有作物的潜水蒸发规律试验研究和理论分析(1)——有作物生长条件下的潜水蒸发规律试验研究

Study on shallow groundwater evaporation laws of crops and bare soil

在干旱与半干旱地区水资源日益紧缺,浅埋深地下水对作物的补给量占较大的比重,准确确定作物的地下水利用量对于合理制定灌溉制度、水均衡计算具有重要的意义。通过开展1m、1.5m、2.0m、2.5m四个不同地下水埋深条件下的冬小麦、夏玉米潜水蒸发与裸地潜水蒸发的对比试验,结果表明,裸地潜水蒸发的主要影响因素为大气蒸发能力及地下水埋深;有作物生长条件下的潜水蒸发的主要影响因素为作物生长发育阶段、作物腾发量及地下水埋深;在相同埋深情况下,作物的潜水蒸发规律与作物的腾发规律存在一定的差异,与大气蒸发能力的变化趋势则存在较大差异;不同潜水埋深情况下的冬小麦和夏玉米潜水蒸发规律随作物生长发育阶段变化相似。

Study of the groundwater evaporation is significant for groundwater resources evaluation, design of irrigation scheme, the law of water transform and consumption of plants in the shallow water table regions. The contrastive lysimeter experiments of groundwater evaporations between winter wheat field and maize field, corn field and bare soil are conducted with water table of lm, 1 .Sm, 2m, 2.5m. The results show that the main influencing factors of bare soil are atmosphere potential evaporation and groundwater depth. The main factors which influence the groundwater uptake of crops are the crops growing degree, evapotranspiration and depth of shallow groundwater. When the groundwater depths are equal, the change laws of groundwater evaporation of cropland are a little different from transpiration laws, but are much different between the law of evapotranspiration and atmosphere potential evaporation. The groundwater evaporation laws of wheat are similar to that of maize.