Human settlement mapping

INTRODUCTION

• South Africa and other countries in Africa are experiencing land

degradation at alarming rates due to unsustainable land use,

agricultural practices, deforestation, rapid urbanizations and population

pressures amongst other causes

• In developing countries, urban population growth has exceeded the

capacity of the cities to provide adequate basic services due to lack of

understanding of current and future urban patterns

• The proportion of people living in urban areas in South Africa increased

from 52% in 1990 to 62% in 2011

• Smaller towns are experiencing the highest growth rates in South

Africa owing to a growing economic activity

• Understanding urban spatial growth is critical for sustainable urban

infrastructure and service planning

• Remote sensing provide the capability to map human settlement

development over larger areas

• Advancement in remote sensing technology provides high spatial and

temporal resolution imagery required:

– detail urban growth assessment

– extraction of information required in the management of urbanisation

Available high resolution satellite imagery for human settlement mapping

• SANSA acquires SPOT imagery through government multi-user

agreement

– SPOT 5 : 2006 – 2015

– SPOT 6 & 7: 2013- now

INTRODUCTION

Human settlement development

20122007

National human settlement data

extraction projects

SPOT Building Count land cover/use

Settlement boundaries:

Administrative

boundaries, village layer,

Informal settlements, EA

Methods:

• Manual digitisation

• Pixel based

classification

• Reduction of time and resource

• Updated human settlement data

• SANSA-JRC collaboration

– Customisation of GHSL system = SA-GHSL

– 2012 layer was developed from SPOT 5

Automation of human settlement detection

Summary of

the

workflow

2012 National Human Settlement

Layer(NHSL)

• 2012 built-up mask extracted using SA-GHSL system

SPOT 5 mosaic Human settlement data

Black- no building structure

White: building structure

2012: Human settlement data -

Gauteng

Gauteng- SPOT 5 mosaic Gauteng- 2012 human settlement data

2012 national Human Settlement

LayerBuilding density – visual interpretation

High

building

area

density

Low

densit

y

Very low

density

2012 national Human Settlement

LayerThohoyandou and surrounding

villages

Durban Bloemfontein

Kimberly Umthatha and surrounding

villages

Cape Town

2012 national Human Settlement

LayerObjective: human settlement types classification

Building density maps

Building density maps

• Population

• Demand of service

• Disaster management

Open/green space assessment

Disaster management

Service or administrative boundary

updateEA

LayerVillage layer

Monitoring and planning of services

Urban growth assessment

2006 2013 Polokwane

Environmental managementHuman settlement encroachment on agriculture Human settlement encroachment on wetland

Human settlement encroachment on agriculture

Automation of human settlement

detection from SPOT 6

Original image Results

Informal settlement

Dense formal/township

Pretoria

Automation of human settlement

detection from SPOT 6/7

Township

Informal

settlement

Industrial

New

development

To evaluate the products

Email: NMudau@sansa.org.za