Mapping of suitable zones for manual drilling in Africa as ...€¦ · increase drinking water...

Mapping of suitable zones for manual

drilling in Africa as a possible strategy to

increase drinking water

Fabio Fussi

6th International Rural Water Supply Network Forum : Kampala, Uganda : 29th Nov-1st Dec 2011

Why UNICEF promotes manual

drilling?


Manual drilling advantages

• Cost Effective

• Easier access to sites

• Tools are made locally

• Creates employment

• Ready in emergencies

But manual drilling can give good results only if it is

done by qualified technicians

PROFESSIONALIZATION OF MANUAL DRILLING

Professionalization of manual

drilling


3 main modules:

Mapping suitable

zones

Technical training Advocacy and

institutional support

And 3 partners: UNICEF, Practica, Enterprise works

Goal of the mapping study

identification of suitable zones at

country level

Definition of zones having highest

priority for the implementation of manual

drilling

Set up a national geographic database


Study area

Mapping at country level has been completed in 12 countries. (Benin, Central African Republic, Chad, Ivory Coast, Liberia, Madagascar, Mali, Mauritania, Niger, Senegal, Sierra Leone Togo (results available at: http://www.unicef.org/wash/index_54332.html),

It is almost completed in Zambia and Burundi

It starts in December in Guinea


http://www.unicef.org/wash/index_54332.html

http://www.unicef.org/wash/index_54332.html

Main criteria to evaluate

suitability to manual drilling

Suitability to manual drilling is determined

on the basis of 3 main parameters:

GEOLOGICAL

SUITABILITY

WATER DEPTH

SUITABILITY

GEOMORPHOLOGICAL

SUITABILITY

SUITABILITY

TO MANUAL

DRILLING

Cross Analysis


Estimating geological suitability

GEOLOGICAL MAP

SIMPLIFIED

GEOLOGICAL MAP

MAP OF GEOLOGICAL

SUITABIITY

Existing geological,

geomorphological and

hydrogeological

studies

Borehole logs

Aggregation

Table

describing main

features of

geological

formations

Water point database

Reclassification

Extraction of data for first layers

and visualization in maps

Distribution of hand dug

wells

Attribute Join

Direct experience of

geologist and drillers


Estimating water depth suitability

DATABASE OF WATER

POINTS

MAP OF WATER

DEPTH SUITABILITY

Visualization by class of water

depth and type of water point

Direct interpretation – identification of

zones with similar expected water depth

Existing

hydrogeological studies

Climatic and

environmental data and

studies

Direct experience of

hydrogeologists and

drillers

Estimation of

predominant

exploitable water

depth by zone


Water depth suitability

Direct and visual

interpretation of distribution

of water level in water points

of the database


Estimating geomorphological

suitability DIGITAL ELEVATION

MODEL (SRTM, 90 m

resolution

SLOPE

Interpolation and

automatic processing Direct interpretation and digitizing

landforms

Geomorphological

studies and maps

MORPHOLOGICAL MAP (SLOPE

POSITION CLASSIFICATION)

MAP OF

GEOMORPHOLOGICAL

SUITABILITY

Topographic Position

Index


Final map of general suitability to

manual drilling


Geological suitability Water depth suitability Morphological suitability

GENERAL SUITABILITY TO MANUAL DRILLING

Some important aspects of the

methodology


GOOD COORDINATION BETWEEN REMOTE

INTERNATIONAL STAFF AND LOCALLY BASED

TECHNICIANS

BASED ON ALREADY EXISTING (BUT NOT ORGANIZED)

DATA. IMPROVEMENT OF THE INFORMATION AVAILABLE

FOR FUTURE STUDIES

MIXED ANALYSIS OF SYTEMATIZED DATABASE AND

QUALITATIVE INFORMATION COMING FROM LOCAL

EXPERIENCE

ALL THE GIS PROCEDURE CAN BE DONE WITH FREE

OPEN SOURCE SOFTWARE

Defining zones with highest priority for

manual drilling

Cross Analysis

PLANNING GEOGRAPHIC LOCATION FOR

MANUAL DRILLING IMPLEMENTATION

•Very good

suitability

•More than

75%without water


From the identification of suitable zones

at country level to detailed localization It is important to carry out a more detailed analysis to go

from the identification at country level to the precise localization of best sites for manual drilling. The same data and approach can contribute to this following step


The geographic database The geographic database produced during this study

contains multi-sectorial information that can be used

for different topics:

Natural resources management and conservation

Agriculture

Water supply

Infrastructure and transport

Demography

Health

•WRITING TECHNICAL NOTES

•MAKING IT ACCESSIBLE (WEB PUBLISHING?)

•COMPLETING WITH OTHER DATA

•KEEP UP TO DATE

How we can maximise

its effectiveness?


Thank you


[email protected]

Mapping of suitable zones for manual drilling in Africa as ...€¦ · increase drinking water...

Documents

Transcript of Mapping of suitable zones for manual drilling in Africa as ...€¦ · increase drinking water...