| China is a country with heavy water shortage. Not only the per capita amount of water is low, but also the spatial and temporal distribution of water resource is uneven. The uneven distribution can not meet the needs well, and leads a conflict between needs and supplies. On the one hand, monsoonal climatology makes water resources chang periodically, which leads to severe droughts and floods; on the other hand, China's rapid economic development has also caused serious pollution of water resources, it aggravates the situation of water shortage. The imbalance of hydroecology becomes a key factor that restricts the sustainable development of China. At present, some unsafe clues in Chinese water supply have appeared. It will be more serious for the water resource under global warming.Tarim River is the longest inland river in China and the second largest inland river in the world (second only to the Volga River). Situated in the north of the dry Tarim Basin, it is a lifeline safeguarding the economy, nature and the life of all ethnic groups in Tarim Basin. Therefore, it is crowned as "The River of Life", or "The Mother River".The Tarim River Basin (TRB) includes 9 main braches, which are the Akesu River, the Kashi River, YeerQiang River, Hetian River, Kaidu-Kongque River, Dina River, Weigan River, Kuche River, Keliya River and Cheercheng River, and 144 minor rivers. It has a watershed area of about 1.02 million sq. km., which is 9.41% of the area of China. The water mainly comes from the source rivers. Been surrounded by mountains, the water vapor transportation to this region is complicated and the the transportation mechanism also has been a pending issue. The climate change and overuse of water resource by human lead to the rivers cutout, the lakes dry up and the land desertification. The environment in this region has been changed a lot; the economy and society development are severely restricted, which causes the whole western ecosystem unsafe. All these results depend largely on the changes and the trends of the air water resource and atmospheric water cycle. Therefore, in order to understand better the situation of water transportation over this region and its future trend, it is important to study the local water recycle and the related land-sea water cycle.TRB locates in the middle of the Taklimakan Desert, with complicated terrain, controlled by westerly circulation and affected by the monsoon some times. It is surrounded by mountains, which is like a letter "U". The geological character over this region is unique and complicated. The effects of westerly circulation and monsoon in the formation of the climate over this region are unclear. Thus, two problems are to be investigated:one is the relation between large scale terrain and the multi-circulation of water vapor transportation over the TRB; the other is affecting mechanism of climate change on the water recycling over different land surface conditions.In this thesis, water vapor, humidity, wind, temperature and DEM (digital elevation model) data over the TRB are caculated and employed; their spatiotemporal evolutions under the climate change are analyzed; comparing analysis is also carried out among different slope direction, elevation and land surface condition. The possible physical mechanism of climate change on the watershed scale water vapor transportation (i.e. the multi-scale circulation interaction over the TRB) is investigated. Than, the relationship between the regional water recycling and mountain precipitation over typical regions is examined to find out the affecting regime of climate change on water cycles. The contents and conclusions are as follows:(1) The spatial-temporal evolution character of the TRB water vapor transportation. The results show that it is a water vapor sink in horizontal direction over the TRB, and zonal contribution is larger than meridional contribution. Horizontal and vertical water vapor net input shows a seasonal variation, it prevails convergence in summer while divergence in winter. Horizontal and vertical water transportations show consistent interannual variations and both have a notable interdecadal saltation. From 1978-2003, when the global warming is significant, horizontal water transportation in the region has a decreasing trend.(2) The spatial-temporal evolution character of the water vapor flux divergence over the TRB. The results show that the whole basin is a water vapor convergence zone. The convergence center locates on the south part of the TRB, near the northern slope of Kunlun Mountains and western of Hetian River Basin on the Pamirs Plateau. The convergence distribution shows an increases trend from northwest to southeast. The water vapor convergence occurs mainly under 600hPa. The amount of the convergence in 1960s are large, but decreases in the 1970s and increases in the 1980s. In 1990s, it decreases again and increases slightly in the first decade of the 21st century.(3) The spatial and temporal evolution of precipiatble water (PW) over the TRB. The results show that the high values of the PW are in the middle of the TRB. The low values are over the surrounding mountains. The PW in wet-years is large than that in dry-years. The largest difference between the wet-year and dry-year occurs in the middle of the TRB, with 2kg per sq.m. The PW over the whole Tarim regions have notable seasonal variations. The most PW contributes throughout the year is in summer; and the annual maximum occurs in July, the minimum occurs in January. The PW over mountains and plain have similar interdecadal variations, which is decreases significantly between the middle of 1960s and the late 1970s, than increases smoothly until 2009.(4) The spatial-temporal evolution of precipitation. The results show that the precipitation distribution shows an increasing trend from northwest to southeast over the TRB; precipitation is difference in various regions, the precipitation in mountains is larger than that in plains; over the whole basin, the maximum of precipitation is on the south slope of the Tianshan Mountains, while the minimum is on the north slope of the Kunlun Mountains; the precipitation increases with the altitude, but the increasing rates depend on the region. Mountain area precipitation changes in lines with the plain area precipitation interannually, but they have large difference in interdecadal variation. Especially, from 1987-2003, when it warms a lot, precipitation over mountains and plains changes inversely.(5) The spatial and temporal evolution of precipitation conversion efficiency (PCE). The results show that PCE in mountains is 6.7 times than that in plains. The interannual variation of PCE in both areas is consistant and the correlation coefficiency is 0.437. But there is a large difference in interdecadal variation, especially from the late 1970s to the early 21st century, when the globe warming is most significant, the precipitation changing rate increases significantly in mountains, while increases slightly in plains.(6) The interaction of multi-scale atmospheric circulation and its impact on water vapor transportation. The results show that the mainly circulation factors affecting the transportation includs the westerly circulation, ENSO, NAO and the related South Asia Monsoon. The main regional environment factors include the U-shaped terrain, the local distance from ocean. The interaction between the U-shaped terrain and the westerly circulation induces that the water vapor transportation turns between upper and lower troposphere and affecting the water vapor transport. In addition, under the impact of ENSO, NAO and South Asia Monsoon, the strength of westerly changes nonlinearly, which will further affects the water vapor transportation over the TRB.Influenced by these factors, water vapor transportation exhibits following characters:the Water Vapor Net Input (WVNI) of the eastern boundary contributed the most. Then the northern and western boundaries follow. The southern boundary export water vapor. This conflicts to the common knowledge that water vapor transportation over the TRB mainly along the west and northwest routines. Over the upper troposphere, zonal and meidional water vapor transportation correlated negatively. But they correlated positively over the lower troposphere.(7) The possible mechanism of the impacts of climate change on the water cycle and precipitation over the TRB. The results show that climate change and human activity causes the global warming and changes the general circulation; global warming accelerates the water cycle, but the response of different scale water cycle to climate change is different. At this point, the regional water cycle is affected by enviremantal factors such as land surface water resource and vegetation, which lead to different responds between mountains and plains over TRB. So, it is porssible that, due to the growing human activities, the amplitude of temperature in mid-high latitudes is larger than that in lower latitudes, which narrows the temperature difference between the middle and low latitudes. Thus, the water vapor transportation from ocean to land will decrease, which will directly leads to a decrease of water vapor transportation from outside to the TRB. Owing to the rare water resource and land surface vegetation over the plain areas, the decrease of water vapor import will affect considerably on the precipitation in plains. While over the mountains, there is dense vegetation and rich land surface water resource, the global warming will accelerate the water cycle and increase the precipitation.
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