Land Consumption and Land Use
Introduction
Regional climate changes, high population growth and changes in land use considerably influence the water resources of the federal district Brasilia. Especially the population growth in the region around Brasilia has significantly increased the demand on land and water during the last decade. The expected water demand will exceed the available water amount in the near future. This situation may worsen by climate changes - e.g. the extension of dry periods - and lower water quality because of a more intensive land use and a higher amount of urban waste water.
Given the fact that the water supply of the capital city Brasilia and the region is predominantly (~70%) based on surface water by drinking water reservoirs, the water supply could become more difficult in the future. Particulary entries of sediments (silting) and nutrients (eutrophication) as well as water shortage during the dry season are major drivers to the deterioration of the quality of life.
Our research approach within the subproject comprises the simulation of effects by land use changes, urbanization and climate change on water quality (sediments, nutrients) and quantity (extension of dry periods). Thereby we pursue a two-scaled approach. Impacts of land use and climate changes are simulated on a meso scale for river basins and more detailed on a micro scale. Results of both simulations are used to develop recommendations for precautions in the catchment areas.
Objectives
- Interactions between land use, sealing and water cycle concerning qualitative and quantitative consequences within land use and climate scenarios
- Development of adaptation strategies for a safe, sustainable water supply in the region
- Analysis and modeling of urban growth in time and space
- Future urbanization scenarios and effects on the water cycle
- Development of a GIS based sustainable land use strategy with specific consideration of migration and climate change
Methods / Data
- Analysis of urban growth in space and time: model approaches as a baseline to outline future urbanization scenarios with their multiple consequences on the hydrological cycle in the Federal District and neighbouring regions. The dynamics of urban growth need to be understood in terms of their spatial expansion, direction and velocity of growth, concerning qualitative and quantitative consequences within land use and climate scenarios
- Analysis and assessment of current agricultural and forest land use systems and characterization of matter and water cycle.
- Vulnerability Impact Analysis for urban and agricultural / forest land use systems.
- Model urban, agricultural, forest, and bare land runoff and quantify impacts on sediment generation and water quality (using SWAT, WEPP).
- Development of GIS-based sustainable land use strategies for optimization of environmental impacts and developing planning instruments considering migration and climate change scenarios.
- Elaboration of “urban structure types” for Brasilia – DF for sustainable future water supply.
- Analysis of urban social structure indicators and recommendations for a sustainable urban development based on spatially assigned water consumption and contamination
Test sites
The test site Pipiripau with an expansion of about 21300 ha has been chosen to calibrate and adjust the SWAT-Model.
Planaltina as one of the oldest and most dynamic cities in DF has been selected as test site to develop and adjust the rule sets for the analysis of urban structure types. The census data have been analysed in detail to delineate socio-demographic and socio-economic parameters for this satellite city. The site is covered by very high resolution Quickbird satellite data. These pieces of information allow to overlay land use indicators with social parameters to derive statements for a sustainable urban planning.
Data (selection)
As the analysis on two spatial scales requires the application of different data sets, high and moderate resolved remote sensing data are applied. Additional GIS, census and hydro-meteorological data are used to improve the quality and validate the results of the land use change analysis.
Remote sensing data - high resolution:
| Quickbird | ALOS |
|---|---|
| geometric resolution: 2.4 m (multi-spectral) | geometric resolution: 10 m (multi-spectral) |
| 0.6 m (panchromatic) | 2.5 m (panchromatic) |
| spectral resolution: blue-green-red-nir | spectral resolution: blue-green-red-nir |
| acquisition date: 2008-08-09 | acquisition date: 2009-09-16 |
Remote sensing data - moderate resolution:
| Landsat 5, Landsat 7 | Landsat 1, Landsat 2 |
|---|---|
| From 1984 to 2009 | From 1973 – 1981 |
| geometric resolution: 30 m | geometric resolution: 80 m |
| spectral resolution: blue-green-red-nir-swir-tir | spectral resolution: green-red-nir |
Additional data:
- digital elevation model
- climate data (precipitation, temperature)
- census data
- economic parameters
Participating research groups
- F. Bakker, Companhia de Saneamento Ambiental do Distrito Federal – Brasília (CAESB)
- Prof. F. Makeschin, PD. Dr. C. Lorz, Technische Universität Dresden (TUD), Department of Forest Science, Institute of Soil Science and Site Ecology
- Prof. H. Roig, Universidade de Brasília (UnB), Department of Geosciences
- R. Hoefer, Helmholtz Centre for Environmental Research – UFZ - Leipzig, Department of Groundwater Remediation
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