地表水与地下水是水资源系统中的两个重要组成部分,由于水体在地表与地下介质中的运移和储存方式不同,在水资源评价中所采用的模型和计算方法各异。中国第一轮水资源评价中,仅全国地下水资源总量一项,不同部门评价计算的结果年资源总量差达1000×108m3/a[1](占全国地下水资源总量的1/8左右),这个数据相当于中国正在组织实施的南水北调工程的总调水量的一倍以上。作者认为在中国第一轮水资源评价中,地表水采用流域分区进行评价,地下水则采用水文地质单元的分区方法进行评价,是引起中国水资源总量误差问题的根本原因。由于自然界的四水转化关系十分复杂,分别采用地表水流域评价法或水文地质单元评价法,都无法避免水资源总量评价的误差问题。论文通过研究提出中国水资源三级评价分区方案,在地下水资源量评价中采用一二级按流域分区与地表水系统取得一致,三级按地下水单元分区的方法,解决中国新一轮水资源评价的误差问题。

Surface water and groundwater are important constitutes of water resource system. Since the water transports and deposited in different ways within the medium between surface and ground, so the modeling and appraising method adopted are different. In the first time of water resources appraising of China, only the difference in national groundwater resources’ gross is up to 10000 billion tons (or about 1/8 of all the national groundwater resources). This data is twice of the data of the water transported from south to north or more. The author thinks that the main reasons for the total error of groundwater resource appraisal are: 1) In the nature, groundwater and surface water frequently converse and replenish with each other. It is improper to appraise them seperately. But in water resources appraising of China, from one level to three level sub areas, ground water moduli were not divided along with surface water together. 2) In water resources appraising, the computing methods of replenishment and evaporation for surface water and ground water are not be united, and the resource quantities’ iteration principles are different, leading to the inconformity of various results. 3) Basic data for water resource’s evaluation of China come from the different management department respectively. Water conservancy department manages surface water and agricultural water. On the other hand, constructed department manages the water for city use. For a few years, the groundwater had been managed by geologic and mining section, which, meantime, could pursue a part of monitoring work. They all have accumulated but different data of many years. The data of above three sections are the foundation on which the water resource’s evaluations in China proceed. The author thinks that in the first time of water resources evaluation of China, surface water should be evaluated according to river valley, while ground water be evaluated through hydrology geology unit, so that the gross’ error can be avoided in water resources’ appraising. The author also brings up the project of three level evaluation and sub area. In the groundwater resources’ quantity evaluation, one and two level sub area methods according to river valley are adopted. Three level sub area methods according to groundwater unites are used to resolve the problem of the water resources’ evaluation error.