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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475 views

Hydrology - Depression cone VS transmissivity

My question concerns the depression cone of a pumping well in a confined aquifer: Say the transmissivity of the aquifer is 1200 m^2/day how will the cone change if the transmissivity is 600 m^2/day? ...
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1answer
59 views

What forms do groundwater flow equations have when Dupuit supposition is not considered?

Near pumping wells or near/beneath a stream, the groundwater flow is not totally horizontal and the vertical component of groundwater movement at these points cannot be ignored in reality. Often, ...
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How to plot lat-lon-rainfall in MATLAB?

I have average annual rainfall values at few grids, as shown in below example; Lat: 25.5 26.5 33.5 34.5 35.5 36.5 41.5 42.5 Lon: 89.5 91.5 78.5 79.5 83.5 84.5 75.5 76.5 Rain: 110 120 122 135 114 ...
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Lithologic and hydrostratigraphic logs for the Deccan volcanic province, India

I need data on depth/thickness of of different lithologic units under Deccan Volcanic Province in MP, Maharashtra and Gujarat. For this if anyone can help in providing help in obtaining well log data ...
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Linear Boussinesq Equation for groundwater flow in inconfined aquifer?

I was reading a paper (equation 1 in linked paper) where they used 'linearized Boussinesq' equation to model groundwater in unconfined aquifer. The linearized Boussinesq equation described in the ...
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What geophysical instruments should I use to detect water without drilling?

How can one detect (preferably artesian) aquifers nowadays that a lot of sensors are available? Should I use ground-penetrating radars, neutron detectors, or any other advanced devices? Can seismic ...
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Why are the Little Colorado River and Havasu Creek blue?

In Grand Canyon there are two side streams that carry heavy carbonate loads and deposit travertine along their lengths. The Little Colorado and Havasu Creek both rise from springs a few miles above ...
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What field studies have developed or supported the Penman-Monteith equations for estimating evapotranspiration?

I'm trying to understand transpiration estimation methods. The FAO recommends a standard Penman-Monteith methodology for modeling evapotranspiration based on meteorological and vegetation parameters (...
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1answer
114 views

Do Hydro-Carbon extraction units pollute ground water?

I am from India, Tamilnadu state. Our nation has planned to have hydrocarbon extraction units in our Thanjavur villages. We, a 70 million people Tamilnadu state get most of our rice from that region. ...
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Is there a database of global rainfall time series?

Is there any institute out there collecting time series data of precipitation, and making them accessible online? I need data for a few different locations, but: Low spatial resolution is fine. For ...
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2answers
629 views

How to perform regridding (1.0d to 0.5d) using bilinear interpolation for an irregular area?

I need to regrid temperature dataset from 1 degree to 0.5 degree. In case we have data available for all grids falling in a square, as shown below, we can simply regrid it using bilinear/bicubic ...
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Calculate Total stress

I'm looking to calculate the total stress at a depth of 10 km in a rock column, where porosity varies with depth. I believe I can figure this out, however I might have copied down an equation wrong. ...
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1answer
270 views

How are biological oxygen demand and depth related?

What is the relation between biological oxygen demand (BOD) and depth? I need to calculate the BOD of a drinking water tank and I have ultimate BOD at the surface of water, but I need to calculate it ...
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Using sodium chloride load as a point source pollutant variable in SWAT model?

I'm currently working with the Soil & Water Assessment Tool (SWAT). My task is to model the loading of sodium chloride into streams. One approach I would like to take is to use the point ...
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1answer
230 views

What is the source of the Big Sur river?

While hiking in the Ventana Wilderness in Big Sur, Calfornia, I kept trying to figure out one question: what is the source of the Big Sur river? Wikipedia reports its tributaries being the Redwood ...
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Capillary rise experiment and obtainable information about the porous medium

I have access to rock core(s) and vacuum saturation chambers as seen in the image below. I can dry the rock core using an oven, measure its geometry and mass. I can place it into the vacuum ...
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603 views

How far can water wick up above the capillary fringe in sediment or soil?

The capillary fringe is the area above the water table where the water is held in tension so that the connected pore space is completely saturated, although variation in pore size means that there is ...
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294 views

Ship turning causing calm water

Can anyone tell me the official or technical term for the effect of when extremely calm water appears when a ship turns sharply in a full circle? I realise it could be related to wakes, but is not a ...
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2answers
57 views

Is it possible to have an AR(0) for streamflow?

Autoregressive models (AR) are extensively used to understand the behavior of streamflow. The literature abounds with examples of AR models from different families applied "everywhere" to fully ...
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1answer
137 views

comparing use of Laplace equation with diffusion equation to simulate flow of fluid/water through porous media?

What is the difference in using Laplace equation (say only in 1D) to simulate water flow in a porous media with that of using diffusion equation for same purpose?
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Why confined aquifers have low storage?

Identical drop in head in unconfined and confined aquifers releases different amounts of water. The confined aquifer releases less water and thus has less specific storage. When both aquifers are ...
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Is there a way to calculate difference initial water content, from curve number method?

I want to calculate difference between initial water content of a soil given that its saturation water content can be found from its type. Is there a way to find initial water content of that soil ...
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What field data do I need for the Green-Ampt infiltration Model?

I want to estimate infiltration in a soil. What kind of parameters should I be measuring in the field?
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192 views

Point source pollution model for South America

I want to model point source pollution in S. America watersheds. Specifically, given a set of pollution points and corresponding pollution output levels, I want to know the course these pollutants ...
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Slope of Saturation vapor pressure versus temperature-A parameter in Penman's equation

How is mm of Hg per degree Celsius converted to kPa per degree Celsius? I also need the equation for computing the value of A (slope) in mm of Hg per degree Celsius.
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1answer
203 views

What divides Hydrological Unit Code areas of the same level?

I'm trying to better understand the Hydrological Unit Code (HUC) system of the United States. I understand the basic hierarchy of it (HUC4, 6, 8, 12) and watersheds/drainage areas. Here's what I want ...
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Averaging watershed areas

If I am looking at different USGS stream gages, calculating their 90th percentile streamflow, and then doing a weighted average of the 90th percentile of the streamflows using the watershed areas - ...
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1answer
158 views

In -20 °C weather, creeks below waterfalls here form ice columns. What are these called? Ice-canoes?

I would like to know the name(s) of this ice formation. How common or rare is it? What other regions of the world does this occur in? What specific requirements are needed to produce it and could it ...
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2answers
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How much time does water takes to reach to the ground?

I want to understand the phenomena where water droplets after precipitation reaches to the ground. How much time does it take to become ground water or in other words how much time is taken by water ...
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1answer
332 views

Cooling effect by evaporation [closed]

Why exactly does water cool down by evaporation? What happens in this process? How much does it cool down? What's the formula to describe this process?
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Any way to increase the amount of water that flows through bedrock?

My pond is fed by a spring that collects inside a large concrete box (6' x 6' x 8'deep) that was formed up many years ago. The walls of this box are sitting on bedrock. Small trickles of water seep ...
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64 views

Near Future Precipitation and Temperature estimations?

I was wondering if anyone here is familiar with temperature and precipitation estimation? I need to estimate P and T from April to July 2016. I am planning to use excel to do the calculation because ...
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1answer
264 views

How to characterize flow of nonreactive tracer in a porous media?

About Tracer Experiment This experiment is conducted by injecting a fluid with nonreactive species of certain concentration inside a column or core composed of sand. The injection of fluid can either ...
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1answer
146 views

Unrealistic solution for advection-diffusion-reaction PDE with heterogeneous porous media

About the code: I have a code which simulates concentration from advection-diffusion-reaction PDE in 2D space (X,Y) with time. The solution is obtained using fully implicit finite-difference method ...
5
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1answer
300 views

In hydrology, what's the difference between specific and total catchment area?

I am getting stuck on the concepts of Total Catchment Area (TCA) and Specific Catchment Area (SCA) as I try to learn more about TOPMODEL and hydrology modeling. What do these metrics mean in hydrology?...
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1answer
848 views

Evaporation loss formulas

A while ago I created a spreadsheet to calculate evaporation loss. I found several formulas to do that, two from Kevin Rafferty and one from Engineering Toolbox. The one from Engineering Toolbox was ...
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2answers
560 views

Could the Dead Sea dry up? and if so, when?

According to recent findings, during the last interglacial period, about 120,000 years ago, the precursor of the Dead Sea (Lake Lisan) dried up perhaps entirely. Today, the Dead Sea level is dropping ...
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159 views

Time series analysis and streamflow data [closed]

Does anyone know of any examples of (common) time series analysis techniques applied to streamflow data? Edit: I am wondering if anyone has come across papers using common time series analysis ...
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1answer
150 views

High Discharge Value in SWAT modelling

At first run I’ve encountered the problem since the values of modeled and observed discharge are significantly different. The correlation between them is nearly 0,2...
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1answer
721 views

'Peak water' in the Ogallala Aquifer, USA?

According to the United States Geological Survey Report (USGS) Groundwater Depletion in the United States (1900–2008), the Ogallala Aquifer (or High Plains Aquifer) is a vital source of groundwater ...
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1answer
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What are Horton's laws?

Robert E. Horton coined these four laws: the law of stream numbers, the law of stream lengths, the limits of infiltration capacity, and the runoff-detention-storage relation. What are they ...
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1answer
253 views

Is there a standard definition of a “dry-down” event in hydrology?

When studying the land surface, dry-down periods - periods after rain where the soil moisture is decreasing due to evapotranspiration and drainage - are of great interested, because soil moisture has ...
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1answer
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How do I prepare for the International Earth Science Olympiad?

Recently I have been selected for the National Camp of INTERNATIONAL EARTH SCIENCE OLYMPIAD of my country. How do I prepare for it? Resources, books, etc. I know there are 4 parts- geology, ...
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693 views

How important is understanding linear algebra in groundwater modeling?

I am considering taking a course in linear algebra and wanted to get a survey to see how important it is. My goal is not just to understand how to push the buttons in some software (e.g. GW Vistas, ...
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1answer
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The relationship between specific discharge and flux

How are specific discharge and flux linked? Is flux simply specific discharge × area? And when we speak of flux of an element eg. N-flux, is that ...
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2answers
765 views

How do perennial rivers in high alpine areas maintain year round flows?

We have several perennial rivers in my country that originate out of high altitude alpine glacier melt. I can understand snow or glacier melting in the summer to increase the flows but it is observed ...
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152 views

Freshwater changes in time?

Taking freshwater as being: Fresh water is naturally occurring water on the Earth's surface in ice sheets, ice caps, glaciers, icebergs, bogs, ponds, lakes, rivers and streams, and underground as ...
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Lake inflow-outflow problem

The evaporation from a lake is to be calculated by the water balance method. Inflow to the lake occurs through three small rivers, A, B and C. The outflow occurs through the river D. Calculate ...
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654 views

To what extent is hydroelectric power really renewable?

One of the more widespread "renewable" ways of generating power is by harnessing hydropower, i.e. by exploiting the movement of falling or flowing water. Some of the most commonly seen implementations ...
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Meaning of the C in the unit “mg C L-1”

Could somebody tell me what the "C" signifies in the unit mg C L-1? I was wondering if it stood for concentration but it seems redundant as litres are mentioned. Thanks. The paper which uses the unit ...