PhD defence Hero Marhaento

Effects of changes in land use and climate on water availability of a tropical catchment 

Hero Marhaento is a PhD student in the research group  Water Management. His supervisor is Professor Arjen Hoekstra from the Faculty of Engineering Technology. 

Land use changes such as deforestation and urbanization influence the hydrology of catchments and hence water availability. Together with climate change, land use changes can affect the frequency of floods or droughts and thus threaten local or regional socio-economic development. For Indonesia, the effects of changes in land use and climate have been projected to cause a food crisis and eventually increase the degree of poverty in the future. In order to mitigate future risks, knowledge on the extent and directions of land use change and climate change impacts on water availability is essential.

The objective of this research is to assess the effects of land use change and climate change on the water availability in the Samin catchment (278 km2) in Java, Indonesia. The research is divided into four parts (papers). The first two papers address the attribution of observed changes in hydrological processes to land use change and climate change, using a data-based approach (first paper) and a modelling approach (second paper). In the third paper, the future hydrological response due to expected land use change and climate change is estimated. Finally, in the fourth paper, the effects of different land use patterns on streamflow characteristics are assessed.

The research provides insight in the impacts of changes in land use and climate on water availability in a tropical catchment in the past and future. Beside contributing to the advancement of the scientific field of hydrology through proposed methods used in this thesis, findings of this study can be useful for supporting the authorities for mitigating future water stress through appropriate land use management.