טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentGoldwasser Karnit
SubjectCalibration and Application of AVGWLF to Lake Kinneret
Watershed
DepartmentDepartment of Civil and Environmental Engineering
Supervisors Professor Avi Ostfeld
Professor Eran Friedler
Full Thesis textFull thesis text - English Version


Abstract

Significant water quality problems are caused by point and non-point source pollution. The recognition of the importance of non-point sources of pollution has led to increased efforts over the last two decades to develop simulation models, which are capable of predicting nutrients and sediments transport in watershed. Due to the time and expense associated with surface water monitoring, simulation models has been relied upon more frequently to provide needed information for the development and implementation of non-point source control programs. Watershed simulation models are commonly considered essential tools for evaluating the sources and control of sediment and nutrient loading to surface waters.

This research describes the implementation and optimal calibration of a hydrodynamic and water quality model entitled Arc-View General Watershed Loading Function (AVGWLF). The AVGWLF simulation model was developed by Haith and Shoemaker (1987) and extended by Evans (2002). The AVGWLF model utilizes Geographic Information Systems (GIS) through an Arc-View interface.

The AVGWLF model provides the ability to simulate runoff, sediment, and nutrient (nitrogen and phosphorus) loading from a watershed given variable-size source areas (i.e., agricultural, forested and developed land). It is a continuous simulation model that uses daily time steps for weather data and water balance calculations. Monthly calculations are made for sediment and nutrient loads, based on daily water balance accumulations.

The application and calibration of the model was performed using a Genetic Algorithm (GA) for optimization. Model parameters were optimized in order to get the best correlation between calculated and measured values. The GA is a heuristic search method, which is based on survival of the fittest principle, and was implemented by Goldberg (1989).

To link the AVGWLF and the GA, a new model was constructed, which is based on an Excel sheet (Shadow model) and computes the runoff and the sediment loads in the watershed. Based on the results of the Shadow model the correlation between the simulated and the measured values was estimated.

The principal objective of this research is to evaluate the runoff and the contribution of different point and non-point pollution sources to Lake Kinneret. The developed method was applied to a selected sub-basin in Lake Kinneret watershed, draining to Pkak Bridge outlet. The results demonstrate a relatively good correlation between the predicted and the measured values using the calibrated parameters.