Abstract: Human activities are the important factors affecting the net primary productivity (NPP),and for this reason,the calculation of human-influenced NPP(NPP_H) is of vital significance.The effect of human activities on ecological environment can be quantitatively estimate by calculating NPP_H,and it is of an important significance to scientifically evaluate the implementation effect of management project. In this paper,the Shiyang River Basin was selected as the study area,the variation coefficient method was used to estimate the values of NPP_H during the periods of 2000-2006 and 2007-2010,which included the spatial distribution,change in value,variation trend and effect evaluation of each county.The results are as follows:① Effect of human activities on NPP was wide spread in the Shiyang River Basin.The values of NPP_H varied from -588.31 g·m²·a^-1 to 653.57 g·m²·a^-1 during the period of 2000-2006 and from -644.30 g·m²·a^-1to 673.63 g·m²·a^-1 during the period of 2007-2010.Both the positive and negative human effects on NPP in the whole drainage basin were significant.Holistically,human influence in the Shiyang River Basin was positive;② The change of NPP_H was significant during the periods of 2000-2006 and 2007-2010,and the NPP_H was reduced from 440.65 g·m²·a^-1 to 401.26 g·m²·a^-1;③ Human effect in the drainage basin was changed by 60.13%.It could be concluded that human activities were slowed down.Some results were achieved by implementing the management project,but the management would be a long-term and hard task;④ Management effect was different from different counties,and it was the most significant in Minqin County and Liangzhou District.

Key words: coefficient variation, human-influenced NPP, management effect, governance effect, environmental evaluation, Shiyang River Basin