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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3
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2answers
59 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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20answers
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Are there any saltwater rivers on Earth?

I'm curious if there are any saltwater rivers on Earth. These would presumably arise if a saltwater lake had a river outlet to the ocean. However, all the saltwater lakes I looked at (Caspian Sea, ...
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1answer
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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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1answer
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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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0answers
34 views

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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0answers
42 views

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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1answer
250 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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2answers
2k views

What keeps water from sinking into earth?

I remember reading somewhere that there's evidence of water on Mars but it all sank into the Martian soil. So what prevents that happening on earth? Some people say it's because the crust is not ...
2
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0answers
29 views

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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0answers
246 views

How to determine associated USGS stream gauges with a watershed HUC?

USGS stream gauges have an associated drainage area, but the associated hydrologic unit listed by USGS is often different than the actual drainage area. How can one determine what hydrologic unit ...
2
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1answer
217 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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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
88 views

Is there a method to determine the point rainfall intensity for small catchments?

I need to design a weir for a small earth dam in an arid area with a small (smaller than 200 ha), fairly flat catchment area in southern Africa. The idea behind the dam is to collect not more than 10 ...
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1answer
423 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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66 views

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 ...
2
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0answers
288 views

What is difference between Riverbed conductance term and streambed leakance/retardation coefficient?

In literature some times to account for semi-pervious sediments at bottom of stream, streambed leakance also called retardation coefficient ($L$) is used. This is equal to the ratio of conductivity of ...
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4answers
7k views

Why do rivers have 'wells' in mountains?

Why/how can rivers have sources in places high above the sea level?
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1answer
163 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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0answers
63 views

How to integrate dry wells into groundwater level mapping automatically (inequality constraints on the interpolation)?

I'm interested in automating spatial interpolation of groundwater level measurements. I'm wondering if anyone knows a method for automatically taking into account things like dry wells, where I can't ...
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0answers
66 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 ...
3
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1answer
274 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 ...
8
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1answer
152 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 ...
3
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1answer
283 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 ...
5
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1answer
372 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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0answers
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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0answers
51 views

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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2answers
191 views

Is the Great Artesian Basin a closed basin?

Areas where topography prevents the outflow of water are called closed basins. Is the GAB a closed basin? What if external bodies of water flowed in? Is that still "closed"?
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0answers
162 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
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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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0answers
774 views

How to calculate the infiltration rate? [closed]

This is Exercise 4.8.1 in Introduction to Physical Hydrology by Martin Hendriks. The water level above flat terrain during an experiment with double ring infiltrometer is 20 mm. The saturated ...
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2answers
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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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1answer
308 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 ...
8
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2answers
676 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 ...
14
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2answers
569 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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2answers
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How do long rivers exist?

I was recently on a long-haul flight over Siberia and it struck me as rather remarkable that something like the Lena River could exist. It seems very surprising that there's a route from some random ...
9
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1answer
896 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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1answer
160 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
2k views

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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0answers
133 views

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 ...
9
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1answer
3k views

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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2answers
197 views

Underwater rock conduit

After looking at this question - Source of water for the Great Artesian Basin in Australia one would like to know whether there are any underwater rock conduits that transport fresh water across seas ...
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3answers
3k views

Source of water for the Great Artesian Basin in Australia

The Great Artesian Basin in Australia covers 23% of the continent and contains 64,900 cubic kilometres of water. Many years ago it was claimed on a TV science show I saw that some of the water in the ...
11
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1answer
231 views

Minimum flow duration curves

It is common to prepare flow duration curves from a set of daily river flow data, but does it make sense to build a flow duration curve from a set of monthly minimum flow data? I searched on internet, ...
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2answers
641 views

How and why do these tree-like river structures form?

I noticed these detailed tree-like river structures in Google Earth Google Maps link How and why do these form? Rivers don't typically split. What would cause the water to keep branching off again ...
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2answers
717 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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5answers
4k views

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 ...
14
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1answer
769 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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0answers
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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2answers
832 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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1answer
1k views

Interpreting some hydropower data. What does DSF mean in this context?

This is the historical feed of the Keystone dam for October 2014: www.swt-wc.usace.army.mil/chartbin/KEYSOct14.shtml Here is the real time feed: www.swt-wc.usace.army.mil/ops_hydropower/KEYShydro....