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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70
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17answers
36k views

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, ...
21
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5answers
3k 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 ...
17
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1answer
596 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 ...
16
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3answers
2k views

How does a meandering river form?

I read this explanation about rivers: "As the river erodes laterally, to the right side then the left side, it forms large bends, and then horseshoe-like loops called meanders" Why does the river ...
16
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2answers
3k views

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 ...
15
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2answers
571 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 ...
15
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1answer
230 views

Are there situations where the groundwater table doesn't follow the morphology of the surface?

In most or all geological site reports I read, the groundwater table (of the uppermost groundwater layer) always followed the morphology of the surface. Is this always the case? Are there signs for ...
14
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2answers
686 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, ...
14
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1answer
249 views

Recharge a dry aquifer?

Aquifers have a natural recharge rate. However, some aquifers rely on fossil water for their primary (or even sole) water supply. When water in a well is pulled from these aquifers faster than they ...
14
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1answer
359 views

What are the impacts of sublimation on an annual mountain snowpack?

Massive amounts of freshwater rests atop the world's mountains in the form of ice, snow, permafrost, and glaciers. Many areas of the world rely upon the melting of snow and ice to recharge their ...
14
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2answers
546 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 ...
14
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1answer
244 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 ...
13
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3answers
3k views

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 ...
13
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1answer
8k views

What is hydraulic diffusivity?

I'm having trouble grasping which properties of the soil are described by hydraulic diffusivity (sometimes referred to as soil-moisture diffusivity which is based on the diffusion equation). What ...
13
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1answer
237 views

How does soil redox potential affect the rate of denitrification?

Denitrification requires low oxygen conditions as wells as organic carbon. Are reduced soils (e.g gleysols) more likely to have higher denitrification rates because they have low oxygen levels?
13
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1answer
711 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 ...
12
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1answer
2k views

Where does the Amazon River really begin?

Where is the true source of the River Amazon? Searching Wikipedia, it suggests the River Apurímac has traditionally been considered the source. However, Google says it is the River Mantaro. In other ...
12
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2answers
379 views

What does groundwater consist of?

I heard that groundwater is rich in minerals and fluorides, but I have no clear thoughts on what else it contains and whether the ground water differs from area to area. Can someone please shed some ...
12
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1answer
402 views

Is the cause of Old Faithful's bimodal distribution for eruption times straightforward?

From wikipedia: With a margin of error of 10 minutes, Old Faithful will erupt 65 minutes after an eruption lasting less than 2.5 minutes or 91 minutes after an eruption lasting more than 2.5 ...
11
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6answers
4k views

If water is a renewable resource, why is there water scarcity?

Water is a renewable resource, renewed by the water cycle. If we use water too quickly, water should get evaporated and come down again as precipitation. So, Why is there water scarcity if water ...
11
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1answer
209 views

Lake outflow forming a “reverse delta”?

While rivers often form a delta when they flow into a lake, the outflow of a lake is usually a single stream. Are there lakes where the water flows off in multiple channels that merge into a single ...
11
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1answer
220 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, ...
11
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0answers
131 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 ...
10
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3answers
2k views

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 ...
10
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1answer
84 views

Rocks sparking under water

I have searched for an answer to this question for years, to verify if it was true. A man that lived on a river in the rugged part of the northern Washington Cascades told me an interesting story. He ...
10
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1answer
1k views

How are minor tributaries of a river determined?

What are the criteria to determine if river A is a major or minor tributary to another River B? Is stream order the only deciding factor i.e. the highest order is the main stem, one less order is a ...
10
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2answers
122 views

Is there any link between sea-water inflitration into groundwater and nitrate?

I recently read a pop-science article about sea-water infilitration into (sweet) groundwater. One specific instance mentioned was the gaza strip: Exzessive well building and drawing of groundwater ...
10
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1answer
255 views

Permeability of well screen as a limitation to a slug-in test

If you were to do a slug-in test where you put in a known volume of water, would there be a point where, say if the formation was extremely permeable, the permeability of the screen itself would be ...
10
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1answer
562 views

What's the geological period of the birth of the river Ganges?

Avatarana or Descent of the Ganges (extracted from Wikipedia): "In late May or early June every year, Hindus celebrate the avatarana or descent of the Ganges from heaven to earth." There are ...
10
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1answer
247 views

How to determine the transmissivity of a system of rocks and faults from the stationary drawdown pattern?

I have a dataset containing high frequency measurements of the hydraulic head at different locations in a 5x6km area. Also known are the precipitation, evaporation, and pumped discharges from a number ...
10
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1answer
4k views

How to calculate flow duration curve for a set of 12 year data?

Given, discharge data alone for each month in each year, is it possible to calculate the flow duration curve? Some of the discharge values in some months were found to be 0. Do we need to consider ...
9
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5answers
895 views

Correct phrase for a 'forgetful' natural system?

This is a rather general question: assume I have a system that has a certain 'forgetful' property, which means that while I can offset its current state for a moment, it will eventually return to its ...
9
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1answer
206 views

Is there a special name for along-course elevation profiles of rivers, and where you can you find them?

Was discussing the terrain and rivers of Europe today with my father and it became apparent that a graph of the elevation versus course of a river would offer interesting insight, including a quick ...
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, ...
9
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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 ...
9
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1answer
3k views

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 ...
9
votes
1answer
974 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....
9
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1answer
153 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 ...
9
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1answer
823 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 ...
9
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1answer
59 views

Lab procedure for analyzing/assessing the presence of semi-volatile solids

I'm looking for a lab experiment design that shows how to measure the presence of semi-volatile solids in water (and not sludge or soil or solids). All I have found so far are chromotography/mass ...
9
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0answers
76 views

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 (...
8
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2answers
191 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 ...
8
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1answer
1k views

Math needed for Hydrology, specifically surface water hydrology

I wanted to know what math is needed for hydrology, in particular surface water hydrology. In my research online, of Master's programs (either in Hydrology or Environmental Science with a ...
8
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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 ...
8
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1answer
143 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 ...
8
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1answer
1k views

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 ...
8
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2answers
609 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 ...
7
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1answer
220 views

Who would know how to manage rainwater erosion on a sloped property?

I'm a meteorologist with little experience in hydrology. I'm studying my land with the rainwater flow patterns during heavy rain events and looking to manage the erosion, flash flooding, and ponding ...
7
votes
1answer
745 views

Are there any DIY conductivity sensors that will hold calibration for long periods? {multiple months}

We've just published our DIY underwater loggers: http://www.mdpi.com/1424-8220/18/2/530 and the #1 thing we would like to add to the platform is conductivity. The loggers themselves will easily run ...
7
votes
2answers
751 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 ...