Zuzana Németová

Among the main elements that contribute to climate change are degradation processes and the ecological level of a landscape. These two topics have been discussed and researched for many years, and many studies have been conducted. The idea behind this article is to determine the correlation between the ecological stability of a territory and the intensity of degradation processes and find out how ecological stability affects the intensity of soil erosion and vice versa. The ecological stability was calculated based on various methods during the years analyzed, i.e., 1990, 2006, 2012, and 2018. The soil water erosion measurements were performed for the same period in order to identify the relationship between ecological stability and the intensity of soil erosion. The investigated area is located in the Slovak Republic, and each year reflects different types of management of the territory, reflecting the current situation in the catchment according to the year evaluated. The intensity of the erosion process was measured using a physically based EROSION-3D model based on the precipitation levels derived using the Community Land Model (the CLM). In addition to identifying the relationship between the level of ecological stability and the intensity of erosion, this study also describes the development of ecological stability during the evaluated period together with changes in soil erosion processes. The results show a dependence between the intensity of ecological stability and soil erosion. First of all, it determines whether such a dependence exists at all and also its extent.

Among the main elements that contribute to climate change are degradation processes and the ecological level of the landscape. These two topics have been discussed and researched for many years and many studies have been conducted. The idea of the article is to determine the correlation between the ecological stability of the territory and the intensity of degradation processes and find out how the ecological stability affects the intensity of soil erosion and vice versa. The ecological stability was calculated based on various methods during the years analyzed, i.e., 1990, 2006, 2012, and 2018. The soil water erosion was performed for the same period in order to identify the relationship between the ecological stability and intensity of soil erosion. The investigated area is located in the Slovak Republic while each year reflects different management of the territory reflecting the current situation in the catchment according to the year evaluated. The intensity of the erosion process was conducted using a phycially-based EROSION-3D model and based on the precipitation derived using Community Land Model (the CLM model). In addition to identifying the relationship between the level of ecological stability and the intensity of erosion, this study also describes the development the ecological stability during the evaluated period together with changes in soil erosion processes.

The aim of the study is to determine the environmental conditions in the territory of the Myjava river basin (Slovakia) in order to analyze changes in the ecological stability from the first military mapping (1769–1784) until the present (2020). Except of the assessment of the ecological condition of the area, the stress factors of the territory were evaluated together with proposed measures according to the need to improve the current situation. The ecological prosperity of the landscape was evaluated based on the several methodologies used in Slovakia including coefficients of ecological stability. The results pointed to changes in ecological stability during the period evaluated, together with analyses of the stress factors that are currently affecting the territory researched.

The objective of the study is an assessment of a Ratka small water reservoir in Slovakia by using two main aspects, i.e., the hydrotechnical, geotechnical and environmental aspects.An evaluation of the actual state of a small water reservoir was solved in a complex way. Based on the field measurements, the quality of surface water was controlled in order to check if the surface water quality indicators meet the requirements of government regulations. In addition to the terrain measurements, laboratory measurements were performed. The results assess the actual state of the small water reservoir in details, including an assessment of the water quality with proposed measures for improving the condition of the water reservoir.

Regional flood frequency analysis is considered to be an important and popular method for estimating different hydrological variables at ungauged sites. The estimation of the index flood is the essential problem when this method is applied. The objective of the study is a comparison of the estimation of the mean annual flood (or index flood) by using two approaches based on the ‘so-called’ index flood method and top-kriging. The concept behind these methods permits estimating the mean annual flood at ungauged locations using information taken from gauged sites located within the same homogeneous pooling groups. The study area comprises 104 gauging stations on the whole territory of Slovakia. The observation period of the annual maximum discharges of the selected stations was from 1961-2010. The identification of the homogeneous pooling group was performed using a non-hierarchical k-means clustering algorithm. The optimal number of clusters is determined by the Silhouette method. As a result, eight homogeneous pooling group clusters were identified. Finally, the results of the estimated mean annual floods using the index flood method and top-kriging were compared with the observed data. Top-kriging provided better results than the classical index flood method for estimating the mean annual flood at ungauged sites.

The testing of a model performance is important and is also a challenging part of scientific work. In this paper, the results of the physically-based EROSION-3D (Jürgen Schmidt, Berlin, Germany) model were compared with trapped sediments in a small reservoir. The model was applied to simulate runoff-erosion processes in the Svacenický Creek catchment in the western part of the Slovak Republic. The model is sufficient to identify the areas vulnerable to erosion and deposition within the catchment. The volume of sediments was measured by a bathymetric field survey during three terrain journeys (in 2015, 2016, and 2017). The results of the model point to an underestimation of the actual processes by 30% to 80%. The initial soil moisture played an important role, and the results also revealed that rainfall events are able to erode and contribute to a significant part of sediments.

The modeling of soil erosion processes is affected by several factors that reflect the physical-geographic conditions of the study site together with the land use linkage. The soil parameters are significant in the modeling of erosion and also runoff processes. The correct determination of a soil's parameters becomes a crucial part of the model's calibration. This paper deals with a sensitivity analysis of seven soil input parameters to the physically-based Erosion 3D model. The results show the variable influence of each soil parameter. The Erosion 3D model is very sensitive to initial soil moisture, bulk density, and erodibility.

The landscape is an open system influenced by natural and anthropogenic factors that in a long-run fundamentally affect its state and development. A comprehensive understanding and assessment of the anthropogenic impacts on the environment is a key prerequisite to maintain its good ecological state. However, as the impacts of anthropogenic activities on the environment are omnipresent, necessary measures for their mitigation should be addressed to improve the landscape ecological stability. In Slovakia, agricultural activities on large blocks of land are considered as one of the main anthropogenic factors negatively influencing the landscape ecological stability, which however could be eliminated by effective landscape management activities. This study assesses the ecological stability of the cadastral area of the village of Vrbovce in both historical and current contexts and suggests several “green” measures aiming at improving its ecological stability. The information about the land types and structures were obtained by manual vectorization of historical and current topographical maps. Based on this information analysis of land utilization and its development was carried out for a period of more than 250 years. For each historical period, a coefficient of ecological stability was evaluated to assign a degree of ecological stability for each period. Moreover, an analysis of positive and negative landscape-ecological impacts was also performed to identify the problematic areas within the cadastral area that need to be addressed by mitigation measures. Based on these analyses several mitigation measures were suggested to improve the ecological stability of the area. Most of them were related to the agricultural land, which makes up a significant part of the area and represents its less ecologically stable part. The proposed measures respect the original rural character of the area and its specific scenery which is a result of centuries of man-land interaction. The measures are mostly focused on transforming some of the less ecologically stable areas into natural grasslands which would be used for ecological cattle and sheep breeding as these activities were historically the primary source of living in this area.

Soil erosion due to water is an extensive problem in many countries, especially accelerated erosion, where the natural rate has significantly increased in the most recent period. Its extent impacts on land management practices and is the main factor causing soil degradation. Rainfall simulators are very popular as a standard instrument to conduct research on topics such as soil erosion, infiltration or surface runoff. They are used in laboratory or field experiments in erosion studies to assess the impacts of changes in the tillage management with regard to the erodibility of soil. Results of the experiments can be used in the modelling of surface runoff and sediment transport by hydrological models. This study presents the results of experimental measurements of surface runoff made by an artificial rainfall on an experimental plot. The artificial rainfall was generated using a small rainfall simulator, which allows changes in rainfall intensity and duration. The object of this study was analysed after the surface runoff occurred and the weight of the soil particles was transported from the experimental plot. These results have been used to determine the soil input parameters for the physically-based EROSION-2D model and for the verification of the model parameters. The EROSION-2D model represents a physically and event-based approach for the prediction of soil loss and runoff. The model only requires eight soil input parameters. Some of those parameters can be easily obtained by classic and widely-used methods (soil analyses, terrain measurements, soil map evaluations), and other parameters can be determined from rainfall experiments which represent the main aim of the study. The rainfall intensity has been set at 5 mm/min with 20 minutes of simulated rain, and it corresponded to an intensity with a return period of 100 years. During the experiment a continuous course of the surface runoff and soil moisture was recorded. The results from the simulations were applied to simulate the soil erosion processes in the physically-based EROSION-2D model. For the parametrization of the model, artificial rainfall events were used with an intensity of 2.7 mm/min and rain durations of 12 and 13 minutes. The parametrization of such models represents a necessary and significant part of any scientific work. The experimental results show that outputs from the rainfall simulations can be reproduced successfully, and, based on the results, the process of determining the model´s parameters can be successfully performed.