内蒙古降水量分布及其对马铃薯灌溉需水量的影响

Distribution of Precipitation in Inner Mongolia and its Impact on Potato Irrigation Amount

马铃薯是内蒙古的优势作物，其生长和产量主要受水分条件的制约。研究内蒙古降水量分布和马铃薯需水规律，可为马铃薯生产合理布局、合理用水以实现稳产提供依据。利用内蒙古1961—2010年46个气象站点的逐日气象资料计算分析了内蒙古马铃薯生育期有效降水量及分布、马铃薯生育期蒸散量和不同年型下马铃薯的灌溉需水量。结果表明：内蒙古马铃薯生育期有效降水量为25—240mm，时空分布不均匀，地区间差异大；马铃薯生育期蒸散量为300～700mm，400mm等值线从呼伦贝尔北部开始，穿过锡林郭勒盟的北部，向东到兴安盟。内蒙古地区马铃薯灌溉需水量由东到西有逐渐增大趋势，需水量等值线呈经向分布。1500m^3／hm^2等值线在内蒙古东北部，等值线以东的呼伦贝尔市、兴安盟的北部地区有效降水基本能满足马铃薯需求，正常年无需灌溉，适合马铃薯大面积种植；内蒙古西部和北部降水资源不足以支撑马铃薯生产，不适合马铃薯种植。歉水年降水量少、蒸散量大，马铃薯灌溉量比平水年平均增加40．4％。

Potato is the dominant crop in Inner Mongolia, its growth and yield is mainly restricted to water conditions. Studying the distribution of precipitation in Inner Mongolia and water requirement rules during potato growth period can provide the basis for the rational distribution of potato producing in Inner Mongolia and rational utilization of water to achieve stable yield. Based on the daily meteorological data of 46 meteorological stations from 1961 to 2010, authors calculated the effective precipitation and its distribution in Inner Monglia, evapotranspiration （ET） during potato growth period and irrigation amount in different rainfall years. The results showed that the effective precipitation was 25 - 240mm during potato growth period and its spatial distribution was non-uniform. ET was 300 -700ram and 400mm ET contour started from northern Hulun Buir, across northern Xilin Col league, east to Hinggan league. As for the irrigation amount, there was an increasing trend from east to west and the irrigation amount contours were distributed by longitude. Hulun Buir and northern Hinggan league, east to the 1500m^3/ha irrigation amount contour, were suitable for planting potato, where effective precipitation could basically meet potato water requirement in normal years. On the other hand, it was not suitable for planting potato in western and northern Inner Mongolia, where effective precipitation was insufficient to support potato producing. Compared to normal years, dry years had less precipitation and more ET, and the potato irrigation amount increased by an average of 40. 4%.