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2016, 8 (2) Online: 01 April 2016 Previous issue Next issue
  • Snow disaster characteristics in Palongzangbu River Basin and mitigation countermeasures for road engineering
  • ShuSu Duan, LingKan Yao, XiaoDan Sun, Qiang Cai
  • DOI: 10.3724/SP.J.1226.2016.00095
  • 2016, Vol.8 (2): 95–102 Abstract ( 28) HTML PDF (5501 KB) ( 14 )
  • The Palongzangbu River Basin contains the highest number of maritime province glaciers in China.There are 130 glacial lakes,64 snow avalanche sites and 28 glacial debris flow gullies distributed within the basin.Snow disasters play a controlling role in the Sichuan-Tibet Highway construction,due to the terrain's special characteristics of high altitude and large height differential.Segmentation mitigation countermeasures for the Sichuan-Tibet Highway are presented based on snow disaster severity level and damage mode of the road.In the Ranwu to Midui section,snow avalanches are regional disasters, so the line should be placed in sunny slopes.In the Midui Gully to Yupu section,the line should be placed in shady slopes and at higher elevations to reduce the risk of glacial lake outburst.In the Yupu to Guxiang section,all three snow disasters are minimal.In the Guxiang to Tongmai section,glacier debris flows are the major threat,thus the road should be placed in shady slopes.
  • Characteristics of land-atmosphere energy and turbulent fluxes over the plateau steppe in central Tibetan Plateau
  • MaoShan Li, ZhongBo Su, YaoMing Ma, XueLong Chen, Lang Zhang, ZeYong Hu
  • DOI: 10.3724/SP.J.1226.2016.00103
  • 2016, Vol.8 (2): 103–115 Abstract ( 27) HTML PDF (676 KB) ( 16 )
  • The land-atmosphere energy and turbulence exchange is key to understanding land surface processes on the Tibetan Plateau(TP).Using observed data for Aug.4 to Dec.3,2012 from the Bujiao observation point(BJ) of the Nagqu Plateau Climate and Environment Station(NPCE-BJ),different characteristics of the energy flux during the Asian summer monsoon(ASM) season and post-monsoon period were analyzed.This study outlines the impact of the ASM on energy fluxes in the central TP.It also demonstrates that the surface energy closure rate during the ASM season is higher than that of the post-monsoon period.Footprint modeling shows the distribution of data quality assessments(QA) and quality controls(QC) surrounding the observation point.The measured turbulent flux data at the NPCE-BJ site were highly representative of the target land-use type.The target surface contributed more to the fluxes under unstable conditions than under stable conditions.The main wind directions(180°and 210°) with the highest data density showed flux contributions reaching 100%,even under stable conditions.The lowest flux contributions were found in sectors with low data density, e.g.,90.4% in the 360°sector under stable conditions during the ASM season.Lastly,a surface energy water balance(SEWAB) model was used to gap-fill any absent or corrected turbulence data.The potential simulation error was also explored in this study.The Nash-Sutcliffe model efficiency coefficients(NSEs) of the observed fluxes with the SEWAB model runs were 0.78 for sensible heat flux and 0.63 for latent heat flux during the ASM season,but unrealistic values of-0.9 for latent heat flux during the post-monsoon period.
  • Assessing artificial neural networks coupled with wavelet analysis for multi-layer soil moisture dynamics prediction
  • JunJun Yang, ZhiBin He, WeiJun Zhao, Jun Du, LongFei Chen, Xi Zhu
  • DOI: 10.3724/SP.J.1226.2016.00116
  • 2016, Vol.8 (2): 116–124 Abstract ( 32) HTML PDF (3471 KB) ( 22 )
  • Soil moisture simulation and prediction in semi-arid regions are important for agricultural production,soil conservation and climate change.However,considerable heterogeneity in the spatial distribution of soil moisture,and poor ability of distributed hydrological models to estimate it,severely impact the use of soil moisture models in research and practical applications.In this study,a newly-developed technique of coupled(WA-ANN) wavelet analysis(WA) and artificial neural network(ANN) was applied for a multi-layer soil moisture simulation in the Pailugou catchment of the Qilian Mountains,Gansu Province, China.Datasets included seven meteorological factors:air and land surface temperatures,relative humidity,global radiation, atmospheric pressure,wind speed,precipitation,and soil water content at 20,40,60,80,120 and 160 cm.To investigate the effectiveness of WA-ANN,ANN was applied by itself to conduct a comparison.Three main findings of this study were:(1) ANN and WA-ANN provided a statistically reliable and robust prediction of soil moisture in both the root zone and deepest soil layer studied(NSE >0.85,NSE means Nash-Sutcliffe Efficiency coefficient);(2) when input meteorological factors were transformed using maximum signal to noise ratio(SNR) and one-dimensional auto de-noising algorithm(heursure) in WA, the coupling technique improved the performance of ANN especially for soil moisture at 160 cm depth;(3) the results of multi-layer soil moisture prediction indicated that there may be different sources of water at different soil layers,and this can be used as an indicator of the maximum impact depth of meteorological factors on the soil water content at this study site.We conclude that our results show that appropriate simulation methodology can provide optimal simulation with a minimum distortion of the raw-time series;the new method used here is applicable to soil sciences and management applications.
  • Influence of short-term experimental warming on heat-water processes of the active layer in a swamp meadow ecosystem of the Qinghai-Tibet Plateau
  • GuangSheng Liu, GenXu Wang
  • DOI: 10.3724/SP.J.1226.2016.00125
  • 2016, Vol.8 (2): 125–134 Abstract ( 24) HTML PDF (3616 KB) ( 13 )
  • Climate change is now evident in the Qinghai-Tibet Plateau(QTP),with impacts on the alpine ecosystem,particularly on water and heat balance between the active layer and the atmosphere.Thus,we document the basic characteristics of changes in the water and heat dynamics in response to experimental warming in a typical alpine swamp meadow ecosystem.Data sets under open top chambers(OTC) and the control manipulations were collected over a complete year.The results show that annual(2008) air temperatures of OTC-1 and OTC-2 were 6.7℃ and 3.5℃ warmer than the control.Rising temperature promotes plant growth and development.The freeze-thaw and isothermal days of OTCs appeared more frequently than the control,owing to comparably higher water and better vegetation conditions.OTCs soil moisture decreased with the decrease of soil depth;however,there was an obviously middle dry aquifer of the control,which is familiar in QTP.Moreover,experimental warming led to an increase in topsoil water content due to poorly drained swamp meadow ecosystem with higher organic matter content and thicker root horizons.The results of this study will have some contributions to alpine cold ecosystem water-heat process and water cycle under climate change.
  • Characteristics and source of aerosols at Shiyi Glacier,Qilian Mountains, China
  • XiaoYu Zhang, ZhongQin Li, Ping Zhou, ShengJie Wang
  • DOI: 10.3724/SP.J.1226.2016.00135
  • 2016, Vol.8 (2): 135–146 Abstract ( 32) HTML PDF (7625 KB) ( 20 )
  • Aerosol samples were collected in the Shiyi Glacier,Qilian Mountains from July 24 to August 19,2012 and analyzed for major water-soluble ionic species(F-,Cl-,NO2-,NO3-,SO42-,Na+,NH4+,K+,Mg2+ and Ca2+) by ion chromatography. SO42- and NH4+ were the most abundant components of all the anions and cations,with average concentrations of 94.72 and 54.26 neq/m3,respectively,accounting for 34% and 20% of the total water-soluble ions analyzed.These mean ion concentrations were generally comparable with the background conditions in remote sites of the Qilian Mountains,but were much lower than those in certain cities in China.The particles were grouped into two dominant types according to their morphology and EDX signal:Si-rich particles and Fe-rich particles.Backward air mass trajectory analysis suggested that inland cities may contribute some anthropogenic pollution to this glacier,while the arid and semi-arid regions of central Asia were the primary sources of the mineral particles.
  • Geostatistical analysis of variations in soil salinity in a typical irrigation area in Xinjiang, northwest China
  • Mamattursun Eziz, Mihrigul Anwar, XinGuo Li
  • DOI: 10.3724/SP.J.1226.2016.00147
  • 2016, Vol.8 (2): 147–155 Abstract ( 33) HTML PDF (6680 KB) ( 17 )
  • Characterizing spatial and temporal variability of soil salinity is tremendously important for a variety of agronomic and environmental concerns in arid irrigation areas.This paper reviews the characteristics and spatial and temporal variations of soil salinization in the Ili River Irrigation Area by applying a geostatistical approach.Results showed that:(1) the soil salinity varied widely,with maximum value of 28.10 g/kg and minimum value of 0.10 g/kg,and was distributed mainly at the surface soil layer.Anions were mainly SO42- and Cl-,while cations were mainly Na+ and Ca2+;(2) the abundance of salinity of the root zone soil layer for different land use types was in the following order:grassland >cropland >forestland. The abundance of salinity of root zone soil layers for different periods was in the following order:March >June >September;(3) the spherical model was the most suitable variogram model to describe the salinity of the 0-3 cm and 3-20 cm soil layers in March and June,and the 3-20 cm soil layer in September,while the exponential model was the most suitable variogram model to describe the salinity of the 0-3 cm soil layer in September.Relatively strong spatial and temporal structure existed for soil salinity due to lower nugget effects;and(4) the maps of kriged soil salinity showed that higher soil salinity was distributed in the central parts of the study area and lower soil salinity was distributed in the marginal parts. Soil salinity tended to increase from the marginal parts to the central parts across the study area.Applying the kriging method is very helpful in detecting the problematic areas and is a good tool for soil resources management.Managing efforts on the appropriate use of soil and water resources in such areas is very important for sustainable agriculture,and more attention should be paid to these areas to prevent future problems.
  • The evolution and enlightenment of water resources accounting from accounts to balance sheet
  • FuHui Jian, XiaoYu Song, LiLi Li, WenQi Gao
  • DOI: 10.3724/SP.J.1226.2016.00156
  • 2016, Vol.8 (2): 156–162 Abstract ( 27) HTML PDF (1051 KB) ( 19 )
  • The Third Plenary Session of the 18th Central Committee of the Communist Party of China has proposed an important national strategic decision:to explore and establish the balance sheet of natural resources,to implement leaders' of-office auditing system about natural resources assets.Water is one of the most essential nature resources of human beings;water resources accounting,as an important water resources management tool,is an essential part of compiling the natural resources balance sheet.In this paper,we provide a summary of the historic evolution of water resources accounting and analyze its application in some typical countries.Although water resources accounting and water resources balance sheet reflect different implications and focus,both require water resources accounts as the basis in system establishment.
  • Measurement for coordinated development of "four modernizations" and its efficiency of prefecture level cities or above in China
  • JingHu Pan, YanXing Hu
  • DOI: 10.3724/SP.J.1226.2016.00163
  • 2016, Vol.8 (2): 163–176 Abstract ( 37) HTML PDF (697 KB) ( 85 )
  • The efficient and coordinated development of industrialization,urbanization,informatization and agricultural modernization(so called "Sihua Tongbu" in China,and hereinafter referred to as "four modernizations") is not only a practical need but also an important strategic direction of integrating urban-rural development and regional development in recent China.This paper evaluated the comprehensive,coupling and coordinated developmental indices of "four modernizations" of China's 343 prefecture-level administrative units,and calculated their efficiency of "four modernizations" in 2001 and 2011.The efficiency evaluation index system was established.The efficiencies and their changing trend during the period 2001-2011 were investigated using the data envelopment analysis(DEA) model.Spatial-temporal pattern of the efficiency of China's prefecture-level units was explored by using exploratory spatial data analysis(ESDA).Finally,the main influencing factors were revealed with the aid of geographically weighted regression(GWR) model.Results indicate that the comprehensive,coupling and coordinated developmental indices and efficiency of "four modernizations" of China's prefecture-level administrative units have obvious spatial differences and show diverse regional patterns.Overall,the efficiency is relatively low,and only few units with small urban populations and economic scale are in DEA efficiencies.The efficiency changing trends were decreasing during 2001-2011,with a transfer of high efficiency areas from inland to eastern coastal areas.The difference between urban and rural per capita investment in fixed assets boasts the greatest influence on the efficiency.