【摘要】 计算分析了甘肃黄土高原的降水变化、农田蒸散和农作物水分亏缺的特征及其对农业生产的影响，表明区域主要降水特征均不利于农业生产；农田蒸散强烈，土壤水分亏缺严重；农作物水分供需差额大，其水分生态位适宜度低，降水产量指数小。更多还原

【Abstract】 Located in the western part of the Loess plateau, Gansu Loess plateau has an area of 1. 13 × 105km2, its climatic and vegetation areas include arid desert steppe area, semi-arid steppe area and semi-humid forest-stepe area. The proprtion of dry farming occupies over 90 % of the local agriculture, therefore, moisture condition is the most important factor for agricultural development. This paper calculates and analyzes the features of annual and seasonal variation of precipitation, field evapotranspiration, and moisture deficit of crops and their impacts on the agricultural production in Gansu Loess plateau. The results show that the less quantity, big variability and heterogeneous seasonal distribution of precipitation restrict crop growth seriously and bring about a low and unstable yield. The violent field evapotranspiration and less precipitation make the field moisture deficits during the growth periods of summer crops and autumn crops be up to 225 - 500mm and 70 ~ 540mm respectively, which are 0. 8 ~3. 7 times and 0. 2 ~ 3. 4 times higher than the precipitation during the same periods. The water niche suitabilities of crops are very low, only 0. 16 ~ 0. 65 and 0. 19.~ 0. 68 during the growing season of crops as daily mean temperatures ≥０°Ｃ and≥０°Ｃ , and that of winter wheat and spring wheat are lower than 0. 7 and 0. 5 respectively during the growing season. The precipitation indexes of crop yield are small, they are 40 % ~82 %, 18%~44%, 38 % ~94%, 0. 3 % ~66% and 6% ~73 % for winter wheat, spring wheat, millet, corn and potao respectively.更多还原