【摘要】 四十多年来 ,豫北地区与作物蒸散耗水密切相关的某些环境要素有了明显变化。例如 :水面蒸发量下降、近地面大气相对湿度上升、日照减少、风速下降等。它与黄河断流、地下水位急剧下降等本地区重大环境问题相似 ,是反映该地区水分生态环境演变的另一个侧面。这种变化与本地区灌溉面积迅速扩大、大面积改造低产地等人类生产活动有关。这些生态环境要素改变将对当地作物水分生产效率、生物种群消长规律、农业产量 ,以至于农业发展的可持续性的影响应予重视和研究更多还原

【Abstract】 Summary In the past forty years, some environmental factors closely related with evapotranspiration in North Henan Province have greatly changed. For example, evaporation from water surface decreased, relative humidity near to the ground surface increased, sunshine hours reduced and wind speed decreased. Similar to the problems of seasonal running dry of Yellow River and ever lowering ground water table in the region, the change of these environmental factors might partly reflect the change of environmental quality ecologically. Our results showed that the change was mainly caused by humane activities, such as marked increase of irrigation areas and improvement of low yield farmland in large area. Great attention should be paid to the problems resulted from the change of these environmental factors.更多还原