气候变化对陕西省冬小麦种植区的影响

选取全省资料年代较长的54个地面测站1961—2004年的温度、降水等基本气象要素资料，探讨丁陕西省气候变化特点，计算了冬小麦越冬期积温变化。研究了陕西省热量资源和水资源对冬小麦种植区的影响。结果表明，陕西省年、季平均气温在20世纪80年代中期发生了突变，80年代中期以前呈波动性的下降趋势，80年代中期后开始增温，90年代后增温迅速。降水量呈阶段性减少趋势。陕西省20世纪80年代中期后气温明显变暖，热量资源增加，冬小麦种植区北界向北扩展．但90年代开始干旱加剧，水资源严重不足。陕西省气候变化对冬小麦的负面影响大于正面影响。

Impact of Climate Change on Planting Area of Winter Wheat in Shaanxi Province

Based on the data of temperature and precipitation at 54 meteorological stations in Shaanxi Province from 1961 to 2004, and the calculation for accumulated temperature during winter, influences of thermal and water resources on winter wheat were analyzed. Results indicated that seasonal and annual mean tempera- tures changed obviously in the mid 1980s, decreasing before the mid 1980s, increasing after the mid 1980s, and increasing rapidly after 1990s. Precipitation showed a reducing tendency. Thermal resource increased and the planting area of winter wheat expanded northward after 1980s. Serious drought and water shortage appeared in 1990s. The negative impact of climate change on winter wheat was greater than the positive.