Tropical rainfall variability — The agroclimatic impact

摘要: Abstract In tropical lowlands, agriculture is largely controlled by rainfall conditions. these areas, most elements of climate, and particularly temperatures, are very uniform both over place time, but much more variable. Lack sufficient the main limiting factor in areas. Long-term predictions, expected from agroclimatologist, should be mainly concerned with rainfall, irregularity this element makes a difficult task. Therefore an obvious need exists for methods to quantify variability relation agriculture. These simple, so that they can used wherever necessary without use computer. Peninsular Malaysia offers favourable conditions study application methods. Annual totals present picture endless variations, no clear trend or cycles. The seasonal distribution regular, as large-scale weather patterns frequently monsoonal wind systems. Agricultural determined described conviniently probability figures. When related crop water needs, done Rainfall Index, risk droughts indicated accurately enough agroclimatic purposes. proper selection crops correct timing planting also decided method. day affects growth yields many crops, those shallow root Even during seasons which generally considered production, temporary shortages surpluses occur often. To obtain estimates effects daily water-balance model introduced. Risks number days severe moisture stress amount surplus rain water. A comparison sophisticated computer programme shows validity accuracy model.