and model evaluation statistic; Nash–Sutcliffe efficiency (NSE) and coefficient of determination (R2). The simulation results showed that the models provided good estimates of monthly average discharge (0.60–0.90 NSE; 0.60–0.91 R2) and satisfactory results for daily discharge (0.46–0.62 NSE; 0.50–0.67 R2). We found that the application of hydrological models serves as a powerful basis for ensemble modelling of average runoff and could enhance our understanding of the eco-hydrological and transport processes within catchments. On the other hand, it can highlight the uncertainty of model forecasts and the importance of goal specific evaluation.

To document

Abstract

The main environmental stressor of the Baltic Sea is elevated riverine nutrient loads, mainly originating from diffuse agricultural sources. Agricultural practices, intensities, and nutrient losses vary across the Baltic Sea drainage basin (1.75 × 106 km2 , 14 countries and 85 million inhabitants). Six “Soil and Water Assessment Tool” (SWAT) models were set up for catchments representing the major agricultural systems, and covering the different climate gradients in the Baltic Sea drainage basin. Four fertilizer application scenarios were run for each catchment to evaluate the sensitivity of changed fertilizer applications. Increasing sensitivity was found for catchments with an increasing proportion of agricultural land use and increased amounts of applied fertilizers. A change in chemical fertilizer use of ±20% was found to affect watershed NO3-N loads between zero effect and ±13%, while a change in manure application of ±20% affected watershed NO3-N loads between zero effect and −6% to +7%.

Abstract

Knowledge of hydrological processes and water balance elements are important for climate adaptive water management as well as for introducing mitigation measures aiming to improve surface water quality. Mathematical models have the potential to estimate changes in hydrological processes under changing climatic or land use conditions. These models, indeed, need careful calibration and testing before being applied in decision making. The aim of this study was to compare the capability of five different hydrological models to predict the runoff and the soil water balance elements of a small catchment in Norway. The models were harmonised and calibrated against the same data set. In overall, a good agreement between the measured and simulated runoff was obtained for the different models when integrating the results over a week or longer periods. Model simulations indicate that forest appears to be very important for the water balance in the catchment, and that there is a lack of information on land use specific water balance elements. We concluded that joint application of hydrological models serves as a good background for ensemble modelling of water transport processes within a catchment and can highlight the uncertainty of models forecast.

To document

Abstract

Soil biological properties and CO 2 emission were compared in undisturbed grass and regularly disked rows of a peach plantation. Higher nutrient content and biological activity were found in the undisturbed, grass-covered rows. Significantly higher CO 2 fluxes were measured in this treatment at almost all the measurement times, in all the soil water content ranges, except the one in which the volumetric soil water content was higher than 45%. The obtained results indicated that in addition to the favourable effect of soil tillage on soil aeration, regular soil disturbance reduces soil microbial activity and soil CO 2 emission

To document

Abstract

The Hungarian Detailed Soil Hydrophysical Database, called MARTHA ver2.0 has been developed to collect information on measured soil hydraulic and physical characteristics in Hungary. Recently this is the largest detailed national hydrophysical database, containing controlled information from a total of 15,005 soil horizons. Two commonly used pedotransfer functions were tested to evaluate the accuracy of the predictions on the MARTHA data set, representative for Hungarian soils. In general, the application of both examined pedotransfer functions (Rajkai, 1988; Wösten et al., 1999) was not very successful, because these PTFs are representative for other soil groups. The classification tree method was used to evaluate the effect of soil structure on the goodness of estimations. It was found that using the soil structure data the inaccuracies of soil water retention predictions are more explainable and the structure may serve as a grouping variable for the development of class PTFs.

mpa_final_cropped_for_oap

Division of Environment and Natural Resources

Riverine Inputs and Direct Discharges - RID


The Comprehensive Riverine Inputs and Direct Discharges (RID) programme aims to monitor and assess all inputs and discharges of selected contaminants to the OSPAR maritime area and its regions that are carried via rivers into tidal waters, or are discharged directly into the sea, for example through sewage pipelines or activities like aquaculture inputting substances directly.

Active Updated: 25.10.2020
End: jun 2022
Start: jul 2019
Project image

Division of Environment and Natural Resources

IRIDA: Innovative remote and ground sensors, data and tools into a decision support system for agriculture water management


Efficient agriculture water use is of crucial importance for water resources management. Evapotranspiration is an important part of the water cycle, as it is the sum of evaporation and plant transpiration from the Earth's land and ocean surface to the atmosphere. Consequently, accurately determining evapotranspiration (ET) is the first step for improving irrigation efficiency and productivity and for quantifying the ecosystem water balance. The IRIDA´s approach is to combine on the ground ET and soil moisture measurements, with remote sensing ET determinations obtained with unmanned aerial vehicle (UAV/RPAS/UAS) (at plot scale) and manned vehicles and satellites (at catchment scale). IRIDA will integrate the methodologies and routines into a decision support system that will serve to manage the large amount of inputs by means of big data analysis tools. The IRIDA platform to be created will provide simple irrigation recommendation supporting end-users and irrigators when deciding the exact location for installing on-ground soil and plant water status sensors. On the other hand, at the water basin level, under conditions of varying land use as in northern Northern Europe, the evaluation of satellite remote sensing will allow increasing the accuracy of the ecosystem water balance determination, improving flood predictions and the water footprint assessment. At the end of the project execution, End Users’ interfaces and applications such as cloud web server and smartphone applications to exploit solution intelligence will be designed. By using the IRIDA protocols, the water savings to be achieved are expected to be around 7 to 15% and the estimated direct farm savings costs could be up to 420 €/ha. These first estimations based on theoretical assumptions, will be validated in several field demo-areas in Spain, Italy, Romania and Norway across different environmental and cropping conditions.

Active Updated: 21.09.2020
End: sep 2022
Start: may 2016
Project image
NORRA: Development of data-modelling system and the decision support tool


The general principles of the water use and protection are established by the Water Act, which is based on the EU Framework Directive on water policy and the Framework Directive on the sea strategy in order to ensure sustainable development and the natural status of water, and keep the quality, amount and regime of surface and groundwater as unviolated by human activity as possible. The aim of both directives is to ensure or acquire a good water status of inland bodies of surface water and coastal waters by 2015 and for the sea by the year 2021.

Active Updated: 21.09.2020
End: apr 2021
Start: mar 2014