Table of Content

15 May 2019, Volume 36 Issue 3 Previous Issue    Next Issue

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Cover 2019, 36 (3):  0.  Abstract ( 317 )   PDF (622KB) ( 83 )   Related Articles | Metrics

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Contents 2019, 36 (3):  0-0.  Abstract ( 244 )   PDF (314KB) ( 119 )   Related Articles | Metrics

Pan-Third Pole Enviornment and Green Silk Road

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Relationship Between Surface Latent Heat Flux over the Qinghai-Tibetan Plateau and Precipitation in Qinghai from May to October QI Yan, YAN Yu-qian, LI Jin-hai, CHEN Wen-jiang 2019, 36 (3):  529-536.  doi: 10.13866/j.azr.2019.03.01 Abstract ( 584 )   PDF (1809KB) ( 2391 )   In this study,the ERA-Interim reanalysis data and the observation data from 43 meteorology stations in Qinghai Province from 1981 to 2010 were used. The purposes of the study were to analyze the spatial and temporal distribution characteristics of the surface latent heat flux (short for slhf) over the Qinghai-Tibetan Plateau and its relationship with precipitation in Qinghai from May to October using the method of EOF (Empirical orthogonal functions),correlation analysis and composite analysis. The result showed that: ① The spatial distribution of first order mode of slhf was different in the eastern and western regions of the plateau,the anomaly was positive in northeast Qinghai and the western and southern regions of the plateau but negative in other areas. The time coefficient of first order mode was in a significant downward trend,it was positive before 2001 but negative after that,which revealed that the slhf in northeast Qinghai and the western and southern parts of the plateau increased before 2001 but decreased after that; ② There was a significant negative correlation between the slhf over the plateau and the precipitation in northeast Qinghai Province. When the slhf over the plateau was increased (or decreased),the precipitation in northeast Qinghai was reduced (or increased); ③ The area where it passed the significance test of 0.1 was regarded as the key area (35.0°-38.5°N,98°-103.0°E) to study the relationship between the two,and 1 standard deviation was used to select the high-value years and low-value years of slhf. The results revealed that the slhf in the key area in recent 35 years was in a significant decrease trend,the precipitation in the key area was increased in the high-value years of slhf,it was decreased in the northeastern part of the key area but increased in other regions,and there was a 60 mm positive anomaly center in the south; ④ In the high-value (or low-value) years of slhf,the potential of the key area was low (or high),the wind speed was high (or low),and the water vapor convergence was weak (or strong) in the south of the key area. Analysis of the intensity of the 100 hPa South Asian High Center and the 300 hPa temperature field revealed that the intensity of the South Asian High and the 300 hPa warm center were slightly lower (or higher) in the years when the slhf was abnormally high (or low),and the establishment (or retreat) of South Asian High was earlier. References | Related Articles | Metrics

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Effect of Short-Term Warming on Dynamic Change of Soil Moisture Content in Growing Season in the Permafrost Regions of the Qinghai-Tibet Plateau LI Yan-ping, SHI Li-jiang, XU Man-hou, LI Wen-gang 2019, 36 (3):  537-545.  doi: 10.13866/j.azr.2019.03.02 Abstract ( 489 )   PDF (1316KB) ( 342 )   The typical alpine meadow vegetation types in the hinterland of the Qinghai-Tibet Plateau were taken as the research objects,the global warming was simulated by infrared lamp heating method,the values of soil moisture content at different depths of 0-100 cm in growing season (from May to September) 2012 were obtained by water probe,and its response to warming was analyzed.The results showed that:① Short-term warming increased soil moisture content in alpine meadow,but the increase was not significant (P＞0.05),and the average increase was 2.85%;② Soil moisture content decreased at first and then increased with the increase of soil depth,and decreased to the lowest value (13.8%) at the depth of 10-20 cm,and reached the highest value (20.57%) near the depth of 60-100 cm.Soil moisture content at 10-20 cm depth in the control group was significantly lower than that in other soil layers in five months,it at 0-20 cm depth in the warming group was significantly lower than that in other soil layers,which indicated that warming affected significantly the topsoil (0-10 cm deep) moisture content,but slightly the deep-soil moisture content,and the short-term warming had no effect on the vertical distribution of soil moisture content;③ Soil moisture content was in an increase trend with the time from May to August,which indicated that the soil moisture content in growing season in Beilu River Basin in the Qinghai-Tibet Plateau increased gradually and to its highest value in August,and it began to decrease from September,but the decrease was not significant.The change trend of soil moisture content with the time in the warming group was basically the same as that in the control group. References | Related Articles | Metrics

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Spatial Distribution of Vegetation Coverage and Its Affecting Factors in the Upper Reaches of the Yellow River PEI Zhi-lin, YANG Qin-ke, WANG Chun-mei, PANG Guo-wei, YANG Li-hua 2019, 36 (3):  546-555.  doi: 10.13866/j.azr.2019.03.03 Abstract ( 1317 )   PDF (2831KB) ( 580 )   The ecosystem in the upper reaches of the Yellow River is fragile,and it is affected by the unique ecological environment and relatively simple vegetation types.The distribution of fractional vegetation cover (FVC) and its driving factors provide a reference for local vegetation protection.In this paper,the monthly data of MODIS1M NDVI (2000-2015) were used to calculate the maximum FVC in the upper reaches of the Yellow River and analyze its distribution and characteristics.Moreover,the corresponding proxy variables were used to quantitatively study the affecting factors of FVC by using the geographical detector (Geodetector) model based on the statistics theory and considering the topographical,geological and climatic factors as well as human activities.The study showed that: ① The FVC in the upper reaches of the Yellow River was improved.The spatial distribution of FVC was stable even if there was a slight fluctuation; ② The distribution of FVC was mainly affected by annual precipitation.There were some regional differences in the effects of other factors,for example,the distribution of FVC in the southwest of the study area was subject to the joint effect of topography and pressure,the effects of topographic factors in the central and northeast regions were relatively low,and the FVC was mainly subject to precipitation,humidity,land use types,soil types and underlying surface; ③ The interaction between the annual precipitation and the soil types and land use types was dominant to affect the spatial distribution of FVC; ④ Holistically,the factors affecting the spatial distribution of FVC were in an order of climatic environment factors > non-climatic environmental factors > human activities.The interaction of human activities with environmental factors (such as precipitation) could be used to fully explain the spatial distribution of FVC; ⑤ In the ecological restoration in this area,the full utilization of precipitation and the improvement of land use ways should be focused on. References | Related Articles | Metrics

Land and Water Resources

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Projection of Future Climate Change in the Kaidu-Kongqi River Basin in the 21st Century LI Xiao-fei, XU Chang-chun, LI Lu, SONG Jia, ZHANG Xi-cheng 2019, 36 (3):  556-566.  doi: 10.13866/j.azr.2019.03.04 Abstract ( 465 )   PDF (3039KB) ( 357 )   Climate change assessments on both global and regional scales rely strongly on the global climate models (GCMs) which are dominantly provided by the Coupled Model Inter Comparison Project Phase 5(CMIP5).Based on the grid datasets of monthly air temperature and precipitation from CRU (Climate Research Unit) and 31 CMIP5 GCMS data from the Downscaled CMIP3 and CMIP5 Climate and Hydrology Projections (DCHP),in this paper the performance of three Multi-Model Ensemble Mean methods (PLS,RR and EE) in simulating the historical climate change processes was evaluated,and the optimal ensemble method was determined and estimated for predicting the future climate change in the Kaidu-Konqi River Basin in the 21st century.The results indicated that:① The performance of the established Partial Least Squares (PLS) model was the best in simulating air temperature and precipitation in the study area.The r values of simulated temperature were all higher than 0.64,they were obviously better than those of simulated precipitation (0.19-0.36).However,there was a spatial heterogeneity in both temperature and precipitation simulations;② In the 21st century,the air temperature in the 4 sub-basins of Kaidu-Kongqi River Basin would be in a significant increase trend.The increase rates of air temperature 〔0.58-0.67 ℃·(10a)-1〕 under the RCP8.5 scenario would be doubled compared with those under RCP4.5 scenario 〔0.25-0.31 ℃·(10a)-1〕.The significant difference between the two scenarios would begin from the mid-21st century.From the perspective of entire watershed,the warming rate increased gradually from the mountainous area in the northwest to the desert in the southeast;③ The distribution of change rates of precipitation was slightly different under different discharge scenarios,but both of them would be in a significant increase trend.The increase rate under RCP8.5 scenario 〔1.22%-1.54%·(10a)-1〕 would be holistically higher than that under RCP4.5 scenario 〔0.80%-1.32%·(10a)-1〕. References | Related Articles | Metrics

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Characteristics of δD and δ18O in Surface Water and Groundwater in the Oases GUO Xing, LI Sheng, YU Bin 2019, 36 (3):  567-574.  doi: 10.13866/j.azr.2019.03.05 Abstract ( 8 )   PDF (2095KB) ( 0 )   In order to perform a detailed investigation on the variation characteristics of δD and δ18O in the oases in south Xinjiang,the samples of surface water and groundwater were collected in July,August and November 2016 and July and August 2017,respectively.After analyzing the characteristics of δD and δ18O in surface water,groundwater and precipitation in different drainage basins in south Xinjiang in the same period,it was found that the distribution of δD and δ18O in surface water and groundwater was similar.The isotopes were distributed at the intersection of precipitation data in winter and summer,and there was no a seasonal difference.The values were all in the range of δD and δ18O in precipitation,snowmelt and glacier water.Which revealed the diversity,variation,accumulation and lagging characteristics of the recharge sources.Moreover,the characteristics of δD and δ18O in surface water,groundwater and precipitation in the oases were jointly affected by both natural factors and human activities based on considering the actual situation of the study area. References | Related Articles | Metrics

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Application of A Snowmelt Runoff Model in the Xilin River Basin WANG Fei, ZHU Zhong-yuan, ZHANG Peng, WANG Hui-min, ZHANG Lu 2019, 36 (3):  575-581.  doi: 10.13866/j.azr.2019.03.06 Abstract ( 16 )   PDF (1258KB) ( 0 )   In this study,the MODIS snow cover data and the measured meteorological and hydrological data in the upper reaches of the Xilin River Basin in snow melt period (from March to May) of 2014-2016 were simulated by WinSRM1.10.The purposes of the study were to verify the applicability of a snowmelt runoff model (SRM) in the drainage basins in arid and alpine steppe based on the description of the model structure and the meaning of the parameters,and to reveal the proportion of spring snowmelt volume in annual runoff volume in the upper reaches of the Xilin River Basin from 2014 to 2016.The results showed that the SRM could be used to ideally reflect the change trend of spring snowmelt volume in the study area,and to predict the time of flood peak of spring snowmelt.The accuracy of the model was evaluated,and the fit goodness coefficient (R2) and volume difference (DV) of the 3-year simulated values were obtained,which were superior to the mean values published by the World Meteorological Organization.Therefore,the SRM has a good applicability in the upper reaches of the Xilin River Basin,and it is of great significance for the rational use of ice-snow resources in grasslands. References | Related Articles | Metrics

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Spatiotemporal Revolution of Soil Salinity in Winter Wheat Fields with Different Years of Drip Irrigation Without Mulching in Arid Area LI Yuan, GEN Qin-long, LAI Ning, LI Qing-jun, CHEN Shu-huang 2019, 36 (3):  582-588.  doi: 10.13866/j.azr.2019.03.07 Abstract ( 17 )   PDF (1053KB) ( 0 )   In order to explore the sustainability of drip irrigation for winter wheat planting in arid area,a long-term located experiment was carried out in Qitai County,Xinjiang.Soil samples were collected along a soil profile with different soil depths of 0-80 cm from outward the central area of drip irrigation.Based on the geostatistical analysis,a winter wheat field where drip irrigation had been used for 8 years was selected for researching the distribution of soil salt.The research results showed that:① Soil salinity was in a logarithm normal distribution.The soil salt content was decreased gradually in 0-80 cm soil layer with increasing the years of drip irrigation.After 8 years of drip irrigation,the soil desalinization was obvious in the 0-20 cm rhizosphere.After 6 years of drip irrigation,the soil desalinization was obvious in the 0-60 cm soil layer,and a salt accumulation occurred under this layer;② With increasing the years of drip irrigation,soil salt migrated down to deep soil layer and outward from the central area of drip irrigation;③ With increasing the years of drip irrigation,wheat yield was gradually increased.It was suggested to increase the frequency but decrease the volume of drip irrigation under the current irrigation system.The study results could provide further support for popularizing drip irrigation of winter wheat without mulching. References | Related Articles | Metrics

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Soil Particle Size and Organic Matter Content of Different Land Use Types in the Mu Us Sandland MAO Li, SU Zhi-zhu, WANG Guo-ling, MA Yi-juan, LI Xiang 2019, 36 (3):  589-598.  doi: 10.13866/j.azr.2019.03.08 Abstract ( 770 )   PDF (1787KB) ( 419 )   In the Mu Us Sandland,the ecological environment is fragile,the soil wind erosion is serious,and the sandland is one of the key areas for desertification control in the sand source area of Beijing-Tianjin zone.In this paper,the soil granularity,organic matter content and their relationship under different land use patterns were studied so as to provide the basic data and the scientific basis for rational land use and desertification control.Through the field investigation in the Mu Us Sandland,the topsoil samples were collected from four land use types,i.e.the semi-fixed dune land,stubble land,ploughed land and grassland.The grain size and organic matter content of soil were analyzed,and the relationship between soil organic matter content and soil particle size distribution was discussed.The results showed that:① Silt(0.002-0.05 mm) was dominant in stubble land,ploughed land and grassland,and its content in topsoil was in an order of grassland(61.06%)>stubble land(53.09%)>ploughed land(48.28%),and that in sub-surface layer was in an order of grassland(61.25%)>ploughed land(49.43%)>stubble land(48.42%).Fine sand(0.1-0.25 mm) was dominant in semi-fixed dune land,its content was 52.69% in topsoil and 54.53% in sub-surface layer;② Soil organic matter content in topsoil was generally in an order of grassland(18.75 g·kg-1)>ploughed land(12.53 g·kg-1)>stubble land(11.25 g·kg-1)>semi-fixed dune land(8.13 g·kg-1),and that in sub-surface layer was in an order of grassland(13.36 g·kg-1)>stubble land(13.05 g·kg-1)>ploughed land(12.67 g·kg-1)>semi-fixed dune land(7.73 g·kg-1);③ Correlation analysis of soil granularity and organic matter content showed that there was a significant positive correlation between organic matter content and silt content in stubble land and semi-fixed dune land,and a very significant positive correlation between organic matter content and moderate sand and fine sand in ploughed land,which revealed that the soil organic matter content in ploughed land was unstable and easily affected by other factors. References | Related Articles | Metrics

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Land Use/Cover Change in the Manas River Basin in Recent 57 Years Ayinu Tuxun, ZHANG Qing-qing, XU Hai-liang, ZHAO Xin-feng, ZHANG Peng 2019, 36 (3):  599-605.  doi: 10.13866/j.azr.2019.03.09 Abstract ( 23 )   PDF (1342KB) ( 0 )   In this paper,the land use/cover change in the Manas River Basin in recent 57 years was studied by using the extract vectorized data based on the aerial images in 1958 and the interpretation data of remote sensing images in 1976,1987,1998,2006 and 2015.The results showed that:① The land use/cover change in the Manas River Basin was general from 1958 to 2015,the areas of cultivated land,unused land and construction land were enlarged by 5 116.72 km2,1 543.32 km2 and 513.83 km2,and the proportions of their total areas were increased by 15.27%,4.6% and 1.53%,respectively;while the proportions of grasslands,woodlands and waters were decreased by 13.5%,5.3% and 2.55% respectively;② According to the analyzed results of dynamic land use change,the change of construction land in the Manas River Basin in recent 57 years was the most significant with an annual change rate of 12.37%,and it was followed by the change of cultivated land with an annual change rate of 6.01%;in addition,the annual change rates of unused land,woodlands,grasslands and waters were 0.21%,-0.99%,-0.54% and -1.39% respectively;③ The land use change resulted in the change of the landscape pattern and towards a fragmental structure in the watershed.From 1958 to 2015,the numbers of patches of cultivated land,grasslands and unused land were increased most significantly,they were increased by 8.50×105,6.54×105 and 2.68×105 respectively;on the contrary,the average areas were reduced by 1.83 km2,26.11 km2 and 20.26 km2 respectively,thus the fragmentation of cultivated land and grasslands occurred.Therefore,the analysis of land use/cover change in the Manas River Basin is of great significance for revealing the internal mechanism of land use change,promoting the rational development of land and water resources in the basin,and maintaining the regional ecological security. References | Related Articles | Metrics

Plant and Plant Physiology

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Distribution Pattern of Caragana roborovskyi Population Based on Ripley’ s K(r) Function LIU Min-xia, XIA Su-juan, NAN Xiao-ning, LI Quan-di, JIANG Xiao-xuan 2019, 36 (3):  606-613.  doi: 10.13866/j.azr.2019.03.10 Abstract ( 17 )   PDF (1543KB) ( 0 )   The spatial pattern and correlation of Caragana roborovskyi at different age levels on different slope aspects in Gaolan County,central Gansu Province was analyzed by using the Ripley K function in the point pattern analysis.The results showed that the C.roborovskyi population in class I and II was dominant in the whole population,and the population regeneration was good.The C.roborovskyi population in class I was clustered in the whole study scale,and that in class II,III and IV was distributed randomly on north slope.On the northwest slope,the population in class I was distributed in an obvious aggregation,that in class II was mostly in a small-scale aggregation and in a random large-scale aggregation,and that in class III and IV was randomly in any-scale aggregations.On the southwest slope,all the age classes of C.roborovskyi were distributed randomly on all scales.On different slopes,the population in class I and II was negatively correlated on the small scale,and it was unrelated with the increase of scale.The population in class III and IV was not related on any scales.In addition,the population at all other age levels was negatively correlated.The population regeneration of C.roborovskyi was not only affected by interspecific and intraspecific competition,but also related to the habitat conditions at different slope aspects.When C.roborovskyi was used to restore and rebuild the soil erosion area in central Gansu Province,the 4 m line spacing between shrubs was suitable on southwest and south slopes,and 3 m one was suitable on northwest and the north slopes. References | Related Articles | Metrics

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Effects of Carbonization Temperature and Time on the Yield and Physicochemical Properties of Biochar from Salicornia europaea MAO Ming-yue, ZHAO Zhen-yong, WANG Shou-le, TIAN Chang-yan 2019, 36 (3):  614-620.  doi: 10.13866/j.azr.2019.03.11 Abstract ( 11 )   PDF (891KB) ( 0 )   Xinjiang is the largest area where saline soil is distributed in China,and rich in resources of halophytes with high capability of accumulating salt. In this paper,the effects of carbonization temperature and time on biochar yield and physicochemical properties of Salicornia europaea were analyzed.The results showed that the carbonization of S.europaea could effectively increase the values of pH,EC and ash content,in which the pH value could be reached to 10.37 and the ash content could be increased by 57.51%-110.98%.With the increase of carbonization temperature (300-600 ℃),the pH,EC and ash content of biochar were increased significantly,but the biochar yield was decreased.The contents of water-soluble Ca2+,Mg2+,total C and total N were decreased with the increase of temperature (≥400 ℃),but the contents of water-soluble Na+,K+,total P and total K were increased.In addition,with the increase of carbonization time,the pH,EC and contents of ash and water-soluble ions were increased gradually,but the content of total C was decreased.According to the physicochemical properties and preparation cost of biochar,it was considered that the best carbonization time was for 2 hours.This study could provide a reference for selecting the raw materials for improving acidic soil under biochar and the optimization of plant biochar preparation process. References | Related Articles | Metrics

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Soil Enzyme Activity and Its Affecting Factors under Pinus sylvestris var. mongolica Plantation in Sandy Land YU De-liang, LEI Ze-yong, ZHANG Yan-song, YU Dong-wei, ZHOU Yan-ping, JIANG Ji-wen 2019, 36 (3):  621-629.  doi: 10.13866/j.azr.2019.03.12 Abstract ( 412 )   PDF (1057KB) ( 595 )   The path analysis was used to analyze the soil physicochemical factors and 5 kinds of soil enzyme activities under the Pinus sylvestris var.mongolica plantation with 10-60 year stand ages in the Zhanggutai area of Liaoning Province.The results showed that the 5 kinds of soil enzyme activities in the study area were significantly correlated with most soil physicochemical factors,so the soil enzyme activities could be used to characterize the comprehensive soil fertility in this region.The main factors affecting the different soil enzyme activities were different,and the main factors affecting the sucrose enzyme were the contents of organic matter,clay and available phosphorus as well as pH value.The main factors affecting the protease were the contents of alkali-hydrolyzed nitrogen,available potassium and soil moisture.The main factors affecting the phosphatase were the contents of total phosphorus,available potassium and powder.The main factors affecting the catalase were the pH value,bulk density and contents of total phosphorus and total potassium.The main factors affecting the urease were the pH value and the contents of clay,total nitrogen and soil moisture.Compared with the simple correlation analysis,the path analysis could be used to better understand the relationship between soil enzyme activity and soil physicochemical factors.It is expected to provide a basis for soil improvement under Pinus sylvestris var.mongolica plantation through studying the main factors affecting soil enzyme activity. References | Related Articles | Metrics

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Grape Recognition Model Based on GF-1/WFV Time Series: A Case Study in Hongsibu District of Ningxia ZHAO Xi-ni, WANG Lei, LIU Ya-qing, QU Xiang-ning, XU Xing, WANG Rui 2019, 36 (3):  630-638.  doi: 10.13866/j.azr.2019.03.13 Abstract ( 3 )   PDF (1642KB) ( 0 )   Grape is one of the most widely distributed fruit tree species,and its accurate spatial distribution is of great significance for the management and development of grape planting and wine industry.In this study,the Hongsibao in Ningxia was taken as the study area to obtain the time series of spectrum data in grape growing season based on the Gaofen-1 satellite (GF-1/WFV),the J-M distance analysis was used to analyze the normalized difference vegetation index (NDVI) of the grape plots,and the best recognition phase was determined.The NDVI values of the best phase,adjacent to the value difference rate and curvilinear integral training samples were put into the Clementine data mining software.The extract grape model of decision tree was developed by using C5.0 decision tree classification algorithm and combining with the expert experience method.The results suggested that the established recognition model could meet the needs of grape recognition,but the accuracy was different from different grape plots due to their different coverage.The overall accuracy based on the decision tree classification was 93.71%,and the Kappa coefficient was 0.91.In which the production precision and users' precision of the grape plots with moderate or low coverage were 90.82% and 88.56%,and those with high coverage were 92.44% and 91.18%,respectively. References | Related Articles | Metrics

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Effects of Soil Moisture Stress on Biomass Allocation of Medicago sativa cv.Xinjiangdaye LIU Jia, LUO Yong-zhong, CHEN Guo-peng 2019, 36 (3):  639-644.  doi: 10.13866/j.azr.2019.03.14 Abstract ( 12 )   PDF (1062KB) ( 0 )   In this study,Medicago sativa cv.Xinjiangdaye was taken as the experimental material,and the pot culture experiment was adopted to reveal the change of component biomass of Medicago sativa cv.Xinjiangdaye under different soil moisture stresses (the field capacities were 85%,65% and 45% respectively).The results showed that:① Under slight water stress,the values of dry weight biomass,taproot length,branch number and leaf number of Medicago sativa cv.Xinjiangdaye were the highest;② The number,dry weight biomass,proportion and growth rate of fine roots of Medicago sativa cv.Xinjiangdaye were in an order of severe water stress>slight water stress>full water supply;③ The allocation proportion of component biomass under different soil water stresses was different.Under full water supply and slight water stress,the proportion was in an order of stem component>leaf component>root component>flower component;under the severe water stress,however,it was in an order of root component>stem component>leaf component>flower component;④ Under slight water stress,the rhizome ratio and the ratio between underground biomass and aboveground biomass were the best,and the plants adapted to the dry environment and could grow healthly.The study results could provide a scientific basis for revealing the efficient water use mechanism of crops and theoretical basis for increasing the yield of Medicago sativa cv.Xinjiangdaye in arid and semiarid regions. References | Related Articles | Metrics

Water and Climate

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Extremely High Temperature and Circulation Features in Xi'an in 2017 and 2014 LI Bo, CHEN Ting, WANG Nan, HUA Deng-xin, WANG Qian 2019, 36 (3):  645-656.  doi: 10.13866/j.azr.2019.03.15 Abstract ( 743 )   PDF (4051KB) ( 695 )   A comparative study on the basic features and causes of high temperature in Xi'an during the period from 2017 to 2014 was carried out based on the observed and analyzed data from the meteorological station and the National Center for Environmental Prediction.The main results were as follows:① High temperature occurred with a conventional modal in Xi'an in 2014.However,high temperature occurred one month in advance (unconventional) in 2017,and this was mainly because that the South Asia High (SH) was stronger than that in the same period in conventional years;② It was dry high temperature in Xi'an and different from the muggy high temperature in south China.Moreover,the diurnal-nocturnal temperature variation was low;③ The typical circulation features related to the high temperature in Xi'an were described in detail,including mainly the simultaneously enhanced SH and Western Pacific Subtropical High (WH);④ SH was an important heat source affecting northwest China according to this study.Under the favorable conditions of deeply meridional circulation,heat air was transported southeastward to the downstream region (e.g.Xi'an) by strong wind; ⑤ With the configuration of up-convergence and down-divergence,sinking airflow was clearly found under the 500 hPa level,and other meteorological factors were also favorable for the occurrence of high temperature in Xi'an. References | Related Articles | Metrics

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Spatial Distribution and Formation Causes of Frequent Dust Weather in West Inner Mongolia LI Kuan, XIONG Xin, WANG Hai-bin, LI Gang-tie 2019, 36 (3):  657-663.  doi: 10.13866/j.azr.2019.03.16 Abstract ( 496 )   PDF (3227KB) ( 526 )   West Inner Mongolia is an important aeolian dust source in East Asia and even in the world.The data including regional geomorphic types,surface sediment composition,and days of sandstorm,dust weather and strong wind in recent 20 years were analyzed to characterize the spatial distribution and reveal the formation causes of dust weather in this region.The results showed that the exposed dried salt lakes rich in silt,sand and clay,deserts and sandy land,such as the Ejina,Guaizi Lake,southern marginal zone of the Tengger Desert and the northwest marginal zone of the Mu Us Sandland,were the sources of occurring dust weather.However,the occurring frequency of dust weather was relatively low in the areas where the silt,clay and moisture contents in topsoil as well as the vegetation coverage were high.Nevertheless,dust weather occurred frequently in the areas with high dust content in topsoil and moderate vegetation coverage.In summary,there was a spatial difference in occurring frequency of dust weather due to the variations of geomorphologic background and other natural factors,such as the surface sediment composition,soil moisture content,vegetation coverage and wind force. References | Related Articles | Metrics

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Automatic Recognition Technology of Weather Systems Resulting in Drought Based on Graphics SHAO Jian, HU Wen-dong, YANG You-lin, PEI Xiao-rong, ZHENG Peng-hui 2019, 36 (3):  664-669.  doi: 10.13866/j.azr.2019.03.17 Abstract ( 8 )   PDF (876KB) ( 0 )   Based on the pattern recognition technique and weather systems which could cause drought were tested with tracking algorithm and vector analysis methods by using MICAPS,NCEP and EC-Thin data.The results showed that:① Synoptic scale troughs and ridges could be recognized with tracking algorithm,and their curvature characteristics could also be obtained; ② By using these methods,the recognition rates of pressure center could be as high as 90%,and the mean errors were lower than 0.5°.However,the recognition rates of troughs varied in a range of 74%-87%,and the mean errors in a range of 0.7°-1.4°.With revising the wind field,the accuracy was obviously improved,and the errors were reduced to some extent,which could basically meet the needs of predicting drought. References | Related Articles | Metrics

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Drought Trend over the Grasslands in the Tianshan Mountains, Xinjiang in Recent 55 Years Based on SPEI GUO Yan-yun, HU Qi, FU Wei-dong, WANG Sen, LIU Yan 2019, 36 (3):  670-676.  doi: 10.13866/j.azr.2019.03.18 Abstract ( 10 )   PDF (1115KB) ( 0 )   Calculated by standardizing the difference between potential evapotranspiration and precipitation,the standardized precipitation evapotranspiration index (SPEI) shows the drought degree deviation from normal conditions.As an ideal indicator for analyzing the drought evolution trend,SPEI is widely used in drought assessment,water resources management and other fields.The characteristics of the temperature,precipitation,temporal distribution and variation of the temperature,precipitation,slight,moderate and severe drought frequencies and their trends in growing season of grasslands were analyzed using the SPEI method based on the monthly mean air temperature and monthly precipitation at 8 meteorological stations over the Tianshan Mountains in Xinjiang during the period from 1961 to 2015.Results showed that the annual temperature in the study area was in a significant increase trend in recent 55 years.The precipitation was generally in a slight increase trend with a larger inter-annual variability,but the change trend was not significant.The numbers of drought events at monthly,seasonal,semi-annual and annual scales in the Tianshan Mountains were 42,25,16 and 7 respectively.The frequencies of slight,moderate and severe drought in growing season of grasslands were 37.5%,7.1% and 1.8% respectively.In recent 55 years,the climate over the grasslands in the Tianshan Mountains in growing season of grasslands became dry,and the annual degree of drought changed dramatically,which affected significantly the growth of the grasslands. References | Related Articles | Metrics

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Quantitative Evaluation of Climate Quality Based on Multiple Indicators:A Case Study on Lycium chinense Growth in East Hexi Corridor GUO Xiao-qin 2019, 36 (3):  677-683.  doi: 10.13866/j.azr.2019.03.19 Abstract ( 5 )   PDF (886KB) ( 0 )   Quantitative evaluation method is the key to scientifically evaluate the climate quality of agricultural products. Based on the multiple coupling index system, in this paper a quantitative evaluation model of climate quality was established by using the entropy weight valuation method and fuzzy comprehensive evaluation method. The indicators of sunshine, temperature, water, etc. during the growth period of Lycium chinense in east Hexi Corridor were used to evaluate the suitable and extreme disastrous meteorological conditions. The evaluation model of extreme disaster impact was established by grading the main meteorological disaster threshold indexes. The comprehensive evaluation model of climate quality was established by combining the meteorological evaluation and production area evaluation. This method could be used as the basis of quantitatively evaluating the climate quality for L.chinense growth. At the same time, this method could also provide a reference for the quantitative assessment of climatic quality for the growth of similar agricultural products. References | Related Articles | Metrics

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Transport of Wind-Drift Sand in Photovoltaic Electric Field in Sand Area CHEN Xi, GAO Yong, ZHAI Bo, LIU Xiang-jie, CHENG Bo 2019, 36 (3):  684-690.  doi: 10.13866/j.azr.2019.03.20 Abstract ( 7 )   PDF (1568KB) ( 0 )   A photovoltaic power station in sand area was taken as the research object to study the transport of wind-drift sand at the front and back eaves of photovoltaic plates and the photovoltaic array roadways so as to figure out the migration of wind-drift sand at different spatial positions of the photovoltaic electric field in sand area.The results showed that:① The sand transport rate at the array was decreased with the increase of height.The optimal fitting equations of sand transport rate at the observation points along the eaves and back eaves of the electric plate and the array roadways were all the polynomial functions with the increase of height.The values of R2 were all higher than 0.95,and the fitted results were reliable;② The eigenvalues of wind-drift sand flow structure at the front and back eaves of the electric plate were higher than 1,and the wind-drift sand flow was unsaturated.The eigenvalues of wind-drift sand flow structure at the array roadways were lower than 1,and the wind-drift sand flow was saturated.The electric plate played a guiding role for wind-drift sand transport.As an airflow acceleration zone formed at the bottom of the electric plate,a wind erosion occurred at the bottom of electric plate.Therefore,the bottom of electric plate should be the key area of wind erosion prevention;③ The sand transport rate at all the observation points in the arrays was lower than that in open field.Therefore,the windward marginal zone of the photovoltaic power station should be the key of preventing wind erosion. References | Related Articles | Metrics

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Precipitation Effectiveness in Desert Steppe in Inner Mongolia:Based on Monitoring of Storm Precipitation in Sonid Right Banner FANG Ting-ting, YAN Yong-zhi, LIU Qing-fu, ZHU Ling, HAN Fang, ZHANG Qing 2019, 36 (3):  691-697.  doi: 10.13866/j.azr.2019.03.21 Abstract ( 524 )   PDF (1050KB) ( 376 )   Climate change has become as one of the global issues in common concern.Water is one of the main limiting factors in semiarid grasslands.The change of precipitation pattern results in the change of soil moisture status.The effect of precipitation events on soil moisture content in desert steppe was studied based on the analysis of the daily precipitation data from May 2015 to December 2016 and the daily continuous observation data of soil moisture content at different depths (0-10 cm,10-20 cm,20-30 cm,30-40 cm and 40-50 cm).The results showed that:① The effect of precipitation on topsoil (0-10 cm and 10-20 cm) moisture content was the most significant,and there was a significant positive correlation between the soil moisture content of these two layers and precipitation.The response of soil moisture content of other three layers to precipitation events was not significant;② The minimum volumes of effective precipitation to 0-10 cm and 10-20 cm soil layers were 6.4 mm and 8.33 mm respectively;③ Inferred the minimum effective precipitation,it was found that the conversion rate of effective precipitation to soil moisture in 0-10 cm layer could be as high as 95%,but it was mostly about 70%;it could be as high as 90% in 10-20 cm soil layer,but it was mostly about 50%. References | Related Articles | Metrics

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Water Vapor Sources of Short-Time Heavy Rainfall in Xinjiang Based on Specific Humidity-Adjusted Lagrangian Modelel ZHANG Ya-ning, ZHANG Ming-jun, WANG Sheng-jie, DU Ming-xia, MA Rong, ZHOU Su-e, MENG Hong-fei, YU Xiu-xiu 2019, 36 (3):  698-711.  doi: 10.13866/j.azr.2019.03.22 Abstract ( 8 )   PDF (5880KB) ( 0 )   The Lagrangian Backward Trajectory Model was used to research the moisture sources of short-time heavy rainfall in Xinjiang based on the change of specific humidity and the hourly observed data from China Ground Weather Station,GDAS meteorological data and NCEP/NCAR data during the period of 2016-2017.The results showed that:① Water vapor sources of Xinjiang were mainly the Caspian Sea,Black Sea,Mediterranean Sea,Atlantic Ocean,Arctic Ocean and nearby inland areas.Xinjiang was affected by the westerly wind all the year round,especially the westerly wind in the south; ② The water vapor transport paths in the Altay-Tacheng Forest Grassland Natural Area and the Desert Natural Area in the Junggar Basin were holistically northerly,and the Ili-Bayanbulak (the central Tianshan Mountains) Natural Area and Hami-Turpan Desert Natural Area were strongly affected by the land water vapor sources,and the water vapor transport path in the Extreme Arid Desert Natural Area in the Tarim Basin was holistically southerly.The result of cluster analysis revealed that the water vapor in the Altay-Tacheng Forest Grassland Natural Area came from Europe; it in the Desert Natural Area in the Junggar Basin came mainly from Central Asia,the Caspian Sea and Mongolian Plateau; and it in the Extreme Arid Desert Natural Area in the Tarim Basin came mainly from the Tarim Basin,West Asia,Central Asia and the Black Sea; ③ After judging the water vapor replenishment by specific humidity,the backtracking path became short,and the water vapor came mainly from Central Asia,the Black Sea,Caspian Sea and nearby land.The water vapor transmission from the main sources needed 3.5 days in average.Seasonally,the water vapor sources were the closest in summer and far in autumn.Regionally,the sources were the farthest in the Altay-Tacheng Forest Grassland Natural Area and the closest in the Hami-Turpan Desert Natural Area; ④ Precipitation in Xinjiang was mainly affected by the northerly and southerly westward airflows,and the northward westward airflow contributed more than the southerly westward one. References | Related Articles | Metrics

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Cloud Macro-Features over the Qilian Mountains and Central Gansu Based on Satellite Remote Sensing SONG Qi-ming, ZHANG Wu, SU Ya-qiao, CHEN yan, YANG Kun, ZHAO Gui-qing, CAO Gang 2019, 36 (3):  712-722.  doi: 10.13866/j.azr.2019.03.23 Abstract ( 13 )   PDF (2592KB) ( 0 )   In this study,the CloudSat and CALIPSO satellite remote sensing data from 2007 to 2010 and the precipitation data provided by China National Meteorological Information Center (CMDC) from 1996 to 2016 were used to analyze the macroscopic characteristics of different cloud types over the Qilian Mountains,central Gansu Province and the Shiyang River Basin.The results showed that the seasonal variation of total cloud fraction over the each research area was consistent,and its high values occurred mostly in spring and summer.The areas with high values of total cloud fraction were mainly located in the southern slope of the Qilian Mountains as those with high values of precipitation.The maximum value of cumulus cloud fraction occurred in summer,and the precipitation frequency of cumulus cloud was higher than that of stratiform cloud.Single-layer cloud was dominant,and its thickness was over 2.0 km.The maximum thickness of single-layer cloud over central Gansu was 3.0 km in spring.The thickness of two-layer clouds was thicker than that of three-layer clouds.Cumulus cloud and single-layer cloud producing precipitation occurred more frequently.The distribution trend of cloud frequency with the height over each research area was similar,the altitude of stratiform cloud ranged from 0.5 km to 12.0 km in altitude,and the peak frequency appeared around 6.0 km in altitude.The distribution altitude of cumulus cloud frequency was obviously lower than that of stratiform cloud,and the peak value occurred around 1.5 km in altitude. References | Related Articles | Metrics

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Radial Growth of Trees in Response to Climatic Factors in the Altay Mountains,South of Kazakhstan LIU Rui, WANG Yong-hui, JIANG Sheng-xia, ZHANG Rui-bo, QIN Li, Bulkajyr T.Mambetov, Nurzhan Kelgenbayev, Daniyar Dosmanbetov, Bagila Maisupova, ZHANG Tong-wen 2019, 36 (3):  723-733.  doi: 10.13866/j.azr.2019.03.24 Abstract ( 894 )   PDF (1866KB) ( 422 )   The response of the radial growth of two tree species to climatic factors before and after a sudden rise of regional temperature in 1988 was analyzed based on the research of Picea obovata and Larix sibirica on the southern slope of the Altay Mountains in Kazakhstan.The results showed that there was a good correlation between the two standardized chronologies of the two tree species,and also a high consistency with the stage of low-frequency change and a high reliability of chronological series change.The GLK values of the two chronologies were high,which indicated that their radial growth was consistent.The radial growth of P.obovata and L.sibirica was faster at their young forest age but slower from the middle forest age to the mature forest age in the study area.The variation trend of tree-ring width index of these two tree species was consistent before and after the sudden rise of temperature.Before the sudden rise of temperature,the tree-ring width index of these two tree species increased unsignificantly with a slow decrease of precipitation and a slow increase of temperature.However,after the sudden rise of temperature,the tree-ring width index of P.obovata and L.sibirica was in a significant decline trend with the slow increase of annual precipitation and annual average temperature.This showed that there was a negative impact of climate change on the growth of trees,and the growth of these two tree species might be slowed down after the sudden rise of temperature.Under global warming,the radial growth of P.obovata and L.sibirica was mainly restricted by temperature,and the influence of precipitation was relatively low.The response of L.sibirica to temperature was slightly stronger than that of P.obovata.Holistically,there was a unsignificant difference in response of the radial growth of these two tree species to climate change.The response of the growth of these two tree species to climatic factors before and after the sudden rise of regional temperature in 1988 was analyzed.The results showed that,during the period from 1960 and 1988,there was a significant negative response of tree-ring width of L.sibirica to the precipitation in May that year,and to the temperature in August last year.There was a significant positive correlation between the radial growth of P.obovata and the precipitation in July of that year,but a significant negative correlation between it and the temperature in August last year.During the period from 1989 to 2016,the response of L.sibirica to the precipitation in May was no longer significant.Instead,there was a significant negative correlation between the growth of L.sibirica and the temperature in May of that year and in August last year.There was a weaker positive correlation and a higher negative correlation between the growth of this tree species and the temperature in growth season,or a change from positive correlation to negative correlation.The significant correlation between the radial growth of P.obovata and the precipitation disappeared.Instead,a negative correlation with temperature strengened,especially in August and October last year.The results showed that the positive response of the tree-ring width of P.obovata and L.sibirica to precipitation decreased but the negative response to temperature increased after the sudden rise of temperature.The response of the radial growth of P.obovata and L.sibirica to climatic factors might different after the sudden rise of temperature. References | Related Articles | Metrics

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Relationships Among O3,VOCs and NOx Concentrations over Kuitun City GUO Yu-hong, ZHU Qiao-qiao, YANG Chun, WANG Hai-lin, ZHANG Xiao-xiao, LIU Wen-jiang, YANG Rong-jiang, TIAN Qing 2019, 36 (3):  734-742.  doi: 10.13866/j.azr.2019.03.25 Abstract ( 8 )   PDF (2989KB) ( 0 )   In this paper,the relationships among O3,VOCs and NOx concentrations over Kuytun City,Xinjiang,northwest China during the period of 2013-2015 were analyzed using the environmental monitoring data.Results showed that an apparent overload of O3 concentration occurred over Kuytun City.O3 concentration over the city was overloaded for 33,14 and 10 days during the period of 2013-2015,and the daily maximum concentrations of O3 were 0.457,0.396 and 0.385 mg·m-3,respectively.The heavy pollution of O3 occurred in summer,and the value of O3 concentration was 2.5 times higher than that in winter.The curve of diurnal variation of O3 pollution was reversely “U-shaped”,and the peak value occurred around 17:00 o’clock.The concentration of VOCs in summer was 3 times higher than that in winter,and there was no significant diurnal variation.It was observed that the high concentration of VOCs and low concentration of O3 occurred in winter.In summer,VOCs concentration changed with NOx accordingly,and O3 concentration was the highest.This study indicated that the O3 pollution occurred mainly in the sensitive areas of VOCs and NOx,and controlled alternatively by VOCs and NOx. References | Related Articles | Metrics

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Ecological Compensation of A Desert Water-Lifting Irrigation Project Based on Opportunity Cost of Ecosystem Service Value:A Case Study on Jingtaichuan Water-Lifting Irrigation Project ZHAO Jian-lin, DONG Zhi-yang, CHANG Zhao-feng 2019, 36 (3):  743-751.  doi: 10.13866/j.azr.2019.03.26 Abstract ( 2 )   PDF (1532KB) ( 0 )   In this paper,the ecological compensation of a desert water-lifting irrigation project was discussed,the ecological service values of vegetation increased by emigration from the Qilian Mountains to the Jingdian Irrigated Area were calculated by factor equivalence,the ecological service values by reducing sandstorm in the leeward area were estimated using cosine distance formula,and the opportunity cost was also calculated.The results showed that: ① Ecological compensation should be based on the opportunity cost of the external ecosystem service value.The ecological service value of the Jingdian Irrigated Area from the Qilian Mountains ecological migration to vegetation regeneration of the Qilian Mountains is 4.01×109 yuan RMB,and the ecosystem service value by reducing sandstorm in the leeward area is 7.09×107 yuan.Opportunity cost of the ecological migration is 2.05×108 yuan,and the opportunity cost of controlling sandstorm in the leeward area is 3.63×106 yuan; ② The main beneficiaries of vegetation regeneration by ecological migration from the Qilian Mountains to the irrigated areas are the counties in the Shiyang River Basin and Jingtai County in the eastern Qilian Mountains in the Yellow River Basin.The state is also one of the beneficiaries.Subjects of the compensation are Gansu Province and Administration of Jingtaichuan Water-lifting Irrigation Project; ③ The prevention and control of desertification and sandstorm and the protection of national ecological forest are the emphases of ecological environment construction in China.Ecological compensation is conducive to driving and promoting the development of similar public welfare undertakings,and vigorously promoting the national ecological environment construction. References | Related Articles | Metrics

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Heavy Metal Pollution in Urban Soil and Environment Quality in Yinin WU Shan-shan, SUN Hui-lan, ZHOU Yong-chao, ZHOU Ling 2019, 36 (3):  752-760.  doi: 10.13866/j.azr.2019.03.27 Abstract ( 3 )   PDF (3099KB) ( 0 )   A total of 52 soil samples were collected from the topsoil beside the main roads in the downtown of Yining,and the contents of 6 heavy metals (Hg,Cr,Ni,Pb,Cu and Zn) were determined by spectrophotometer.The environmental quality related to heavy metal pollution in urban soil was studied by using CF and PLI index based on geostatistics.The results showed that: ① The mean values of Hg,Ni,Pb and Cu in topsoil were 2.75,1.48,2.60 and 1.52 times higher than the background values of soil in Xinjiang respectively,and neither Cr nor Zn exceeded their background values of soil in Xinjiang.In addition to Pb,the contents of other elements did not exceed the level Ⅰ of national soil environmental quality (mg·kg-1); ② The 6 elements in urban soil were all distributed in point and planar patterns,and high values of all these elements occurred in urban soil in the study area,which indicated that human activities,such as economic production,industrial development and road traffic,had negative effects on soil habitats; ③ The Hg and Pb pollution was serious,and the Ni and Cu pollution was slight.Cr and Zn accounted for 17.31% and 82.69% at slight pollution level and 23.08% and 59.62% at non-pollution level,respectively;④ The mean CF values of these elements in urban soil in the study area were in an order of Pb>Hg>Ni>Cu>Zn>Cr.The mean value of heavy metal PLI was 1.20,which indicated that the urban soil was slightly polluted.Pb pollution was more serious than other heavy metals. References | Related Articles | Metrics

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Establishment of Assessment Model for Debris Flow Susceptibility:A Case Study Along the Yangtang River Reach in Shimen Township in the Bailong River Basin WANG Gao-feng, YANG Qing, TIAN Yun-tao, YE Zhen-nan, CHEN Zong-liang, GAO You-long, GUO Ning, DENG Bing 2019, 36 (3):  761-770.  doi: 10.13866/j.azr.2019.03.28 Abstract ( 1 )   PDF (4056KB) ( 0 )   In this study,the hierarchy analysis,GIS means and normalized values of 9 evaluation factors,such as loose material surface density,stratigraphic lithology,tectonic fracture density,seismic density,slope aspect,soil erodibility,land use type,slope length and gradient,gully bed slope and gully density,and average annual rainfall,were used.The purposes of the study was to develop an assessment model for debris flow susceptibility along the Yangtang river reach in Shimen Township in the Bailong River Basin.Finally,the grid diagram of assessing debris flow susceptibility in the study area was divided into 4 grades.The results showed that the proportion of the areas with high debris flow susceptibility accounted for 51.04% of the whole study area,and the areas with mid-high debris flow susceptibility accounted for 68.71%.The debris flows were distributed along the large active fault zones,especially in the zones with intensive secondary fractures and small folds.They were also distributed along the slidable strata,especially in the zones with dense gullies.Debris flow occurred easily on the slopes with high soil erosion.The results were tested by the database of debris flow in the study area. References | Related Articles | Metrics

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Information Extraction of Desert Surface Types Based on UAV Image PENG Jia-yi, WANG Xin-jun, ZHU Lei, ZHAO Chen-yi, XU Xiao-long 2019, 36 (3):  771-780.  doi: 10.13866/j.azr.2019.03.29 Abstract ( 6 )   PDF (2933KB) ( 3 )   Based on the images of unmanned aerial vehicle (UAV),in this study the surface type information of the Gurbantunggut Desert was extracted,and the object-oriented multi-scale segmentation was used to extract the information of the sample plots of surface types from the spectrum,shape,texture and vegetation index.The results showed that:① The best segmentation scale for the different desert surface types was different;② The features of surface types with different desertification levels were similar and could not be distinguished by single characteristics;③ Compared with the pixel-based maximum likelihood method,the object-oriented multi-scale segmentation method was improved significantly.The overall classification accuracies of the object-oriented slightly,moderately and seriously desertified areas were 93.00%,91.83% and 93.50% respectively,and they were 10.34%,11.86% and 12.50% higher than those of the pixel-based maximum likelihood method.The results revealed that the object-oriented multi-scale segmentation method could be used to extract the desert surface type information with high accuracy for the UAV visible image. References | Related Articles | Metrics

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Extraction of Crops in Oasis Based on GF-1/WFV Time Series LIU Ya-qing, WANG Lei, ZHAO Xi-ni, QU Xiang-ning, XU Xing, WANG Rui 2019, 36 (3):  781-789.  doi: 10.13866/j.azr.2019.03.30 Abstract ( 8 )   PDF (1739KB) ( 0 )   The rapid extraction of regional crops is of great significance for agricultural production management,planting structure adjustment and optimization,and food security.The use of time series data of remote sensing image for extracting crops is an important means,and the time resolution and spatial resolution are constraints.The time resolution of medium spatial resolution of remote sensing data is significantly improved with the successful launch of the first satellite GF-1 of China High-resolution Earth Observation System.However,the seasonal rhythm features of crops differ greatly under different climate backgrounds.The Hetao Oasis is irrigated by the Yellow River.It has an ecological landscape with obvious microclimate effect.The extraction of remote sensing data of crops is typical and representative.The Hetao Oasis in Ningxia is selected as the study area to analyze and evaluate the applicability of GF-1 satellite data in extracting crops.According to the characteristics of crop planting in the study area,the four main crops including rice,corn,wheat and alfalfa were extracted.Firstly,the GF-1/WFV image was calculated by band,and the NDVI and NDWI time series of remote sensing data sets were obtained.The values of NDVI and NDWI of the main crops were extracted,and the time series curves of NDVI and NDWI were constructed.The time series data of remote sensing indexes of the main crops were analyze,the farming information was determined to extract the phases and thresholds of the crops,construct the decision tree and extract the crops.The time series data of natural grasslands,reed and grape and of other vegetation types were combined to establish the CART decision tree so as to verify the classification effect of the correlation time series and the decision tree constructed by the farming information.The results are as follows:① The morphological characteristics of time series curves were different from different farming ways,and the NDVI time series data could be used to describe the growth status of crops in different periods; the NDWI time series data obtained from GF-1/WFV could be used to describe the soil moisture status of different crops and reflect the different irrigation systems of different crops in the study area.The NDVI time series and the NDWI time series could be used to accurately express the surface dynamic change information of the surrounding areas of the study area,correlate the crop time series with farming information,and effectively recognize different crops;② Compared with the CART decision tree,the decision tree of classification phase,classification threshold and classification accuracy constructed by combining different crop farming information and main crop curve features were similar.These indicated that the farming ways were different from different crops in the study area,and the time series of corresponding NDVI and NDWI values were significantly different. References | Related Articles | Metrics