Rob
  • Member for 4 years, 7 months
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Is there a quick way to roughly estimate how quickly a flood will move downstream?
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7 votes

My first thought would be to use Manning equation as an approximation. It does not take into account the effect of a dam burst providing excess water and immediate flooding, although for larger scales ...

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Hydrology- flow accumulation
5 votes

The flow accumulation algorithm essentially determines the upstream contributing area of every grid cell; in other words, what area or how many other cells will drain into a given cell. The flow ...

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Does negative reference evapotranspiration make sense using FAO Penman-Monteith equation?
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5 votes

Short answer, especially if it is about 1% of the time series and these values are just slightly negative, this likely indicates that the ET needs to be recalibrated slightly, and for practical ...

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Are the water year/hydrological year different around the world?
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4 votes

The water year does vary depending on the region, for example in Australia the water year begins on July 1. I am not sure about other regions, I believe the October 1st water year is quite standard ...

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Topography & physiography
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4 votes

Physiography explains the physical characteristics of the area more generally describing the physical processes or forces that formed the landscape, while topography describes particular features, ...

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What's the difference between these most basic, first-order models for estimating runoff?
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4 votes

The models are similar in that they simplify the rainfall-runoff relationship into a few parameters, and essentially use some kind of first-order coefficient to partition rainfall into infiltration ...

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Code for DEM based flow routing in R
3 votes

Take a look at the RSAGA package on CRAN, or the rgdal package. Many of the GIS methods can be done in R but basically act as a wrapper for saga or gdal. RSAGA is likely your best bet for processing ...

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What would be a reasonable set of thresholds for flood severity classes?
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3 votes

One existing classification for return period events is minor and major flows, which basically classifies floods into those that the storm network (pipes and small conveyance network) is designed to ...

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Can we define "drainage density" for a soil column (point-scale)?
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2 votes

Fundamentally it doesn't make sense to describe the point scale model with hillslope length and drainage density. If you are looking to model a soil column, you could use Darcy's law or Richard's ...

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How to estimate the runoff time for my area?
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2 votes

The suggestion above to check historical data to get an idea of the time to peak/ time of concentration, and a get sense of the general storm response time is a good one. There are also empirical ...

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How to check the recurrence intervall of heavy rain events
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2 votes

In engineering it is common practice to build intensity-duration-frequency (IDF) curves, which basically map out the frequency of a given rainfall event based on its average intensity (mm/hr) and ...

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Comparing Pros and Cons of SWAT and HSPF
2 votes

This is a broad question, the best way to compare the models is to go through the manuals and compare the process algorithms to see how the various hydrologic processes are handled. There are other ...

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Accepting/refusing high rainfall measurement
2 votes

The comments suggesting there are lots of ways to remove extreme values but also a great need for caution with precipitation is correct. I am not aware of any good way to test for this from a ...

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Area reduction factor reference for precipitation
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2 votes

The answer depends on whether your data is from a single gauge or a network of gauges, and whether you have storm tracking data or not. Sounds to me like you have daily precip at a single gauge ...

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How to obtain the correlation between monthly streamflows based on physical concepts?
1 votes

One suggestion on generating the monthly flows is to use a seasonal ARMA model directly (e.g. see course notes), since you are looking at ARMA model for stochastic generation anyway. That would allow ...

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how to know the correct results in watershed delineation in ArcGIS?
1 votes

I would recommend looking at automatic stream network delineation and/or known stream locations features, and overlaying those as a check on the final watersheds created through whatever procedure you ...

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Are there ways stormwater attenuation can be quantified for comparison between different systems or conditions?
1 votes

A typical ratio calculated to quantify this type of response, especially at larger scales (such as for land use changes) is the runoff ratio: $$R = Q/ P$$ where $R$ is the runoff ratio [mm/mm or ...

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