In this paper a new method is developed for solving the dynamic problems of elastic wave propagation. It is suitable for tayered media and buried point source model. The method is based on a combination of partial separation of variables and finite difference techniques. It has wide zene of computational freqtcency, high accuracy and good stability. For examining the efficiencg of this method,numerical results of a multilayered media model are given.

In this Paper the finite eclment-finite difference method is used to solve numerically two problems of 15-degree and 45-degree one-way wave equations For 15-degree one-way wave equation we have obtained the seismic profile when linear elements and quadratic elements are used, It has been proven that the linear element method is the Claerbout difference method.

In this paper a mathematical model for the extraction-injection of geothermal reservoir in multiple wells is developed, It silplidies a complicated tridimentionsl heat conduction problem to a bi-dimentional one, The latter is a problem of coupling equations, one of wbich is a one-dimentional heat conduction equation in vertical, and another is a one-dimentional convection-conduction eqyation in horizontal, It deduces several different schemes for coupling solutions as the differential equations are discrtized, and discusses the procecdure of computation, We have prepard the software for drwing the groundwater has been exploited with double wells, three wells and five wells.