Local climate change and the impacts on hydrological processes in an arid alpine catchment in Karakoram

Climate change and the impacts on hydrological processes in Karakoram region are highly important to the available water resources in downstream oases. In this study, a modified quantile perturbation method (QPM), which was improved by considering the frequency changes in different precipitation intensity ranges, and the Delta method were used to extract signals of change in precipitation and temperature, respectively. Using a historical period (1986-2005) for reference, an average ensemble of 18 available Global Circulation Models (GCMs) indicated that the annual precipitation will increase by 2.9-4.4% under Representative Concentration Pathway 4.5 (RCP4.5) and by 2.8-7.9% in RCP8.5 in different future periods (2020-2039, 2040-2059, 2060-2079 and 2080-2099) due to an increased intensity of extreme precipitation events in winter. Compared with the historical period, the average ensemble also indicated that temperature in future periods will increase by 0.31-0.38 degrees C/10a under RCP4.5 and by 0.34-0.58 degrees C/10a under RCP8.5. Through coupling with a well-calibrated MIKE SHE model, the simulations suggested that, under the climate change scenarios, increasing evaporation dissipation will lead to decreased snow storage in the higher altitude mountain region and likewise with regard to available water in the downstream region. Snow storage will vary among elevation bands, e.g., the permanent snowpack area below 5600 m will completely vanish over the period 2060-2079, and snow storage in 5600-6400 m will be reduced dramatically; however, little or no change will occur in the region above 6400 m. Warming could cause stronger spring and early summer stream runoff and reduced late summer flow due to a change in the temporal distribution of snowmelt. Furthermore, both the frequency and intensity of flooding will be enhanced. All the changes in hydrological processes are stronger under RCP8.5 than those under RCP4.5. In Karakoram region, the transformations among different forms of water resources alter the distributions of hydrologic components under future climate scenarios, and more studies are needed on the transient water resources system and the worsening of flood threats in the study area

Assessment of different modelling studies on the spatial hydrological processes in an arid alpine catchment

To assess the model description of spatial hydrological processes in the arid alpine catchment, SWAT and MIKE SHE were jointly applied in Yarkant River basin located in northwest China. Not only the simulated daily discharges at the outlet station but also spatiotemporal distributions of runoff, snowmelt and evapotranspiration were analyzed contrastively regarding modules' structure and algorithm. The simulation results suggested both models have their own strengths for particular hydrological processes. For the stream runoff simulation, the significant contributions of lateral interflow flow were only reflected in SWAT with a proportion of 41.4 %, while MIKE SHE simulated a more realistic distribution of base flow from groundwater with a proportion of 21.3 %. In snowmelt calculation, SWAT takes account of more available factors and got better correlations between snowmelt and runoff in temporal distribution, however, MIKE SHE presented clearer spatial distribution of snowpack because of fully distributed structure. In the aspect of water balance, less water was evaporated because of limitation of soil evaporation and less spatially distributed approach in SWAT, on another hand, the spatial distribution of actual evapotranspiration (ETa) in MIKE SHE clearly expressed influence of land use. Whether SWAT or MIKE SHE, without multiple calibrations, the model's limitation might bring in some biased opinions of hydrological processes in a catchment scale. The complementary study of combined results from multiple models could have a better understanding of overall hydrological processes in arid and scarce gauges alpine region

Inclusion of modified snow melting and flood processes in the SWAT model

Flooding, one of the most serious natural disasters, poses a significant threat to people's lives and property. At present, the forecasting method uses simple snowmelt accumulation and has certain regional restrictions that limit the accuracy and timeliness of flood simulation and prediction. In this paper, the influence of accumulated temperature (AT) and maximum temperature (MT) on snow melting was considered in order to (1) reclassify the precipitation categories of the watershed using a separation algorithm of rain and snow that incorporates AT and MT, and (2) develop a new snow-melting process utilizing the algorithm in the Soil and Water Assessment Tool Model (SWAT) by considering the effects of AT and MT. The SWAT model was used to simulate snowmelt and flooding in the Tizinafu River Basin (TRB). We found that the modified SWAT model increased the value of the average flood peak flow by 43%, the snowmelt amounts increased by 45%, and the contribution of snowmelt to runoff increased from 44.7% to 54.07%. In comparison, we concluded the snowmelt contribution to runoff, flood peak performance, flood process simulation, model accuracy, and time accuracy. The new method provides a more accurate simulation technique for snowmelt floods and flood simulation

Advanced predication of geological anomalous body ahead of laneway using seismic tomography technique

Advanced predication of geological anomalous body (GAB) of laneway can provide scientific references for mine safety production. It refers to reveal the position, shape and size of GAB in advance. Seismic tomography technology (STT) can realize the prediction of GAB using tunnel surface waves. Tunnel Reflection Tomography (TRT) 6000 system, which is on the basis of STT, has the advantages of convenience and high reliability. In this paper, TRT6000 is introduced to forecast the GAB ahead of laneway in underground metal mine. The operation steps, data processing and notes about TRT6000 are detailed. The research results show that there are two water flowing fractures, separately located at around 50meters and 85meters ahead of laneway. And the prediction results match the actual situation well. Therefore, the seismic tomography technology improves the mine safety management, and the TRT6000 provides a new method for predicting GAB in advance

Supplementation of hyaluronic acid injections with vitamin D improve knee function by attenuating synovial fluid oxidative stress in osteoarthritis patients with vitamin D insufficiency

ObjectivesThere is still controversy about the effect of vitamin D supplementation on osteoarthritis (OA). The purpose of this study was to investigate the effects of vitamin D supplementation with Hyaluronic acid (HA) injection on OA.MethodsWe investigated serum vitamin D levels and oxidative stress (OS) in synovial fluid from patients with OA who underwent total knee arthroplasty (grade IV, n = 24) and HA injection (grade II and III, n = 40). The effects of HA injection with or without oral vitamin D supplementation on synovial fluid OS and knee pain and function were then further investigated. Finally, patients underwent HA injection were divided into two groups according to vitamin D levels (vitamin D < or > 30 ng/ml), and the efficacy of the two groups were compared.ResultsThe results showed that the levels of glutathione peroxidase (GSH-PX) (P < 0.05) in the synovial fluid were lower in patients with stage IV OA than that in patients with stage II-III OA, while the levels of malondialdehyde (MDA) (P < 0.05) and lactate dehydrogenase (LDH) (P < 0.01) were significantly higher. Moreover, we found that age, BMI and vitamin D levels were significantly associated with the levels of oxidants and/or antioxidants in synovial fluid, and that vitamin D was significantly negatively correlated with BMI (R = −0.3527, p = 0.0043). Supplementation of HA injections with vitamin D significantly reduced the OS status in synovial fluid, attenuated knee pain and improved knee function in OA patients with vitamin D insufficiency.ConclusionWe conclude that maintenance of vitamin D sufficiency may be beneficial for the treatment of OA by improving OS in synovial fluid

Open-source genomic analysis of Shiga-toxin–producing E. coli O104:H4

An outbreak caused by Shiga-toxin–producing Escherichia coli O104:H4 occurred in Germany in May and June of 2011, with more than 3000 persons infected. Here, we report a cluster of cases associated with a single family and describe an open-source genomic analysis of an isolate from one member of the family. This analysis involved the use of rapid, bench-top DNA sequencing technology, open-source data release, and prompt crowd-sourced analyses. In less than a week, these studies revealed that the outbreak strain belonged to an enteroaggregative E. coli lineage that had acquired genes for Shiga toxin 2 and for antibiotic resistance

Monitoring the Amery Ice Shelf front during 2004−2012 using ENVISAT ASAR data

The Amery Ice Shelf is the largest ice shelf in East Antarctica. It drains continental ice from an area of more than one million square kilometres through a section of coastline that represents approximately 2% of the total circumference of the Antarctic continent. In this study, we used a time series of ENVISAT ASAR images from 2004–2012 and flow lines derived from surface velocity data to monitor the changes in 12 tributaries of the Amery Ice Shelf front. The results show that the Amery Ice Shelf has been expanding and that the rates of expansion differ across the shelf. The highest average annual rate of advance from 2004–2012 was 3.36 m∙d-1 and the lowest rate was 1.65 m∙d-1. The rates in 2009 and 2010 were generally lower than those in other years. There was a low correlation between the rate of expansion and the atmospheric temperature recorded at a nearby research station, however the mechanism of the relationship was complex. This study shows that the expansion of the Amery Ice Shelf is slowing down, reflecting a changing trend in climate and ice conditions in East Antarctica