Abstract:

Exploring the spatiotemporal evolution patterns of Net Primary Productivity (NPP) of vegetation in Hutuo River Basin is of great significance for understanding and improving the surrounding ecological environment. Using MOD17A3 NPP data, the spatiotemporal evolution of vegetation NPP in Hutuo River Basin from 2003 to 2022 was analyzed using methods such as univariate linear regression analysis and coefficient of variation. The vegetation NPP was combined with land cover types and terrain factors for zoning statistics. The results show that from 2003 to 2022, the average vegetation NPP in Hutuo River Basin was concentrated at 300gC/(m²·a) ~400gC/(m²·a); The peak values of maximum and average NPP of vegetation appear in 2020 and 2022, respectively, at 828gC/(m²·a) and 424.33gC/(m²·a). The area with linear increase of vegetation NPP in Hutuo River Basin from 2003 to 2022 accounts for 96.46% of the study area. The relative annual change rate of vegetation NPP is mainly 20%-40%, and the stability of vegetation NPP over the years is mainly characterized by low fluctuations. The vegetation cover type with the lowest average NPP of vegetation in Hutuo River Basin from 2003 to 2022 is agricultural land, which is 331.92gC/(m²·a). Grassland has the highest NPP which is 384.40gC/(m²·a); As elevation and slope increase, vegetation NPP increases, and from aspect, vegetation NPP of plane is the lowest.

Key words: net primary productivity(NPP), Hutuo River Basin, spatiotemporal evolution, variation coefficient, zoning statistics