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The differences between δ18O and δ2H in throughfall and open rainfall were studied for a selected typhoon event in a watershed within the Taihu Lake drainage basin, eastern China. In this event, the isotopic composition of precipitation exhibited a strong temporal variation. Comparison results show that an isotopic composition difference existed not only between gross rainfall and average incremental rainfall, but also between different calculation methods used to derive average. The differences between incremental precipitation and throughfall isotopic composition were observed in this study. Considering the temporal variation in rainfall and throughfall during this typhoon event, the incremental value can have an effect on hydrograph separation more accurately in evaluating the importance of ‘new’ water. In addition, isotopic fluctuations of surface water and groundwater differed from those of rainfall and throughfall throughout the event. [ABSTRACT FROM PUBLISHER]

Most glaciers in the Tibetan Plateau ( TP) are not closely monitored for mass balance (MB) due to their inaccessibility, which makes it difficult to better understand the dynamics of glacial advancement or retreat. Surface energy budget, MB, and the resulting melt runoff were calculated for Zhadang glacier (5,710 m above sea level) of the central TP. Energy balance was calculated on 30-m square grids for the summers of 2007 and 2008. On average, net radiation dominated the total energy source (66%) while the residual was supplied by sensible heat flux. More than 67% of the energy sink was available for melting on the glacier. Thus, less than 33% of the total energy was consumed by latent heat flux. A large and a slightly negative summer MB were calculated for the 2007 and 2008 summers, respectively. The high sensitivity of the glacier to air temperature may indicate that the lower than average seasonal temperature was more important than the increased precipitation for the slightly negative MB in the summer of 2008. Comparisons of glacial melt runoff indicated that rainfall and snowmelt were the dominant contribution to total runoff in the glacierized basin and the ice melting is also very important. Glacial melt calculation provides a basis for quantifying glacial melt-runoff contribution to the river streamflow in the TP. [ABSTRACT FROM AUTHOR]

As an important component of the natural cycle, climatic change can exert a great impact on water resources which play an important role in both the natural ecosystem and people's life and production. To understand the interdependence of climatic change and water resources, this paper analyzed the recent 50 years’ climatic and hydrologic data at three sites in Anhui province, using statistics, linear trend variation, accumulated anomaly, coefficient of variability and coefficient of association methods. The results show that the temperatures and precipitations at these three sites have been increasing at different levels, and may keep increasing in the future. Affected by temperature, precipitation, evaporation and complex landform conditions, total water resources at Ningguo and Chaohu are increasing While which at Chuzhou is decreasing slightly. In general, there is an obvious and positive correlation between precipitation and total water resources. In the past 25 years, the inter-annual heterogeneous distribution of climatic and hydrologic elements is more conspicuous than the whole period, through which extreme climate events occur more frequently [ABSTRACT FROM AUTHOR]

The headwater regions in the Tibetan Plateau play an essential role in the hydrological cycle, however the variation characteristics in the long-term precipitation and throughout-the-year apportionment remain ambiguous. To investigate the spatio-temporal variability of precipitation in the source region of the Yellow River (SRYR), different time scale data during 1979–2015 were studied based on Shannon entropy theory. Long-term marginal disorder index (LMDI) was defined to evaluate the inter-annual hydrologic budget for annual (AP) and monthly precipitation (MP), and annual marginal disorder index (AMDI) to measure intra-annual moisture supply disorderliness for daily precipitation (DP). Results reveal that the AP over the SRYR exhibits remarkable variation, with an inclination rate of 2.7 mm/year, and a significant increasing trend. The climatic trend reversed from warm–dry to warm–wet around the turn of this century. The start of the wet season has advanced from May instead of June, supported by the proportion of MP in AP and the LMDI for May are both comparable with the values during June–September. May contributes the main changes in AP, as it is the only month in the wet season which shows a significant increasing trend during 1979–2015, and has a value in the LMDI that divides the basin in half spatially, the same as AP, with a high value in the northwest and low in the southeast. The AMDI roughly rises with latitude in spatial distribution, with wetlands and glaciers disturbing the continuity of the pattern for a relatively perennial moisture supply. AP has increased on northwest high-altitude areas first and then the southern corner since the beginning of this century. Wetting is mainly attributed to the enhanced southwest monsoon and the warming-induced freeze-thaw process. Meanwhile, AMDI variation concentrated on the Zoige Plateau Wetland, the headwater corner, the summit and part of the North Slope in the Bayan Har Mountain, as a result of a single or combined effect of global climate change and human protection. [ABSTRACT FROM AUTHOR]

The precipitation rate dominates meteoric 10Be in soils rather than soil dynamics, and the relation of the two is indicated in a binomial way with positive correlation in low precipitation regions (<1200 mm per year) and negative in high precipitation regions (>1200 mm per year). • 10Be concentrations in topsoil are influenced by precipitation and soil dynamics. • Precipitation shows more control on 10Be using PCA and correlation analysis. • 10Be concentrations-precipitation shows different trends in dry and humid regions. • Underlying surface affects 10Be without changing 10Be-precipitation relationships. Meteoric beryllium-10 (10Be) is commonly used as a proxy of landscape dynamics (erosion and sedimentation rates) and soil development. Soil represents the first-stage reservoir of meteoric 10Be, and variability in the concentration of the isotope in soils may be affected by soil properties and atmospheric deposition. Although many investigations have targeted this issue, there are still problems in estimating the atmospheric input of the isotope in different soil environments. Here, we used 10Be data measured in soils distributed across China to explore the potential influence of meteorological and pedological conditions on the isotope concentration and related applications. In addition, to determine the mechanisms controlling 10Be concentrations in topsoil on a regional scale, the soil samples were sub-divided into 18 different catchments according to fluvial systems. The results indicated that there were significant negative correlations between precipitation and the soil 10Be concentration in high-precipitation regions (>1200 mm·y−1) and significant positive correlations for soils in low precipitation regions (<1200 mm·y−1). The data also revealed that precipitation is the most important variable controlling the 10Be concentration in soils of China when compared with the effects of soil properties such as grain size, mineralogy, pH, and cation exchange capacity. Land use and soil erosion may have limited impacts on the distribution of 10Be in soils. [ABSTRACT FROM AUTHOR]