Climate change impacts on irrigation water requirements for rice-wheat cultivation in Bagmati River Basin, Nepal | |
| Author | Gyawali, Birat |
| Call Number | AIT Thesis no.WM-12-05 |
| Subject(s) | Climatic changes--Nepal Irrigation water--Nepal |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Water Engineering and Management, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Abstract | Climate change is a global phenomenon, its impacts exist in almost every sectors and water sector is one of them. The impacts of climate change on food production are equally important because the overall economy of a country is dependent on the scale of productivity and ricewheat production has been the major part in the South-East Asia. As we know the natural rain is not sufficient to meet the crop water demand because rainfall is converted to runoff, infiltration etc and hence effective rainfall is less. The deficit in water requirement is then fulfilled by the irrigation water. The irrigation water that is applied to the field will depend on the future climate on the long rnn which has been important to the policy makers in the water management. This study is focused on the impacts that the future climate will bring to the irrigation water requirement for the rice-wheat cultivation in the Bagmati River Basin, Nepal. The research methodology includes the forecast of future climate by means of the statistical downscaling model (SDSM) using the GCM outputs of the study area, the estimates of irrigation water requirement for different time windows under climate change conditions by using Cropwat Model and adoption of suitable water management practices in the context of irrigation. The analysis has been done for three zones: Mid Hills, High Hills and Terai separately and Kathmandu Airport, Daman and Manusmara have been used as the stations to represent Mid Hills, High Hills and Terai respectively. Results from the SDSM show that the degree of variation in temperature and precipitation is higher for the Hills than the Terai. Temperature changes are negligible and can be considered minor in the Terai however, precipitation forecasts are important here as there has been an increase in the precipitation trends in the early stage and the trends followed in all three time windows are almost identical. For a large area like Terai where crop production is feasible crop water and irrigation water requirement will definitely be crncial. Comparision in climatic scenarios show that the model results from the A2 scenario are higher than the B2 scenario for each zone in all three time windows. The next part which includes the results of the climatic forecasts from the SDSM when run through the Cropwat Model indicates that the irrigation water requirement for rice in the Mid Hills will be sufficient for paddy and deficit for wheat wheareas in the High Hills, irrigation water requirement is sufficient for the wheat and deficit for paddy. However there will be deficit of irrigation water in the Terai for both crops |
| Year | 2012 |
| 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) | Shresth, Sangam |
| Examination Committee(s) | Babel, Mukand S. ;Clemente, Robe1to S. ;Perret, Sylvain Roger |
| Scholarship Donor(s) | ADB-JSP |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 2012 |