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The identification of non-point source pollution risks in watersheds using GIS and remote sensing techniques | |
Author | Dayawansa, N. D. K. |
Call Number | AIT Thesis no.SR-97-5 |
Subject(s) | Nonpoint source pollution--Remote sensing |
Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science, School of Environment, Resources and Development |
Publisher | Asian Institute of Technology |
Series Statement | Thesis ; no. SR-97-5 |
Abstract | The objective of this study is to identify critical non-point source pollution risk locations using remote sensing techniques and through the application of Agricultural Non-Point Source Pollution Model (AGNPS). The catchment selected for the study is of Nilambe river which is a main tributary of Mahaweli river in Sri Lanka. A land use/land cover map was developed using digital analysis of Indian Remote Sensing Linear Imaging and Self Scanning System (IRS LISS II) data which has a ground resolution of 37 .5 meters to identify five model parameters related to land cover. Optimum Index Factor (OIF) approach was employed to obtain best three-band combination for digital analysis of satellite data. The digital thematic maps prepared on soil texture, slope, aspect and stream network of the study area were incorporated into the model using grid map of 40 acre cells with the aid of a GIS. The AGNPS provided detailed output of runoff, upland erosion, sediment yield, nitrogen, phosphorus and Chemical Oxygen Demand (COD) concentrations in sediment and runoff at any point of the catchment as well as at the outlet. Accordingly, the critical locations in the study area in terms of sediment and nutrient production were identified. The model's behavior on storms with different magnitudes, with different slopes and the relationship of upland erosion potential and sediment yield were studied. Sloping Agricultural Land Technology (SALT) was identified as a better way of managing soil and other land resources. From the study, it can be recommended that multi-date imagery can be used to study the effects of dynamics of land use on water quality as well as to simulate number of Best Management Practices (BMPs) for identifying the most cost effective and efficient BMP based on AGNPS results. |
Year | 1997 |
Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. SR-97-5 |
Type | Thesis |
School | School of Environment, Resources, and Development (SERD) |
Department | Other Field of Studies (No Department) |
Academic Program/FoS | Space Technology Application and Research (SR) |
Chairperson(s) | Delsol, J.P.; |
Examination Committee(s) | Andrianasolo, Haja;Murty, V.V.N.; |
Scholarship Donor(s) | Government of France; |
Degree | Thesis (M. Sc.) - Asian Institute of Technology, 1997 |