基于GIS的西峰区沟道雨洪资源可利用量研究

利用庆阳市西峰区的DEM、Quickbird影像资料对西峰区沟道特征进行沟道特征分析,并分析了沟道不同降水频率下雨洪特征。以司家沟为典型沟道,采取典型年法和单次暴雨分析法将不同降水频率典型年中大于20mm的单次降水与基准暴雨量相对应,计算出典型年的雨洪总量(可收集利用量)和单次降水的洪峰流量,并进一步分析了不同降水保证率的各区域雨洪资源量。结果表明,西峰区各沟道雨洪资源量的总体趋势为高保证率雨洪资源量少、低保证率雨洪资源量大,但是由于洪水频率跟降雨频率不同步,在干旱年降水频率低时,洪水频率有可能较大,因此干旱年份对雨洪资源的利用尤为重要。

Research on Available Channel Rainwater Resources in Xifeng District Based on GIS Technology

The channel characteristics were obtained by analyzing the DEM data and quickbird images of Xifeng District, and the characteristics of the channel floods with different frequencies were also analyzed. Typical year method and single rainstorm analysis method were used to normalize the storm frequency and precipitation frequency, and make a relation between the single rainstorm precipitation over 20mm in different precipitation frequencies typical years and the baseline storm amount, so as to calculate the total amount of channel rainwater and single rainfall peak flow. The results show that high precipitation frequency has less rainwater resources quantity, and low precipitation frequency has more rainwater resources quantity. However, the flood frequency is not synchronized with the rainfall frequency, and when the low precipitation frequency in drought years, there may be greater flood frequency, thus, the use of rainwater resources is particularly important in drought years.