Questions tagged [hydrology]

Hydrology is the study of the properties and behaviour of water. It concerns both surface as well as subsurface water, although water in the oceans and atmosphere is generally excluded. Those are studied by oceanography and meteorology, respectively.

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76 views

Why would channelizing a river reduce any nearby wetlands?

Channelization is when you straighten a river to make a shorter path from A to B. This makes the water flow faster, since the path is shorter but the volumetric flow rate of water must be the same (...
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1answer
55 views

Calculation of river width in relation to contributing area

I'm looking for a mathematical method to estimate the river width based on the basic topographic information of the specific sections of stream under consideration. Is there a formula to estimate the ...
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48 views

How to interpret the negative (actual) evapotranspiration values?

I am exploring FLUXNET sites for actual evapotranspiration (ETP) data (I convert the energy balance closure-corrected latent heat to ETP). I am interested in the half-hourly data. During the night we ...
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1answer
62 views

Can we define “drainage density” for a soil column (point-scale)?

From what I read all over the web and articles, drainage density is a parameter that is defined for a catchment. I want to use a hydrological model to simulate the percolation from the bottom of a ...
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15 views

What percentage of oceans and seas fall in tropical, subtropical, temperate and cold zones?

It is easy to find information on total area of oceans and seas. For example Atlantic ocean is 106 500 000 km², Indian ocean is 70 560 000 km² and Pacific ocean is 165 200 000 km². But waht percent of ...
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What is the scientific reason for Falgu river being subterranean?

According to wikipedia "The Phalgu or Falgu, a river that flows past Gaya, India in the Indian state of Bihar, is a sacred river for Hindus and Buddhists. Lord Vishnu's Temple Vishnupad Mandir is ...
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Is there any river that does not discharge into larger body of water?

Do you know any example of a river that does not flow into sea or lake? For example, if water rises from the underground spring and forms a river but water vaporises in hot climate before it reaches ...
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55 views

How to obtain the saturation point of a soil layer from the volumetric soil water content data?

Would you please let me know if the following is accurate as an answer to the question: Suppose we have sensors which measure the volumetric soil water content of a soil layer for a long period (more ...
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62 views

Where to find reliable snowfall rate data?

Would you please let me know where I can find/download reliable snowfall rate datasets? I am looking for multiple weather stations (in different regions) or field measured data, that contain both ...
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15 views

Is there a database for Strahler numbers of rivers?

I'm looking for the Strahler stream order number of rivers in Germany. Of course it would be possible to obtain the Strahler number myself by looking up each source of each rivers. But I have to ...
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21 views

How to use gridded data for a catchment scale analysis?

I need to use gridded rainfall data (0.1 degree grids) and station discharge data for analysing rainfall-runoff relationships. How do I process the data in such a way that it is justifiable to compare ...
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116 views

Why would a rincon provide more reliable water? [closed]

I am reading a book that argues that the Ancestral Puebloans settled along the rincons, or nooks, along the canyon walls, because that was where water was reliable. I can't understand the argument, as ...
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43 views

What is the “pressure gradient” within the richards equation

I'm trying to understand the Richards equation that can be used to compute the flow of water in soil. In a textbook I found the following: Unfortunately, the textbook doesn't really explain what the ...
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1answer
53 views

How to estimate the runoff time for my area?

I want to use an rainfall-runoff model for pluvial flash floods and need to choose for my synthetic rain event the appropriate duration. In the literature it often says that the chosen duration should ...
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25 views

How to transfer surface roughness from the unit mm into Strickler coefficient m1/3 per second

I have a hydrodynamic model to simulate flash floods. This model expects roughness data in the Strickler coefficient format (kst) in the unit m1/3 per second. I got a table with roughness values I'm ...
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Modeling the total water inflow across multiple reservoirs

I'm new to hydrology and I have a question regarding the modeling of multiple reservoirs. I need to estimate the total water inflow to multiple reservoirs that will be observed tomorrow, conditional ...
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31 views

How to choose “relevant” precipitation durations for flash flood modelling?

For my thesis, I model flash floods in urban areas. A book with recommended practices says to use events with a recurrence interval of 30 and 50 years. Regarding the duration of the precipitation ...
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45 views

Rainfall guage stations outside the watershed

How can I determine the rainfall depth for an event over the watershed, if I just have two stations, S1 and S2, that are outside the catchment? Methods I have thought of were to take the average of ...
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struggling to find a good research question in rainfall runoff modelling [duplicate]

I'm writing my thesis on modelling extreme rainfall and I'm still struggling to find a good research question. I have asked a similar question before in this post. Maybe you guys can give me some ...
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How much water will flow into the Caspian Sea if it is connected to the World Ocean?

I wonder how much benefit would a hydroelectrical project built on this inflow bring. There are projects to fill up the Erie, Salton, Qattara and the Dead Sea. But for the Caspian, there is only a ...
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48 views

how does model validation work? What is needed for an appropriate validation

I have an 2D hydrodynamic model in a approx. 10km² catchment and one rain event that goes one hour with measurements in a 5min interval. The reccurance interval for an event like that is close to ...
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66 views

If the top layer of a large river freezes, is the remainder's rate of flow affected?

This question is a hypothetical, and has to do with the notion of cheap, modular turbines that can be sunk and anchored to a specific depth in a body of water. Each would not generate much power, but ...
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47 views

hydrologic vs. hydrodynamic modelling of surface runoff

In the description of a Software it says that it computes the net rainfall, runoff formation and runoffconcentration on a surface hydrologically. With an extra module, the runoff formation can also be ...
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52 views

research question for modelling extreme rainfall event with coupled 2D surface and 1D sewersystem model

I would like to write my thesis on modelling extreme rainfall events in urban areas coupling a 2D surface model with an 1D sewer channel model. I have access to a good software which models ...
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1answer
66 views

How to check the recurrence intervall of heavy rain events

Heavy rain or flood events have recurrence intervalls. I.e. 100 year, 50 year or 25 year events. However, with increasing data and global warming and other factors these intervalls change. How can I ...
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How do oases form in the middle of the desert?

I am wondering if there are any theories about the formation of oases, and I am also curious about why an oasis can even last for a very long period of time. I have heard that fresh water exists on ...
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what is a sensitivity analysis in heavy rain 2D surface / 1D drainage network models

For my thesis, the lecturer proposed to make a "sensitivity analysis" with a 2D surface model connected with a 1D drainage Network model for a storm rain event. However, I'm having problems to figure ...
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3answers
212 views

formula to convert precipitation in mm/h to runoff in m³/s

I have precipitation data in mm/h but to use them for my model I need them in m³/s. Is there a formula to convert them?
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Modelling extreme rainfall events: 'blanket approches' when considering soil infiltration

For my thesis on modelling an extreme rainfall event with a 2D surface runoff model I'm supposed to consider the effect of soil infiltration on the runoff: In my work description it says I'm supposed ...
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2answers
4k views

Do dams reduce the flow of river downstream?

There is a conflict between Egypt and Ethiopia, because the latter wants to build a dam on the Nile river. Citing this article: [Egypt] fears the Nile dam will reduce its share of the river and ...
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2answers
108 views

Loop in the continental divide

Various maps of the Continental Divide (the hydrological feature, not the trail) contain a loop that looks like this: What is the hydrologic meaning of the loop in Wyoming? Even if it's a basin, ...
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Avra valley aquifier region boundary

Attached is an image of the Avra valley in Southern Arizona, USA from Effects of Kriging and Inverse Modelling on Conditional Simulation of the Avra Valley Aquifier in Southern Arizona -- Clifton and ...
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How are aquifers found and traced?

Recently a line from a news article about an aquifer in the path of a tunnel boring machine for Metro networks caught my attention: Ahead of tunnelling, the builders conduct hydrogeology, a study ...
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1answer
113 views

Run Hydrus-1D from the command line

Hydrus-1D, is a modeling environment for analysis of water flow and solute transport in variably saturated porous media. This program has a graphical environment which works very well, however a lot ...
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What does a “closed basin” mean in groundwater terms?

This answer talks about a "closed basin" that has an outflow to the sea. I had previously assumed that "closed basin" meant the same as "endorheic basin", but that is obviously not the case. What is ...
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1answer
53 views

How to recharge ground water directly from river water

I am not sure if I am asking it on a correct platform or not. A rainy river passes through my village. We suffer both in summer and in rainy seasons due to this. Could anyone explain how to recharge ...
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1answer
157 views

Code for DEM based flow routing in R

I have a DEM as shown for which I have determined flow paths using D8 algorithm (My own code) in R. The resulting DEM with the flow paths is also shown. The flow paths are generated in the form of ...
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2answers
107 views

Can I interpolate rainfall data from stations outside of watershed for the watershed?

I have only few station inside the watershed so I want to use the stations outside if I can to get better results
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45 views

Flood and Statistics

A recent flood was due to combined effect of rainfall(precipitation) and reservoir storage. I have daily rainfall data and reservoir storage data. How can I correlate these two to get a statistical ...
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232 views

Hydrology- flow accumulation

I'm not specialist in hydrology, and I would be very grateful if you answer my question: What is flow accumulation in hydrology? Why algorithms used to calculate it over a raster DEM don't take ...
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1answer
116 views

What effect does concretization (paving/flooring with concrete) has on ground water table

I am a newbie for hydrology. If the question seems to have "well known answer", I appreciate if you point me to the resources. I will add details to the question based on comments. Consider a town of ...
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1answer
44 views

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

When working with extreme hydro-meteorological events, flood in particular, it is common procedure to classify each event by its return period/recurrence interval. This probabilistic measure has the ...
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126 views

Is there an approximate rate for water temperature by depth that could be modeled simply?

I know that there are a couple of questions covering latitude and longitude for water temperature, but overall I'm more interested in the rate of temperature change by depth. Thought Process: ...
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How is it possible to use up the water in a region?

The Dead Sea, rivers in California and the Aral Sea are said to be shrinking due to water usage, e.g. for agriculture. Yet the water must go somewhere. After the fields are irrigated, the water ...
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102 views

In winter, is pond water warmer with or without a fountain? I have goldfish [closed]

I know that goldfish can hibernate but I'd like to keep the water warmer for them. Is moving water colder or warmer than still water? The water shoots out of "pipes" about 3" above the water's ...
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2answers
785 views

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

Following the commonly-known USGS definition of Water Year (or Hydrological Year) we know that it starts on the 1st October and ends on the next 30th September. Is this definition valid only for ...
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When will the weight of melted polar ice release the (currently stuck) subduction of the oceanic plate West of the Oregon coast?

Melted polar ice water makes the oceans deeper on average. The extra water on top of the oceanic plates makes them sink relative to the continental plates. This relative vertical displacement will ...
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How to obtain the correlation between monthly streamflows based on physical concepts?

I've been tasked with generating synthetic streamflow scenarios through disaggregation. First, I will generate 50 years of streamflow data. For that, I will probably use a simple model as AR(1) or an ...
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Environmenal flow in the context of global gridded hydrological analyses

Environmental flow (EF) is a widely used concept in river basin management and river ecology. There are more than 200 methods to estimate the flow that should be left to the rivers to ensure a ...
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968 views

Why do we consider hydrostatic pressure and lithostatic pressure separately?

In petroleum geology, why do we consider hydrostatic pressure and lithostatic pressure separately? Surely the pressure at any point, whether fluid or rock, at depth is simply equal the weight of all ...