Application of models with limited data: A case study from Oman

Non-availability of reliable data is a serious constraint in model application. This problem is even more serious when models are first applied in a country without adequate database especially for field conditions. Efforts were made to use LEACHN under field conditions to optimize water and fertilizer input in Omani soils to reduce the potential for groundwater pollution. Because of the significant number of processes being modeled, LEACHN requires large amount of input data. Very few relevant data were available in Oman for LEACHN application. To overcome this constraint gathering of data through laboratory experiments, from literature review, processing of data through other models and discussions with experts was undertaken. The model was then applied to simulate field conditions. Eight (8) different simulations were performed. They enabled the assessment of different management options in reducing nitrate loss through drainage.