地下水非稳定流中erfc(λ)、ierfc(λ)逼近公式的推求及其应用

Reckoning of Erfc(λ) and Ierfc(λ) Approximation Formula in Non-Stable Groundwater Flows and Their Application in Tarim River Watershed

对erfc(λ)和ierfc(λ)公式传统的求算手段是通过查表的方法。是在已有的erfc(λ)和ierfc(λ)不可积公式的基础上 ,作者初步推导了不带不可积积分的erfc(λ)和ierfc(λ)的逼近公式 ,亦即不需要查表也能够算出其精确结果 ,并引用它建立了地下水非稳定流混合模型。此外 ,作者通过使用可视化开发语言VisualBasic和GIS工具软件MapObjects开发了塔里木河水资源决策支持系统。最后用该决策支持系统验证了以上逼近公式的精确性和有效性 。

Tarim River is the longest continental river in China, and is essential to the oases in the watershed and of the 'Green Corridor' in its lower reaches. The research of groundwater transportation is more and more important to the ecological restoration. Based on the groundwater movement in different stages of filtration of water from the river, an one dimensional unsteady groundwater flow model in the intermittent water infusing process is established and a new method of converting boundary conditions of the first kind and second kind each other is introduced to solve the model. And finally applying the method to the analyses of groundwater movement in the riverside in the water infusing process at the lower parts of Tarim River. The results show the feasibility and reliability of this method. Basing on the conventional erfc(λ) and ierfc(λ) formula, a new method is introduced in this paper to determine groundwater transport parameters, which do not require integral and table consultation in the cause of calculation. By referring to them, a mixed model for non stable groundwater flow was established. The author additionally developed the Decision Support System of water resources in Tarim River watershed by making use of the languages of Visual Basic and GIS. The accuracy and validity of the formula were tested through DSS at the end of this paper, suggesting certain practical value.