In Shiyang River Basin, the average temperature since 1951 was sustained upward trend. Which, 1992 is a significant
warming of the year, with significant warming ago, the temperature rose by 0.85°C, higher than the national 0.79°C
warming of nearly 97 years, but lower than the nearly 51 1.1°C increase in the level. East Qilian Mountains of snow in
the area overall decrease, in the basin precipitation generally increasing, runoff from mountain pass is reducing, the
groundwater level rapidly declined in Minqin oasis. After temperatures notable warming, annual precipitation increased
by 18.2 mm, an increase of 5.8%. runoff reduce 410 million m<sup>3</sup>, Groundwater dropped by 1-2 times in Minqin oasis. The
analysis of water resources changing reasons showed that runoff from mountain pass reducing because of mountain
precipitation decrease and Hongyashan Reservoir Inflow to the sustained, rapid decrease is one of reasons which leading
to a rapid decline of groundwater in Minqin Oasis. Subject to the effects of climate change, the Shiyang River basin
runoff from a mountain pass in advance of the peak, Human activities are seriously affected the middle reaches of the
Shiyang River basin runoff and downstream utilization of available volume ratio. Climate change and human activities
affect the common, Reducing of vegetation area and the patches number in Shiyang River Basin shows not only changes
in vegetation types, there are also sparse vegetation to the bare land into the trend, which is the deterioration of
ecological environment tends to the obvious signs.
In the context of 1960~2003 summertime rainfall and small-sized pan evaporations from 131 stations distributed over NW China covering Xinjiang, Qinghai, Gansu, Ningxia, Shaanxi as well as western Nei Mongolia, and Arctic Oscillation Indices (AOI) we define a homogenized index for aridity or wetness feature, with which to examine the relations between AOI and NW China aridity-wetness regime, indicating their noticeable relations on an interdecadal basis. It is found that during the decade of summer Arctic oscillation stronger than mean, the sea level pressure field shows positive (negative) anomalies over Asian landmass, a stronger anticyclonic anomaly circulation appears at 700 hPa over Lake Baikal and to the south, westerly (northerly) departure emerges in the westerly (monsoon) portion of NW China, as well as over NW China there appears a structure with a low in the west and a high in the east at the 500 hPa height field, suggestive of east-Asian summer monsoon weaker than normal such that westerly flows prevail in the westerly zone of NW China, leading to rainfall more than mean for a wetter climate while in its monsoon area the northerly winds are dominant, with precipitation less than normal, resulting in a climate drier in comparison to mean and v.v. for the decade with summer AO weaker than normal.