Impact of climate change on the availability of stream flows in Darawat dam watershed in Sindh, Pakistan | |
| Author | Langah, Iftikhar Ahmed |
| Call Number | AIT Thesis no.WM-19-42 |
| Subject(s) | Climatic changes--Pakistan--Darawat dam Stream ecology --Pakistan--Darawat dam Watershed ecologyl--Pakistan--Darawat dam |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Water Engineering and Management |
| Publisher | Asian Institute of Technology |
| Abstract | Change in climate refers to variations in earth's environmental conditions. This is because of numerous factors within and outside. In recent decades, climate change has become a global concern. Furthermore, these changes in climate have different ecosystem and ecological effects. Impact of climate change on future surface water availability is a critical task for understanding the dynamics of stress level at basin scales for water managers. This study investigates the future water availability and stress level from the perspective of changing climate in Darawat dam watershed, Sindh, Pakistan. The historical meteorological data and observed discharge is collected within the watershed. The SWAT model is developed to observe the impact of land use and soil on present water availability through different water availability indicators. Three Regional Climate Models (RCM) from Conformal Cubic Atmospheric Model (CCAM) project have been selected. The climate data forecasted by ACCESS, CNRM and MPI for two future periods; Near Future (20202049), and far future (2050-2079) and RCP 4.5 and RCP 8.5 scenarios were corrected using linear downscaling technique. All RCMs predict that the temperature is continuously increasing in the study area, however, future precipitation is highly complex and uncertain and there was a significant difference among various RCMs and both RCPs scenarios. After successful development of SWAT hydrological model for the future climate projections, the streamflow was simulated in two future time scales (2020-2049) and (2050-2079) using two concentration pathways climate change scenarios RCP 4.5 and RCP 8.5 respectively by the end of the century and compared with the base-line flow (2008-20014). The Darawat watershed is an arid watershed with an average annual precipitation of 164 mm and the base-line mean annual surface flow in the study area is 4.25 3/sec and the projected change in annual mean flows varies under RCP 4.5 and RCP 8.5. The Falkenmark indicator has been sued to assess the present and future per capita water availability (3/capita/year) and the water scarcity level of Darawat watershed. The future per capita water availability will vary in the watershed but the ensemble scenario predicts the watershed will get maximum water availability under RCP 4.5 and RCP 8.5 will be 987 3/capita/year and 1191 3/capita/year. As a whole, the Darawat dam watershed will face more precipitation in the future and it will increase the stream flows in the watershed as compare to the baseline stream flows in Darawat watershed meanwhile the population will also increase in the future and the basin will under the water stress and water scarcity. These outcomes suggest that it is important to consider the influence of climate change on water resources to frame appropriate guidelines for planning and management in the watershed. |
| Year | 2019 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Water Engineering and Management (WM) |
| Chairperson(s) | Shanmugam, Mohana Sundaram; |
| Examination Committee(s) | Shrestha, Sangam;Asadi, Mohammad Esmaeil;Roa, Arturo Gementiza; |
| Scholarship Donor(s) | Irrigation Department, Government of Sindh, Pakistan; |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 2019 |