Peter Szilassi

Predicting land cover changes and their impact on the sediment influx in the Lake Balaton catchment

The land cover pattern in the Lake Balaton catchment (Hungary) has been changing since decollectivization in the 1990s. These land cover changes significantly impact the landscape connectivity, controlling the influx of sediments into the lake. A comparison of high resolution land cover maps from 1981, 2000 and 2005 showed a significant extensification of the agriculture with land cover conversions from arable land and vineyards to grassland and forest. For each land unit transition probabilities were assessed using logistic regression techniques to evaluate to which extent land cover changes are controlled by physical or socio-economic parameters. A stochastic land cover allocation algorithm was applied to generate future land cover patterns. The landscape connectivity for each of the simulated land cover patterns was assessed by means of a distributed routing algorithm. The simulations suggest that further land abandonment in the upslope parts of the catchment will cause a non-linear reduction of average soil erosion rates. The changes, however, have a relatively low impact on the sediment volume entering the lake because of the land unit’s poor connectivity with permanent river channels. The major contributors to the lakes sediment load are the vineyards near the lakeshore. They are likely to be maintained because of their touristic value. A significant reduction of the total sediment input in the lake can be expected only if soil conservation measures in the vineyards near the shorelines are undertaken.

Sensitivity analysis of logistic regression parameterization for land use and land cover probability estimation

The recent availability of regional-scale land use and land cover data made it possible to apply land use and land cover models at regional-, national- and even continental-scale levels. A commonly used modelling approach is based on the assessment of land cover probabilities by means of logistic regression equations. In most cases, however, the error involved in the parameterization of logistic regression equations is not known. In this article, the sensitivity of logistic regression parameterization for land use and land cover probability assessments is analysed by comparing the results using input maps from different sources. Land cover maps with a range of accuracy levels were collected for a sub-catchment of the Lake Balaton watershed in Hungary. The results show that the parameterization of the logistic regression coefficients is highly dependent on the quality of the input maps. Both the spatial pattern and the area covered by a specific land cover type have a direct influence on the error propagation in the land cover probability maps. These findings should be taken into account when interpreting the results of land use and land cover change models at regional- and national-scale levels.

Drought Severity and its Effect on Agricultural Production in the Hungarian-Serbian Cross-Border Area

Abstract Several environmental and economic consequences of drought and the accompanying water shortage were observed in the plain area of the Carpathian Basin in the last decades. This area is mostly used for agriculture, thus it is a key problem in the future to maintain food safety in the changing circumstances. Therefore, involvement and identification of areas affected by drought hazard and revealing steps of efficient adaptation are of high importance. In this study influence of drought severity on agricultural production is investigated in the Hungarian-Serbian cross-border area. The tendency in drought severity was analysed by PaDI and MAI drought indices. The effect of drought on agricultural production is evaluated on maize yield data as the most drought sensitive crop in the region. Increasing drought frequency and severity was indicated for the study area for the period of 1961-2012. The spatial assessment of annual PaDI maps revealed the higher exposure of the north and northeastern part of the study area to drought, where drought frequency was also experienced to be the highest. Increased sensitivity was detected based on maize yield loss after the early 1990s and annual yields were in strong connection with d rought severity. In spite of the technological development of agriculture, environmental factors still substantially affect crop yie lds. The observed unfavourable changes in the region mean that water management and spatial planning faces conceptual challenges to prevent and mitigate the damages of drought.

Small-scale agricultural landscapes promote spider and ground beetle densities by offering suitable overwintering sites

ContextIntensive agricultural management practices and landscape homogenisation are the main drivers of biodiversity loss in agricultural landscapes. Agricultural fields are regularly disturbed and provide unstable habitats due to crop management regimes. This may lead to movement of arthropods into neighbouring non-arable habitats, as natural and semi-natural habitats provide suitable overwintering sites.ObjectivesHere we assessed the effect of landscape composition and configuration on the overwintering spider and carabid fauna of grassy field margins and hedgerows.MethodsWe sampled ground-dwelling arthropods at field edges of different types (grassy field margin and hedgerows), landscape composition (diverse and simple) and configuration (mosaic and large-scale agricultural landscapes).ResultsWe detected larger spiders in hedgerows than in grassy field margins and in complex landscapes rather than in simple landscapes. We found a significant effect of interaction between landscape composition and edge type on ballooning propensity of spiders. Agrobiont carabids were more abundant in field edges of compositionally simple and large-scale agricultural landscapes. Furthermore, we showed an effect of interaction between landscape composition and edge type on agrobiont spiders. We collected larger carabids in grassy field margins than in hedgerows and carabids were smaller in simple landscapes than in diverse landscapes. The spider community was affected by edge type, and landscape composition had a significant effect on the carabid community.ConclusionsSmall-scale agricultural landscapes may have higher overall densities of ground-dwelling spiders and carabids than large scale landscapes due to the relatively high edge density and the higher quantity of available overwintering sites.

Public Perception on Hydro-Climatic Extremes and Water Management Related to Environmental Exposure, SE Hungary

Increasing climate extremities, as consequences of climate change, highly affect the public and farmers in the SE Carpathian Basin. Our research aimed at the investigation of the perceptions and experiences of public, farmers and decision-makers on drought and inland excess water problems on the Hungarian part of this region, since their knowledge and cooperation are essential in the future planning of sustainable water management. Their opinions were explored by 481 questionnaires and 52 in-depth interviews addressing the perceived climate change impacts in everyday life and agriculture, causes of drought and inland excess water, possibilities of mitigation and adaptation, and sustainability of the present farming structure. The spatial distribution of the answers was compared with the spatial pattern of drought and inland excess water sensitivity based on environmental indicators. The results confirmed their high correspondence reflecting a realistic knowledge on severity, significance and the contributing factors. Individual responsibility, the lack of financial resources and an uncertain vision of public were considered as major weak points that could be improved to foster the implementation of an effective water management strategy. High efforts are necessary to outline the framework of inclusive planning processes with exact roles of all actors and find ways to motivate co-operation willingness and increase individual responsibility.