University of Twente Student Theses


Modeling land use and water quality management scenarios for the Upper Citarum Basin, Java, Indonesia

Venema, R. (2015) Modeling land use and water quality management scenarios for the Upper Citarum Basin, Java, Indonesia.

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Abstract:The Citarum River is one of the most polluted rivers in the world. The main reasons for the impaired water quality are the high population density and the rapid industrialization in the catchment. Because of the size and variety of the problems in the Upper Citarum Basin, the high poverty levels and an under-resourced government, the relevant institutions lack overview of how best to react to the problems. The goal of this research is to determine relevant scenarios and calculate the effect of these scenarios which give stakeholders a handhold on what measures are most effective. These scenarios are based on alternative land use and water quality management as suggested in interviews with involved stakeholders and have the purpose to lower the concentration of pollutants in the river compared to a reference scenario based on the current situation. The changes in concentration for the different scenarios are modelled by a one-dimensional hydrodynamic and water quality model (SOBEK). In the interviews the stakeholders were asked to pinpoint the problems and associated solutions for the impaired water quality in the Upper Citarum Basin related to agriculture (crop growing and animal husbandry), industry and households. These solutions are combined in scenarios and the effects on water quality are quantified for the substances COD, BOD, nitrate, sulphate, zinc and fecal coliform. These substances characteristic emissions of the land use types mentioned before. The current status of the river is used as reference scenario for comparison with the other scenarios. The current status is determined by using data sets of PJT-II (an organization responsible for measuring the water quality). The measured concentrations are averaged per monitoring station per season (wet and dry). The average concentrations for most substances and at most places are much larger than the maximum permissible concentrations. From the monitoring data it is not clear what the sources of the different substances are. This information is needed to determine the changes in emissions for the different scenarios. Therefore the emissions from crop growing, stockbreeding, industry and households are estimated and compared to measured concentration to verify the reliability of the estimated emissions. The scenarios determined based on the interviews are: Reference scenario: The current status in 2015 is used as basis scenario Worst case scenario 2030: An autonomous growth of population and economy without interventions to prevent emissions is taken as the worst case scenario Improved sanitation: People without any sanitation facilities are provided with a septic tank Livestock in communal barns: The dispersed cattle is concentrated on a few places in large barns and the manure is used for other purposes such as biogas production to control the emissions Changing crops: The paddy fields are changed into fields for dry crops Changing industry: This is evaluated by three sub scenarios. First is evaluated what happens if the industries have zero emission to the river; secondly if the emission of only the textile industry is reduced to zero; and third if the textile industry is converted to other types of industry The scenarios lead to changes in emissions to the river. Together with a fixed discharge for the wet and the dry season, this is used as input for the SOBEK model to determine the concentration at the end of the Upper Citarum Basin (Nanjung). The calculated concentration is compared to the reference scenario to evaluate the change in concentration For all scenarios except the worst case scenario, the water quality overall improves. Based on the results, providing septic tanks to people without any sanitation is the most promising scenario. This leads to the biggest drop for BOD, COD and fecal coliform. The biggest drop in nitrate is when the cattle is hold in communal barns. The scenarios involving change in industry causes that most of the substances decrease, except zinc. Zinc increases because of an increase in factories which emit zinc. The scenario involving the change of crops, has no significant effect on the water quality. The results show that although measures will lead to an improved water quality, the maximum permissible concentration is still not in reach. This means that the measures in the separate scenarios are not enough to get the river clean enough. However it gives an idea of the effect of the different measures. Combining the measures (e.g. septic tank, communal barns, change industries) in the scenarios can lead to a water quality below the maximum permissible concentration (not calculated in this research).
Item Type:Essay (Master)
Faculty:ET: Engineering Technology
Subject:56 civil engineering
Programme:Civil Engineering and Management MSc (60026)
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