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.

Filter by
Sorted by
Tagged with
11
votes
1answer
95 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 ...
16
votes
3answers
3k 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 ...
3
votes
1answer
80 views

How did the Rhine originally look like? (before human intervention)

For personal reasons I decided to examine the shape and formation of the Rhine. Unfortunately though, the Rhine has long been diverted from its original course by human intervention, so I tried to ...
2
votes
2answers
129 views

Searching for ground water

I would like to attempt to build a well-type structure in a woodland area. This woodland is mainly inhabited with Silver Birch and Sycamores and there is a shallow stream running down off of a ...
6
votes
1answer
87 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 ...
15
votes
2answers
609 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 ...
8
votes
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 ...
5
votes
2answers
154 views

Comparing Pros and Cons of SWAT and HSPF

To model hydrology in a watershed, two of the most famous and widely used distributed models are SWAT and HSPF. I have some good understanding of HPSF, but I don't know when and why should one prefer ...
0
votes
2answers
142 views

Time of concentration - Difference between large and small basins

I am looking for any academic reference (i.e. articles) regarding the time of concentration for large and small basins. E.g. I would expect that a large basin (area > 1,500 km^2) will flood (or reach ...
11
votes
1answer
228 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, ...
6
votes
1answer
135 views

Does a hurricane classification exists where estimated rainfall is taken into account?

Hurricanes are classified with the Saffir–Simpson hurricane wind scale. However an extreme amount of rainfall can cause a disaster although the windspeeds are not extreme. Is there some sort of ...
2
votes
1answer
187 views

Clarification of overbank flows

Apologies for what may be a very basic question, but I am struggling to understand the definition of overbank flow. Overbank flow is defined along the lines of this: Water flow over the top of the ...
4
votes
1answer
84 views

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

When I use one DEM in my study area to delineate watersheds, the results are different from when I mosaic 4 DEM layers adjacent to each other. After the mosaic process, 3 of the basins were merged in ...
0
votes
2answers
728 views

Rivers flowing into Pakistan

Why do Rivers flowing into Pakistan come from either Afghanistan or India and not from inland mountains? Is it possible for Pakistan to source fresh water from its northern mountains avoiding India ...
2
votes
0answers
233 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
votes
1answer
109 views

Hydrology - Flowrate vs. radius of influence

I am using the following equation (Theim/Dupuit) to determine radius of influence for an unconfined aquifer. Assume all other variables are held constant. If Q increases, does the Radius of ...
5
votes
1answer
119 views

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

There are a lot of variations of basic, first-order hydrology models to estimate runoff from rainfall with a few other parameters. From what I can tell, most very basic rainfall-runoff models use one ...
4
votes
2answers
77 views

Does nitrate take a particular long time to percolate from surface into groundwater?

In a recent discussion with a farmer, the (at least in northwestern Germany) "popular" topic of nitrate infiltration into groundwater came up. The general view is that lots of fields receive more ...
1
vote
1answer
341 views

Area reduction factor reference for precipitation

For a large catchment (>1000ha) I'm looking for some method to use a area reduction factor to adapt precipitation values. I have a large dataset of daily precipitation values but I have to use some ...
1
vote
1answer
516 views

Concept of artesian aquifers and pressure is not clear.

I do not understand how the Artesian aquifer is causing the water in the flowing well to reach a level higher than the ground surface? And what role does the piezometric surface play in it?
7
votes
1answer
225 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 ...
6
votes
3answers
97 views

Accepting/refusing high rainfall measurement

I have a series of records of annual maximum daily rainfall for a station for about 80 years (1935-2014). Only one value is very high compared with the others, but in this year, the other close rain-...
4
votes
1answer
63 views

Looking for a reference for identifing stream regimes(Intermittent, Perennial)

I'm a hydrologist with a good background in GIS. I'm looking for a reference (Methodology, Technical guide) for identification of temporary, intermittent and perennial streams. I google and only found ...
7
votes
1answer
957 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 ...
9
votes
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 ...
4
votes
0answers
177 views

How to relate RCM/GCM RCP climate projections to observational data for use in a hydrologic model

As a (smaller) part of my research, I want to look at climate projection data and how that might influence the hydrology within a study catchment in Rajasthan, India. For "the present day" climate, I ...
4
votes
2answers
537 views

Could parallel rivers flow in opposite directions?

Some rivers have been moving backwards. This got me thinking about an unusual idea. Could there be terrain that causes two rivers, within a few miles of each other (10?), to flow in opposite ...
2
votes
0answers
76 views

Best material for Piezometer tube in water well

I have a 150M deep borehole. We want to measure ground water level using a pressure sensor. I believe that it is best practice to make use of a Piezometer tube ...
2
votes
0answers
78 views

Approaches for estimating potential evapotranspiration for non agricultural landuse classes

We are studying the water balance of a small catchment close to Jaipur, Rajasthan India in a semiarid climate. About a quarter of the landuse within the catchment is agriculture, the rest is divided ...
2
votes
0answers
93 views

Why Coastal catchments should be appended for watershed analysis (Archydro Suggestion)?

I'm a GIS specialist with a good background in watershed hydrology and geomorphology theories. In a project, I should analyse coastal and inland catchments separately. I have some neighbourhood ...
4
votes
1answer
72 views

How stormy (wave height) does Lake Baikal get?

I'm trying to find info on the storminess of Lake Baikal. I want to compare wave heights in a storm on this lake to wave heights in a storm on the ocean. All I could find was very general information ...
1
vote
1answer
58 views

Freeze variations

We fish on several lakes on one property. Some lakes are frozen to 3 inches and others are ice free. If it has been below freezing for weeks, why haven't all lakes froze ?
9
votes
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....
3
votes
0answers
62 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 ...
2
votes
4answers
6k views

Why do rivers have 'wells' in mountains?

Why/how can rivers have sources in places high above the sea level?
2
votes
0answers
282 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 ...
3
votes
2answers
1k views

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

I computed the daily reference evapotranspiration $ET_0$ using the Crop evapotranspiration - Guidelines for computing crop water requirements - FAO Irrigation and drainage paper 56. The outputs seems ...
3
votes
1answer
78 views

High resolution global land use projections

I am looking for global land use projections for a large scale hydrological analysis. The most widely used datasets are the LUH (v1) Products used for CMIP5 based on Hurtt et al 2011. These products ...
2
votes
1answer
273 views

Derive Reference Potential Evapotranspiration from Potential Evapotranspiration

I'm working on a project in Rajasthan, India involving modelling water supply and demand in a catchment. For this, I am working with WEAP which has modules for estimating groundwater recharge using a ...
1
vote
0answers
73 views

Missing Data in GSOD Data

I been accessing daily historical NOAA GSOD data through Google BigQuery. I am interested in long term time series of snow, precipitation, and to a lesser extent temperature for areas around the Volga ...
16
votes
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 ...
1
vote
1answer
49 views

Unable to prepare input file for HSPF software for watershed modeling!

I am trying to use BASINS 4.1 software to prepare input file for HSPF (.uci). When I launch HSPF from BASINS software, I have to direct the sofware to read a time series file (.wdm). In my case I am ...
1
vote
0answers
56 views

Modelling the unsaturated zone in FeFlow in seawater intrusion scenarios

Does anyone have experience with modelling seawater intrusion scenarios in Feflow? In my models, my mass-concentration seems to drive up into the unsaturated vadose zone, which I don't believe is ...
1
vote
0answers
750 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 ...
2
votes
0answers
28 views

Designing FIR or other filters for soil water content

I have 250 or so soil sensors that I need to QC. They monitor various parameters such as soil temp, soil water content, soil co2, and soil heat flux. It isn't unusual for a sensor to behave poorly due ...
2
votes
1answer
50 views

Different peak and mininum discharge times for Newfoundland rivers

I have been studying the Humber, Gander and Terra Nova rivers in Newfoundland. I have been given a table of discharges, and for the peak discharges I see: Gander: around April and May (rougly from ...
2
votes
1answer
255 views

What is difference between partially penetrating stream and fully penetrating stream?

If fully penetrating stream means, the stream penetrates fully to the depth of aquifer, then doesn't it mean that there is zero conductance or leakance? The leakance or conductance is a term used to ...
1
vote
1answer
96 views

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

Various sources agree land cover changes impact the attenuation of stormwater. E.g. forest areas generally slow the rainfall-runoff response and moderate it, reducing peaks in hydrographs, as compared ...
8
votes
1answer
99 views

Is there a quick way to roughly estimate how quickly a flood will move downstream?

At the time of this post, there was urgent danger of spillway failure at the Oroville Dam in California, with evacuations in place for hundreds of thousands, and even larger populations further ...
10
votes
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 ...