scholarly journals Determination of surface flow paths from gridded elevation data

2009 ◽  
Vol 45 (3) ◽  
Author(s):  
Stefano Orlandini ◽  
Giovanni Moretti
Keyword(s):  
Surface Flow ◽  
Flow Paths ◽  
Elevation Data

scholarly journals Scale effect on overland flow connectivity at the plot scale

2013 ◽  
Vol 17 (1) ◽  
pp. 87-101 ◽  
Author(s):  
A. Peñuela ◽  
M. Javaux ◽  
C. L. Bielders
Keyword(s):  
Scale Effect ◽  
Overland Flow ◽  
Soil Surface ◽  
Real Field ◽  
Flow Paths ◽  
Essential Information ◽  
Elevation Data ◽  
Distributed Hydrological Models ◽  
Outflow Boundary ◽  
Degree Of Filling

Abstract. A major challenge in present-day hydrological sciences is to enhance the performance of existing distributed hydrological models through a better description of subgrid processes, in particular the subgrid connectivity of flow paths. The Relative Surface Connection (RSC) function was proposed by Antoine et al. (2009) as a functional indicator of runoff flow connectivity. For a given area, it expresses the percentage of the surface connected to the outflow boundary (C) as a function of the degree of filling of the depression storage. This function explicitly integrates the flow network at the soil surface and hence provides essential information regarding the flow paths' connectivity. It has been shown that this function could help improve the modeling of the hydrograph at the square meter scale, yet it is unknown how the scale affects the RSC function, and whether and how it can be extrapolated to other scales. The main objective of this research is to study the scale effect on overland flow connectivity (RSC function). For this purpose, digital elevation data of a real field (9 × 3 m) and three synthetic fields (6 × 6 m) with contrasting hydrological responses were used, and the RSC function was calculated at different scales by changing the length (l) or width (w) of the field. To different extents depending on the microtopography, border effects were observed for the smaller scales when decreasing l or w, which resulted in a strong decrease or increase of the maximum depression storage, respectively. There was no scale effect on the RSC function when changing w, but a remarkable scale effect was observed in the RSC function when changing l. In general, for a given degree of filling of the depression storage, C decreased as l increased, the change in C being inversely proportional to the change in l. However, this observation applied only up to approx. 50–70% (depending on the hydrological response of the field) of filling of depression storage, after which no correlation was found between C and l. The results of this study help identify the minimal scale to study overland flow connectivity. At scales larger than the minimal scale, the RSC function showed a great potential to be extrapolated to other scales.

Integrated microfluidic pumps and valves operated by finger actuation

Lab on a Chip ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 2973-2977 ◽  
Author(s):  
Juhwan Park ◽  
Je-Kyun Park
Keyword(s):  
Flow Paths ◽  
Fluid Delivery

Integrated microfluidic pumps and valves for fluid delivery and determination of flow paths are operated simultaneously by pushing a button.

scholarly journals Determination of Primary and Secondary Lahar Flow Paths of the Fuego Volcano (Guatemala) Using Morphometric Parameters

2019 ◽  
Vol 11 (6) ◽  
pp. 727 ◽  
Author(s):  
Marcelo Cando-Jácome ◽  
Antonio Martínez-Graña
Keyword(s):  
Shallow Landslide ◽  
Pyroclastic Flows ◽  
Economic Losses ◽  
Hazard Maps ◽  
Topographic Wetness Index ◽  
Flow Paths ◽  
Differential Interferometry ◽  
Fuego Volcano ◽  
Morphological Indices

On 3 June 2018, a strong eruption of the Fuego volcano in Guatemala produced a dense cloud of 10-km-high volcanic ash and destructive pyroclastic flows that caused nearly 200 deaths and huge economic losses in the region. Subsequently, due to heavy rains, destructive secondary lahars were produced, which were not plotted on the hazard maps using the LAHAR Z software. In this work we propose to complement the mapping of this type of lahars using remote-sensing (Differential Interferometry, DINSAR) in Sentinel images 1A and 2A, to locate areas of deformation of the relief on the flanks of the volcano, areas that are possibly origin of these lahars. To determine the trajectory of the lahars, parameters and morphological indices were analyzed with the software System for Automated Geoscientific Analysis (SAGA). The parameters and morphological indices used were the accumulation of flow (FCC), the topographic wetness index (TWI), the length-magnitude factor of the slope (LS). Finally, a slope stability analysis was performed using the Shallow Landslide Susceptibility software (SHALSTAB) based on the Mohr–Coulomb theory and its parameters: internal soil saturation degree and effective precipitation, parameters required to destabilize a hillside. In this case, the application of this complementary methodology provided a more accurate response of the areas destroyed by primary and secondary lahars in the vicinity of the volcano.

Probability Distribution of Tidal Elevation Data around Korean Coasts

2013 ◽  
Vol 284-287 ◽  
pp. 1484-1488
Author(s):  
Hong Yeon Cho ◽  
Shin Taek Jeong ◽  
Dong Hui Ko ◽  
Sang Ho Lee
Keyword(s):  
Normal Distribution ◽  
Density Function ◽  
Optimal Parameter ◽  
Kernel Functions ◽  
Normal Distribution Function ◽  
Tidal Elevation ◽  
Significance Level ◽  
Normality Test ◽  
Elevation Data

Frequency information of tidal elevations in the coastal zone is essential for the determination of datum level, the classification of inhabitation zones, and the analysis of mean sea level variation. In this study, the non-parametric density function is suggested for the analysis of hourly tidal elevation data provided by the Korea Hydrographic and Oceanographic Administration. The density function was estimated for six principal locations, Incheon, Mokpo, Jeju, Yeosu, Busan, and Pohang in the Korean coastal area using a kernel function. The parameter required for the probability density function was optimally estimated with the Sheather and Jones (SJ). And the optimal parameter appropriate for the normal distribution function was about 30% higher than that predicted by the SJ method or the Cross Validation (CV) method. It can be seen that the final kernel functions were less affected. The smoothing parameters for all of the tidal elevation data were optimized to be in the range of 0.13-0.17 with the SJ method. From the normality test of the observed tidal elevation data, it was proposed that the hypothesis of a normal distribution was inappropriate in the test techniques with a 95% significance level.

scholarly journals Simulating pollutant transport over complex terrain: the hydrological component

2012 ◽  
Vol 10 (4) ◽  
pp. 1223-1235 ◽  
Author(s):  
Constantina Mita ◽  
Nicolaos Catsaros
Keyword(s):  
Channel Flow ◽  
Accurate Determination ◽  
Ground Surface ◽  
Pollutant Transport ◽  
Surface Flow ◽  
Valuable Insight ◽  
Distributed Hydrological Model ◽  
Channel Network ◽  
The Impact

AbstractThe accurate determination of surface water flow pathways is of primary importance when assessing the impact of pollutant transport and watershed physical characteristics on overland and channel water quality. The mathematical description of hydrological processes over natural watersheds, requires a detailed representation of the topography, on which the accurate determination of overland and channel flow trajectories often poses difficulties. The hydrological component of the DELTA code aims to provide valuable insight into this direction by using the semi-irregular triangulated (semi-TIN) topography model DELTA/HYDRO for establishing surface flow paths that can represent reliably the natural characteristics of a watershed, addressing several major physical hydrodynamic processes. The validity of the generated paths is tested via the integration of a conventional distributed hydrological model by routing excess rainfall over ground surface and through a channel network to the watershed outlet, for a series of storm episodes on a small, but relatively complex watershed. The encouraging results obtained demonstrate the promising application potential of the model, which can be additionally complemented with a pollutant transport component to address the interactions of soluble chemicals between soil surface and overland/channel flow, in the context of a fully integrated model.

scholarly journals Determination of constituents receipt Kakhovka Reservoir water balance

2017 ◽  
pp. 209-214
Author(s):  
O.S. Koryagina
Keyword(s):  
Surface Water ◽  
Water Resources ◽  
Water Balance ◽  
Practical Importance ◽  
Surface Flow ◽  
Probable Error ◽  
Scientific Interest ◽  
Reservoir Water ◽  
Surface Water Flow

The study of the reservoirs is of great scientific interest and is of practical importance for the solution of problems of rational use and protection of water resources. The paper describes the latest reservoir in the cascade of Dnipro Kakhovka Reservoir and its component of water balance. The methods of determining the components of the water balance that were once offered the Kakhovka  hydrometeorological observatory are submitted. Great attention is drawn to the surface flow of water into the reservoir from unexplored rivers, which is determined by the method of analogy. The probable error of this method, in turn, is equal to for monthly values 30-50% and annual – 10-20%. So, there is provided somewhat different a method for determining the surface flow using the curve of security component amount of annual precipitation, maps of the norm runoff and tables SNiP 2.01.14.83. The proposed method simplifies and accelerates the process of calculating the amounts of surface water flow in unexplored rivers to Kakhovka reservoir.

scholarly journals Delineation of a catchment boundary using velocity and elevation measurements

1998 ◽  
Vol 27 ◽  
pp. 140-144 ◽  
Author(s):  
S. F. Price ◽  
I. M. Whillans
Keyword(s):  
Field Measurements ◽  
Surface Velocity ◽  
Data Sampling ◽  
West Antarctica ◽  
Ice Surface ◽  
Ice Stream ◽  
Elevation Data ◽  
Boundary Location ◽  
Ice Stream B

The determination of catchment boundaries is a major source of uncertainty in net balance studies on large ice sheets. Here, a method for defining a catchment boundary is developed using new measurements of ice-surface velocity and elevation near the Ice Stream B/C boundary in West Antarctica. An objective method for estimating confidence in the catchment boundary is proposed. Using elevation data, the resulting mean standard deviation in boundary location is 13 km in position or 6000 km2 in area. Applying a similar uncertainty to both sides of the Ice Stream Β catchment results in a catchment-area uncertainty of 9%. Much larger uncertainties arise when the method is applied to velocity data. The uncertainty in both cases is primarily determined by the density of field measurements and is proportionally similar for larger catchment basins. Differences in the position of the velocity-determined boundary and the elevation-determined boundary probably result from data sampling. The boundary positions determined here do not support the hypothesis that Ice Stream Β captured parts of the Ice Stream C catchment.

Sign in / Sign up

Export Citation Format

Share Document