dc.contributor.author	Mohamed, Khairul Anuar
dc.date.accessioned	2023-08-28T04:26:16Z
dc.date.available	2023-08-28T04:26:16Z
dc.date.issued	2019
dc.description	Thesis (PhD. (Civil Engineering))
dc.description.abstract	Optimum fertilisation and nutrient losses in agriculture watershed systems are strongly affected by land use characteristics, oil palm nutrient processes and climate change. Nutrient losses from oil palm fertiliser accumulate in Johor Straits, leading to algal bloom and eutrophication. The main objective of this study is to identify the main contributor of nutrient loading at upper Johor River watershed based on oil palm fertilisation, land use and climate data. This study proposes optimum fertilisation months and rate for oil palm systems in order to reduce the nutrient losses into Johor River for better water quality, tackling current and future conditions. Four land-use scenarios from the year 2000 to 2014 and one projected climate change scenario obtained from the United States Centre for Atmospheric Research were used. These land use and climate model were incorporated into Hydrological Simulation Program-FORTRAN (HSPF) to determine the impact of long-term land-use, climate, and contaminants control via oil palm uptake and nitrate leaching in a tropical watershed. The model was calibrated and validated against observed data from two stations, Johor River at Rantau Panjang and Sayong River at Jambatan Johor Tenggara. Good correlations were obtained between the observed and simulated streamflows, total sediment concentration, water temperature, biochemical oxygen demand (BOD), dissolved oxygen (DO), nitrate nitrogen (NO3-N), ammoniacal nitrogen (NH3-N), and orthophosphate (PO4). The simulated model indicates that the hydrological water balance and yield of the watershed vary under different land-use scenarios and evapotranspiration is the primary contributor of water deficit. Proper soil management practices and improved water infiltration reduce sediment yield and suspended solids concentration by almost 70% and 30%, respectively. Considerable depletion of dissolved oxygen occurs primarily from August to October due to low flow and high water temperatures. For oil palm nutrient components, organic mineralisation is the most sensitive since the mineralisation rate is related to soil temperature via air temperature and microbial activity. As agriculture development expanded from 68% to 90% within 14 years, total nitrogen and total phosphorus loads increased by 2.9% and 2.1% respectively. Analyses using extreme future climate scenario (until year 2100) stipulated that only 5% of nitrate leached if fertilisation rate is reduced by 30% and more frequent fertilisation (from three times to five times per year) is introduced. The phosphorus yield from oil palm plantation is higher from June to August due to surface runoff and sediment attachments. This study suggests optimum fertilisation schemes that optimise nutrient uptake and reduce nutrient leaching in tropical oil palm dominated watershed, therefore improving water quality status in Johor River.
dc.description.sponsorship	Faculty of Engineering - School of Civil Engineering
dc.identifier.citation	NA
dc.identifier.issn	NA
dc.identifier.uri	http://openscience.utm.my/handle/123456789/652
dc.language.iso	en
dc.publisher	Universiti Teknologi Malaysia
dc.relation.ispartofseries	NA; NA
dc.subject	Watersheds—Research
dc.subject	Watersheds—Environmental aspects
dc.subject	Water quality
dc.title	The fate and transport of nutrients using deterministic model in tropical watershed
dc.type	Thesis
dc.type	Dataset

The fate and transport of nutrients using deterministic model in tropical watershed

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