Mapping groundwater resilience to climate change and human development : a case study of Bangkok and its vicinity, Thailand and Kathmandu Valley, Nepal | |
| Author | Neupane, Sanjiv |
| Call Number | AIT Diss no.WM-23-02 |
| Subject(s) | Climatic changes--Thailand--Bangkok Climatic changes--Nepal--Kathmandu Groundwater--Thailand--Bangkok Groundwater--Nepal--Kathmandu Climatic changes--Developing countries |
| Note | A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Engineering in Water Engineering and Management, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Series Statement | Dissertation ; no. WM-23-02 |
| Abstract | Groundwater is ideally depicted as world’s real hidden treasure, and it constitute 94% of the freshwater resources. Groundwater is the most desirable source of water supply, and it is less vulnerable to quality degradation and drought than surface water. Groundwater plays an important role in the sustainable development of major cities in Asia (Bangkok and its vicinity, and Kathmandu Valley). Importance of groundwater for the city’s water supply will probably intensify under climate change and human development (population growth, urbanization) in the future. Therefore, it is imperative to assess the resiliency of groundwater under climate change and human development for strategic planning and management of water resources in urban areas. This research first aims to develop robust framework to access the resiliency of groundwater system. The framework was developed using several parameters of resiliency. Then the framework was applied in two Asian cities (Bangkok and its vicinity and Kathmandu valley) to assess the resiliency of groundwater to climate change and human development. To access the resiliency of groundwater in Asian cities, twenty-one regional climate models (RCMs) from the Coordinated Regional Climate Downscaling Experiment (CORDEX) were evaluated based on their ability in simulating climate extremes in the fast-growing Asian cities which are highly vulnerable to climate change. The top five better performing RCMs along with two RCPs scenarios (RCP 4.5 and RCP 8.5) were used to project future climate in respective Asian cities for three future period: Near Future (2010-2039), Mid Future (2040-2069) and Far Future (2070-2099). To remove the biasness from future climate data quantile mapping technique was used. All RCMs project that both the Asian cities are expected to be warmer in future and will receive more rainfall in future. An empirical land use projection model Dyna-CLUE was used to project the future land use change of the study area. Three future land-use scenarios of Low Urbanization Scenario (LU), Medium Urbanization Scenario (MU) and High Urbanization Scenario (HU) were developed in Dyna-CLUE focusing on the increase of built-up area to generate land-use maps of the Asian cities until the year 2099. The climate data through baseline and future scenarios by climate models and land use change scenario created by Dyna-CLUE was feed into the hydrological model SWAT and WetSpass to simulate future groundwater recharge. In both the Asian cities groundwater recharge is projected to decrease in high urbanization scenario and both RCPs scenarios whereas it is projected to increase for low and medium urbanization scenario and both RCPs scenarios while moving to future. The future groundwater abstraction computed using population and water demand forecasting (domestic, industrial, and agricultural) along with future groundwater recharge was then input into calibrated groundwater model GMS-MODFLOW to obtain future groundwater level. The result reveals that in case of Bangkok and its vicinity, the average groundwater level is projected to decrease under high urbanization scenarios and all RCPs scenarios. Whereas, for medium and low urbanization scenario and both RCPs scenarios it is projected to increase in future. For Kathmandu valley, on average, the groundwater level will decrease in future for all three pumping scenarios: high, medium, and low urbanization and both RCPs scenarios. Finally, the groundwater resiliency indicator was developed based on the result obtained which in-turn was used to access the groundwater resiliency of the study area. The result reveals that, outskirts part of both the Asian cities are resilient to climate change and human development whereas, the center area or the urban areas are not resilient. |
| Year | 2023 |
| Corresponding Series Added Entry | Asian Institute of Technology. Dissertation ; no. WM-23-02 |
| Type | Dissertation |
| School | School of Engineering and Technology |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Water Engineering and Management (WM) |
| Chairperson(s) | Shrestha, Sangam; |
| Examination Committee(s) | Shanmugam, Sundaram Mohana;Sarawut Ninsawat; |
| Scholarship Donor(s) | GROUNDWATER-ASIA-HYDRO-ASIA Projects;Asian Institute of Technology Fellowship; |
| Degree | Thesis (Ph. D.) - Asian Institute of Technology, 2023 |