Was ist Grundwasser?

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Из курса от партнера University of Zurich

Wasser in der Schweiz

8 оценки

University of Zurich

Wasser in der Schweiz

8 оценки

Wasser in der Schweiz. Tauchen Sie ein! Woher kommt das Wasser in der Schweiz? Was ist ein Jahrhunderthochwasser? Wie viel Wasser braucht die Schweiz? Warum ist Wasser so wichtig für die Schweiz? -- Wasser ist so zentral für unser tägliches Leben und trotzdem ist das Wissen über Wasser häufig begrenzt. Dieser Kurs beantwortet viele Fragen rund um das Wasser in der Schweiz – schwimmen Sie mit! In sieben Modulen berichten verschiedene Wasserexperten über die vielen Aspekte des Wassers in der Schweiz. In den ersten Modulen eignen Sie sich verschiedene hydrologische Grundlagen an und erfahren mehr zu Niederschlag, Abfluss und wichtigen hydrologischen Konzepten. Auf diesem Wissen bauen die weiteren Module auf, in denen dann Themen wie Wasserqualität, Hochwasser und Wasserkraft behandelt werden. Mit einem Einblick über die Bedeutung von Wasser für Kultur und Kunst wird der Kurs abgerundet. Lernen Sie mehr über die hydrologischen Bedingungen in der Schweiz, staunen Sie über die Vielfältigkeit des Wassers und erfahren Sie, wie das Element Wasser den Alltag in der Schweiz prägt.

Из урока

Vom Regen in die Traufe

Was ist Niederschlag? Wie wird er gemessen? Um diese zwei Fragen wird sich das Kapitel 2.1 drehen. Dabei werden die Entstehung, die verschiedenen Arten und die räumliche Verteilung von Niederschlag angeschaut. Im zweiten Teil dieses Kapitels wird gezeigt, wie der Niederschlag gemessen werden kann. In Kapitel 2.2 beschäftigt uns unterirdisches Wasser. Dieses wird unterschieden in Bodenwasser und Grundwasser. Es wird jeweils aufgezeigt, was Hydrologen unter Boden- und Grundwasser verstehen und wie diese zwei wichtigen Komponenten des Wasserkreislaufs gemessen werden können.

Was ist Bodenfeuchte6:59

Messung von Bodenfeuchte2:50

Was ist Grundwasser?4:19

Wie variieren Grundwasser und Bodenfeuchte in Raum und Zeit?4:58

Messung von Grundwasser4:08

Познакомьтесь с преподавателями

Jan Seibert
Prof. Dr.
Department of Geography
Ilja van Meerveld
Senior teaching and research associate
Department of Geography
Daniel Viviroli
Senior Scientist
Department of Geography

Welcome to this lecture on groundwater.

Almost 80% of all drinking water in Switzerland comes from groundwater,

either from groundwater water directly,

or from springs that are fed by the groundwater.

Globally 600 to 700 cubic kilometers of water are extracted each year.

This makes groundwater the most extracted raw material on Earth.

In Switzerland, the amount of groundwater extracted for

drinking water increased until the mid-1980s.

Since then it has decreased slightly due to water savings.

If we dig a hole in the ground,

at some point we reach the groundwater table.

Below the groundwater table,

all of the ports are filled with water.

Above the groundwater table,

some of the ports are filtered water,

other ports are filled with air.

Aquifers are material that not only store a lot of water,

but it also transmit water.

We do an experiment and we pour water

through different types of soils for example a clay soil,

a silt soil and a sand soil then we see that

the water flows very slowly through the clay and very quickly through the sand.

This means that sand is a good aquifer and clay is not.

The first person to study how the material of

aquifer affects groundwater flow was Henry Darcy.

He did experiments in the 1850s in order to understand

the water supply for the city of Dijon and the supply to its springs and fountains.

He did column experiments,

and in these column experiments he found what we now call Darcy's Law.

That is that the amount of flow shown here as Q

is dependent on the cross-sectional area of the column, A,

multiplied by the difference in height at the beginning of the column and

the end of the column divided by the length of the column.

This difference in the height at the beginning of the column and the end of the column,

divided by the length of the column is what we call the hydraulic gradient.

In addition, there is a proportionality constant.

This depends on the material.

We call this the hydraulic conductivity.

It describes how quickly water can move through the soil.

It's high for sands and very low for clay.

When we pump groundwater,

we can change the hydraulic gradient.

Initially the groundwater level is quite flat,

but then when we start pumping,

the groundwater level decreases and we create around the

well what we call a cone of depression; here gradient steeper.

We may also change the direction of flow.

Here we have a situation where water flows from the land to the river,

but then when we create a new well and start pumping from it,

we change the direction.

We now have water flowing from the river into our well.

In Switzerland, there are strict legal requirements around wells.

Each groundwater well it's protected by three different protection zones.

Protection zone one shown here in red protects the well it's usually fenced off.

Protection zone two is at least 100 meters long in the direction of flow.

Water stays in this protection zone usually for at least 10 days.

This is enough time to kill most microbial organisms.

Housing is not allowed in these protection zone.

In addition, there is protections zone three;

in this area no activities are allowed that may harm the groundwater.

Here we have a map of the protection zones for wells around Zurich.

We see in red the wells and the springs.

In blue, the different flow lines to watch these wells and springs.

In dark blue, protection zone one.

In light blue, protection two.

And in a very light color, protection zone three.

In this lecture we've talked about groundwater

and the importance of groundwater for drinking water in Switzerland.

In the next lectures we will talk about the different types of aquifers in Switzerland,

as well as how we measure groundwater levels.

We look forward to seeing you there.

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