PEMODELAN SISTEM RESAPAN AIR HUJAN DAN LIMBAH AIR WUDHU DI AREA MASJID

Abstract

As already known, one alternative to solve run-off problem is by recharging the water

into soil by mean of adiffusion system. This way can be expected to be able to conserve ground water.  This research was aimed to model a diffusion system conserving  rainfall  runoff  and ablution  waste from  the  mosque  of  Al-Wasi'i  of Lampung University.  This research was conducted from July to September 2011. Experiment data  used in  the  modeling consisted of  a week daily   ablution waste discharged     from     the     mosque,     percolation     rate, surface evaporation.   The ablution waste data was collected both on and off semesters.   Percolation rates  of three  location  sites  aroung  the  mosque  were  measured  by  using  double  ring infiltrometer.   Surface evaporations were measured by contructing a 30x30x45 cm glass container simulating a runoff collector.   The actual evaporation was then used  to  calibrate the constant (K) by comparing with the Penmann reference evapotranspiration (ETo).   The contant was then validated by another group of actual evaporation data.  In addition to the experimental  data,  a  10  year  daily climotological data was also used and collected from the nearest weather station. The  model  consisted  of  input  conponents:  praying  ablution wsate, runoff from the mosque’s roof, direct rainfall, and output components: overflow, evaporation, and percolation.    The  model  simulated  daily  up  and  down  water  surface  of  the diffusion system. The result showed that there were three different percolation rates from three diferent locations, but the stable rate of 1666.12 mm/day was more likely representative and used in this model.  Based on the simulation, diffusion system of 3 m depth and 8 m2 area could conserve the water by 70%.