Flash flood events are common in the Mediterranean basin, because of a combination of rugged coastal topography and climatological characteristics. The Balearic Islands are a flood-prone region with the research area, Sóller (Mallorca) being no exception. Between 1900 and 2000, Sóller experienced 48 flash floods with 17 categorised as catastrophic. In Sóller, the local surface water network comprises ephemeral streams. These are natural water networks that only carry water during periods of intense rainfall. Using the available evidence from the 1974 flash flood, this research used Flood Modeller to simulate the event. The research developed a one-dimensional (1D) and a onedimensional two-dimensional (1D-2D) model that assisted in the understanding of the behaviour of the ephemeral stream during the flood. Analysis of hydraulic parameters such as water flow, depth and velocity provided an appreciation of the interaction between the channel and floodplain. Model development aims to forecast the impending impacts of climate change and urbanisation. The results suggest that the characteristics of Sóller’s catchment area naturally encourage flash flooding and hence can be deemed a flashy catchment. The model demonstrates that the interaction between the channel and floodplain relies heavily on surface roughness of both areas. The model proves that if flood intensity increases with climate change, the extent of flooding and consequently the damage will become more severe.
Wildfires naturally occur worldwide, however the potential disruption to ecosystem services from subsequent post-fire flooding and erosion often necessitates a response from land managers. The impact of high severity wildfire on infiltration and interrill erosion responses was evaluated for five years after the 2003 Hot Creek Fire in Idaho, USA. Relative infiltration from mini-disk tension infiltrometers (MDI) was compared to rainfall simulation measurements on small burned and control plots. Vegetation recovery was slow due to the severity of the fire, with median cover of 6–8% on burned sites after 5 years. Consequently, interrill sediment yields remained significantly higher on the burned sites (329–1200 g m–2) compared to the unburned sites (3–35 g m–2) in year 5. Total infiltration on the burned plots increased during the study period, yet were persistently lower compared to the control plots. Relative infiltration measurements made at the soil surface, and 1- and 3-cm depths were significantly correlated to non-steady state total infiltration values taken in the first 10 minutes of the hour-long rainfall simulations. Significant correlations were found at the 1-cm (ρ = 0.4–0.6) and 3-cm (ρ = 0.3–0.6) depths (most p-values <0.001), and somewhat weaker correlations at the soil surface (ρ = 0.2–0.4) (p-values <0.05 and up). Soil water repellency is often stronger below the soil surface after severe wildfire, and likely contributes to the reduced infiltration. These results suggest that relative infiltration measurements at shallow depths may be useful to estimate potential infiltration during a short-duration high-intensity storm and could be used as an input for post-fire erosion models.
In this paper, I try to argue that, from the methodological position of reflected equilibrium, it seems to be reasonable to build a theory of personal identity that enables a person to continue her existence after the biological death of her body. This conclusion is supported by the argument that our practice reflects that our identity-presupposing concerns reach beyond biological continuity. We have also good reasons to maintain such concerns and practices. As the best candidate to implement such concerns in a theoretical account of practical identity, I will identify the person-life view, where personal identity depends to a great extent on social conditions. I also show how this theory can implement the classical belief in the afterlife, and how it could conceptualize the difference of the afterlife from a physicalistic and a theistic point of view. and V této práci se snažím argumentovat, že z metodologické pozice odrážející rovnováhy se zdá být rozumné stavět teorii osobní identity, která umožňuje člověku pokračovat ve své existenci po biologické smrti jejího těla. Tento závěr je podpořen argumentem, že naše praxe odráží skutečnost, že naše předpoklady týkající se identity překračují rámec biologické kontinuity. Máme také dobré důvody k udržení těchto obav a postupů. Jako nejlepší kandidát na realizaci těchto zájmů v teoretickém popisu praktické identity budu identifikovat pohled člověk-život, kde osobní identita závisí do značné míry na společenských podmínkách. Ukazuji také, jak tato teorie dokáže zavést klasickou víru v posmrtný život,
The necessity to generate time series of runoff for planning and design purposes and environmental protection at ungauged sites is often the case in water resources studies. As in the case of the absence of measured runoff optimisation techniques cannot be used to estimate the parameters of rainfall-runoff models, regional estimation methods are used instead. In previous studies usually regression methods were used for relating the model parameters to the catchment characteristics in a given region. In the paper a different method for the regional calibration of a monthly water balance model is proposed for the case of sparse runoff data. Instead of using the regional regression, the method involves the regional calibration of a monthly water balance model to several gauged catchments in a given region simultaneously. These catchments were pooled together using cluster analysis of selected basin physiographic properties. For the model calibration a genetic programming algorithm was employed and two problem specific fitness functions were proposed. It is expected, that the regionally calibrated model parameters can be used in ungauged basins with similar physiographic conditions. The performance of such a regional calibration scheme was compared with two single site calibration methods in the Záhorie region of West Slovakia. and Článok sa zaoberá možnosťami využitia hydrologického modelovania pre účely určovania prietokov v povodiach bez ich pozorovaní. V takýchto prípadoch nemožno určiť parametre modelu klasickou kalibráciou, pri ktorej sa pri hľadaní parametrov modelu posudzuje čo najlepšia zhoda medzi simulovanými a pozorovanými prietokmi. Jednou z možností je zisťovanie parametrov modelu na základe posudzovania ich vzájomného vzťahu s hydrologickými, topografickými alebo fyzicko-geografickými vlastnosťami povodí, ktoré zohrávajú pri tvorbe odtoku dominantnú úlohu, ďalšia možnosť je určenie jednotných parametrov modelu kalibráciou modelu pre skupinu povodí (región alebo regionálny typ), vyčlenenú na základe podobných vlastností ovplyvňujúcich tvorbu odtoku. V článku je aplikovaná metodika určovania regionálnych parametrov hydrologického bilančného modelu v mesačnom časovom kroku na vybraných povodiach západného Slovenska. Namiesto prístupu regionálnej regresie je tu využitý spôsob regionálnej kalibrácie modelu pre regióny vyčlenené na základe podobnosti rôznych fyzicko-geografických vlastností. Pri regionálnej kalibrácii modelu boli využité metódy genetického algoritmu, pričom boli testované dve objektívne funkcie. Výsledky regionálnej kalibrácie sú porovnané s výsledkami kalibrácie modelu pre jednotlivé povodia. Regionálne určené parametre modelu môžu byť využité na modelovanie priemerných mesačných prietokov v povodiach bez pozorovaní, patriacich do príslušného regiónu alebo regionálneho typu.
Regional design flood computation formulae in Slovakia were traditionally based on the regionalisation of the 100-year flood discharge. Floods with shorter return periods have usually been computed by regional frequency factors from the 100-year flood discharge. Several previous studies have indicated that a rather high safety factor is included in some of the traditional regional formulae. In this paper therefore an alternative method for the determination of the flood frequency curve in ungauged catchments in the high core mountain region of Slovakia has been investigated. Floods from rainfall and snowmelt were treated separately; the study was focused on summer floods. For the division catchments into pooling groups subjective and objective methods e.g. cluster analysis were used. The methodology was based on the regional estimation of the index flood and its standard deviation from catchment characteristics. Flood quantiles were determined from a two-parameter distribution. The performance of several regional methods was compared and the applicability of the tested methods for various hydraulic and hydro-ecological design tasks was also discussed. and Odhad N-ročných maximálnych prietokov bol na Slovensku tradične založený na regionalizácii maximálnych storočných prietokov. V príspevku sme preto navrhli a testovali alternatívne regionálne metódy nepriameho odhadu štatistických charakteristík maximálnych prietokov v letnej sezóne v oblasti Tatier. Skúmali sme viaceré možnosti rozdeliť tento región na oblasti s rovnakým vzťahom medzi podmieňujúcimi činiteľmi tvorby odtoku a priemernou hodnotou a smerodajnou odchýlkou maximálnych letných prietokov. Subregióny boli konštruované použitím subjektívnych úvah, logickým delením, ako aj pomocou objektívnych metód využívajúc princípy zhlukovej analýzy. Regionálne vzťahy na určovanie charakteristík maximálnych letných prietokov boli odvodené použitím viacnásobnej regresie. V závere sme porovnali hodnoty N-ročných maximálnych letných prietokov určené použitím viacerých metód a diskutovali sme vhodnosť použitia aplikovaných postupov pre inžiniersku prax.
In this paper a comparison of methods for estimating rainfall-runoff model parameters in ungauged basins based on geographical location are presented. As a pilot basin the Hron River basin in Slovakia with an available daily flow, precipitation and air temperature time series needed for calibration to obtain model parameter values in subcatchments was selected. The rainfall-runoff model was calibrated using a daily time step at 23 subcatchments. The Nearest Neighbour, Lumped Basin and Best Similarity Index methods were used to transfer the model parameters from the gauged to ''ungauged'' subcatchments. Finally, the effectiveness of the estimation method for ungauged basins was tested by comparing the model simulations to observed hydrographs and computing the Nash-Sutcliffe optimization criterion. The results were finally compared, and the best method was recommended for practical application by estimating of the rainfallrunoff model parameters in an ungauged catchment in this region. and V štúdii sú prezentované výsledky nepriamych metód odhadu parametrov zrážkovo-odtokového modelu na povodiach bez priamych hydrologických pozorovaní, ktoré sú založené na geografickej polohe povodí. Povodie Hrona bolo vybrané ako pilotný región s 23 čiastkovými povodiami, ktoré mali dostupné časové rady pozorovaní priemerných denných prietokov, zrážok a teploty vzduchu, potrebné na kalibráciu modelu. Zrážkovo-odtokový model bol v týchto podpovodiach nakalibrovaný na údajoch s denným časovým krokom. Následne boli použité na regionalizáciu parametrov modelu metódy Nearest Neighbour (Metóda najbližšieho suseda), Lumped Basin (Metóda sústredeného povodia) a Best Similarity Index methods (Metóda najlepšej podobnosti). Kvalita regionalizačných metód sa overovala pomocou optimalizačného kritéria Nash-Sutcliffe. Najlepšie výsledky boli dosiahnuté Metódou najlepšej podobnosti, ktorá môže byť v praxi odporúčaná na odhad parametrov zrážkovo-odtokového modelu na testovanom povodí.
As to be able to draw up outlook development plans of the integrated water management it is required to define and know much more hydrological parameters of subcatchments, as are available from measurements in outflow profiles of water courses. Thus, a continuous and significant task of hydrology i working out of estimation methods for evaluation of non-existing, or only sporadically monitored hydrologic parameters in selected profiles of water courses. One of the way how to obtain required data is regionalization. The ''regional analysis'' focused in a given territory on elucidation of variations of hydrological regularities (laws). ''Regionalization'' implies interpolation of information, available in given monitoring stations, to the whole concerned territory. and Perspektívne rozvojové plány integrovaného vodného hospodárstva vyžadujú znalost väcšieho množstva hydrologických parametrov ciastkových povodí, než nám poskytujú pozorovania vo vodomerných profiloch tokov. Preto je trvalou úlohou hydrológie vypracovanie metód odhadov pre hodnotenie chýbajúcich alebo občasne pozorovaných hydrologických parametrov vo zvolených profiloch vodných tokov. Jednou z ciest k získaniu potrebných údajov je regionalizácia. Pod ''regionálnou analýzou'' sa rozumie postup, ktorý sa na danom území zaoberá objasnením zákonitostí zmien hydrologických parametrov. Pod ''regionalizáciou'' sa rozumie interpolácia informácií, ktoré sú k dispozícii v daných uzloch monitorovania, na celé záujmové územie.
There is an emerging challenge within water resources on how, and to what extent, borrowing concepts from landscape ecology might help re-define traditional concepts in hydrology in a more tangible manner.
A stepwise regression model was adopted in this study to assess whether the time of concentration of catchments could be explained by five landscape structure-representing metrics for land use/land cover, soil and geological patches, using spatial data from 39 catchments.
The models suggested that the times of concentration of the catchments could be predicted using the measures of four landscape structure-representing metrics, which include contiguity index (r2 = 0.46, p ≤0.05), fractal dimension index (r2 = 0.51, p ≤0.05), related circumscribing circle (r2 = 0.52, p ≤0.05), and shape index (r2 = 0.47, p ≤0.05).
The models indicated that the regularity or irregularity in land use/land cover patch shape played a key role in affecting catchment hydrological response. Our findings revealed that regularity and irregularity in the shape of a given patch (e.g., urban and semi-urban, rangeland and agricultural patches) can affect patch functions in retarding and/or increasing flow accumulation at the catchment scale, which can, in turn, decrease or increase the times of concentration in the catchments.