SOFTWARE CAPABILITIES OF NUMMOL MODEL

Abstract

An applied numerical model NUMMOL ( NUMerical Modelling of Leachate ) has been developed to simulate the water movement into, through and out of landfills . The model accepts precipitation , potential evapotranspiration and landfill design site data , as inputs from the user . It uses solution techniques that account for the runoff infiltration, surface storage , percolation , lateral subsurface drainage, leachate recirculation , < unsaturated flow , saturated flow, flow to drainage systems and seepage losses through a clay liner . These processes in a landfill are linked together in a sequential order starting at the surface , proceeding downwards through the landfill profile to the bottom . The solution procedure is applied repetitively for each day as it simulates the water routing throughout the simulation period. The primary purpose of the model is to estimate the leachate quantity and to assist in the comparison of landfill design alternatives as judged by their water balances . The NUMMOL model consists of simulation and interface modules . The simulation module includes four sub - modules: SURFACE , UNSATURATED, RESERVOIR and COLLECTOR . Each of these modules individually simulates the hydrologic response associated with it by using input data and / or using output data of other modules . The user friendly interface module controls all the different scenarios via pop - up windows. The program source code is written in FORTRAN and is compiled using Salford Fortran Compiler ( DBOS ) 1 .