PREDICTION OF DUSTFALL GENERATION IN AMBIENT AIR OVER AN INCEPTISOL SOIL AREA

Abstract

Air quality deterioration due to bare land mishandling tends to increase according to the human activity acceleration. The environmental impact thereof is an increase of dustfall and particulate matter concentration in ambient air, increase of human respiratory diseases as well as visibility reduction. The objective of the research is firstly to measure dustfall concentration in ambient air over an area of which the land consisted of mainly Inceptisol soil. The second objective is to measure dustfall concentration in a laboratory scale ambient air. The third objective is to develop a mathematical model to predict dustfall concentration in ambient air as influenced by soil wafer content and wind speed. The field experiment was conducted in an open area in Bogor Municipality where the land consisted mainly of Inceptisol soil. The laboratory experiment was conducted in a, tunnel model where the land surface was covered by Inceptisol soil layer of 3 cm depth. The development of mathematical model was based on those field and laboratory experiments. The materials and instruments used during the field and laboratory experiments were a set of dustfall canister [AS-2011-1], blower [Hercules:  60 cm; 220 V; 170 W], digital anemometer [Lutron AM-4201] , digital moisture tester [OGA TA-5], tunnel [ 7.6 m length; 0.76 m width; 2.4 m height] , analytical balance [OHAUS Aventuror Pro] , Petri dish [=80 mm], filter paper 10µ [Whatmann #41], universal oven [UNB 400] and timer. The result of the experiments showed that average dustfall concentration in ambient air was 8.6 and 11.1 [ton /km2.month] for field and laboratory scale experiment, respectively. The fittest mathematical model to predict dustfall generation [Y] over an area of Inceptisol soil as influenced by wind speed was Y=8.87x2-2.34x+ 5.198 where "x" denoted the wind speed over the land. The prediction model as influenced by moisture content was Y=259.1- 11.7x where "x” represents the soil moisture content. The result of the experiment indicated that dustfall concentration in ambient air was strongly influenced by soil moisture content.