The northeastern Tibetan Plateau (NETP), bordering the endorheic lake basins and the Upper Yellow River region, has been disturbed by increasing human activities in recent years. The NETP water storage changes could be a combined effect of climate variability/change and human activities (e.g., reservoir operation). However, whether the human activities have evidently altered hydrological processes and become key drivers of total terrestrial water storage (TWS) changes in the NETP remains unclear. To explore the roles of human interventions in changing surface water storage (SWS) and thus influencing regional TWS changes in the NETP, in comparison with natural drivers, this study quantitatively disaggregated and compared the contributions of TWS changes from climate-dominated natural lakes and man-regulated reservoirs at different timescales. Time series of Gravity Recovery and Climate Experiment (GRACE) TWS anomalies (TWSA) exhibited an overall upward trend (0.78 +/- 0.06 Gt/yr, p < 0.01) with evident periodic fluctuations from April 2002 to August 2020. Although the GRACE TWSA was more substantially influenced by changes in natural lake water storage (0.96 +/- 0.02 Gt/ yr) rather than reservoirs (0.54 +/- 0.04 Gt/yr) in the long-term trend, the man-regulated reservoir water storage changes can significantly dominate the GRACE TWSA on interannual and intra-annual timescales, especially in the second sub-period (2013.01-2017.06; GRACE TWSA change rate:-1.82 +/- 0.29 Gt/yr, p < 0.01, in comparison with the change rate of reservoir water storage of-1.28 +/- 0.17 Gt/yr, and the natural lakes of 0.72 +/- 0.07 Gt/yr). In some abnormal years, the reservoir storage changes were even close to the overall signal of region-wide GRACE TWSA. In addition, the increase in soil moisture storage (long-term linear trend: 0.65 +/- 0.06 Gt/yr, p < 0.01) was also a key factor that cannot be neglected. Our results suggest that human activities are becoming one of the key factors influencing TWS changes in the NETP.

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.

Daily floods including event, characteristic, extreme and inundation in the Lancang-Mekong River Basin (LMRB), crucial for flood projection and forecasting, have not been adequately modeled. An improved hydrological-hydrodynamic model (VIC and CaMa-Flood) considering regional parameterization was developed to simulate the flood dynamics over the basin from 1967 to 2015. The flood elements were extracted from daily time series and evaluated at both local and regional scales using the data collected from in-situ observations and remote sensing. The results show that the daily discharge and water level are both well simulated at selected stations with relative error (RE) less than 10% and Nash-Sutcliffe efficiency coefficient (NSE) over 0.90. Half of the flood events have NSE exceeding 0.76. The peak time and flood volume are well reproduced while both peak discharge and water level are slightly underestimated. The results tend to worsen when the characteristics of flood events are extended to annual extremes. These extremes are generally underestimated with NSE less than 0.5 but RE is within 20%. The simulated rainy season inundation area generally agrees with observations from remote sensing, with about 86.8% inundation occurrence frequency captured within the model capacity. Ignoring the regional parameterization and reservoir regulation can both deteriorate flood simulation performance at the local scale, resulting in lower NSE. Specifically, systematically higher water levels and up to 27% overestimation of peak discharge are found when ignoring regional parameterization, while ignoring reservoir regulation would cause up to 23% overestimation for flood extremes. It is expected that these findings would contribute to the regional flood forecasting and flood management.

Brown carbon (BrC) is known as a light-absorbing organic aerosol which affects the visibility and radiative forcing budget in the troposphere. The optical properties were studied for filter-based PM2.5 samples collected from the winter of 2015 to the summer of 2016 at one rural and three urban sites in the Three Gorges Reservoir (TGR) region, China. The average light absorption coefficient for BrC (beta(abs,405, BrC)) at 405 nm and its contributions to total aerosol light absorption during winter were 12.1 +/- 7.0 Mm(-1) and 23.8 +/- 9.1% respectively, higher than those during summer (1.7 +/- 0.8 Mm(-1) and 11.2 +/- 4.1%). Spatially, the average beta(abs,405, BrC) was higher at the urban sites (13.4 +/- 7.3 Mm(-1)) than that at the rural site (7.8 +/- 3.2 Mm(-1)). The average mass absorption efficiency of BrC at 405 nm (MAE(405),(BrC)) was 0.8 +/- 0.4 m(2) g(-1) during winter which was 2.7 times higher than that during summer (0.3 +/- 0.1 m(2) g(-1)). Furthermore, the absorption Angstrom exponents (AAE) at 405-980 nm (AAE(405-980)) were 1.1 +/- 0.1 in summer and 1.3 +/- 0.2 in winter respectively. Correlation analysis suggests that biomass burning (BB) played an important role in beta(abs,405, BrC) during winter. Additionally, the relatively high AAE(405_980) during winter was mainly due to the BrC from both BB and secondary organic aerosol. The fractional contribution of solar energy absorption by BrC relative to BC in the wavelengths of 405-445 nm was 23.9 +/- 7.8% in summer and 63.7 +/- 14.2% in winter, significantly higher than that in the range of 405-980 nm (11.9 +/- 3.4% and 29.9 +/- 6.1% respectively). Overall, this study contributes to the understanding of sources of BrC in the climate-sensitive TGR region of southwestern China.