Search

Start Over Creator Lichner, Ľubomír Format svazek Data provider Academy of Sciences Library/Knihovna Akademie věd ČR

3. Comparison of two methods to assess heterogeneity of water flow in soils

Creator:
Lichner, Ľubomír, Dušek, Jaromír, Dekker, Louis W., Zhukova, Natalia, Faško, Pavol, Holko, Ladislav, and Šír, Miloslav
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
degree of preferential flow, effective cross section, preferential flow in soil, infiltration experiment, and radioactive tracer technique
Language:
Slovak
Description:
The heterogeneity of water flow and solute transport was assessed during radioactive tracer infiltration experiment in a black clay loam soil using modified methods to estimate the effective cross section (ECS) and the degree of preferential flow (DPF). The results of field and numerical experiments showed that these parameters characterized the heterogeneity of water flow in the soils unequivocally. The ECS decreases non-linearly and the DPF increases linearly with an increase of the bypassing ratio (ratio of macropore flow rate to total flow rate). The ECS decreased and the DPF increased with depth, which suggests an increase in the heterogeneity of water flow with depth. The plot of the DPF against ECS values calculated from the tracer experiment data was consistent with the relationship obtained by the numerical simulation assuming preferential flow in the neighbourhood of three probes.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

5. Efektívnosť ílových minerálov pri znižovaní vooodpudivosti počas dlhého suchého a teplého obdobia

Creator:
Lichner, Ľubomír and Dlapa, Pavel
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
water repellency, sand, stearic acid, clay minerals, vodoodpudivosť, piesok, kyselina stearová, and ílové minerály
Language:
Slovak
Description:
The aim of this study was to evaluate an efficiency of clay minerals (kaolinite, illite, Na- and Ca-montmorillonite) in alleviating the water repellency of stearic acid sand during the course of long-term hot and dry spell. This spell was simulated by prolonged drying (incubation) of the samples in oven at 50°C. It was found that the kaolinite addition resulted in a drop in the persistence of water repellency of the stearic acid sand. On the contrary, the Ca-montmorillonite addition increased markedly the persistence of water repellency of the stearic acid sand. In most cases, the illite addition resulted in an increase in the persistence of water repellency, even though not so markedly as it was in the case of Ca-montmorillonite addition. In the case of Na-montmorillonite addition, the striking drop in the persistence of water repellency of the stearic acid sand was registered only after lowering the moisture below 5 %. An increase in the persistence of water repellency of the sand-clay mixture with an increase in the clay amount is another interesting finding, observed in case of kaolinite and Ca-montmorillonite. and Cieľom tejto štúdie bolo zhodnotenie efektívnosti ílových minerálov (kaolinitu, illitu, Na- a Camontmorillonitu) pri znižovaní stálosti vodoodpudivosti piesku pokrytého kyselinou stearovou počas dlhého suchého a teplého obdobia, simulovaného inkubáciou vzoriek pri teplote 50 °C. Zistili sme, že pridanie kaolinitu výrazne znížilo stálosť vodoodpudivosti piesku pokrytého kyselinou stearovou prakticky počas celého cyklu sušenia. Pridanie Ca-montmorillonitu naopak stálosť vodoodpudivosti piesku pokrytého kyselinou stearovou výrazne zvýšilo. Pridanie illitu vo väčšine prípadov zvýšilo stálosť vodoodpudivosti piesku pokrytého kyselinou stearovou, aj keď nie tak výrazne ako pridanie Ca-montmorillonitu. V prípade pridania Na-montmorillonitu sme výrazné zníženie vodoodpudivosti piesku pokrytého kyselinou stearovou zaznamenali až po poklese vlhkosti vzorky pod 5 %. Ďalším zaujímavým poznatkom je vzrast vodoodpudivosti so zvyšujúcim se obsahom ílu, ktorý sme zaregistrovali v prípade kaolinitu a Ca-montmorillonitu.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

6. Extent and persistence of soil water repellency induced by pines in different geographic regions

Creator:
Iovino, Massimo, Pekárková, Pavla, Hallett, Paul D., Pekár, Ján, Lichner, Ľubomír, Mataix-Solera, Jorge, Alagna, Vincenzo, Walsh, Richard, Raffan, Annette, Schacht, Karsten, and Marek, Rodný
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
pine, soil, water repellency, water drop penetration time, and repellency index
Language:
Slovak
Description:
The extent (determined by the repellency indices RI and RIc) and persistence (determined by the water drop penetration time, WDPT) of soil water repellency (SWR) induced by pines were assessed in vastly different geographic regions. The actual SWR characteristics were estimated in situ in clay loam soil at Ciavolo, Italy (CiF), sandy soil at Culbin, United Kingdom (CuF), silty clay soil at Javea, Spain (JaF), and sandy soil at Sekule, Slovakia (SeF). For Culbin soil, the potential SWR characteristics were also determined after oven-drying at 60°C (CuD). For two of the three pine species considered, strong (Pinus pinaster at CiF) and severe (Pinus sylvestris at CuD and SeF) SWR conditions were observed. Pinus halepensis trees induced slight SWR at JaF site. RI and RIc increased in the order: JaF < CuF < CiF < CuD < SeF, reflecting nearly the same order of WDPT increase. A lognormal distribution fitted well to histograms of RIc data from CuF and JaF, whereas CiF, CuD and SeF had multimodal distributions. RI correlated closely with WDPT, which was used to develop a classification of RI that showed a robust statistical agreement with WDPT classification according to three different versions of Kappa coefficient.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

7. Impact of soil compaction on water content in sandy loam soil under sunflower

Creator:
Nagy, Viliam, Šurda, Peter, Lichner, Ľubomír, Kovács, Attila J., and Milics, Gábor
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
soil compaction, soil penetration resistance, bulk density, and water flow
Language:
Slovak
Description:
Soil compaction causes important physical modifications at the subsurface soil, especially from 10 to 30 cm depths. Compaction leads to a decrease in infiltration rates, in saturated hydraulic conductivity, and in porosity, as well as causes an increase in soil bulk density. However, compaction is considered to be a frequent negative consequence of applied agricultural management practices in Slovakia. Detailed determination of soil compaction and the investigation of a compaction impact on water content, water penetration depth and potential change in water storage in sandy loam soil under sunflower (Helianthus annuus L.) was carried out at 3 plots (K1, K2 and K3) within an experimental site (field) K near Kalinkovo village (southwest Slovakia). Plot K1 was situated on the edge of the field, where heavy agricultural equipment was turning. Plot K2 represented the ridge (the crop row), and plot K3 the furrow (the inter–row area of the field). Soil penetration resistance and bulk density of undisturbed soil samples was determined together with the infiltration experiments taken at all defined plots. The vertical bulk density distribution was similar to the vertical soil penetration resistance distribution, i.e., the highest values of bulk density and soil penetration resistance were estimated at the plot K1 in 15–20 cm depths, and the lowest values at the plot K2. Application of 50 mm of water resulted in the penetration depth of 30 cm only at all 3 plots. Soil water storage measured at the plot K2 (in the ridge) was higher than the soil water storage measured at the plot K3 (in the furrow), and 4.2 times higher than the soil water storage measured at the most compacted plot K1 on the edge of the field. Results of the experiments indicate the sequence in the thickness of compacted soil layers at studied plots in order (from the least to highest compacted ones): K2–K3–K1.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

9. Plants and biological soil crust influence the hydrophysical parameters and water flow in an aeolian sandy soil

Creator:
Lichner, Ľubomír, Holko, Ladislav, Zhuková, Natalia, Schacht, Karsten, Rajkai, Kálmán, Fodor, Nándor, and Sándor, Renáta
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
sandy soil, vegetation, water repellency, hydrophysical parameters, water flow, piesočnatá pôda, vegetácia, vodoodpudivosť, hydrofyzikálne parametre, and prúdenie vody
Language:
Slovak
Description:
This study tested the hypothesis that the changes in hydrophysical parameters and heterogeneity of water flow in an aeolian sandy soil have the same trend as the process of succession. Three sub-sites were demarcated at the area of about 50 m x 50 m. The first sub-site was located at the pine-forest glade covered with a biological soil crust and represented the initial stage of succession. The second sub-site was located at the grassland and represented more advanced stage of succession. The third sub-site was located at the pine forest with 30-year old Scots pines and represented advanced stage (close to climax) of succession. The sandy soil at the surface was compared to the soil at the pine-forest glade at 50 cm depth, which served as a control because it had a similar texture but limited impact of vegetation or organic matter. It was found that any type of vegetation cover studied had a strong influence on hydrophysical parameters and heterogeneity of water flow in an aeolian sandy soil during hot and dry spells. The changes in some hydrophysical parameters (WDPT, R, k(-2 cm), Sw(-2 cm), ECS and DPF) and heterogeneity of water flow in an aeolian sandy soil had the same trend as the process of succession, but it was not so in the case of Ks and Se(-2 cm), probably due to the higher content of smaller soil particles in grassland soil in comparison with that content at other sub-sites. Both the persistence and index of water repellency of pure sand differed significantly from those of grassland, glade and forest soils. The highest repellency parameter values in forest soil resulted in the lowest value of both the water sorptivity and hydraulic conductivity in this soil in comparison with other soils studied. The highest value of ethanol sorptivity and the lowest value of saturated hydraulic conductivity in the grassland soil in comparison with other soils studied were due to the higher content of fine-grained (silt and clay) particles in the grassland soil. The effective cross section and the degree of preferential flow of pure sand differed significantly from those of grassland, glade and forest soils. The change in soil hydrophysical parameters due to soil water repellency resulted in preferential flow in the grassland, glade and forest soils, while the wetting front in pure sand area exhibited a form typical of that for stable flow. The latter shape of the wetting front can be expected in the studied soils in spring, when soil water repellency is alleviated substantially., The columnar shape of the wetting front, which can be met during heavy rains following long dry and hot spells, was attributed to redistribution of applied water on the surface to a series of micro-catchments, which acted as runon and runoff zones., V príspevku sa testovala hypotéza, že zmeny hydrofyzikálnych parametrov a heterogenita prúdenia vody v piesočnatej pôde majú rovnaký trend ako proces sukcesie. Na ploche asi 50 m x 50 m sa vytýčili tri parcely. Prvá parcela sa nachádzala na čistine pokrytej biologickým pôdnym pokryvom a reprezentovala počiatočné štádium sukcesie. Druhá parcela sa nachádzala na zatrávnenej ploche a reprezentovala rozvinutejšie štádium sukcesie. Tretia parcela sa nachádzala v borovicovom lese a reprezentovala rozvinuté štádium sukcesie (blízke ku klimaxovej vegetácii). Piesočnatá pôda na povrchu parciel sa porovnávala s pôdou z čistiny v hĺbke 50 cm, ktorá slúžila ako kontrola, pretože mala skoro rovnakú textúru, avšak veľmi malý vplyv vegetácie alebo organickej hmoty. Zistili sme, že akýkoľvek typ študovaného vegetačného pokryvu mal veľký vplyv na hydrofyzikálne parametre a heterogenitu prúdenia vody v piesočnatej pôde počas horúcich a suchých období. Zmeny niektorých hydrofyzikálnych parametrov (WDPT, R, k(-2 cm), Sw(-2 cm), ECS a DPF) a heterogenity prúdenia vody v piesočnatej pôde mali rovnaký trend ako proces sukcesie, neplatilo to však v prípade Ks a Se(-2 cm), pravdepodobne v dôsledku vyššieho obsahu malých pôdnych častíc v pôde s trávnatým pokryvom v porovnaní s inými parcelami. Stálosť aj index vodoodpudivosti čistého piesku sa štatisticky významne líšili od hodnôt týchto parametrov v pôde pod trávou, biologickým pôdnym pokryvom a borovicami. Najvyššie hodnoty parametrov vodoodpudivosti v tráve pod borovicami mali za následok najnižšie hodnoty sorptivity pre vodu a hydraulickej vodivosti v tejto pôde v porovnaní s ostatnými študovanými pôdami. Najvyššie hodnoty sorptivity pre etanol a najnižšie hodnoty nasýtenej hydraulickej vodivosti v pôde pod trávou v porovnaní s inými pôdami boli pravdepodobne spôsobené vyšším obsahom malých pôdnych častíc v tejto pôde. Efektívny prierez (ECS) a stupeň preferovaného prúdenia (DPF) čistého piesku sa štatisticky významne líšili od hodnôt týchto parametrov v pôde pod trávou, biologickým pôdnym pokryvom a borovicami. Zmeny hydrofyzikálnych parametrov pôdy v dôsledku jej vodoodpudivosti mala za následok preferované prúdenie v pôde pod trávou, biologickým pôdnym pokryvom a borovicami, zatiaľ čo čelo omáčania v čistom piesku malo tvar typický pre stabilné prúdenie. Takýto tvar čela omáčania možno vo všetkých študovaných pôdach očakávať na jar, keď je vodoodpudivosť pôdy podstatne znížená v dôsledku jej zvýšenej vlhkosti., and Čelo omáčania v tvare prstov, ktoré možno očakávať počas prívalových dažďov nasledujúcich po dlhých suchých a horúcich obdobiach, možno pričítať redistribúcii vody na povrchu pôdy do viacerých mikropovodí, ktoré sa správali ako vtokové a odtokové oblasti
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

10. Projev klimatické anomálie 1992 - 1996 v odtokových poměrech na povodí Liz

Creator:
Šír, Miloslav, Tesař, Miroslav, Lichner, Ľubomír, and Syrovátka, Oldřich
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
hydrologic cycle, precipitation, runoff, hydrologický cyklus, srážky, and odtoky
Language:
Slovak
Description:
Hydrologic cycle in the Liz catchment is described with an anomaly in the vegetation seasons 1992-1996. Experimental catchment Liz is located in the Šumava Mts. in the Czech Republic. The fully forested watershed is covered by mature spruce forest, and its basic characteristics are as follows: drainage area 0.99 km2, mean discharge 0.01m3 s-1, runoff coefficient 0.38, mean annual air temperature 6.30 oC, average slope 17 %, basin length 1.45 km, water course length 1.43 km, elevation 828-1074 m a.s.l., precipitation sum 851 mm year-1, and runoff depth 324 mm year-1. Air temperature, precipitation, global radiation, and discharge in the closing profile are measured in the catchment. It is characteristic for hydrologic cycle in the catchment that the share of seasonal sums of both the global radiation and temperature was nearly constant in 1983-2000. However, the seasonal sums of both the global radiation and temperature were changed considerably in 1983-2000. Similarly, the share of seasonal sums of both the rainfall and runoff was nearly constant in 1983-1991 and 1997-1999. An anomalous course of climate was registered in 1992-1996, manifested by a deviation on the double mass curve of the seasonal sums of rainfall and runoff. Stabilised elsewhere, the ratio of rainfall and runoff is changed during the vegetation seasons 1992-1996. Starting from the 1997 season, this ratio has obtained the value held before 1992. The reason of the 1992-1996 anomaly of hydrologic cycle in the experimental catchment had to be significant external phenomenon, most likely explosion of the Mount Pinatubo volcano in Philippines on June 15, 1991. and Hydrologic cycle in the Liz catchment is described with an anomaly in the vegetation seasons 1992- 1996. Experimental catchment Liz is located in the Šumava Mts. in the Czech Republic. The fully forested watershed is covered by mature spruce forest, and its basic characteristics are as follows: drainage area 0.99 km2 , mean discharge 0.01m3 s -1, runoff coefficient 0.38, mean annual air temperature 6.30 ºC, average slope 17 %, basin length 1.45 km, water course length 1.43 km, elevation 828-1074 m a.s.l., precipitation sum 851 mm year-1, and runoff depth 324 mm year-1. Air temperature, precipitation, global radiation, and discharge in the closing profile are measured in the catchment. It is characteristic for hydrologic cycle in the catchment that the share of seasonal sums of both the global radiation and temperature was nearly constant in 1983-2000. However, the seasonal sums of both the global radiation and temperature were changed considerably in 1983-2000. Similarly, the share of seasonal sums of both the rainfall and runoff was nearly constant in 1983-991 and 1997-1999. An anomalous course of climate was registered in 1992-1996, manifested by a deviation on the double mass curve of the seasonal sums of rainfall and runoff. Stabilised elsewhere, the ratio of rainfall and runoff is changed during the vegetation seasons 1992-1996. Starting from the 1997 season, this ratio has obtained the value held before 1992. The reason of the 1992-1996 anomaly of hydrologic cycle in the experimental catchment had to be significant external phenomenon, most likely explosion of the Mount Pinatubo volcano in Philippines on June 15, 1991.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public