黄土地区不同埋深条件下潜水蒸发的研究

为分析黄土地区潜水蒸发的规律,建立适宜于本地区的数学模型。采用地中渗透仪对自然条件下的潜水蒸发进行了模拟试验,根据宝鸡峡灌区扶风县段家乡试验场地连续5年的观测资料,分析了黄土地区不同地下水埋深的蒸发蒸腾规律。结果表明,潜水蒸发量与埋深呈负相关关系,潜水蒸发量与埋深关系曲线以埋深1.0m为界,埋深小于1.0 m时曲线较陡,即埋深小于1.0 m时的潜水蒸发量大,且随埋深的变化较大;地下水埋深大于1.0 m时,潜水蒸发量小,且随埋深变化较小;裸地和玉米、小麦生育期潜水蒸发的极限埋深分别为4.5,5.3和6.3 m。最后还以5年实测资料为依据建立了潜水蒸发的指数型数学模型。

Research on the evaporation of underground water in different burying depth conditions on the Loess area

To establish a proper mathematical model in loess region,we studied the law of underground water evaporation.We utilized Osmoscope to simulate the underground water evaporation in our region under natural conditions.According to the 5 years data of Duanjia hometown in Baoji Gorge,we analyzed the law of evaportranspiration under different underground water levels.And discovered the negative correlationship between the underground water level and evaporation.The relationship curve between the amount of evaporation and underground water level was divided by the 1.0 m level;the curve was abrupt less deep than 1.0 m,namely the evaporation changes along with the underground water level,when burying depth was less than 1.0 m,the evaporation changed great,but changed little when the underground water level deep was more than 1.0 m.We also established the mathematical model for calculating the underground water evaporation.When the underground water level of infrequent vegetation land was 4.5 m,there was no evaporation when the underground water deep than 4.5 m.During the growing stages the utmost evaporation depth for maize was 5.3 m for wheat was 6.3 m.