【摘要】 <正> 一、水环境容量图编制的意义水环境容量的研究,是关系到国计民生的重大问题。尽管对于什么叫“环境容量”在学术界还存在着不同的认识,但是,随着工业的发展、城市的扩大、人口的增长,江、河水体污染问题日趋严重,是人们普遍关注的问题。江、河受污染后水质会变坏。水质的好坏是按一定的标准来衡量的,当河水中污染物的含量超过一定限度时,人类和生物就不能适应,而会发生危害;反之,当水体中的污染物浓度较低时,不会给人类和生物造成危害。从上述的意义来说,水环境容量可以理解为指某单元水域内所允许承纳污染物质的限量。更多还原

【Abstract】 t he principles of compiling the series maps with the selected contents are discussed in this paper. The thought of meeting the needs of users and improving the usage efficiency were followed throughout the compilingwork. According to the theory of cartographic perception. All the graphs were represented in 3-D. Also some viewpoints concerning therequirement of compiling the thematic maps are put forward.更多还原