| Based on the daily meteorological data from 5 climatic stations during 1971 to 2012 in source area of the Yellow River, using the revised Thornthwaite Memorial model, the Net primary productivity (NPP) during vegetation growing season (Apr.-Oct.) was calculated. The temporal and spatial change characteristic of NPP was analyzed. At the same time, the sensitivity of NPP to each meteorological factor and the contribution degree of each meteorological factor to the NPP change in source area of the Yellow River were discussed. The results showed that: The NPP during growing season in source area of the Yellow River has shown an upward trend year by year by the average rate of 125.1 kg·hm-2·a-1·10a-1 in past 42 a, and existed main cycle change of 10 years and sub cycle change of 5～6 years. There was obvious regional difference for the NPP in spatial change, had the decreasing distribution characteristic of NPP from south to north, and from east to west. The sensitivity of NPP to the maximal temperature, sunlight and precipitation were the strongest, and relatively weak to the wind speed, relative humidity and minimal temperature. The total contribution of meteorological factors to the NPP in northwest was greater than southeast. It was consistent with the regional distribution characteristics of the NPP relative changes over the years. |