基于土地利用类型的大气降水入渗补给量计算

Calculation of Precipitation Infiltration Recharge Based on Land-Use Type

影响大气降水入渗补给量的因素较为复杂,主要有土地利用类型、降水量、包气带厚度及岩性等。随着遥感影像解译技术的发展,人们能更精确地识别空间土地利用类型,从而更精确地计算大气降水入渗补给量,并了解其空间分布。综合考虑这些影响因素,本文提出了一种基于土地利用类型,并结合地理信息系统(GIS)和VBA(visual basic for applications)编程技术的大气降水入渗补给量计算方法(PIRCL)。以广州市广花盆地为例,利用PIRCL法计算得到该地多年平均大气降水入渗补给量为14 369万m3,该结果与水量平衡法计算得到的大气降水入渗补给量结果相近,相对误差约为2.4%;并且,计算得到的大气降水入渗补给量空间分布基本合理。与水量平衡法相比,PIRCL法计算大气降水入渗补给量只需区域遥感数据、区域降水量数据、对应时段地下水位动态变化及区域水文地质参数,不需要计算地下水其他的补给、排泄项,可以省略大量的工作量,且方便编程实现。

Factors that affect the recharge from precipitation infiltration into groundwater are complex, mainly land use types, precipitation, the thickness and lithology of aeration zone and so on. With the development of remote sensing image interpretation technology, people can identify the type of land use more accurately, so as to calculate the precipitation infiltration rate more accurately and know its spatial distribution more precisely. With the consideration of all these influencing factors, this paper presents a precipitation infiltration rate calculation method based on land use type, combining with GIS and VBA. The application of the PIRCL method in Guanghua basin shows that the annual average precipitation infiltration rate of this region is about 143.69 million m3. This result is close to the result calculated by using the water balance method, and the relative error is about 2.4%; Moreover, the calculated spatial distribution of precipitation infiltration rate is basically reasonable. Comparing with the Water balance calculation method, the calculation of precipitation infiltration rate by the PIRCL method only needs regional remote sensing data, regional precipitation data, dynamic variation of groundwater level and regional hydrogeological parameters in the calculation time period, and you don＇t need to calculate the other recharge and discharge items of groundwater. It may save a lot of work and is convenient to be implemented by programming.