A climate transition towards warm-wet conditions in Northwest China has drawn much attention. With continuous climate change and universal glacier degradation, increasing water-related hazards and vulnerability have become one of the important problems facing the Tarim Basin. However, the impacts of the climate transition on streamflow abrupt change and extreme hydrological events were less discussed, especially in glacial basins. In the present study, the discharge datasets in four glacial basins of Tarim Basin from 1979 to 2018 were constructed using the GRU-GSWAT thorn model first. The differences in streamflow characteristics, the shift of hydrological extreme pattern, and potential changes of the controlling factors before and after the abrupt changes were investigated. The results indicated that the abrupt change point (ACP) in streamflow occurred in 2000 in the Qarqan River Basin, 2002 in the Weigan River Basin, and 1994 in the Aksu River Basin and the Yarkant River Basin. A general decrease in streamflow before the ACP has shifted to a notable upward trend in the Qarqan River Basin and the Aksu River Basin, while minor upward fluctuations were observed in other basins. Moreover, the hydrological characteristics in extreme events vary dramatically before and after the ACPs, characterized by a pronouncing shift from drought-dominant pattern to wet events dominated pattern. The driven climate factors have been altered after the ACPs with notable spatial heterogeneity, in which temperature remained as the dominant role in meltwater-dominated basins while the influence of precipitation has increased after the ACPs, whereas the sensitivity of temperature on streamflow change has been enhanced in basins dominated by precipitation such as the Qarqan River Basin. Owing to the evident warming-wetting trend and glacier compensation effect, both the inter-annual and intra-annual streamflow fluctuations can be efficiently smoothed in basins with a high glacier area ratio (GAR). These findings provide a further understanding of the abrupt change in streamflow under the exacerbated climate and glacier change in mountainous arid regions.

The climate change impacted glacio-hydrological regime and thus the availability of water resources in arid region of Central Asia. The effects of climate change in the magnitude or seasonality of regional glacier runoff were still poorly understood in Central Asia. In this study, the glacier runoff, components of glacier runoff, equilibrium line altitude (ELA) and Glacier Mass Balance (GMB) during 1959-2017 are evaluated by elevation-dependent Degree-Day glacier melt model in eight sub-basins of Tarim Basin over Central Asia. The impacts of climate change on glacier and hydrology are assessed. The results suggested that climatic regime shifted to more warm-wet pattern on glacier zone after 1990 in study area. The ablation and accumulation of glaciers showed different patterns in eight sub-basins. All sub-basins showed a glacier mass deficit and GMB displayed a marked decreasing trend, but also exhibiting discrepancy. The mean ELA and rising rate of ELA were higher in the southern region. The glacier runoff increased significantly after 1990 in Tarim Basin, with obviously temporal and spatial variations in sub-basins. The mean annual volume of glacier runoff was 175.8 x 108 m3. The ice melt was a larger component of glacial runoff in Tarim Basin. The influence of rainfall runoff on glacier runoff was more obviously than snow melt runoff as more precipitation fell as rain in northern region. The larger proportions of snow melt runoff imply more precipitation fell as snowfall in southern region. The elevation-dependent contributions in glacier runoff showed differences in individual basins. Temperature and precipitation played different role for the glacier runoff increases among the sub-basins. Differences in sensitivity of GMB and glacier runoff were distinct and vary considerably. A thorough assessment of the spatially and temporally varying melt water originated by glaciers is crucial for the success of water scarcity adaptation under climate change. The glacier mass balance displayed a marked decreasing trend in Tarim Basin of Central Asia. The mean equilibrium line altitude and its rising rate were higher in the southern region. The ice melt runoff, snow melt runoff, rainfall runoff and glacier runoff exhibited normal distribution along with increasing elevation. The glacier runoff was 175.8x108m3, with obviously temporal and spatial variations of components in sub-basins, which varied considerably in response to warm-wet climate in Tarim Basin.image

Thin sandstone reservoirs of the fan delta front sub-facies occur in the early Neogene (Miocene) series of the Aketao (Akto) structural belt within the Kunlun piedmont zone of the Tarim Basin. Oil and gas reservoirs in this area correspond to stratigraphic traps. However, owing to the low density of the 2D seismic survey grid deployed in the Aketao belt, inferior seismic data quality, and lack of well logging data, reservoir prediction in this area suffers from a multiplicity of problems and it is difficult to effectively identify sand bodies. Here, a new research approach is proposed involving the use of 3D seismic, well logging, and drilling data from a neighboring highly-explored 3D seismic survey area as a reference for the 2D seismic interpretation of the non-drilled Aketao survey area. Moreover, this approach is integrated with forward modeling and the inversion of post-stack seismic data to identify sand bodies. A comparison of the seismic reflection characteristics clarifies that these 3D and 2D seismic survey areas share similar sedimentary environments. Forward modeling confirms their similar reservoir characteristics, while the reservoir distribution in the 2D seismic survey area is effectively mapped via the inversion. The results show that for a 2D seismic survey area characterized by a low degree of hydrocarbon exploration and appraisal, and a lack of well logging data, the proposed approach can confirm the sedimentary characteristics that correspond to the seismic reflection characteristics, and can quantitatively map the reservoir thickness.