Effect of vegetation properties on evapotranspiration and volumetric water content of soil under extremely dry conditions in Singapore

• Main Author: Tian, Zuyu
• Other Authors: Harianto Rahardjo
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2022
• Subjects: Engineering::Civil engineering
• Online Access: https://hdl.handle.net/10356/157833
• Institution: Nanyang Technological University

Climate change has led to more extreme weather events such as prolonged period of drought. Deficient precipitation, combined with rising temperatures, poses severe threat to plants, especially those plants used to growing in environments with abundant moisture. Different vegetation properties can cause plants to evaporate at different rates, resulting in different changes in soil water content. The objective of this project is to study the effects of different vegetation properties and soil types on evapotranspiration (ET) and volumetric water content (VWC) of the soil under extremely dry conditions in Singapore. Index properties tests, soil-water characteristic curve (SWCC) tests and triaxial permeability test were conducted in the laboratory to obtain the soil properties. The laboratory results were input into a hydrological model, GEOtop, to simulate the changes of ET and VWC over a period of time. To analyse the results from GEOtop, line graphs were plotted in order to compare between different parameters. The comparisons showed that factors such as Leaf Area Index (LAI), vegetation height and soil types are closely linked to ET and VWC, whereas the root depth is a relatively insignificant factor for changes in ET and VWC. Therefore, plants with properties that are more drought-tolerant are recommended for planting in Singapore.