Based on the different function of a river,this paper discussed that the quantity of river water is divided into three portions such as: ecology water,resource water and disaster water,and took the trunk streams of Shonghua and Nenjiang River as the case,analyzed and calculated the three portions of water,as well as,discussed the change tendency and law of each part water.

Comparison between two water resources quantity investigation and assessment for Haihe River Basin;

Research on analysis method of water resources quantity balance in plain river-net areas;

Characteristics of temperature and precipitation change as well as the water resources quantity change which caused by climatic change were analyzed in Jinzhong from 1956 to 2004.

In order to keep the guarantee of the city scale suitable,it must consider the saving of the water resources in the city.

Based on water resources investigating and evaluating for the Yellow River Basin,this paper analyzed the change characteristics of the water resources since 1956,on which the change reasons were studied.

The drying-up event in the lower reaches of the Yellow River during the 1990s was the most serious problem of water resources issues in China that involved the concept of water resources renewability in the Yellow River basin.

Based on the monthly mean temperature and precipitation data during the past 100 years plus in Chongqing city the interannual and interdecadal variation features of water resources have been analyzed.

The article consists of six chapters:preface;introduction; precipitation and evaporation;water resources quantity;water quality;conclusion.

The paper studies the variation of various kinds of land area in 1985 and 2000 in Ningxia and the influence to the volume of water resources.