15 research outputs found
Analysis of Genesis and Activity of Slope Deformation Běleč in Context of Evolution of the Svratka River Valley between Doubravník and Borač
Analýza geneze a aktivity svahové deformace Běleč Název práce: Analýza geneze a aktivity svahové deformace Běleč v kontextu vývoje údolí Svratky mezi Doubravníkem a Boračí Autor: Daniel Žížala Katedra: Katedra fyzické geografie a geoekologie, Přírodovědecká fakulta, Univerzita Karlova v Praze Vedoucí diplomové práce: Doc. RNDr. Vít Vilímek, CSc. Abstrakt Předkládaná diplomová práce se zabývá otázkou geneze a aktivity hluboce založené svahové deformace Běleč, nacházející se v hlubokém průlomovém údolí Křeptovského potoka cca 1,5 km východně od Doubravníku na východním okraji Českomoravské vrchoviny. Práce přispívá k otázce vlivu svahové poruchy na havárii vodovodního přivaděče Vírského oblastního vodovodu v roce 2005. Metodikou řešení geneze deformace byla geomorfologická analýza, řadící iniciaci svahových pohybů na poruše do středního pleistocénu. Morfotektonická analýza přispěla k otázce podílu neotektonických poruchových zón na vznik deformace a prokázala výskyt směrné a příčné tektonické poruchy v údolí Křeptovského potoka, narušující pevnostní charakteristiky masivu. Aktivita svahových pohybů byla řešena v rozsahu let 1880 - 2007 prostřednictvím dendrogeomorfologické analýzy. Letokruhovou analýzou ze vzorků buku lesního (fagus sylvatica) nebyly prokázány kontinuální pohyby v celém rozsahu deformace....Analýza geneze a aktivity svahové deformace Běleč Title: Analysis of genesis and activity of slope deformation Běleč in context of evolution of the Svratka river valley between Doubravník and Borač Author: Daniel Žížala Department: Department of Physical Geography and Geoecology, Faculty of Science, Charles University in Prague Supervisor: Doc. RNDr. Vít Vilímek, CSc. Abstract Submitted diploma thesis deals with genesis and activity of deep-seated slope deformation Běleč, situated in a deep fault valley of Křeptovský stream at the eastern boundary of Bohemian-Moravian upland. The study contributes to resolve a question of the failure Běleč impact on Vír water pipeline crash in 2005. In the thesis, several research methods were adopted. For determination of the deformation genesis, geomorphologic analysis was used. According to this method, initiation of the slope movements on the failure zone can be classified as Middle Pleistocenic. In the research on neotectonic failure zones influence on the Běleč deformation creation, morphotectonic analysis was applied. In Křeptovský stream valley, presence of a longitudinal and transversal failure affecting the strength characteristics of the massif was demonstrated. The activity of the slope movements was studied between 1880 - 2007 by means of dendrogeomorphologic...Katedra fyzické geografie a geoekologieDepartment of Physical Geography and GeoecologyFaculty of SciencePřírodovědecká fakult
Quantification of soil organic carbon redistribution in eroded soils
Decline in organic carbon, organic matter in soil is generally seen as a major threat to the sustainability of agriculture, especially of fertility of soils. The soil represents a considerable pool of carbon and is therefore an important component of the whole carbon cycle on Earth, particularly in the context of expected changes in climate and land use. Therefore, research of soil organic carbon is recently in the spotlight of soil scientists worldwide.
Very discussed is the redistribution of organic carbon lateral movements due to soil erosion. In this regard, however, still a lot of ambiguity between the scientific communities exists on the dynamics of carbon in various stages of erosion-accumulation process. In this respect, the soil scientists increased emphasis on further research in this issue.
New technologies and practices contribute to solving these gaps in existing knowledge. However, these bring new specific problems. Therefore, the aim of this work is to define and quantified prediction of variability of soil organic matter in areas affected by soil erosion using advanced remote sensing methods. Captured aerial hyperspectral and multispectral satellite images for selected sites of interest is used. On these test sites ground soil survey is targeted. Using digital soil mapping methods and sophisticated statistical methods spatial maps of soil properties are created. These are further interpreted to effect redistribution of soil organic carbon content in different parts of the relief
Analysis of Genesis and Activity of Slope Deformation Běleč in Context of Evolution of the Svratka River Valley between Doubravník and Borač
Analýza geneze a aktivity svahové deformace Běleč Title: Analysis of genesis and activity of slope deformation Běleč in context of evolution of the Svratka river valley between Doubravník and Borač Author: Daniel Žížala Department: Department of Physical Geography and Geoecology, Faculty of Science, Charles University in Prague Supervisor: Doc. RNDr. Vít Vilímek, CSc. Abstract Submitted diploma thesis deals with genesis and activity of deep-seated slope deformation Běleč, situated in a deep fault valley of Křeptovský stream at the eastern boundary of Bohemian-Moravian upland. The study contributes to resolve a question of the failure Běleč impact on Vír water pipeline crash in 2005. In the thesis, several research methods were adopted. For determination of the deformation genesis, geomorphologic analysis was used. According to this method, initiation of the slope movements on the failure zone can be classified as Middle Pleistocenic. In the research on neotectonic failure zones influence on the Běleč deformation creation, morphotectonic analysis was applied. In Křeptovský stream valley, presence of a longitudinal and transversal failure affecting the strength characteristics of the massif was demonstrated. The activity of the slope movements was studied between 1880 - 2007 by means of dendrogeomorphologic..
Soil Organic Carbon Mapping Using Multispectral Remote Sensing Data: Prediction Ability of Data with Different Spatial and Spectral Resolutions
The image spectral data, particularly hyperspectral data, has been proven as an efficient data source for mapping of the spatial variability of soil organic carbon (SOC). Multispectral satellite data are readily available and cost-effective sources of spectral data compared to costly and technically demanding processing of hyperspectral data. Moreover, their continuous acquisition allows to develop a composite from time-series, increasing the spatial coverage of SOC maps. In this study, an evaluation of the prediction ability of models assessing SOC using real multispectral remote sensing data from different platforms was performed. The study was conducted on a study plot (1.45 km2) in the Chernozem region of South Moravia (Czechia). The adopted methods included field sampling and predictive modeling using satellite multispectral Sentinel-2, Landsat-8, and PlanetScope data, and multispectral UAS Parrot Sequoia data. Furthermore, the performance of a soil reflectance composite image from Sentinel-2 data was analyzed. Aerial hyperspectral CASI 1500 and SASI 600 data was used as a reference. Random forest, support vector machine, and the cubist regression technique were applied in the predictive modeling. The prediction accuracy of models using multispectral data, including Sentinel-2 composite, was lower (RPD range from 1.16 to 1.65; RPIQ range from 1.53 to 2.17) compared to the reference model using hyperspectral data (RPD = 2.26; RPIQ = 3.34). The obtained results show very similar prediction accuracy for all spaceborne sensors (Sentinel-2, Landsat-8, and PlanetScope). However, the spatial correlation between the reference mapping results obtained from the hyperspectral data and other maps using multispectral data was moderately strong. UAS sensors and freely available satellite multispectral data can represent an alternative cost-effective data source for remote SOC mapping on the local scale
Using dendrogeomorphology in research on a slope deformation in Běleč, Czech-Moravian Highland (Czech Republic)
Research on the Běleč creeping slope deformation is a contribution to identification of the causes of a breakdown of the water-supply conduit of the Brno regional water-supply network and to ensuring its regular operation. Field geomorphological mapping was used for the research and dendrogeomorphologic methods, especially the method of analysis of tree rings (eccentric tree rings, growth changes), were used for studying the slope failure dynamism. Slope movement activity in the years 1900–2007 was monitored with the help of 45 boring samples. The analysis of tree rings of common beech (Fagus sylvatica) samples did not prove continual movements over the whole extent of the deformation. The present activity is characterized only by local episodic movements of creeping character in the years 1947, 1975, 1993, 1997 a 2006. It was proved that the slope deformation did not have a direct impact on the breakdown of the water-supply conduit in 2005.
Využití dendrogeomorfologických metod při výzkumu svahové deformace Běleč, Českomoravská vrchovina (Česká republika)
Výzkum hluboce založené plouživé svahové deformace Běleč je příspěvkem k identifikaci příčin vzniku poruchy vodovodního přivaděče Brněnských oblastních vodovodů a zajištění jeho provozu. Při výzkumu poruchy bylo využito geomorfologického mapování a dendrogeomorfologických metod (analýza excentrických letokruhů, růstové změny), které sloužily ke studiu dynamiky svahové poruchy. Aktivita svahových pohybů mezi roky 1900–2007 byla zkoumána pomocí 45 vyvrtaných jádrových vzorků. Analýza letokruhů buku lesního (Fagus sylvatica) neprokázala kontinuální pohyby v celém rozsahu deformace. Současná aktivita je charakteristická spíše lokálními epizodickými pohyby plouživého charakteru v letech 1947, 1975, 1993, 1997 a 2002. Bylo tak prokázáno, že svahová deformace neměla přímý vliv na poruchu vodovodního přivaděče v roce 2005
Analýza vývoje jakosti povrchových vod v souvislosti se změnami využití krajiny v povodí horní Vltavy
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Assessment of Soil Degradation by Erosion Based on Analysis of Soil Properties Using Aerial Hyperspectral Images and Ancillary Data, Czech Republic
The assessment of the soil redistribution and real long-term soil degradation due to erosion on agriculture land is still insufficient in spite of being essential for soil conservation policy. Imaging spectroscopy has been recognized as a suitable tool for soil erosion assessment in recent years. In our study, we bring an approach for assessment of soil degradation by erosion by means of determining soil erosion classes representing soils differently influenced by erosion impact. The adopted methods include extensive field sampling, laboratory analysis, predictive modelling of selected soil surface properties using aerial hyperspectral data and the digital elevation model and fuzzy classification. Different multivariate regression techniques (Partial Least Square, Support Vector Machine, Random forest and Artificial neural network) were applied in the predictive modelling of soil properties. The properties with satisfying performance (R2 > 0.5) were used as input data in erosion classes determination by fuzzy C-means classification method. The study was performed at four study sites about 1 km2 large representing the most extensive soil units of the agricultural land in the Czech Republic (Chernozems and Luvisols on loess and Cambisols and Stagnosols on crystalline rocks). The influence of site-specific conditions on prediction of soil properties and classification of erosion classes was assessed. The prediction accuracy (R2) of the best performing models predicting the soil properties varies in range 0.8–0.91 for soil organic carbon content, 0.21–0.67 for sand content, 0.4–0.92 for silt content, 0.38–0.89 for clay content, 0.73–089 for Feox, 0.59–0.78 for Fed and 0.82 for CaCO3. The performance and suitability of different properties for erosion classes’ classification are highly variable at the study sites. Soil organic carbon was the most frequently used as the erosion classes’ predictor, while the textural classes showed lower applicability. The presented approach was successfully applied in Chernozem and Luvisol loess regions where the erosion classes were assessed with a good overall accuracy (82% and 67%, respectively). The model performance in two Cambisol/Stagnosol regions was rather poor (51%–52%). The results showed that the presented method can be directly and with a good performance applied in pedologically and geologically homogeneous areas. The sites with heterogeneous structure of the soil cover and parent material will require more precise local-fitted models and use of further auxiliary information such as terrain or geological data. The future application of presented approach at a regional scale promises to produce valuable data on actual soil degradation by erosion usable for soil conservation policy purposes
Using dendogeomorphology in research on a slope deformation in Běleč, Czech-Moravian Highland
Research on the Běleč creeping slope deformation is a contribution to identification of the causes of a breakdown of the water-supply conduit of the Brno regional water-supply network and to ensuring its regular operation. Field geomorphological mapping was used for the research and dendrogeomorphologic methods, especially the method of analysis of tree rings (eccentric tree rings, growth changes), were used for studying the slope failure dynamism. Slope movement activity in the years 1900-2007 was monitored with the help of 45 boring samples. The analysis of tree rings of common beech (Fagus sylvatica) samples did not prove continual movements over the whole extent of the deformation. The present activity is characterized only by local episodic movements of creeping character in the years 1947, 1975, 1993, 1997 a 2006. It was proved that the slope deformation did not have a direct impact on the breakdown of the water-supply conduit in 2005.738
An integrated approach for management of agricultural non-point pollution sources in the Czech Republic
We report a new, integrated approach to the identification and localization of potential critical areas of non-point agricultural water pollution in the Czech Republic. The methodology is presented in model catchments of IV. order, namely the Hrejkovický and Bilinský brooks in the water reservoir Orlík watershed. The risk rate of non-point source pollution is evaluated with the help of GIS tools, integrating the assessment of geomorphology, land use and soil conditions within a territory in conjunction with the agricultural tile drainage systems. Besides the areas prone to erosion and ‘direct protection localities’ along water courses, spots with increased potential of nutrient leaching into groundwater and drainage water are delineated, based on a synthetic map of shallow groundwater vulnerability. These spots are classified using analysis of the Valuated Soil Ecological Units (VSEU) code, while agricultural drainage systems are identified according to the documents of the former Agricultural Water Management Authority of the Czech Republic. Results from geographical analysis show differences between intrinsic parameters of model catchments, which influence the vulnerability potential towards diverse types of non point pollution. The potential pollution thread of surface and groundwater by leaching is relatively high in both catchments, in the Bilinský brook catchment due to prevailing arable land on first and second vulnerability classes within the tile drainage subcatchments and in the Hrejkovický brook catchment due to dense occurence of first and second vulnerable clasess in the catchment area, though comprised from a third by grassland. Water erosion potential jeopardy is bigger within the Bilinský brook catchment with 10% of arable land having the average soil loss 4–10 t ha−1 y−1, contrary to 2% within the Hrejkovický brook catchment. Presented approach can help in prioritizing protective measures and management strategies in a catchment to curtail the negative impacts of non point agricultural pollution in water bodies and in the whole environment.
Integrovaný přístup k řešení problematiky plošného zemědělského znečištění v ČR
Příspěvek popisuje nový, integrovaný přístup v metodách identifikace a lokalizace potenciálních kritických zdrojových oblastí plošného znečištění povrchových vod dusíkem a fosforem, který je představen na modelových povodích IV. řádu Hrejkovického a Bilinského potoka v povodí vodní nádrže Orlík. Ohroženost vod plošným znečištěním je posuzována geografickou analýzou, která hodnotí geomorfologii, způsob využití a půdní podmínky území, ve vazbě na stavby zemědělského odvodnění. Vedle ploch podléhajících erozi a lokalit tzv. přímé ochrany podél vodních toků, jsou vymezovány oblasti zvýšeného potenciálního vyplavování živin do podzemních a drenážních vod, stanovené na základě syntetické mapy zranitelnosti mělkých podzemních vod. Tyto oblasti jsou klasifikovány na základě analýzy kódu bonitovaných půdně ekologických jednotek (BPE J) a zemědělské odvodnění podle podkladů bývalé Zemědělské vodohospodářské správy (ZVHS). Z výsledků geografické analýzy vyplývá rozdíl mezi dvěma sousedními povodími a jejich potenciálem k působení plošného zemědělského znečištění. Z výsledků analýzy LULC je patrný zhruba stejný podíl zemědělské půdy pro obě povodí ovšem struktura základních dvou druhů pozemků (orná půda x trvalé travní porosty) je odlišná. Vyšší podíl zatravnění je v povodí Hrejkovického potoka oproti Bilinskému, kde je zastoupení TTP relativně nízké. Z hlediska zranitelnosti vyplavování rizikových látek do povrchových a podzemních vod jsou náchylná obě povodí; povodí Bilinského potoka z důvodu převahy orné půdy na plochách se zranitelností 1. a 2. kategorie v mikropovodích drenážních systémů, povodí Hrejkovického potoka pro velmi častý výskyt ploch s 1. a 2. kategorií zranitelnosti (58% ZPF). Z hlediska potenciálního rizika výskytu eroze na zemědělské půdě je ohroženější Bilinský potok, zejména v dolní části povodí
Mapping soil degradation using remote sensing data and ancillary data: South-East Moravia, Czech Republic
Data on the real extent of soil that is degraded by erosion represent important information for the purposes of conservation policy. However, this type of data is rarely available for large areas. A remote-sensing-based method for identifying of eroded areas at the regional scale has been tested using a combination of time series of free access Sentinel-2 image data, airborne orthoimages and ground-truth data. The unsupervised classification ISODATA of the Sentinel-2A images has been performed. The minimum distance method has been applied for the assignment of unsupervised classes to four erosion classes using the ground-truth data. The automatic classification of eroded soils achieved an overall accuracy of 55.2% for three distinguished classes. An accumulated class has been eliminated as no unsupervised classes were assigned to this erosion class. A simplified classification of two classes (strongly eroded and other soils) reached an accuracy of 80.9%. The overall accuracy of the simplified classification increased to 86.9% after the visual refinement using orthoimages. This study shows the potential of the tested approach to produce valuable data on actual soil degradation by erosion. The limitations of the method are related to the soil cover variability, masking effect of clouds, vegetation or litter and the spectral separability of individual classes