The role of crust thickness in runoff generation from microbiotic crusts

2014 ◽  
Vol 29 (7) ◽  
pp. 1783-1792 ◽  
Author(s):  
Giora J. Kidron
Keyword(s):  
Runoff Generation ◽  
Microbiotic Crusts ◽  
Crust Thickness

Understanding the role of different geographical features in the hydrological response of humid mountainous areas through a stepwise clustering scheme

2021 ◽  
Author(s):  
Yaqian Yang ◽  
Jintao Liu
Keyword(s):  
Bulk Density ◽  
Optimal Parameter ◽  
Soil Bulk Density ◽  
Model Parameters ◽  
Hydrological Response ◽  
Runoff Generation ◽  
Explanatory Variables ◽  
Hydrological Responses ◽  
Rainfall Patterns

<p>In the mountainous basins with less anthropogenic influence, the hydrological function is mainly affected by climate and landscape, which makes it possible to measure hydrological similarity indirectly by geographical features. Due to the mechanisms of runoff generation can vary geographically, in this study, a simple stepwise clustering scheme was proposed to explore the role of geographical features at different spatial hierarchy in indicating hydrological response. Research methods mainly include (1) Stepwise regression was used to quantitatively show the correlation between 35 geographical features and 35 flow features and identify the important explanatory variables for hydrological response; (2) 64 basins were divided by stepwise clustering scheme, and the overall ability of the scheme to capture hydrological similarity was tested by comparing the optimal parameters; (3) The hydrological similarity of basin groups was measured by the leave-one cross validation of hydrological model parameters. The results showed that: (1) Rainfall features, elevation, slope and soil bulk density are the main explanatory variables. (2) The NSE of basin groups based on stepwise clustering is 0.64, reaches 80% of the optimal parameter sets (NSE=0.80). The NSE of 90% basins is greater than 0.5, 80% is greater than 0.6, and 49% is greater than 0.7. (3) In humid areas, the hydrological responses of the basins with more uniform monthly rainfall and more abundant summer rainfall are more similar, e.g., the NSE of Class 4 is 0.77. Under similar rainfall patterns, the hydrological responses of the basins with higher average altitude, greater slope, more convergent of shape and richer vegetation are more similar, e.g., the NSE of Class 3-2 is 0.72 and that of Class 1-2 is 0.70. In the case of similar rainfall patterns and landforms, the hydrological responses of the basins with smaller soil bulk density are more similar, e.g., the NSE of Class 3-2-2 is 0.80. In conclusion, the stepwise clustering enhances the interpretability of basin classification, and the effect of different geographical features on hydrological response can show the applicability of hydrological simulation in ungauged basins.</p>

scholarly journals On the role of the runoff coefficient in the mapping of rainfall to flood return periods

2009 ◽  
Vol 13 (5) ◽  
pp. 577-593 ◽  
Author(s):  
A. Viglione ◽  
R. Merz ◽  
G. Blöschl
Keyword(s):  
Monte Carlo ◽  
Return Period ◽  
Threshold Effect ◽  
Flood Frequency ◽  
Runoff Coefficient ◽  
Return Periods ◽  
Runoff Generation ◽  
Design Storm ◽  
Shed Light

Abstract. While the correspondence of rainfall return period TP and flood return period TQ is at the heart of the design storm procedure, their relationship is still poorly understood. The purpose of this paper is to shed light on the controls on this relationship examining in particular the effect of the variability of event runoff coefficients. A simplified world with block rainfall and linear catchment response is assumed and a derived flood frequency approach, both in analytical and Monte-Carlo modes, is used. The results indicate that TQ can be much higher than TP of the associated storm. The ratio TQ /TP depends on the average wetness of the system. In a dry system, TQ can be of the order of hundreds of times of TP. In contrast, in a wet system, the maximum flood return period is never more than a few times that of the corresponding storm. This is because a wet system cannot be much worse than it normally is. The presence of a threshold effect in runoff generation related to storm volume reduces the maximum ratio of TQ /TP since it decreases the randomness of the runoff coefficients and increases the probability to be in a wet situation. We also examine the relation between the return periods of the input and the output of the design storm procedure when using a pre-selected runoff coefficient and the question which runoff coefficients produce a flood return period equal to the rainfall return period. For the systems analysed here, this runoff coefficient is always larger than the median of the runoff coefficients that cause the maximum annual floods. It depends on the average wetness of the system and on the return period considered, and its variability is particularly high when a threshold effect in runoff generation is present.

scholarly journals The dominant runoff processes on grassland versus bare soil hillslopes in a temperate environment - An experimental study

2019 ◽  
Vol 67 (4) ◽  
pp. 297-304 ◽  
Author(s):  
Gabriel Minea ◽  
Gabriela Ioana-Toroimac ◽  
Gabriela Moroşanu
Keyword(s):  
Overland Flow ◽  
Bare Soil ◽  
Rainfall Runoff ◽  
Runoff Generation ◽  
Rainfall Events ◽  
Natural Rainfall ◽  
Antecedent Precipitation ◽  
Temperate Environment ◽  
The Relationship

Abstract This paper aimed to investigate the dominant runoff processes (DRP’s) at plot-scale in the Curvature Subcarpathians under natural rainfall conditions characteristic for Romania’s temperate environment. The study was based on 32 selected rainfall-runoff events produced during the interval April–September (2014–2017). By comparing water balance on the analyzed Luvisol plots for two types of land use (grassland vs. bare soil), we showed that DRP’s are mostly formed by Hortonian Overland Flow (HOF), 47% vs. 59% respectively. On grassland, HOF is followed by Deep Percolation (DP, 31%) and Fast Subsurface Flow (SSF, 22%), whereas, on bare soil, DP shows a higher percentage (38%) and SSF a lower one (3%), which suggests that the soil-root interface controls the runoff generation. Concerning the relationship between antecedent precipitation and runoff, the study indicated the nonlinearity of the two processes, more obvious on grassland and in drought conditions than on bare soil and in wet conditions (as demonstrated by the higher runoff coefficients). Moreover, the HOF appeared to respond differently to rainfall events on the two plots - slightly longer lag-time, lower discharge and lower volume on grassland - which suggests the hydrologic key role of vegetation in runoff generation processes.

Role of macroporosity in runoff generation on a sloping subsurface drained clay field — a case study with MACRO model

2008 ◽  
Vol 39 (2) ◽  
pp. 143-155 ◽  
Author(s):  
Salka Hintikka ◽  
Maija Paasonen-Kivekäs ◽  
Harri Koivusalo ◽  
Visa Nuutinen ◽  
Laura Alakukku
Keyword(s):  
Surface Runoff ◽  
Soil Structure ◽  
Three Dimensional ◽  
Runoff Generation ◽  
Three Dimensional Modeling ◽  
Dimensional Modeling ◽  
Drain Flow ◽  
Extensive Field ◽  
Sloping Field

Macroporosity and its effect on runoff processes were studied on a sloping subdrained clay field (very fine Aeric Cryaquept) in Southern Finland. An extensive field campaign was carried out to measure the spatial variability of soil macroporosity and hydraulic properties. According to the field data, macropore conductivity decreased with depth and soil properties showed differences between the upper and lower parts of the field. A one-dimensional model (MACRO) was applied to quantify the effect of these differences on the hydrological response of the upper and lower field sites. Based on the measurements, five separate parameterizations characterizing the differences in soil structure between the measurement sites were formulated. The change in soil structure had a great effect on the relative proportions of simulated drain flow and surface runoff but influenced only slightly the total amount of runoff. Evapotranspiration and percolation were similar in all cases. Examining model simulations, measured runoff components and groundwater table suggested that a two- or three-dimensional modeling approach is necessary, when prediction of proportional fractions of drain flow and surface runoff, and simulation of groundwater level in a sloping field are of interest.

The role of dew as a moisture source for sand microbiotic crusts in the Negev Desert, Israel

2002 ◽  
Vol 52 (4) ◽  
pp. 517-533 ◽  
Author(s):  
Giora J. Kidron ◽  
Ilana Herrnstadt ◽  
Eldad Barzilay
Keyword(s):  
Negev Desert ◽  
Moisture Source ◽  
Microbiotic Crusts

The role of run-on for overland flow and the characteristics of runoff generation in the Loess Plateau, China

2012 ◽  
Vol 57 (6) ◽  
pp. 1107-1117 ◽  
Author(s):  
Dengfeng Liu ◽  
Fuqiang Tian ◽  
Hongchang Hu ◽  
Heping Hu
Keyword(s):  
Loess Plateau ◽  
Overland Flow ◽  
Runoff Generation ◽  
The Loess Plateau

The role of catchment scale and landscape characteristics for runoff generation of boreal streams

2007 ◽  
Vol 344 (3-4) ◽  
pp. 198-209 ◽  
Author(s):  
Hjalmar Laudon ◽  
Viktor Sjöblom ◽  
Ishi Buffam ◽  
Jan Seibert ◽  
Magnus Mörth
Keyword(s):  
Runoff Generation ◽  
Catchment Scale ◽  
Landscape Characteristics ◽  
Boreal Streams
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