The Evaluation of the Accuracy of Interpolation Methods in Crafting Maps of Physical and Hydro-Physical Soil Properties

Abstract

The goal of this study was the spatial processing and showcasing selected soil properties (available water capacity, total organic carbon content and the content of clay fraction <0.001 mm) in the Nitra River Basin (Slovakia) via the usage and the subsequent evaluation of the quality of applied interpolation methods (Spline, inverse distance weighting (IDW), Topo to Raster). The results showed the possibilities of “conversion” of point information obtained by field research as well as research in the laboratory into a spatial expression, thus providing at least relevant estimation of the soil properties even in localities not directly covered by soil sampling. Based on the evaluation and mutual comparison of the accuracy of the used interpolation methods (by using the so-called cross-validation and trust criteria), the most favorable results were achieved by the Spline method in the GRASS GIS environment, and in the ArcGIS environment. When comparing the measured and estimated values of given soil properties at control points, the interpolated values classified as very accurate up to accurate prevailed in the verification dataset. Qualitatively less favorable (but still acceptable) were the results obtained with Topo to Raster (ArcGIS) interpolation method. On the contrary, the Spline method in the ArcGIS environment turned out to be the least accurate. We assume that this is most likely not only a consequence of insufficient density of points (resources), but also an inappropriate implementation of the method into the ArcGIS environment.

Comparison of Meteorological and Agricultural Drought in the Nitra River Basin in 2014–2020

“…1) with an area of 4501 km 2 is located in the western part of Slovakia to the west of Hron River basin, and to the south and west of the Váh River basin (Mazúr, Lukniš, 1980;Igaz et al, 2021). According to the orographic division, the territory is in the orographic subsystem of the Carpathian Mountains and the Pannonian basin (Borgula, 2004;Igaz et al, 2021). The basin consists of agricultural land (61% of the area) and forest (30% of the area) (Tárník, Igaz, 2015).…”

“…The mean annual temperature in the studied basin, according to long-term normal parameters, falls within the range of 7.5 to 10°C. Long-term average annual precipitation in the basin ranges from 540 mm (in the south part) to 733 mm (in the north part) (Atlas krajiny SR, 2002;Igaz et al 2021). Table 1 lists selected stations with their altitude, soil type at the location, hydraulic conductivity, and particle size distribution of the soil.…”

“…Prior to every increase of pressure potential, the undisturbed soil samples were weighed and the water content corresponding to each pressure potential was calculated. Finally, the soil samples were dried for 24 h at 105 °C in the oven and weighed (Igaz et al, 2014;Igaz et al, 2021). The total precipitation in the studied period was provided by the Slovak Hydrometeorological Institute (daily precipitation totals), as the object of the present study is meteorological drought defined as a period with no precipitation.…”

Evaluation of Monitored Erosion Events in the Context of Characteristics of Source Areas in Czech Conditions

“…Various studies [30][31][32] describe direct runoff as the amount of rainwater that drains off the soil surface after causal rainfall or snowmelt. Several authors [33][34][35] state that a crucial influence on the formation of surface runoff is played by the intensity of rainfall, the topography of terrain (gradient, length, and shape of slope), soil characteristics (texture, content of organic matter, compaction, soil erodibility), and land use.…”

Mitigation of Flood Risks with the Aid of the Critical Points Method

“…The floods that affected large areas of the Czech Republic (CZ) in recent decades have raised many questions and contradictory views on further progress in the field of water management within the landscape, in particular, the issue of river basin protection against the adverse effects of flash flooding during extreme hydrological events. Direct losses due to flooding [1] take the form of damage to buildings, industrial areas [2], and urban and landscape infrastructure such as roads and railways, including damage to arable land due to water erosion on sloping areas [3] and land in the path of concentrated surface run-off [4,5]. These types of loss are evaluated using financial terms, if possible, or by other forms of classification [6,7].…”