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25 June 2011, Volume 28 Issue 3 Previous Issue    Next Issue

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Distribution of Soil Moisture Content in Different Types of Sand Dunes in the Southeastern Marginal Zone of the Mu Us Sandy Land FU Chao-feng, ZHAO Jing-bo 2011, 28 (3):  377-383.  Abstract ( 2140 )   PDF (467KB) ( 1329 )   The study area is located in the southeastern marginal zone of the Mu Us Sandy Land, and it is a semiarid climate area with annual precipitation of 394.7 mm. Based on the investigation in the study area in late-April 2009, the sand dunes were divided into bare migratory dunes, shrub-covered dunes and tree-covered dunes according to the vegetation types and vegetation coverage on the sand dune surface, and the samples of drilling holes of 4 m in depth at different topographic sites of the dunes were taken for analyzing the change of soil moisture content and soil granular properties of the sand dunes. The results are as follows: (1) Average soil moisture content at depth of 4 m was different from different dune types, that of the shrub-covered dunes and tree-covered dunes was in an order of dune intervale>windward slope>leeward slope, but that of the bare migratory sand dunes was in an order of dune intervale>leeward slope>windward slope. Furthermore, the variation of soil moisture content at different depth of each dune type was different, and that of shrub-covered dunes at different depth was more significant than that of the tree-covered dunes and bare migratory dunes; (2) Vegetation types and surface vegetation coverage affected the variation of soil moisture content of dunes at the same topographic positions of different dune types. Results of the test show that the soil moisture content on windward slope was in an order of shrub-covered dunes>tree-covered dunes>bare migratory dunes, it on leeward slope was in an order of shrub-covered dunes>bare migratory sand dunes>tree-covered dunes, and it at dune intervale was in an order of shrub-covered dunes>tree-covered dunes>bare migratory dunes; the variation coefficient of soil moisture content of shrub-covered dunes was higher than that of other dune types, the soil moisture content of shrub-covered dunes at different depth fluctuated more obviously compared with that of other dune types, and the shrubs and trees growing over the sand dunes affected obviously the change of soil moisture content of sand dunes; (3) Shrubs intercept strongly atmospheric dust. The average silt and clay content of the shrub-covered dunes was higher than that of other dune types, which reveals that the shrubs are beneficial to the loamification and soil moisture conservation of sand dunes. Therefore, it is valuable to plant shrubs for preventing and controlling desertification in the Mu Us Sandy Land. References | Related Articles | Metrics

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Effect of Two Kinds of Soil Ameliorant on Saline Soil Improvement and Cotton Growth ZHANG Jiang-hui, BAI Yun-gang, ZHANG Sheng-jiang, CAO Wei 2011, 28 (3):  384-388.  Abstract ( 1813 )   PDF (391KB) ( 1278 )   Soil salinization has been the main obstacle for agricultural development in arid area. It has been a focus how to improve saline or alkaline soil. In this paper, the experiments of different ameliorants named Handilong and Hekang under different irrigation ways were carried out to test their respective effects on soil improvement, cotton growth and cotton yield. The experiments show that, after applying the ameliorants, the soil sallinity in cotton field under drip irrigation was decreased, the desalinizalion ratios were 30.3% and 17.7% respectively, but the desalinizalion ratio was only 10.4% in the contrast field; the analysis on soil Na+ composition by means of sodium adsorption ratio reveals that Handilong was the most effective in reducing detrimental ion Na+ in soil. Compared with the contrast group, the cotton plant growth including cotton height, density, number of fruit-bearing shoots, buds and bolls as well as their weight was significantly improved after applying Handilong and Hekang, the unginned cotton yields per hectare were as high as 3 549.0 kg and 3 451.5 kg and increased by 618 kg (21.1%) and 522 kg (17.8%), and the incomes per hectare were increased by 2 491.5 and 1 371.0 yuan RMB, respectively. References | Related Articles | Metrics

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Effect of Surface Roughness on Runoff over Cultivated Soil in the Longdong Loess Plateau NIU Yi-ning, NAN Zhi-biao, SHEN Yu-ying 2011, 28 (3):  389-393.  Abstract ( 2069 )   PDF (330KB) ( 1376 )   A simulated rainfall experiment was carried out to investigate the runoff and rainfall storage capacity under different surface roughness levels of cultivated soil in the Longdong Loess Plateau. The rainfall simulation was carried out at the Qingyang Experimental Station of Lanzhou University, a rain-fed agricultural production zone in the west Loess Plateau. The rainfall intensity was 66 mm/h in the field after winter wheat was harvested. The values of soil surface roughness were measured. There were three treatments: light roughness (LR, RR=7.6 mm), moderate roughness (MR, RR=10.1 mm) and heavy roughness (HR, RR=21.0 mm). The results show that the proportion of cumulative runoff in total rainfall was 16% for LR plots and 10% for MR plots, whereas it was only 4% for HR plots when rainfall continued for 20 minutes. When rainfall continued for 40 minutes, the proportion of cumulative runoff for HR plots was 8%, whereas it ranged from 21% to 25% for the LR and MR plots. The last or steady runoff rate was similar under three treatments (LR, 35 mm/h; MR, 38 mm/h; HR, 33 mm/h). This suggests that the soil surface with high roughness could store more water at the beginning of rainfall, but this trend was diminished with the continuance of rainfall. It is concluded that fallow could store more water through increasing soil surface roughness. References | Related Articles | Metrics

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Volume Fractal Characteristics and Significance of Soil Particles in the Shenmu Colliery in North Shaanxi Province SHI Zhan-fei, WANG Li, WANG Jian-guo 2011, 28 (3):  394-400.  Abstract ( 1952 )   PDF (415KB) ( 1525 )   Soil is produced from the parent material by weathering. Soil particle composition inherits many properties of parent material, one of which is fractal dimension. PSD affects not only the soil hydraulic conditions and fertility, but also relates directly to the soil erosion and degradation. In this study, a laser particle size analyzer was used to measure the particle size distribution of 60 soil samples collected from the Liangshuijing, Sidaogou and Hongjiannao coal mining areas in Shenmu Colliery. Soil particle volume fractal dimension (D) was obtained with volume fractal dimension model. In the meantime the relationships between D value and soil physicochemical properties were analyzed. The results showed that the D value varied in a range of 1.95-2.68, and its average was 2.42. The average D values of the Sidaogou, Hongjiannao and liangshuijing coal mining areas were 2.47, 2.43 and 2.33 respectively. There was a significant positive correlation between D value and clay and silt content (P<0.01), but a significant negative one between D value and sand content (P<0.01). There was also a significant positive correlation between D value and pH value and total phosphorus content, but there was no significant correlation between D value and the contents of organic matter, total nitrogen and available potassium. Moreover, the effect of diminant vegetation types on D value was in an order of Stipa bungeana > Caragana microphylla > Astragalus adsurgens > Artemisia Capillaris > arbors. References | Related Articles | Metrics

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Application of Stable Isotope Techniques in the Study on Soil Salinization CUI Yong-qin, MA Jian-ying, SUN Wei, LIU Xiao-ning, WANG Shao-ming 2011, 28 (3):  401-407.  Abstract ( 2383 )   PDF (421KB) ( 1545 )   It has been an increasing trend of the studies in ecological research using stable isotope techniques since recent two decades. In this paper, the progress of the application of stable isotope techniques in the study on soil salinization at home and abroad is briefly reviewed. As the new but useful techniques, stable isotope techniques have been widely applied in the studies on the dynamic change of soil water evaporation, soil salinization and soil improvement as well as the salt-tolerant plant breeding. However, the mechanisms of the impacts of various environmental factors on plant isotope composition need to be carefully studied, since most researches have focused on the impacts of single factors on plant isotope composition. To gain the insights in soil salinization and soil improvement, especially soil salinization in arid and semiarid areas, it is essential to combine and compare the stable isotope techniques and other methods, such as the field observation and remote sensing technology. References | Related Articles | Metrics

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Experimental Study on the Impact of pH Value on Fluoride Release from Lacustrine Sediments in the Low Plain in West Jilin Province LIU Xuan, LIANG Xiu-juan, ZHOU Yu-bo, JIN Cheng-ji, XIAO Xiao 2011, 28 (3):  408-412.  Abstract ( 1788 )   PDF (372KB) ( 1317 )   In the experimental study, three lakes named Huaaopao, Daozipao and Dabusupao in west Jilin Province were selected as the study area to investigate the long-term (28 days) fluorine release from lacustrine sediments and the impact of pH value on fluorine release. The results show that the quantity of fluorine released from lacustrine sediments varied in a range of 37.31-223.03 mg/kg. The release rate of fluorine from lacustrine sediments to alkaline water varied in a range of 1.88-22.53 mg/(kg·d), and that from lacustrine sediments to acidic water varied in a range of 0.71-5.41 mg/(kg·d). The high release rate of fluorine from lacustrine sediments to alkaline water was mainly caused by the processes of fluorine solution containing minerals, peculiar adsorption of iron and aluminum oxides and replacement of clay containing fluorine with OH-. The complexation-dissociation of free iron and aluminum is the key factor that the quantity and rate of fluorine release from lacustrine sediments were increased slightly with the decrease of pH value and the increase of acidity. References | Related Articles | Metrics

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Study on Ecological Management and Building of Green Infrastructure in Arid Area —A Case Study in the Lower Reaches of the Tarim River TANG Xiao-lan, DU Yao 2011, 28 (3):  413-420.  Abstract ( 1966 )   PDF (666KB) ( 1625 )   In this paper, the current ecological degeneration and the degeneration of the "Green Corridor" in the lower reaches of the Tarim River in Xinjiang, caused by shortage and reduction of water resources, are analyzed. It is found that overflow of the natural river channel is the main factor affecting the health of the "Green Corridor", and the mechanism mode of regenerating the ecology in such arid area is put forward based on delimiting the extent of ecological water demand for regenerating the ecology in the lower reaches of the Tarim River. It is suggested to design and build the stream system and the green infrastructure with artificial wetlands, river corridor, ecological network, landscape geomorphology and outdoor activities. The stream system and the green infrastructure should be maintained by taking some project and natural measures so as to change the original spontaneous vegetation into the vegetation under the combination of spontaneous regeneration and human intervention, and achieve the goal of regenerating the necessary functions of ecosystem and of realizing self-sustaining. References | Related Articles | Metrics

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Study on Optimized Redistribution of Water Resources in Well-canal Irrigated Area Based on Stochastic-determination Model HE Yi, ZHU Tianduowa 2011, 28 (3):  421-426.  Abstract ( 1459 )   PDF (542KB) ( 1116 )   Situated in Shaanxi Province of northwest China, the Jinghui Canal Irrigated Area is a typical area irrigated with both pumped groundwater and canal-diverted surface water. The Jinghui Canal Irrigated Area belongs to a continental semiarid climate region with high temperature and relatively plentiful rainfall in summer, and it is cold and arid with high evaporative capacity in winter. In fact, groundwater has been the main water source for most water demands in this area, including agriculture, industry and livelihood. However, water consumption has been dramatically increased with rapid industrial and agricultural development, population growth and sharp reduction of surface runoff inflow, and groundwater is pumped in big volume in most areas. The overdraft of groundwater has caused many problems. On account of irrational groundwater utilization, a continuous drawdown of groundwater level occurs and results in a series of environmental geological problems, such as the cone of depression, subsidence of land and deterioration of water quality. Therefore, it is significant to study how to develop and utilize groundwater resources rationally and how to redistribute irrigating water in an optimized way in the irrigated area. At present, the most urgent challenges for the local government are how to perform the rational redistribution of irrigating water resources and realize the sustainable development of this irrigated area so as to solve the relevant water issues caused by groundwater overexploitation. In recent decades, the researchers at home and abroad have adopted large amounts of methods to study the optimized redistribution of water resources in various irrigated areas in China. However, most of the current studies focus on the numerical solution of optimized redistribution per se, as a result, some significant facts are ignored, such as the impacts of mechanism conditions including geology, hydrogeology and environment in research areas. In order to employ the research results in practice, the Visual Modflow software is used as a platform, and a groundwater stochastic-determination model (GSDM) is developed based on time-series model and radial basis function neural network model (RBF-ANN) to make an intensive analysis of water pattern on a basis of prediction model of groundwater regime for Jinghui Canal Irrigated Area.The results provide a useful and powerful basis for the sustainable development and utilization of groundwater and optimized redistribution of water resources in irrigated areas. References | Related Articles | Metrics

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Hydrochemical Properties of Shallow Groundwater along the Weihe River in Huaxian County and Huayin City, Shaanxi Province LAI Kun-rong, JIANG Jun, LIU Xiu-hua, ZHOU Wei-bo 2011, 28 (3):  427-432.  Abstract ( 1864 )   PDF (630KB) ( 1186 )   The Weihe River flows through Huayin City and Huaxian County. According to the analyzed results of shallow groundwater samples collected in Huayin City and Huaxian County, in this paper the spatial hydrochemical properties and their evolution of groundwater are studied systemically. The results show that shallow groundwater in the study area is mainly recharged by groundwater from the Qinling Piedmont, and it in the areas along the riverbanks relies mainly on the lateral recharge of the Weihe River. The hydrochemistry type in the areas of groundwater recharge, runoff and discharge changes from HCO3·SO4-Ca·Mg to SO4·HCO3-Na·Ca and then to SO4·Cl-Na; the salinity and hardness of groundwater increase gradually and reach to their maximum values in the funnel-shaped zone of groundwater; Cl-, Mg2+ and Na+ are gradually accumulated, and groundwater quality trends to salinization. The study results can provide the references for understanding the effect of the Weihe River on groundwater quality in the areas along the river and for rationally utilizing groundwater resources in the study area. References | Related Articles | Metrics

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Classification of Snowmelt Flood and Analysis on Its Formation Causes in the Kumalak River Basin FU Hua, JIA Li-hong, XIAO Ji-dong, LI Cong, FENG Zhi-min 2011, 28 (3):  433-437.  Abstract ( 2690 )   PDF (426KB) ( 1866 )   Base on the information of satellite observation (EOS/MODIS) and the meteorological and hydrological data observed by the meteorological and hydrological stations in the Kumalak River Basin, this paper analyzes the formation causes of snowmelt flood and the relations between the change of snow cover depth and the meteorological factors in the Kumalak River Basin during the period of 2002-2008, and studies the weather system and the meteorological factors resulting in the mixed and snowmelt flood in the drainage basin. The results show that snowmelt caused by high temperature is the cause of flood during the period from mid-July to mid-August. The change of 0 ℃-level height over the drainage basin in summer can be regarded as a good index of predicting flood. Snowmelt flood in midsummer is dominant in the Kumalak River Basin. References | Related Articles | Metrics

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Monitoring and Analysis on Overflow in the Hotan River Basin Based on MODIS Data ZUO Min, CHEN Hong-wu, WANG Lei, FENG Zhi-min, WANG Hai-lei 2011, 28 (3):  438-443.  Abstract ( 1619 )   PDF (511KB) ( 1418 )   In this paper, the overflow in the middle and lower reaches of the Hotan River in summer was monitored and analyzed using the visual interpretation, supervised classification in ENVI 4.5 and functions of localization, measurement and layer overlay of ArcGIS 9.2. The results are as follows: (1) The overflow in the middle and lower reaches of the Hotan River was very serious, and the overflow in the irrigated areas in oasis should also be paid attention to; (2) Compared with other river sections, the overflow in the marginal zone of the oasis in the middle reaches was low, the overflow area was smaller than 35 km2 at 94.4% monitoring dates, and there was no overflow at 45% monitoring dates. At the intersection of the section from Keshen Mishen to the old river channel and the Hotan River, the overflow areas were all larger than 35 km2 at 45% monitoring dates except that there was no overflow on August 5, 2004 and July 29, 2008. Overflow along the river section from the intersection of the old river channel and the Hotan River to Xiaota was the most serious, the overflow area was larger than 70 km2 in the most cases and 111 km2 in maximum; (3) There were 10 overflow sites in total in the drainage basin, in which 4 overflow sites and 1 new floodplain were distributed along the left riverbank of the Hotan River, and 4 overflow sites and 1 new floodplain were distributed along the right one; there was also a overflow site on the left riverbank of the Karakax River. The overflow sites were mainly distributed along the mainstream of the Hotan River. References | Related Articles | Metrics

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Experimental Study on Artificial Groundwater Recharge in Valley MA Xing-hua, HE Chang-ying, LI Wei, JIN Jia-qiong 2011, 28 (3):  444-448.  Abstract ( 2027 )   PDF (475KB) ( 1553 )   In this study, the groundwater recharge experiments by pit irrigation and well irrigation were carried out in a valley by measuring the attenuation of recharge volume and the variation of permeability coefficient so as to analyze the recharge effect. The results show that the attenuation of pit irrigation recharge volume was 24% at the metaphase and 40% at the last stage respectively, the rise of groundwater level varied in a range of 1.1-1.3 m, but the formed water dome was small, which reveals that the horizontal permeation capability of the test layer was high. The attenuation of well irrigation recharge volume was 33%, it was stable at the last stage, and the permeability coefficient of the aquifer was gradually decreased with the increase of distance away from the main hole. Recharge volume and permeability coefficient decreased rapidly at the early stage, then they were decreased gradually till relatively stable, and such process was universal. Mechanical blockage of pores was caused by suspended solids in the pit and well irrigation experiments, for the pit irrigation experiment, slurry was more direct, the groundwater recharge by irrigation was decreased with the increase of mud cake thickness. It is considered that the large-scale groundwater recharge should be dominated by pit irrigation. References | Related Articles | Metrics

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Study on Particle-size Properties of Suspended Load in Glacier Runoff from the Tomor Peak GAO Wen-hua, LI Zhong-qin, ZHANG Ming-jun 2011, 28 (3):  449-454.  Abstract ( 1849 )   PDF (441KB) ( 1110 )   Based on the data of suspended load in Glacier No.72 runoff at Qingbingtan in the Tomor Peak region, measured in August 2008, in this paper the mathematical statistical method is used to find out the particle size properties of suspended load in glacier runoff. The results show that the suspended load was dominated by fine materials, there was a high fluctuation in the contents of grain-size components of suspended load, the proportions of particles <63 μm, >63 μm and <4 μm were 68%, 32 % and 1.34 % of the total suspended load respectively, and their distribution curves were bimodal. There were different relationships between silt content and grain size of suspended load. With an increase of silt content, sand-sized material increased, but silt-sized and clay-sized materials decreased. There was no significant relationship between particle size parameters and discharge. Such weak correlation reveals that the suspended load of glacier runoff is mainly affected by the sand-silt source regime, ice-snow melt water can increase sand-sized material, and precipitation events can increase the silt-sized material. References | Related Articles | Metrics

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Study on Water Resources and Its Utilization in Kyrgyzstan WU Miao, ZHANG Xiao-yun, WANG Li-xian, CHEN Xi, ZHANG Jie-bin, BAO An-min 2011, 28 (3):  455-462.  Abstract ( 3270 )   PDF (566KB) ( 2391 )   Kyrgyzstan is one of the countries with the most abundant water resources in Central Asia, and several large regional transboundary rivers rise in it. However, as a result of dominant mountain landscape features of the land, most of fresh water resources in Kyrgyzstan is distributed in forms of alpine glaciers, lakes and deep groundwater, and the proportion of stream water in water resources is low, so it is difficult to develop fresh water resources. Spatially, there is a positive correlation between the distribution of stream water and the altitude. The lakes are mainly located in the alpine zones. The distribution of glaciers is related to the altitude and aspect. In the field of development and utilization of water resources, Kyrgyzstan is rich in hydroenergy, and some large reservoirs have been built along the rivers. In field of water utilization of society and economy, surface water is a major source, and agricultural water consumption is dominant in total water consumption and also the main factor affecting water consumption in recent years. There is also a relative shortage of irrigation water in Kyrgyzstan because of the imperfect water facilities, low water use efficiency, policies of sharing transboundary water resources, reduction of some waters, water pollution, etc. under the combined impact of both natural and artificial factors. References | Related Articles | Metrics

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Progresses in Evapotranspiration Research and Prospect in Desert Oasis Evapotranspiration Research ZHAO Wen-zhi, JI Xi-bin, LIU Hu 2011, 28 (3):  463-470.  Abstract ( 3452 )   PDF (372KB) ( 2958 )   Evapotranspiration is one of the most important processes in both the hydrologic and ecological cycles in desert oasis system. Because of the dominant role of water resources in oasis ecosystem, observation and simulation of evapotranspiration (ET) flux are fundamental to the effective management of water resources in such environment. Recent progresses in evapotranspiration research are reviewed in this paper from a multi-scale perspective (e.g. leaf, individual, field and landscape). It was highlighted that following aspects should be included and focused on in future research: (a) Application of eddy covariance technique in researching oases with intense heterogeneity and uneven surface; (b) Partition of evapotranspiration between plant transpiration and soil evaporation and the spatiotemporal dynamics and driving and regulating mechanisms of evapotranspiration; (c) Estimation of the instantaneous and cumulative evapotranspiration; (d) observation, simulation, comparison and validation at multiple scales, such as the research plots, irrigated area and oasis. References | Related Articles | Metrics

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Study on Dew Formation in Linze in the Middle Reaches of the Heihe River YU Shao-wen, SUN Zi-yong, ZHOU Ai-guo, DUAN Li-jun 2011, 28 (3):  471-477.  Abstract ( 2164 )   PDF (597KB) ( 1320 )   Dew plays an important role in maintaining ecosystems in arid area. In order to study the dew formation, a series of observations on dew yield were conducted in Linze County, Zhangye City in the middle reaches of the Heihe River during the period from June to September 2008. The results are as follows: (1) Dew formed only when the board temperature was lower than dew point, and dew yield and occurred times were decreased with the increase of distance away from the Heihe River and of groundwater depth as well as the decrease of vegetation coverage; (2) Dew occurred for 52, 34 and 13 times and the accumulated dew yields were 4.26 mm, 1.52 mm and 0.63 mm in riparian zone, oasis and desert respectively during the period from June 20 to September 17, 2008. There was also a temporal variation of dew yield at all three observation sties; (3) Dew intensity and average dew yield were increased from dry season to rainy season, and vice versa; and (4) It is found that rainfall is favorable for increasing dew yield at all three sites, and dew could form in desert only if previous rainfall exceeded a certain amount. Air relative humidity, weather and wind speed also affect dew formation. References | Related Articles | Metrics

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Long-term Change of Ground Temperature in the Shiyang River Basin LIU Ming-chun, LI Ling-ping 2011, 28 (3):  478-484.  Abstract ( 1763 )   PDF (630KB) ( 1052 )   In this paper, the variation trend, abrupt change and anomalous years of annual and seasonal ground temperature in the Shiyang River Basin in 47 years are analyzed based on the monthly ground temperature data observed in the upper, middle and lower reaches of the drainage basin during the period of 1961-2007. The results show that the ground temperature was holistically in an increase trend, and it was decreased during the period from the 1960s to the 1970s, increased in the mid-1980s, and increased obviously during the period from the 1990s to 21st century; the increase of ground temperature was the highest in the lower reaches, then in the middle reaches, and it was the lowest in the upper reaches. Ground temperature in the Shiyang River Basin in spring, summer and winter was in a decrease trend during the period from the 1960s to the 1980s but in an increase trend in autumn of the 1980s, and the seasonal ground temperature was increased during the period from the 1990s to 21st century. Ground temperature increase made a contribution to heat increase in spring and winter, and the maximum and minimum ground temperatures occurred in July and January respectively. Temporally, there were the ground temperature fluctuation periods of 6-7 a and 9-10 a in the Shiyang River Basin, a sharp ground temperature increase has occurred since 1989, and the low ground temperature occurred mainly during the period from the late-1960s to the 1970s. References | Related Articles | Metrics

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Analysis on the Change of Sunshine Duration and Its Affecting Factors in the Tianshan Mountains in Recent 50 Years XIN Hong, ZHANG Ming-jun, LI Rui-xue, GAO Wen-hua 2011, 28 (3):  485-491.  Abstract ( 2494 )   PDF (608KB) ( 1302 )   In this paper, the annual and seasonal trend variation of sunshine duration in the Tianshan Mountains in China is analyzed using linear trend analysis based on the data of monthly sunshine duration, mean cloudage and precipitation from 24 meteorological stations in the mountains from 1960 to 2009. By using the method of IDW under ArcGIS, the spatial distribution of sunshine duration is analyzed so as to research the regional difference. The results show that the average annual sunshine duration in the Tianshan Mountains was significantly decreased in recent 50 years with a decreasing rate of 32.9 h/10 a. The change of seasonal sunshine duration was different, and the sunshine duration was decreased with a rate of-19.4 h/10 a in winter but increased with a rate of 0.7 h/10 a in spring. In addition, the sunshine duration in the 1960s was long in summer, autumn and winter, but short in spring. The positive anomaly of sunshine duration occurred in all seasons in the 1970s, especially in autumn. The sunshine duration was long in spring and winter but short in summer and autumn, and a negative anomaly of annual sunshine duration occurred in the 1980s. During the period from the 1990s to the beginning of the 21st century, the annual sunshine duration was short, especially in winter of the 1990s. Since the 21st, the sunshine duration was short in autumn and winter, but it was slightly increased in spring and summer. Moreover, more anomalous years of annual sunshine duration occurred in the 1960s, whereas less ones occurred in the 1990s. The results reveal that the change of sunshine duration is related to precipitation and cloudage. References | Related Articles | Metrics

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Study on Climatic Differentiation in the South and North Qinling Mountains in Recent 50 Years SONG Dian-xing, YAN Jun-ping, MA Li 2011, 28 (3):  492-498.  Abstract ( 2978 )   PDF (687KB) ( 1337 )   As for regionality, the study emphases of global climate change are always in the ecological fragile regions and the transitional zones of physical geographic areas, such as the coastlines, mountains and the gradient zones with sufficient moisture. The Study on climate change in the south and north Qinling Mountains is of important significance in studying global climate change. In this study, the values of mean annual and seasonal temperature and precipitation were calculated based on the data observed by the meteorological stations in the south and north Qinling Mountains so as to analyze the climate change trend from the aspects of temperature and precipitation anomalies, 5-year sliding tendency and long-term sliding tendency. In order to investigate the sharp climate change, the Mann-Kendall, sliding T and Yamamoto test method were plied. The results reveal that the average temperature in the south and north Qinling Mountains was in an increase trend, but there was a certain difference in the sharp change time and range: the sharp temperature increase (0.034 ℃/a) in the north Qinling Mountains occurred in 1989, especially in summer and winter, but that (0.014 ℃/a) in the south Qinling Mountains occurred in 1992, especially in summer and winter similarly. Precipitation in the south and north Qinling Mountains was decreased, it was decreased by 2.66 mm/a in the north Qinling Mountains and by 1.36 mm/a in the south Qinling Mountains, respectively, and its reduction was high in summer and autumn in the northern Qinling Mountains but in spring and autumn in the south Qinling Mountains. References | Related Articles | Metrics

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New Progress of the Study on Climate Change in Xinjiang HE Jin-yun, ZHANG Ming-jun, WANG Peng, XIN Hong, HUANG Xiao-yan 2011, 28 (3):  499-508.  Abstract ( 2608 )   PDF (462KB) ( 2102 )   Global warming has attracted much more attention all over the world. In this paper, the new progress of the studies on climate change in Xinjiang since the 1990s is reviewed from the aspects of fact, impact, countermeasure and prediction of climate change. The results are as follows: (1) Holistically, both temperature and precipitation in Xinjiang have been increased, and climate in Xinjiang has trended towards warming-wetting type since recent 50 years; (2) Such climate change results in a redistribution of water and heat resources in Xinjiang and brings about a tremendous effect on water resources, ecological environment, agriculture, etc.; (3) The ecosystem vulnerability assessment is a quantitative evaluation on ecological environment. The studies on it, however, are so insufficient and need to be further explored. Moreover, there is a big uncertainty of predicting climate change, and all the models of predicting climate change are need to be improved so as to increase the prediction accuracy. References | Related Articles | Metrics

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Envirenmental Response to Variation of the Atmospheric Maximum Mixing Depth in Urumqi ZHAO Ke-ming, LI Xia, YANG Jing 2011, 28 (3):  509-513.  Abstract ( 2215 )   PDF (409KB) ( 1223 )   It is well known that Urumqi is one of the cities with the severest air pollution in China and even over the world. A large numbers of researches on calculation methods of maximum mixing depth (MMD) and relations between MMD and air pollutant concentration have been performed in the world in recent 50 years. However, there have been only a few studies focusing on the characteristics of MMD over Urumqi and the impacts of MMD on local air quality so far. According to the fundamentals of estimating MMD by the assumption of a dry adiabatic lapse rate and method of stepwise approach, in this paper the MMD values in Urumqi were calculated and their variable characteristics and relations with air pollution were analyzed based on the daily surface and sounding meteorological data observed during the period from January 2003 to April 2009. The result reveals that the annual change of monthly mean MMD was singly periodic. That is, the minimum value (389 m) of monthly mean MMD occurred in January but the maximum value (2 071 m) occurred in June. The occurrence frequency of MMD over 2 000 m during the period from April to September was higher than 50%. Moreover, the occurrence frequency of MMD below 500 m during the period from November to next February was relatively high. There was a negative correlation between air pollution index and MMD. As the air pollution level was increased, the MMD values with peak occurrence frequency was correspondingly decreased, that is, the MMD is one of the important factors affecting local air pollution, and there is an exponential relation between the daily mean PM10 concentration and the MMD. References | Related Articles | Metrics

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Analysis on the Heavy Rainstorms in Shaanxi Province in Relation to Typhoon Far Away LI Ming, GAO Wei-ying, DU Ji-wen, HOU Jian-zhong 2011, 28 (3):  514-523.  Abstract ( 1842 )   PDF (1615KB) ( 1175 )   This paper analyzes three rainstorms in Shaanxi Province in 21st century in relation to typhoon far away. The results show that there were the high-pressure systems over central-east Chinese Mainland, they made the westerly trough or plateau trough move slowly over the Great Bend of the Yellow River, the main function of typhoon was to transport a large amount of water vapor by its easterly wind, or to obstruct warm-wet air to flow eastward and drive warm and wet air to move northward into Shaanxi Province; the 200-hPa upper jet axis trend played an important role in the heavy rainstorms; the heavy rainstorms relied on the 850-hPa frontogenesis center or nearby frontogenesis axis; the warm-wet air end of energy ratio axis of "Ω" systems in surface cold front aroused easily the mesoscale convective cloud cluster. References | Related Articles | Metrics

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Application of Ecological Footprint in Evaluating Regional Sustainable Development Based on Energy Analysis Theory —A Case Study in Gansu Province ZHAO Xue-yan, LIU Shuang, ZHAO Hai-li 2011, 28 (3):  524-531.  Abstract ( 1671 )   PDF (461KB) ( 1011 )   Sustainable development has become as a common view in the world. Along with rapid economic development and population growth, a series of contradictions, such as ecological degeneration and land degradation, have to be faced. In order to maintain the sustainable development, humanity must live within the limits of natural carrying capacity. In the 1990s, Rees and Wackernagel put forward an ecological footprint model, in which an easy and rapid method was offered to measure the environmental situation of eco-economic system. In the theory and method, however, there are some shortcomings to evaluate regional sustainable development. Energy theory offered by Odum H T was applied widely to track energy flow and evaluate ecological benefits and economic returns in eco-economic system. In this paper, the energy analysis and the conventional ecological footprint model were used to quantitatively evaluate the ecological footprint in Gansu Province during the period from 2000 to 2008. The results are as follows: (1) During the period from 2000 to 2008, the per capita ecological carrying capacity in Gansu Province was maintained at 55.5-63 hm2 and was in a decrease trend; (2) The ecological footprint was rapidly increased with an average annual increase rate of 10.6%; (3) The ecological deficit was rapidly increased with an average annual increase rate of 10.6%; (4) Continued high consumption of energy resources was the main cause resulting in the ecological deficit. Based on the conclusions above, some strategies were put forward for promoting sustainable development in Gansu Province. References | Related Articles | Metrics

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Analysis on Ecological Footprint of Grasslands in Plain Blue Banner, Inner Mongolia HAI Quan-sheng, Alatengtuya, NING Xiao-li, Baosachuronggui 2011, 28 (3):  532-536.  Abstract ( 1828 )   PDF (433KB) ( 1197 )   Ecological footprint is always obtained by the conversion of beef. This kind of means, however, is not suitable for the severely degenerated grasslands. At present, most domestic researchers quote the fixed conversion factor to calculate ecological carrying capacity. In this paper, the ecological footprint method, "RS" means and field research are integrated to research the temporal and spatial change of the ecology footprint by taking townships in Plain Blue Banner of Inner Mongolia as the study units based on ecological footprint theory. The deficiency of the fixed conversion factor is improved and the regional suitability of ecological footprint model is increased after adjusting the grassland yield factor. On which the values of ecology footprint in all the townships are calculated and analyzed. The results show that the ecological footprint requirement was exceeded the ecological carrying capacity in all the townships in 2005, which reveals that the utilization degree of local resources and the current development mode have become as a threat to the implementation of sustainable development strategy in the study area. References | Related Articles | Metrics

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Analysis on Species Diversity and Flora of Cruciferae in the Karakorum Mountains of China XU Xiao-min, MA Zhen, TAO Jin, YAN Ping 2011, 28 (3):  537-541.  Abstract ( 2871 )   PDF (366KB) ( 1552 )   There are 66 species and 1 variety in 32 genera of Cruciferae in the Karakorum Mountains of China, in which there are 20 species in 20 monotypic genera, 22 species in 9 oligotypic genera and 24 species in 3 multiplicate genera. At the level of genera, the proportion of monotypic genera and oligotypic genera is dominant (90.63%). At the level of species, the difference among them is not significant. Hemicryptophytes of Cruciferae are dominant (69.69%) in the study area, and therefore they are the dominating components in the plant life form spectrum in this area, then followed by annual plants, and their proportion is 28.79%. The flora contains 8 areal types and 6 subtypes, the proportion of north temperate elements is as high as 33.33%, and the main distribution type is temperate nature in this area. Compared with the peripheral regions, the similarity coefficients of the Pamirs and the Karakorum Mountains of China are the highest at the level of genera and species, accounting for 71.64% and 52.62% respectively, and then those of the east Himalaya and Afghanistan, accounting for 45.82% and 26.87% respectively at the level of genera, but their similarity coefficients are low at the level of species. References | Related Articles | Metrics

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Analysis on the Factors Affecting Seed Dispersal and Seedling Survival Rate of Ulmus pumila var. sabulosa in the Otindag Sandy Land WANG Xue, HU Chun-yuan, LI Gang-tie, ZUO He-jun 2011, 28 (3):  542-547.  Abstract ( 1934 )   PDF (402KB) ( 1212 )   In this study, the seed dispersal pattern and seedling survival rate of Ulmus pumila var. sabulosa in the Otindag Sandy Land in Inner Mongolia were researched, the seed-dropping quantity of U. pumila var. sabulosa on 5 kinds of land surface including the flat sandy land, windward slope of sand dune, inter-dune lawn, sparse shruberry land and shruberry land was investigated using transect method, and the relationships between the distribution quantity of U. pumila var. sabulosa seeds and the distance from mothertree, surface conditions, vegetation types, coverage and height, and soil moisture content were analyzed. The results show that the distance from mothertree was the main factor affecting seed dispersal, and the effect of other factors was not significant. Precipitation and soil moisture content during the period from June to August were the main factors affecting seed germination and seedling survival rate, and the effect of other factors was not significant. References | Related Articles | Metrics

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Diurnal Activity Rhythm of Goitred Gazelle (Gazella subgutturosa) in Different Seasons XIA Can-jun, XU Wen-xuan, YANG Wei-kang, QIAO Jian-fang, LIU Wei 2011, 28 (3):  548-554.  Abstract ( 2173 )   PDF (527KB) ( 1429 )   The diurnal activity rhythm of Gazella subgutturosa was studied by focal-sampling in the Kalamaili Mountain Ungulate Nature Reserve from november 2007 to november 2008. In the study 1917 individuals of G. subgutturosa were observed, and 319.5-hour activity data were collected. The activities of G. subgutturosa were categorized as foraging, moving, vigilance, rest and "others". The results show that there were two or three foraging peaks of G. subgutturosa everyday, which appeared generally in early morning, late afternoon or midday. Rest peaks appeared usually after foraging peaks, so the activity rhythm of G. subgutturosa was as the serial foraging-resting-foraging. Kruskal-Wallis tests reveal that there was no significant temporal difference in the moving and "others" in spring, vigilance and "others" of females; vigilance of males in fall, "others" of females, moving, rest and "others" of males in winter (p>0.05), but there was a significant temporal difference in other activities (p<0.05). There was also a significant seasonal difference in the activity rhythm of G. subgutturosa. The activity rhythm of G. subgutturosa was affected by the forage quality and quantity, environment temperature, and physiology cycle. References | Related Articles | Metrics

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Molecular Phylogeny of Schizothoracinae Fishes in Xinjiang Based on Mitochondrial Cytochrome b Gene Sequences YANG Tian-yan, MENG Wei, HAI Sa, ZHANG Ren-ming, GUO Yan 2011, 28 (3):  555-561.  Abstract ( 2084 )   PDF (422KB) ( 1458 )   Totally 712 bp fragments of mitochondrial cytochrome b gene of 7 species in 4 genera of Schizothoracinae fishes in Xinjiang were amplified and sequenced. For the Cyt b gene, the average nucleotide contents of T, C, A and G were 30.1%, 27.4%, 25.6% and 16.9% respectively. There were 201 variable sites, of which 162 were parsimony-informative sites, their sequence variability was 22.8%, the transition/transversition was 15.03, and the nucleotide substitution occurred mostly at the third position. Three molecular phylogenetic trees were constructed with different methods, in which the neighbor-joining (NJ) tree and maximum parsimony (MP) tree were based on Kimura 2-parameter method, and the maximum likelihood (ML) tree was based on the best nucleotide substitution model. The results show that there were the close genetic relationships among the primordial-grade Schizothoracinae species and among the specialized-grade Schizothoracinae species. It is referred from the molecular evolution rate that the divergence of the 7 Schizothoracinae species occurred during the period from the late Pliocene to the Miocene with the uplift of the Qinghai-Tibet Plateau. References | Related Articles | Metrics

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A New Record of the Avian in Xinjiang —Pechora Pipit Anthus gustavi Swinhoe,1863 DING Peng, CHEN Ying, MA Ming, YUAN Guo-ying 2011, 28 (3):  562-563.  Abstract ( 3102 )   PDF (311KB) ( 1358 )   On Sep.15th,2010,one bird was found in Hami Region (41°13' N,93°29' E.The altitude is 1 143 m),Xinjiang.Through careful observation and identification of pictures,it is Pechora Pipit Anthus gustavi,a new record of the avian for Xinjiang.The geographical distribution,character,habitat,ecology habit and subspecies of the Pechora Pipit were discussed. References | Related Articles | Metrics