Figure.8 Annual variations of different driving factors
Pearson’s coefficient and t -test were utilized to express the
relevance between oasis transitions and driving factors in Figure 9.
Among the natural driving factors, oasis transitions showed positive
correlation with temperature (P -value < 0.05, r= 0.88) and insignificant correlation with precipitation. Temperature
was positively related to forest (P -value < 0.01,r = 0.94) and shrubland changes (P -value < 0.01,r = 0.95). Notably, precipitation had negative effects
(P -value < 0.05) on shrubland changes. It indicated
that the most natural oasis changes in Tuha Basin was highly sensitive
to temperature, and scarcely affected by precipitation due to the
extremely low precipitation and its downward trend during 1990 and 2020
over Tuha Basin. Generally, natural factors mainly affected natural
oasis with the average coefficient of 0.92 (P -value <
0.01), and had insignificant effects on artificial oasis.
All the human driving factors, population, total power of agricultural
machinery, raw coal production, and total agricultural output showed
positive correlations with the oasis changes, with the coefficients of
0.83, 0.94, 0.90 and 0.91 (P -value < 0.05),
respectively. Cropland, shrubland and built-up changes were mainly
controlled by human activities, and built-up had the most positive
response to population, total agricultural machinery power, raw coal
production, and agricultural output, with the coefficients of 0.93,
0.94, 0.96 and 0.98 (P -value < 0.01), respectively.
Shrubland changes were influenced significantly by the total power of
agricultural machinery, raw coal production, and agricultural output
value, with the coefficients of 0.87, 0.89, and 0.87, respectively
(P -value < 0.05). With the same coefficient of 0.89,
human activities had obvious driving forces on both natural oasis and
artificial oasis. Human activities mainly affected shrubland in natural
oasis; the four human factors showed significant positive correlations
on artificial oasis, with the coefficients of 0.86, 0.86, 0.85 and 0.89,
respectively (P -value < 0.05). The spatial allocation
of water resources improved with the development of agriculture and
industry of Tuha Basin. Moreover, the policies supporting the shrub
planting and growth were encouraged to combat desertification and
reinforce sand.