Berlin - Thursday, 17.07.2003

„Transboundary Watermanagement“ 14 - 24 JulyW

ork

sho

p o

n

Ecosystem Analysis and Integrated Ground Water ManagementEcosystem Analysis and Integrated Ground Water Management

Dr.

H. K

ehl

Internationale Weiterbildung und Entwicklung GmbH

SalinizationSalinizationWhere the salt comes from

In general, different salts are inherent parts of all parent rocks. Soils are weathering products of rocks of different origin and salt contents. Therefore, in all soils we can find neutral salts (Na+, K+, Ca2+, Mg2+, SO4

2-, CO3

2-, HCO3-, Cl-).

Silty and loamy soils contain more soluble minerals than sandy soils.

The soils in drylands have developed in an environment of limited rainfall and significant periods of drying. This excess of evapotranspiration to rainfall draws water from depth and causes many soluble minerals to accumulate in the upper soil horizons.

Ecosystem Analysis and Integrated Ground Water ManagementEcosystem Analysis and Integrated Ground Water Management

Dr.

H. K

ehl

Internationale Weiterbildung und Entwicklung GmbH

”Reactivation of Traditional Ground WaterEnrichment and/or Formation through

Rain-Water Harvesting/Catchment Systems"

Todays Topic of Conversation and Discussion:Todays Topic of Conversation and Discussion:

Ecosystem Analysis and Integrated Ground Water ManagementEcosystem Analysis and Integrated Ground Water Management

Dr.

H. K

ehl

Internationale Weiterbildung und Entwicklung GmbH

Preconditions for artificial ground water enrichment and small-scale watershed management

Today, ground water enrichment through reforestation is a typical task of West-European Countries in the framework of watershed management. Very often it has been discused in connection with waste water re-use, river bank infiltration and ground water pollution through fertilizers.

Ground water enrichment and watershed management must therefore be a mangement for demand and equitable allocation.

In arid countries ground water enrichment can be achieved mainly by rain water harvesting (percolation to the ground water). However, it should be clear that watershed management with additional rain water can never provide unlimited extra water.

Ecosystem Analysis and Integrated Ground Water ManagementEcosystem Analysis and Integrated Ground Water Management

Dr.

H. K

ehl

Internationale Weiterbildung und Entwicklung GmbH

Desirable preconditions for ground water enrichment and small-scale watershed management

Data mining:

- topographical data (geomorphology and slope conditions)- climate variability, e.g. yearly amount and variation of

precipitation (arid, semi-arid, humid climate)

- weather-related dynamics of small-scale watersheds of river basins- pedology (distribution and types of soils, storage capacity)- flow data for ephemeral channels (wadis)

- water needed for different purposes

- aerial photographs and satellite data

Ecosystem Analysis and Integrated Ground Water ManagementEcosystem Analysis and Integrated Ground Water Management

Dr.

H. K

ehl

Internationale Weiterbildung und Entwicklung GmbH

Desirable preconditions for ground water enrichment and small-scale watershed management

AND - ONCE MORE : As the most recent DGIS (directorate general for international cooperation, Den Haag, NL) Policy Supporting Paper emphasized:

„Watershed management approaches may be over reliant on an idealized ‚community‘. The reality is one of groups - landless and landlords, high and low caste, men and women.“

Run-on area of different size

Ecosystem Analysis and Integrated Ground Water ManagementEcosystem Analysis and Integrated Ground Water Management

Dr.

H. K

ehl

Internationale Weiterbildung und Entwicklung GmbH

The principle of water harvesting and ground water enrichment

Run-off area(catchment)

of different sizeor

river redirection

adapted from FAO (strongly modified)

storage

storage

soilstorage

Pasture / Field

Domestic Water for People

Natural Vegetation

Ecosystem Analysis and Integrated Ground Water ManagementEcosystem Analysis and Integrated Ground Water Management

Dr.

H. K

ehl

Internationale Weiterbildung und Entwicklung GmbH

Possible techniques for ground water enrichment

Roof water harvesting

Concrete Slab with Filter Bed

Well

Ground Water

Source: Directorate of Town Panchayats, India

Care for Ground water before it becomes rare

Ecosystem Analysis and Integrated Ground Water ManagementEcosystem Analysis and Integrated Ground Water Management

Dr.

H. K

ehl

Internationale Weiterbildung und Entwicklung GmbH

Possible techniques for ground water enrichment

Roof water harvesting

Direct ground waterenrichment withoutconcret slab and filter bed.

Ecosystem Analysis and Integrated Ground Water ManagementEcosystem Analysis and Integrated Ground Water Management

Dr.

H. K

ehl

Internationale Weiterbildung und Entwicklung GmbH

Rain water harvestingfrom roads andpavements

e.g. Greece, Italy

Possible techniques for ground water enrichment

or Cisterns

Ecosystem Analysis and Integrated Ground Water ManagementEcosystem Analysis and Integrated Ground Water Management

Dr.

H. K

ehl

Internationale Weiterbildung und Entwicklung GmbH

Possible techniques for ground water enrichment

Water harvesting from macrocatchments

source: FAO