黑龙江省玉米田土壤旱涝预报

玉米旱涝预报模型考虑了土壤-大气-植物之间的水分交换关系,基于土壤水分平衡原理,以旬为预报时段,以黑龙江省34个测墒站点每旬玉米田土壤相对湿度代表所在县的平均玉米田土壤相对湿度,利用上一旬末土壤相对湿度和下一旬降水预测值来预报下一旬末的土壤相对湿度。根据土壤旱涝指标来确定土壤旱涝等级。用2007年3月上旬至11月上旬实测玉米田土壤湿度对其检验。结果表明:黑龙江省春季和秋季预报比较准确,绝对误差在5%以下;夏季预报误差比春秋季节略高,绝对误差在6%以下,有些县市绝对误差甚至达到0。根据确定的土壤旱涝等级检验土壤旱涝预报准确率表明,准确率较高,效果较好。

Soil Drought/Flood Forecasting for Corn Fields in Heilongjiang Province

Based on the principles of soil-moisture balance,the core of the model takes full account of the exchange relations of soil,atmosphere,and plant,with the forecast period being ten days.The cornfield soil relative humidity for every 10 days from 34 moisture measurement stations in Heilongjiang Province were used to represent that of the corresponding county.The soil relative humidity at the end of the last 10 days and the forecasted precipitation of the next ten days were used to forecast the soil relative humidity at the end of the next 10 days.According to soil drought indicators,the level of soil droughts/floods was determined,and a test was made with the observed soil humidity in the cornfields from March to November in 2007.The results show that the forecasts were more accurate in spring and autumn,with absolute errors being less than 5 percent;errors in summer were slightly higher than those in spring and autumn,with absolute errors being under 6 percents,even zero in some places.To use the determined levels of soil droughts/floods to test the forecasting accuracy of soil droughts/floods,the results proved satisfactory.