说明：  Toro的一维浅水程序采用waf+hll， 模拟圆形溃坝
(Program name: HW-WAFI File name: hw_wafi.f Purpose: To solve the time-dependent non-linear one dimensional shallow water equations with geometric source terms due to cylindrical symmetry by the Weighted Average Flux (WAF) Method using the HLL approximate Riemann solver, with choice of six limiter functions. The source terms are treated by the standard splitting scheme. )