Assessment of groundwater potential zone and its sustainable yield in Dili Aquifer, Timor Leste | |
| Author | Pinto, Domingos |
| Call Number | AIT Diss. no.WM-16-01 |
| Subject(s) | Groundwater--Timor Leste Aquifers |
| Note | A dissertation submitted in partial fulfillment of the requirements of the degree of Doctor of Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Series Statement | Dissertation ; no. WM-16-01 |
| Abstract | Groundwater is a vital natural resource for domestic use in majority of the coastal areas in Timor Leste. Dili city, the capital of the country, depends heavily on groundwater and receives more than 60% of the total annual water supply from groundwater. With a high rate of population growth and urbanization and subsequent increase in water demands over the last decade, Dili is facing water scarcity particularly during dry season. Since the country started to develop in 1999, water demand is increasing rapidly for various uses (e.g., agriculture, industrial, tourism, and domestic). In dry season from June through October, surface water mostly dries up and water supply from National Director Water Supply and Sanitation (DNSAS), the authority responsible for water distribution, rely completely on groundwater. Inadequate understanding of groundwater availability in aquifers, inadequate planning and investment in infrastructures and no attention towards groundwater management are exacerbating the problem further. Ever increasing water demand and lack of management, combined with the inevitable pressures from climate change and sea level rise reflect an urgent need to advance the understanding of groundwater environment from the perspectives of groundwater availability, potential zones for groundwater development and recharge, and likely impacts of various pressures on groundwater availability and its development. This study aims to delineate groundwater potential zones and quantify its sustainable yield from Dili aquifer located within the Comoro watershed of Timor Letse. It uses a set of methods/approaches for the purpose, such as i) Remote Sensing (RS) and Geographic Information System (GIS), and Analytical Hierarchy Process (AHP) to delineate groundwater potential zones; ii) WETSPASS model to estimate the recharge; iii) MODFLOW model to estimate aquifer safe yield and sustainable yield; and iv) simple mathematical approach for forecasting groundwater abstraction in future. Results revealed that the Comoro watershed can be classified into five groundwater potential zones, namely: i) very high potential zone, covering 5.4% of total watershed located in the downstream of the watershed ; ii) high potential zone, covering 4.8% of the watershed located in the Eastern part of the alluvial area; iii) moderate zone, covering 2.0% of the watershed located along the foot hill; iv) poor zone, covering 45% of the watershed area; and v) very poor zone, covering 42.8% of the total watershed area. According to the simulation from WETSPASS model the average annual recharge and surface runoff are estimated as 118.6 mm/year and 395.8 mm/year, respectively, during 2008-2013. Analyzing a set of future development scenarios with the calibrated groundwater flow model (MODFLOW) determined safe yield of the Dili aquifer as 0.28 m3/sec and sustainable yield in the range of 0.23 to 0.28 m3/s |
| Year | 2016 |
| Corresponding Series Added Entry | Asian Institute of Technology. Dissertation ; no. WM-16-01 |
| 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) | Babel, Mukand Singh ;Sarawut Ninsawat; |
| Scholarship Donor(s) | Ministry of Education, Republic Democratic of Timor Leste; |
| Degree | Thesis (Ph. D.) - Asian Institute of Technology, 2016 |