People living in delta cities always have to be prepared for certain threats directly or indirectly caused by the forces or use of water. The Indonesian capital, Jakarta, is an example of a mega delta city which is frequently suffering from typical disasters in a river delta, such as coastal flooding and riverine flooding. Sea level rise in combination with an increasing subsidence rate, due to extensive groundwater extraction threatens neighbourhoods close to the coastline every day. Riverine flooding is a yearly threat for the city in the wet season as high intensity tropical rain showers can result in peak discharges in a short time period via the numerous rivers crossing Jakarta, originating from mountainous upstream areas. Recent devastating riverine floods, resulting in big economic damage and casualties, occurred in 2002, 2007, 2013, 2014 and 2015. Due to ongoing deforestation and change of land use in the upstream part of the catchments of these rivers the storage capacity is decreasing. As a consequence, the amount of direct runoff increases after a heavy rainfall event and the attenuation of peak discharge is decreasing, thereby increasing the risk of floods in the densely populated downstream parts of the catchment. 

Research goals and questions
This thesis research will focus on the impact of the use of high frequency measurements for the analysis of the propagation of a discharge peak, modeling and prediction of runoff response related to land use change in the upstream part of the Ciliwung catchment in two different seasons. The objectives of this research are:

• To describe the recent rainfall characteristics in the wet and dry season in the upstream part of the Ciliwung catchment
• To analyze the response of the discharge/water levels at different locations of the Ciliwung catchment for different rainfall events
• To model the current discharge in the upstream part of the Ciliwung catchment using recent 10-minutes interval measurements for model calibration and validation
• To simulate the response of the water levels for future land use scenarios and predict at which combination of land use certain past rainfall events would not have caused a risk for downstream areas

>> Read more in the thesis research proposal

Contact
Rizky Moes
Lieke Melsen
Roel Dijksma