Sammanfattning av doktoranduppgiften
Spatial and temporal variations in water regime and quality in response to changes in land use and climate in a semi-arid peri-urban catchment
Sacaba city in the Cochabamba region, Bolivia, has experienced substantial and uncontrolled urbanisation in the past 30 years. This has led to lack of basic sanitation services for the new inhabitants, which in turn has created conditions of accelerated contamination of waters, particularly surface waters.
The aim of this PhD project is to improve understanding of the spatial and temporal variability in water regime and quality in waterways, in relation to land use, climate and catchment characteristics, in a peri-urban/rural area in Sacaba valley.
This will be achieved by: 1) assessing the influence of historical land use and climate change on water regime and water quality in waterways, 2) assessing the pollution from non-point sources as a function of land use, geomorphology and position in relation to waterways, 3) assessing water regime variability in surface waterways and surrounding soils under different climate scenarios and 4) evaluating pollution transport by continuous rainfall-runoff modelling using SWAT.
Land use and climate change will be evaluated in the project based on relevant historical data (30 years), in order to assess their influence on water regime and quality at catchment level. A GIS and remote sensing approach will be used to analyse historical and current climate, runoff and water quality data. In addition, data on soil properties will be collected, measured and analysed according to FAO methodology. To calculate future pollution, the potential non-point pollution index (PNPI) developed by Munafò et al. (2005) will be used. It applies the multicriteria technique on a GIS-based system to pollutant dynamics and water quality, in order to classify and display areas that are likely to produce pollution coming from land units, as a function of three indicators: a) land use, b) runoff and c) position or distance with respect to waterways. The SWAT model will be used to predict the variability in water regime and pathways and its impact on water quality and pollutant transport in future climate scenarios considering the driest, wettest and normal scenarios, for 30, 50 and 80 years, on the basis of previous work by Escurra et al. (2014).