4.5 Driving factors for oasis
changes
The inter-annual variations of driving factors during 1990 and 2020 were
displayed in Figure 8. the average monthly temperature in growing season
ranged from 15.64 ⁰C and 22 ⁰C to 20.15 ⁰C and 25.79 ⁰C. The mean
temperature in growing season ranged from 19.22 ⁰C to 23.07 ⁰C, with a
slight upward tendency. Precipitation decreased obviously from 1990 to
2020, and the variations in growing season ranged from 1.44 mm and 16.99
mm to that of between 2.77 mm and 6.24 mm. In growing season,
precipitation expressed as significant decreased tendency. The four
human driving factors- population, total power of agricultural
machinery, production of raw coal and total output value of plantation
industry, all showed upward tendency over the study period. The
production of raw coal and the total output value of the plantation
industry were increased dramatically after 2005.