| Abstrakt: |
Abstract: Serious attention is paid today to the problems of landscape regionalization with respect to its hydrological response. The quantification and the spatial pattern of soil drought indicators (SDI) are considered crucial for a correct hydrological zonation of agricultural lands with regard to water-related phenomena of practical importance, such as drought risk, runoff generation and soil erosion. The paper deals with regional estimation of hydrolimits (field capacity, point of limited availability, wilting point) and water storage capacity (expressed as the difference between the field capacity and the wilting point) of the root zone of agricultural landscape and their interpretation as potential soil drought indicators (SDI). A spatial and pedotransfer approach was applied to the region of the Záhorská nížina Lowland. Relevant outputs (parameters of soil water retention curves) were derived from the data of the Comprehensive Agricultural Soil Survey digital database (KPP DB) using pedotransfer functions (Rosetta model). A spatial processing of model outputs to the form of the regional maps of SDI was performed using GIS tools. SDI were then quantitatively evaluated for (i) individual textural soil units and (ii) individual pedo-ecological regions of Záhorská nížina Lowland respectively. Water storage capacity of soil represents the maximum volume of long-term available water in the effective root zone of cultural crops. To be used as soil-drought indicator, the water storage capacity data should always be interpreted in combination with information about the water contents related to the field capacity and the wilting point. Generally, it is assumed that spatial pattern of SDI is closely related to the soil textural units, while in the case of Záhorská nížina Lowland the segmentation of the landscape to pedo-ecological regions is considered inadequate from hydrological point of view. |
