我国东部季风区不同自然带年径流特征及人类活动影响的比较研究

A COMPARATIVE STUDY ON THE ZONAL DIFFERENCDS IN RIVER RUNOFF AND HUMAN INFLUENCE IN CHINA

本文在分析我国东部季风区不同自然带年径流与气侯因子关系的基础上，揭示了径流深随纬度和经度变化的规律，并对不同自然带中人类活动对河川径流的干预强度进行了比较，指出半干旱区是人类活动对径流影响最严重的地区，在这里应加强水资源的保护并大力推行各种节水措施。

This paper deals with the zonal differences in river runoff and human innuence in China,based on the data from 700 river basins. Some regression equations have been established be-tween mean annual runoff and climatic variables such as mean annual precipitation,tempera-ture and aridity index,indicating that precipitation is the major controlling factor of runoffformation from a macroscopic point of view. Therefore,the zonality of runoff is resuIted fromthe zonality of precipitation. Based on data from 700 and 400 river basiins respectively,twocurves showing the latitudinal and longitudinal variations in runoff have been established inthis study,In the monsoon-influenced eastern China,mean annual runoff decreases fromsouth to north,and reaches the minimum in the zone 36°-40°N;going further into NortheastChina,itincreases slightly,The longitudinal variation in runoff is controlled by the joint op-eration of the east Asian monsoon and the three-stepped macro relief of China,From south-east to northwest,mean annual runoff declines,However,when crossing the bordering zonebetween the first and the second great steps of macro relief,runoff increases sharply due tothe rapidly increased precipitation induced by topographical uplift,and then the runoff de-clines again. Two sensitive zones are identified from the above two curves, where monitoringstations should be established for the study of regional hydrological response to the globalclimatic change. Based on 30 representative rivers from different natural zones,the human im-pact on runoff has been analyzed,showing that the intensity index of human influence Im in-creases with an increased river basin aridity index;here lm is defined as the difference be-tween the natural and actually measured runoffs divided by the natural runoff.In semi-aridzones,mainly the North China,the human impact on river runoff is the strongest,and thewater-saving agricultural measures are urgently needed.