【摘要】 应用EPIC模型对黄土高原南部旱塬地苜蓿水分生产潜力进行了长期的模拟研究。结果表明,用EPIC模型中的气象模型模拟的30 a降水特征与本地区实际规律较为接近。30 a降水模拟值和13 a实际值的多年平均值相对误差为1.53%、标准差误差为1.86%,变异系数误差为1.99%;30 a苜蓿水分生产潜力模拟值在2.018~17.521 t/hm2,平均值为7.7 t/hm2。模拟试验前5 a,年均干旱胁迫日数较少,仅为10.2 d,苜蓿生水产潜力值较高且波动平稳。模拟试验后25 a,年干旱胁迫日数增加为123.1 d,苜蓿水分生产潜力值较低且随年降雨量的丰缺而变化。苜蓿水分生产潜力长期模拟试验结果说明了该区降水无法满足苜蓿长期稳定维持较高生产力的水分要求。更多还原

【Abstract】 The water potential productivity of alfalfa on rain fed highland in south of loess plateau was simulated for long term(30 years) using EPIC model.Simulated results show that: the character of precipitation variation law simulated by using weather model in EPIC for 30-year and measured for 13-years is alike.The average precipitation deviation between 30-year simulated and 13-year really measured is 1.53%,the S-deviation is 1.86%,CV-deviation is 1.99%;The simulated water potential productivity fluctuates between 2.018～(17.521) t/hm~2,the average value is 7.7 t/hm~2.The average water stress day is only 10.2 days yearly,the water potential productivity is high and steady-going during first 5-years.During the last 25 years the water stress day increases to 123.1days,and water potential productivity reduced and changed with precipitation annually.The study of long-term simulation of water potential productivity for alfalfa shows that the precipitation of study area can’t satisfy water request for high productivity.更多还原