说明：  随机水文学中常会用到符合Gamma分布的随机数，用于模拟一些随机的水文过程，这里水文工具集介绍一种使用C++语言的TR1新特征中的随机数发生器来产生Gamma分布随机数
(Frequently used stochastic hydrology meet Gamma distributed random numbers, used to simulate some random hydrological processes, hydrological tools here to introduce a C++ language using the new features of TR1 in the Gamma random number generator to generate random numbers)