Table of Content

15 January 2014, Volume 31 Issue 1 Previous Issue    Next Issue

Select

Arid Ecological and Geographical Conditions in Five Countries of Central Asia HU Ruji , JIANG Fengqing , WANG Yajun, LI Junli, LI Yaoming，Abdimijit Ableki 2014, 31 (1):  1-12.  Abstract ( 2804 )   PDF (4893KB) ( 4062 )   As an important part of arid land in Central Asia, the five countries, i.e., Uzbekistan, Kazakhstan, Turkmenistan, Tajikistan and Kyrgyzstan are located in the largest arid region in northern hemispheric temperate zone of the terrestrial earth and on northwestern slope of the Pamirs on the west side of the Qinghai-Tibetan Plateau. Moreover, these countries are characterized by very fragile ecosystems, but rich in natural resources, especial energy resources. It is necessary for social and economic sustainable development in these countries to reveal the formation and evolution process of ecological and geographical conditions. Since 1989, many international coresearch programs focused on the issues of regional ecological and geographical conditions in arid land of the Asian inland have been conducted. In this paper, a comprehensive review on previous researches was carried out, and the formation and evolution process and basic ecological and geographical features and conditions in the five countries in Central Asia were discussed so as to prompt the harmonious, balanced and rapid development of society and economy in these countries. References | Related Articles | Metrics

Select

Composition and Distribution of Elements of Different Soil/Deposits in Tajikistan ZENG Hai-ao , WU Jing-lu 2014, 31 (1):  13-19.  Abstract ( 1088 )   PDF (4197KB) ( 1173 )   Tajikistan is a mountainous country in Central Asia and borders by China to the east. The background values of elements and the problems of environment and resources are very important for researching the similar climatic regions in China. In this study, seventeen elements in samples collected from topsoil, lacustrine and fluvial deposits in Tajikistan from September to October 2011 were measured so as to analyze their spatial distribution and further explore the formation causes and affecting factors. The results showed that the mean contents of the elements in all the soils/deposits were in an order of Ca>Al>Fe>Mg>Na>Ti>P>Mn>Sr>Zn>V>Cr>Ni>Cu>Pb>Co>Cd. Based on principal components analysis, it could be primarily considered that the distribution of elements in different soils/deposits were affected by both natural factors and human activities, and their affecting proportions were 60% and 12.6% respectively. The contents of Cd, Cu, Pb and Zn in urban soils and cultivated land soils were higher than that in basement and mountainous soils impacted slightly by human activities. The contents of heavy metals in soils/deposits in the western area with high population density were higher than that in the eastern sparselypopulated region. The Cd content in fluvial deposits near Dushanbe was much higher than that in other areas. The study results revealed that the topsoils/deposits in Tajikistan were gently affected by human activities at all, in some local regions, however, they were polluted by heavy metals in varying degrees. Moreover, Cu pollution was more serious than Pb and Zn pollution, and the Cd pollution was related to the industrial point source pollution. Related Articles | Metrics

Select

The Qarqan River in Xinjiang and Its Water Resources Utilization FAN Zi-li,XU Hai-liang,ZHANG Peng,ZHAO Xin-feng,Abudu Limijit,FU Jin-yi 2014, 31 (1):  20-26.  Abstract ( 1809 )   PDF (2883KB) ( 969 )   The Qarqin River is the largest river in the southeast Tarim Basin, and it is mainly fed by glaciersnow melt water and groundwater. Because of the regulation of the Kumukuli Basin and Tula Basin to runoff from the mountainous region in the upper reaches of the Qarqin River, the change of seasonal runoff volume was stable, the proportion of runoff volume of the Qarqin River in spring was as high as 29% of the total annual runoff volume, and the Qarqan River was one of the rivers with the highest proportion of spring runoff volume in Xinjiang. Such situation reveals that there is basically no shortage of farming irrigation water in the study area in spring. The proportions of farming irrigation water and water consumption for ecology were almost 50% of the total volume of water resources. There were no the large water conservancy projects along the Qarqan River yet. Groundwater level in the study area was still high and an obvious vegetation degeneration had not occurred yet although the oases were continuously expended in the past. Oasis expansion consumed large volume of water, and a certain volume of water had to be transferred from the Qarqan River to the Taitema Lake in recent few years. Therefore, large water conservancy projects should not be built along the Qarqan River so as to keep the original utilization pattern of water resources. Moreover, the 50% proportions of farming irrigation water and water consumption for the ecology should be continuously maintained. The study area is an ideal natural groundwater reservoir, because there was a huge pluvialalluvial fan in the debouchure area of the Qarqan River, and the leakage accounted for 30% of the runoff volume. Therefore, the water consumption for the economic development in the future should be dominated by groundwater.   Related Articles | Metrics

Select

Change Trend of Glaciers in the Hami Region XIE Wei,JIANG Feng-qing 2014, 31 (1):  27-31.  Abstract ( 1643 )   PDF (1233KB) ( 994 )   Glaciersnow melt water in the main form of surface runoff in the Hami region, Xinjiang, China. Affected by global climate warming, the glaciers in the Hami region are currently at the accelerating melt stage, and the shortage of water resources is the main restriction factor for social and economic development in the Hami region. In this study, the values of material balance, area and thickness of glaciers and the hydrological and meteorological data in the Hami region were measured and observed so as to predict the change trend of glacial hydrology and water resources, provide the references for further utilizing limited water resources, and work out the measures for the local sustainable development. The results revealed that the area and thickness of the glaciers in both Yushugou and Miaoergou valleys were in a slow reduction, a violent change of fluvial recharge will not occur in next decades, and such change trend will continue in the future. Related Articles | Metrics

Select

Progresses on the Study of Drought Impact on Surface Water Quality CHENG Bing-fen,YAN Deng-hua,LUO Xian-xiang, WANG Gang, XIAO Wei-hua, FENG Jing 2014, 31 (1):  32-37.  Abstract ( 3220 )   PDF (1174KB) ( 1094 )   As the occurring frequency and intensity of drought is in increase, drought affects both water volume and water quality. Considering from the drought impact to environment, drought events are considered to be more dangerous due to their moderateterm, longterm and largescale impacts. The joint effect of temperature increase and runoff volume reduction results in a deterioration of water quality, and water quality during drought period is also affected by land use change, regional climate change and human activities. Nonpoint source pollutant is currently the main factor resulting in water pollution in drainage basin, and the entering time and content of nonpoint source pollutants are the main factors polluting waters during drought period. A lot of nonpoint source pollutants are eroded into waters due to the accumulation of pollutants during drought period and the increase of precipitation intensity after drought. Therefore, droughtrewetting cycles may impact water quality more significantly. Related Articles | Metrics

Select

Distribution of Soil Moisture under Different Planted Shrubs on the West Loess Plateau LI Xiao-ying , DUAN Zheng-hu , CHEN Xiao-hong , TAN Ming-liang 2014, 31 (1):  38-43.  Abstract ( 1139 )   PDF (1670KB) ( 1139 )   The distribution of soil moisture on slope in the western loess hilly areas was studied based on the observed data of soil moisture content under different shrubs in different habitats with neutron moisture meter. The results showed that soil moisture content was the highest on shady slope, then on semishady and semisunny slopes, and it was the lowest on sunny slope. There was a significant positive correlation between slope aspect and soil moisture storage, and the correlation between slope position and soil moisture storage was not significant. For the same slope aspect, Caragana korshinskii and Helianthemum soongoricum consumed more soil moisture than other shrubs, and the soil moisture consumption of Caragana opulens,C.roborovskyi and Lycium chinense was low. Therefore, the choice of shrubs for regenerating vegetation on different slope aspects should depend on the drought resistance of plant species. Horizontally, soil moisture content increased generally along with the increase of distance away from rhizosphere, but there was a difference of soil moisture content among different soil depth. Related Articles | Metrics

Select

Organic Carbon Density and Storage in Different Soils on the Loess Plateau FU Dong-lei,LIU Meng-yun,LIU Lin,ZHANG Kun,ZUO Jin-xiang 2014, 31 (1):  44-50.  Abstract ( 2082 )   PDF (1509KB) ( 1097 )   Soil organic carbon is an essential material foundation for controlling soil erosion and conserving ecological environment on the Loess Plateau. Adequate acquaintance of soil organic carbon density (SOCD) and soil organic carbon storage (SOCS) are of practically significance for largescale ecological construction. In this paper, SOCD and SOCS in topsoil (0-20 cm) of different soils on the Loess Plateau were estimated based on the data of soil depth, soil organic matter content and bulk density, from the Second National Soil Survey. The results showed that the weighted mean of SOCD was 2.00 kg·m-2, that of brunisolic soil was the highest (15.56 kg·m-2), and that of aeolian soil was the lowest (0.24 kg·m-2). In spatial distribution pattern, SOCD was low in the central area of the plateau but high in the marginal zone. The total SOCS on the Loess Plateau was 1 239.85 Tg, SOCS in grey cinnamonic soil and loessal soil were high and occupied 46.86% of the total, and that in grey desert soil, frozen desert soil and alkali soil were low and accounted for 0.17% only. SOCS in all soils increased gradually from the northwest to the southeast. Loessal soil and aeolian soil were extensively distributed on the Loess Plateau, but their SOCD were low. Therefore, it is very important to increase the organic carbon content in loessal soil and aeolian soil in ecological reconstruction on the Loess Plateau in the future. Related Articles | Metrics

Select

Soil Salinization and Its Causes in the Irrigated Areas along the Yellow River in Gansu Province YANG Si-cun, CHE Zong-xian, WANG Cheng-bao, HUO Lin , JIANG Wan-li 2014, 31 (1):  57-64.  Abstract ( 1520 )   PDF (1077KB) ( 970 )   The irrigated areas along the Yellow River are very important in economic development in Gansu Province. Saline or alkaline wasteland, secondary soil salinization and irrational utilization of water resources are the main factors to restrict the agricultural development. In this paper, the general situation of soil salinization in the irrigated areas along the Yellow River in Gansu Province was expounded. Available data were used to analyze the characteristics of soil salt content, ionic composition and distribution as well as soil pH value and groundwater salinity. The climate, topography, soil parent material and human factors related to the formation of saline or alkaline land were also analyzed. On which some suggestions were put forward for improving soil: ① Partition improvement of saline or alkaline land should be implemented, and the prevention of secondary soil salinization must be paid great attention to; ② Utilization of water and soil resources should be optimized so as to regulate the agricultural industry structure; ③ The efficient utilization of saline or alkaline land in agricultural development should be focused on, and the biological control measures should be strengthened; ④ It is suggested to enhance the utilization of water resources so as to develop the watersaving farming system; ⑤ The dynamic monitoring of water and salt transference should be strengthened so as to develop an earlywarning system of soil salinization. Related Articles | Metrics

Select

Radiation Balance over Riparian Forest Belt in the Lower Reaches of the Tarim River XUE Sha-sha , YUAN Guo-fu, LUO Yi 2014, 31 (1):  65-73.  Abstract ( 1148 )   PDF (1668KB) ( 1111 )   Solar radiation plays a critical role in the process of energy and material exchange over land surface. It is not only the drive force of land surface physical process, but also the input parameter of Land Surface Model and Remote Sensing Model. Researchers focused on the semiarid and arid regions because of its special geographic environment. Therefore this paper took a typical arid area in the lower reaches of the Tarim River as a case to discuss the radiation balance over riparian forest belt and the measured radiation data, and to evaluate the applicability of FAO56 method used to calculate the net radiation in arid region. FAO56 method is used to calculate shortwave radiation through sunshine duration and longwave radiation through air temperature, humidity and cloud amount. Accuracy was evaluated by Model Efficiency (ME), Root Mean Square Difference (RMSD) and Mean Bias Error (MBE). Statistical results of measured values showed that the daily variation of radiation flux was in a typical normal distribution trend. The maximal values of solar radiation, reflected radiation and net radiation occurred at Beijing time 14:00 o’clock and were 629.96 W·m-2, 106.51 W·m-2 and 520.76 W·m-2 respectively. Maximal value of averaged ground surface longwave radiation occurred at Beijing time 16:00 o’clock and was 460.08 W·m-2. As a result, response of surface temperature to solar radiation lagged for about 2 hours. Seasonal difference was highly related to zenith angle and albedo. Annual variation of net radiation was unimodal with a slight interannual fluctuation, the net radiation increased gradually from January to June, reached its maximum in June, and decreased gradually from June to December. Daily total value of net radiation fluctuated between 0.5 MJ·m-2·d-1 and 18 MJ·m-2·d-1, and its average in full year was 7.81 MJ·m-2·d-1. Weather conditions, such as windy or cloudy weather, affected significantly the radiation flux. Wind and cloud could reduce solar radiation and correspondingly reflected radiation. Effective radiation was slightly affected, thus net radiation dropped to some extent compared with that on sunny day. The curve of daily albedo was Ushaped, it was high at sunrise and sunset but low around midday. Albedo was closely related to the stage of vegetation growth. The averaged albedo was 0.18 at vegetation growth stage and 0.20 at nongrowth stage. Simulated result showed that ME values of net shortwave radiation and net radiation were 0.87 and 0.80 respectively. The slopes of the correlation analysis for them were 0.95 and 0.89 respectively, for effective radiation, although ME was 0.19, the slope of the correlation analysis was 0.99. It could be concluded that FAO56 radiation simulation could be applied to calculate net radiation over the lower reaches of the Tarim River. Related Articles | Metrics

Select

Spatial and Temporal Variation of [ NDVI in the Hedong Region of Gansu Province during the Period of 1998 to 2011 YANG Shang-wu ,ZHANG Bo,ZHAO Yi-fei,WANG Qiang,JI Ding-min ,ZHOU Dan 2014, 31 (1):  74-79.  Abstract ( 1155 )   PDF (1302KB) ( 1280 )   Based on the SPOT VGTNDVI data during the period from 1998 to 2011, in this paper the spatial and temporal variation of vegetation coverage in the Hedong region of Gansu Province was systematically studied using the NDVI average method, retrieval of vegetation coverage and linear regression trend analysis. The results show that the NDVI in the north of the Hedong region was lower than that in the south. Temporally, NDVI in the study area in recent 14 years was holistically in an increase trend with an increase rate of 0.028·(10a-1). In which it was decreased in the first 4 years (from 0.392 in 1998 to 0.314 in 2001); in the later 10 years, it was increased in a fluctuation way (from 0.330 in 2002 to 0.378 in 2011). Temporally, NDVI in recent 14 years was in an increase trend in the northerncentral mountainous region in south Gansu Province, southern parts of the central Gansu Plateau, but it was in a certain decrease in the southeast of the east Gansu Plateau and the grasslands in south Gansu Province. Related Articles | Metrics

Select

Change of Vegetation Coverage in the Qilian Mountains in Recent 10 Years WU Zheng-li, JIA Wen-xiong , LIU Ya-rong , ZHANG Yu-shun 2014, 31 (1):  80-87.  Abstract ( 1323 )   PDF (1736KB) ( 1061 )   As the best instruction factor of vegetation coverage, NDVI is regarded as the most effective indicator to monitor regional or global change of vegetation and ecological environment. Based on MODIS NDVI data with spatial resolution of 250 m and climate data during the period from 2000 to 2011, in this paper the spatiotemporal change of vegetation coverage and its correlations with climatic factors in the Qilian Mountains were researched using the methods of maximum value composite, trend line analysis and correlation analysis as well as averaging method. The results showed that the vegetation coverage in the Qilian Mountains increased gradually from the west to the east, and it in the eastern part of the Qilian Mountains was higher than that in the western part. There were some significant spatial differences of vegetation coverage change, for example, it increased in the central and western parts of the Qilian Mountains, but decreased in the eastern part. The area with an increase of vegetation coverage was 79 149 km2 and accounted for 52.93% of the total area investigated in the Qilian Mountains, and the area with a decrease of that was 22 865 km2 and accounted for 11.09％ of the total. The vegetation coverage was in a significant increase trend in recent 10 years, and the monthly vegetation coverage in growth season was also in an increase trend. The increase of vegetation coverage in the Qilian Mountains was caused by the increase of precipitation under global warming. There were the significant correlations between NDVI and temperature and precipitation, and there was also a time lag in their changes. There was a significant correlation between the NDVI in June and July and the precipitation in previous one month and two months, and their correlation coefficients were 0.788 and 0.684, respectively; there was an extremely significant correlation between the NDVI in August and September and the temperature in the same month and previous one month, and their correlation coefficients were 0.825 and 0.829, respectively. Related Articles | Metrics

Select

Community Structure of Planted ]Picea asperata Mast.Forest in Huajialing DUAN Ya-nan , WANG Hui 2014, 31 (1):  88-93.  Abstract ( 1328 )   PDF (1157KB) ( 985 )   In this paper, the planted Picea asperata forest, a typical mode of transforming the low benefit ecological public welfare Populus forest in the Huajialing loess hilly region, was investigated and researched, and the community structure of the Picea asperata Mast.forest in the western, centraleastern and southern parts of the study area was analyzed. The results are as follows: ① The community structure of the planted Picea asperata Mast.forest in the study area was simple, and there was a negative correlation between the structural parameters of arborous layer and of shrub and herbaceous layers; ② The Picea asperata Mast.forest was dominated by young trees with low height and small DBH. Affected by the site conditions, there was a big difference in DBH and height of Picea asperata Mast.trees, and the Picea asperata Mast.forest in the centraleastern part grew better than that in the western and southern parts; ③ Growth of the planted Picea asperata Mast.forest was repressed by the high planting density, the proportion of pure forest was too high, and these were disadvantageous for sustainable development of ecological public welfare forest in the loess hilly region. Related Articles | Metrics

Select

Community Structure and Population Ecological Features of Planted Haloxylon ammodendron in Different Habitats in Minqin Oasis LIU You-jun , LIU Shi-zeng , JI Yong-fu , ZHANG Jing-chun , CHEN Fang , WANG Fang-lin 2014, 31 (1):  94-99.  Abstract ( 1223 )   PDF (791KB) ( 904 )   The important values and the ShannonWiener indexes were analyzed based on carrying out a field investigation on sample plots of planted   [WTBX]Haloxylon ammodendron[WTBZ] communities in different sandy habitats in Minqin Oasis.The planted [WTBX]H.ammodendron[WTBZ] communities were classified into three types,i.e.,the [WTBX]H.ammodendron[WTBZ] (annual herbage) community,[WTBX]H.ammodendron[WTBZ] (annual herbage with shrubs) community and [WTBX]H.ammodendron[WTBZ]shrub community,and these communities were distributed on mobile sand dune,semifixed sand dune and fixed sand dune respectively.With the increase of sandfixed degree,the community succession was ranked from [WTBX]H.ammodendron[WTBZ] community (annual herbage,pioneer community with a coverage of 23% and ShannonWiener index of 0.26) to [WTBX]H.ammodendron[WTBZ] (annual herbage with shrubs with a coverage of 30% and ShannonWiener index of 0.34),and then to [WTBX]H.ammodendron[WTBZ]shrub community (with a coverage of 40% and ShannonWiener index of 0.60).In the succession,the growth of planted [WTBX]H.ammodendron[WTBZ] populations in different habitats was different,a recession of planted [WTBX]H.ammodendron[WTBZ] populations occurred from mobile sand dune to semifixed sand dune and then to fixed sand dune,and such recession was related to soil moisture content. Related Articles | Metrics

Select

Response of Growth of Four Halophyte Species in Oil-contaminated Soil HUANG Jian, TIAN Chang-yan, BIAN Wei-guo, YIN Hai-long, REN Jing, CHEN Chun-xiu 2014, 31 (1):  100-104.  Abstract ( 1219 )   PDF (697KB) ( 981 )   Five treatments with different petroleum pollution levels were designed, and the values of height, fresh weight and rootshoot ratio of 4 halophyte species as well as the total petroleum hydrocarbon content in soil were measured to investigate the adaptability of growth of the tested halophytes in Xinjiang and the improvement of petroleumcontaminated soils. The results are as follows: ① Compared with the blank group, petroleum could promote the growth of the 4 tested plant species, but the difference of plant growth was not significant when the petroleum concentration in the oilcontaminated soil was 0.5%; ② Growth of the tested plant species was restricted with the increase of petroleum pollution degree, and the leaf scorch and even death of Salicornia europaea and Atripex aucheri in growth season occurred when the petroleum pollution concentrations were 1.5% and 2.0% respectively, and the growth of these halophytes could be maintained for about 20 days; ③ The oilcontaminated soil could be improved to a certain degree after a 120day phytoremediation, and the decomposition efficiency of total petroleum hydrocarbon content of the four tested plant species was in an order of A.tatarica>Suaeda salsa>A.aucheri>S.europaea; ④ Compared with other two plant species,A.tatarica and S.salsa were more effective in improving the oilcontaminated soil. Related Articles | Metrics

Select

Effect of Irrigation Patterns on Water Consumption of  Wheat-corn Intercropping in Irrigated Area in Oasis CHAI Qiang , YANG Cai-hong , CHEN Gui-ping 2014, 31 (1):  105-110.  Abstract ( 1146 )   PDF (2905KB) ( 793 )   In an oasis irrigated area, a field experiment of wheatcorn intercropping was carried out under different irrigation levels and irrigation patterns so as to determine the effect of alternative irrigation on water consumption of crops and soil evaporation, and the main factors related to water consumption of crops and soil evaporation were investigated. The purpose of this research was to provide the academic bases for reducing the evapotranspiration (ET) of intercropping and optimizing the irrigation technology. Results showed that the ET of wheatcorn intercropping varied in a range of 12.7%-20.1%, it was higher than that of the weighted average ETs of sole cropping wheat and corn, and alternative irrigation could be used to decrease the ET of intercropping compared with the conventional irrigation. Intercropping could be used to increase the daily average soil evaporation (E) by 9.19%-13.6% compared with that of the weighted average of sole cropping systems, and the alternative irrigation could be used to decrease the E of intercropping by 10.1% compared with the conventional irrigation. Compared with the sole cropping wheat and corn, the E/ET of intercropping was significantly increased, and to control E might be an effective way to improve available soil moisture in intercropping. The high ET of intercropping was mainly caused by low leaf area index (LAI) and high leaf area duration (LAD). Compared with conventional irrigation, the alternative irrigation could be used to decrease the soil moisture content in topsoil of intercropping, and it was beneficial to decrease soil evaporation. Related Articles | Metrics

Select

Effect of Hormone Change in Reciprocal Fourth Leaf on Cotton Yield and Quality after Topping LI Li，TIAN Chang-yan,CHEN Guan-wen，LI Zhong-jun 2014, 31 (1):  111-117.  Abstract ( 2078 )   PDF (1464KB) ( 918 )   In this study, the change of endogenous hormones in reciprocal fourth leaf of cotton plant after topping was researched by carrying out the plot experiments, and the effect of topping on cotton yield and quality was analyzed. The results are as follows: ① After topping, the ratios of IAA, CTK, GA3 and ABA in reciprocal fourth leaf of cotton plant within a certain period of time were decreased, and the ABA concentration was significantly increased; ② After topping, the ratios of IAA, CTK, GA3 and ABA in reciprocal fourth leaf of cotton plant could be increased by daubing NAA, and the content of ABA in reciprocal fourth leaf of cotton plant could be maintained; ③ After topping, the content of chlorophyll and the disease index of reciprocal fourth leaf of cotton plant were significantly higher than that without topping, and the ageing process of cotton leaves could be slowed down by using NAA externally; ④ The exfoliation rates of cotton buds and bolls could be reduced after topping. The cotton bolls and buds grew mainly on the lower and central parts of cotton stem, but the preponderance of boll setting and bolls on upper branches was not significant; ⑤ The difference of cotton yield and quality among the situations after topping, without topping and by daubing NAA after topping was not significant, but three was a potentiality to increase cotton yield under the treatments of taking improved variety, applying fertilizer, hormone and inhibitor, enhancing management, etc. Related Articles | Metrics

Select

Drought Characteristic in the Weihe River Basin Based on Water Shortage Index of Crops WANG Yu-juan, WANG Shu-dong,ZENG Hong-juan,CAI Ming-yong,SONG Wen-long 2014, 31 (1):  118-124.  Abstract ( 1588 )   PDF (1164KB) ( 908 )   The Weihe River Basin, with an obvious horizontal and vertical zonality of climate, is distributed in three climatic zones including the temperate, warmtemperate semiarid and warmtemperate semihumid zones in the Guanzhong region. Annual temperature decreases gradually from the south to the north and from the lowland to the highland, and its average was in a range of 7.8-13.5 ℃. Affected by topography, precipitation in the drainage basin is limited and distributed unevenly with obvious seasonal and annual changes, and the annual precipitation is in a range of 450-700 mm. Annual potential evaporation is 700-1 200 mm, and the frostfree season is for 120-220 days. Surface runoff in the Weihe River Basin comes mainly from precipitation, and its distribution is consistent with precipitation. The average annual runoff volume is 62.2×108 m3, and more than 55% of which is from Qinling Mountains. Surface water resources is poor at the Weihe River plain and the north Shaanxi Loess Plateau, and the annual runoff depth is only 10 to 25 mm. In this paper, the crop water stress index (CSWI) method was used to monitor drought in the Weihe River Basin, and the derived involving potential evapotranspiration (ETp) and actual evapotranspiration (ETa) parameters were introduced. Based on the results, the drought conditions in the Weihe River Basin were studied, and the results were validated with the observed data. The monitoring results are follows: ① The model was validated by comparing the simulated data with the observed data, and the correlation coefficient was 0.80. These results reflect the effectiveness of the model; ② Drought in the Weihe River was slight in 2006, 2007 and 2009 and moderate in 2008; the CSWI was decreased from March to July, and increased gradually from August to December; ③ For the different vegetation types, the CSWI of woodland was the highest, that of grassland and farmland was similar, and drought was slight.   Related Articles | Metrics

Select

Effect of Climate Change on Annual Runoff Volume of the Tailan River   WANG Zhi-jie ,WANG Xin-hui ,DAN Muren-jiafu ,GENG Shu-ping 2014, 31 (1):  125-130.  Abstract ( 1427 )   PDF (1564KB) ( 1077 )   The Tailan River rises in the southern piedmont of the Tomor Peak in the southwest Tianshan Mountains, and some modern glaciers are distributed in the headwaters of the Tailan River. The Tailan Hydrologic Station is located at the debouchure of the river, and the area upstream from the station is 1 324 km2. In this study, the variation of mean annual runoff volume at Tailan Hydrologic Station during the period of 1957-2011 was analyzed using the SPSS Statistical Product and Service Solutions programs. The results revealed that the annual distribution of runoff and precipitation was quite uneven, runoff occurred mainly in summer and autumn, and precipitation mainly in spring and summer. A trend regression model was developed after recognizing and extracting the trend function QS(t) of the time series of mean annual runoff volume of the Tailan River. The annual runoff volume of the Tailan River was in decrease during the period of 1957-1981, increase during the period of 1981-1999, and decrease again during the period of 1999-2011. Precipitation and temperature were the main factors resulting in the variation of annual runoff volume of the Tailan River, and the change of annual runoff volume was similar to the variation of precipitation and temperature.   Related Articles | Metrics

Select

General Circulation over North China in Drought and Flood Summers SHAO Xiao-lu, YAO Feng-mei, ZHANG Jia-hua, LI Xian-hua, CHEN Yan, Boken Vijendra 2014, 31 (1):  131-137.  Abstract ( 1636 )   PDF (2488KB) ( 843 )   The abnormal atmospheric circulation related to drought and flood over north China in summer in recent 50 years was analyzed using the data of monthly precipitation at 17 weather stations in north China during the period from 1960 to 2009 and the NCEP/NCAR reanalysis data, such as the average height of potential and wind speed. The results show that there was a significant difference in atmospheric circulation between the drought and flood summers over north China. The general circulation over north China in drought summer was characterized by that, at the middle level, there was a trough of low pressure near the Ural Mountains, but a ridge of high pressure over the Lake Baikal region. There was also a trough of low pressure over the Korean Peninsula, north China was affected by a high pressure, and the Western Pacific Subtropical High was shifted southeastward. At the low level, the Mongolia cyclone was very strong, and an obvious anomaly of northerly winds over east China occurred, so the transportation of atmospheric water vapor from the south to the north was blocked. There was an opposite atmospheric circulation in the flood years. The atmospheric circulation over north China in spring was very similar to that in summer before both flood and drought years. Related Articles | Metrics

Select

Influence of Climate Change and Human Activities on Groundwater Level in Baotou City   LIAO Zi-long, LONG Yin-hui,LIU Hua-lin , SONG Yi-fan, GUO Zhong-xiao,WEI Yong-fu 2014, 31 (1):  138-143.  Abstract ( 1382 )   Related Articles | Metrics

Select

Variation of Reference Crop Evapotranspiration on East and West Sides of the Liupanshan Mountain in Last 46 Years WANG Li-na 2014, 31 (1):  144-148.  Abstract ( 969 )   PDF (1607KB) ( 952 )   In this study, the values of reference daily crop evapotranspiration were calculated using the PenmanMonteith model based on the daily meteorological data observed by 7 meteorological stations on the east and west sides of the Liupanshan Mountain in Pingliang City, Gansu Province during the period from 1965 to 2010. The seasonal and annual values of reference crop evapotranspiration were analyzed using the MannKendall nonparametric method. The results are as follows: ① The average of reference crop evapotranspiration in Pingliang City varied in a range of 890-1 142 mm during the period of 1965-2010. The minimum occurred in the southeast and the maximum in the east of Pingliang City. The maximum value of reference crop evapotranspiration in Pingliang occurred in summer, it was followed by that in spring and autumn, and the minimum occurred in winter; ② The annual reference crop evapotranspiration was significantly decreased at most meteorological stations in Pingliang in last 46 years; ③ Wind speed and sunshine duration were the main climatic factors affecting the seasonal change of reference crop evapotranspiration in Pingliang, especially wind speed. Related Articles | Metrics

Select

Optimized Modes of Planted Sand-fixing Vegetation in the Horqin Sandy Land JIANG De-ming, ZHANG Na, A Lamusa,ZHOU Quan-lai,WANG Yong-cui,MIAO Ren-hui,Toshio Oshid 2014, 31 (1):  149-156.  Abstract ( 1123 )   PDF (2638KB) ( 771 )   By analyzing the soil moisture content, evapotranspiration and vegetation coverage under 7 modes of planted vegetation in growing season, the preferred modes of planted vegetation were optimized, and these modes could be used to maintain the good soil moisture conditions, efficient vegetation coverage and ideal effectiveness of sand stabilization in the Horqin sandy land. Soil moisture content varied in a range of 2.32%-3.41% and could basically satisfy the water consumption for plant growth at the early stage of sand fixation. It, however, was low in dry season, and the normal growth of vegetation was impacted. The proportion of evapotranspiration under the 7 modes of planted sandfixing vegetation occupied over 94% of rainfall, and the balance of soil moisture content could be basically maintained. The planted sandfixing plantations including the pure Caragana korshinkii shrubbery (525 plants/hm2), mixed plantation of Hedysarum fruticosum (500 plants/hm2) with Artemisia desterorum (2 800 plants/hm2), and Hedysarum fruticosum shrubbery (3 300 plants/hm2) were good for popularize in the study area. The planting density of pure Hedysarum fruticosum (3 300 plants/hm2) was high, but the water consumption was also high, so some measures should be taken to reduce its density. The sandfixing effect of pure Populus simonii Carr. (1 350 plants/hm2) was relatively poor because of its high soil moisture consumption and low vegetation coverage. Related Articles | Metrics

Select

Change of Ecological Vulnerability in the Minqin Oasis since Diversion of the Shiyang River Basin in 10 Years JIANG You-yan, HAN Tao , WANG You-heng, HUANG Jin, LIU Wei-gang 2014, 31 (1):  157-162.  Abstract ( 1190 )   PDF (1267KB) ( 1021 )   The Jingdian Hydropower Project in Gansu Province, built in September 2009, lifts water from the Yellow River to the Hongyashan Reservoir every year so as to relieve the shortage of water resources in the Minqin Oasis in Gansu Province. In this study, the RS and GIS means were used to develop a model for evaluating the ecological environment by referring to both the domestic and foreign studies, and the TM images were used to assess the ecological vulnerability in the Minqin Oasis before the diversion in 2000 and after it since 2010. The results revealed that the ecological environment was extremely vulnerable in the deserts, vulnerable in the desertoasis ecotone, and moderately and slightly vulnerable in the oasis. The comprehensive evaluation index was increased in the south of the oasis and northern part in the lower reaches, but decreased in the central area of the oasis. The area of the Minqin Oasis was enlarged from 8.93% of the total Minqin area in 2000 to 11.98% in 2010, which revealed that the benefits of diversion for regenerating the ecology in Minqin Oasis in recent 10 years were significant. Related Articles | Metrics

Select

Fractality and Stability of Sand Dunes in Lowland among Composite  Longitudinal Ridges in the Central Taklimakan Desert WANG Nin-bo,GU Feng, LI Sheng-yu, WANG Hai-feng, XU Xin-wen, LEI Jia-qiang, ZHANG Zhong-liang 2014, 31 (1):  163-168.  Abstract ( 1376 )   PDF (1276KB) ( 893 )   The distribution of composite longitudinal ridges alternating with interdune corridors is the largescale morphological pattern in the Taklimakan Desert, where almost all the types of dunes are distributed. Interdune corridors are the optimal experiment sites to study the development process of sand dunes. Based on the Google Earth images, this paper is to investigate the fractal characteristics of dunes along the local prevailing wind direction in the Taklimakan Desert. Some conclusions are as follows: ① There was a significant double logarithmic relationship between size and frequency of dune shape index (floorageperimeter relationship), which proved that the sand dunes in the interdune corridor alternating with the composite longitudinal ridges had the fractal characteristics independent of scales used in statistics; ② Sand dunes in the interdune corridors alternating with the composite longitudinal ridges had different fractal dimensions, the fractal dimension of pieshaped dunes was the highest (1.337), it was moderate (1.170) for the barchans and the lowest (1.087) for the simple linear dunes; ③ The spatial difference of the fractal dimension of sand dunes alternating with the composite longitudinal ridges was high and varied in a range of 1.187-1.656, and the fractal dimension was in an order of leeward slope (1.24) < central ridge (1.40) < windward slope (1.50), and the coefficient of variation was 0.106; ④ The spatial distribution of dune stability index was opposite to the dune fractal dimension in the interdune corridor, that is in an order of leeward slope (0.26) > central ridge (0.16) > windward slope (0.10); ⑤ The spatial difference of dune fractal dimension was related to the development level of sand dunes. Fractal dimension of dunes could be used as an integrated quantitative index to evaluate aeolian environment in mobile desert.   Related Articles | Metrics

Select

Change of the Oasis-desert Ecotone and Its Causes in Qira County during the Period of 2001-2010 PAN Guang-yao,MU Gui-jin,YUE Jian ,HE Jun-xia,SUN Lin 2014, 31 (1):  169-175.  Abstract ( 1309 )   PDF (1719KB) ( 991 )   In this paper, the variation of the Normalized Difference Vegetation Index (NDVI) in the oasisdesert ecotone in Qira County, Xinjiang during the period from the year 2001 to 2010 was analyzed so as to understand the variation of spatial structure of the oasisdesert ecotone. Moreover, the effects of natural environment and human activities on the variation of NDVI were discussed. The results are as follows: ① In general, the vegetation coverage decreased gradually from the oasis to the desert. Groundwater level was the most important factor affecting the variation of vegetation in the oasisdesert ecotone in Qira County. The variation of vegetation near the oasis was higher than that far away from the oasis, because the zone near the oasis was affected by irrigation water, and such effect was decreased with the increase of distance away from the oasis. In the oasisdesert ecotone, the distribution of vegetation is patchy. There were some mobile or semimobile dunes among the vegetation patches, and the vegetation coverage was extremely low. Based on the variation of vegetation coverage, the oasisdesert ecotone was divided into three types, i.e., the unidirectional graded type, bidirectional graded type and mutant type; ② There was a rapid shift of the oasisdesert boundary during the period from 2001 to 2010, and such shift was mainly affected by human activities. Boundaries of the desert and the oasisdesert ecotone were far away from the Qira Oasis, the impact of human activities on them was low, and the outer boundary was mainly affected by natural factors; ③ Although there was the excessive exploitation of groundwater and land reclamation in the ecotone, vegetation in the ecotone was improved to some extent, its stability was basically maintained, and its coverage was slightly increased because of closing the hillsides for facilitating afforestation and grass planting; ④ Variation of vegetation coverage in the ecotone was consistent with the change of annual precipitation. There was a poor correlation between annual temperature and NDVI. Vegetation in the ecotone was also impacted by aeolian sand disasters. Related Articles | Metrics

Select

3D Fluorescence Spectroscopy of Dissolved Organic Matter in Sediment Pore Water of the Bosten Lake REHEMANJIANG Wupuer, LIU Ying , BAO An-ming, CHEN Xi , ZHANG Dao-yong, PAN Xiang-liang 2014, 31 (1):  176-181.  Abstract ( 1423 )   PDF (1831KB) ( 934 )   Fluorescence characteristics of dissolved organic matter (DOM) in sediment pore water of the Bosten Lake were investigated using the 3D fluorescence spectroscopy. There were 2-4 fluorescence peaks in the fluorescence spectra of the samples. Peaks A and C were the protein peaks, peak B was the fulvic acid peak, and peak D the humic acid peak. At the sampling sites from No.1 to No. 10, the fluorescence intensity of peaks A and C was higher than peaks B and D. Fluorescence intensity of all peaks was generally in a decrease trend from the entrance to the lake center. There was no the significant correlation between salinity and fluorescence intensity. Fluorescence intensity of DOM in pore water was increased with the increase of sediment depth. Average value of r(B/D) was 1.01. Humic fluorescence intensity was stable, and the change of organic matter structure and maturity was not significant, indicating that they might come from the same source. Fluorescence intensity ranged from 1.80 to 2.10, and its average was 1.82, These revealed that DOM in the Bosten Lake originated from biological sources. These novel findings are important in studying the sources, properties and interaction with pollutants of DOM in aquatic environment. Related Articles | Metrics

Select

Spatial and Temporal Distribution of Oases in Hami Region and the Dynamic Mechanism in Historical Periods WEI Jian-bin, ZHANG Duo-yong , KANG Li-jun 2014, 31 (1):  182-187.  Abstract ( 1591 )   PDF (1056KB) ( 779 )   Fifty thousand years ago, the primitive people of north China had lived in the Hami Basin, which could be proved by the Hami Qijiaojing and Sandaoling sites of ancient cultural remains. Saka had settled in Hami Sibao and Wubao in the late 14th and 13th centuries BC. Yiwulu became as the first oasis in the Hami region since the time with written historical records in Eastern Han Dynasty. Yi State that consisted of Yiwu, Nazhi, Rouyuan counties was founded in Tang Dynasty, the oases in Hami were significantly enlarged. In the Yuan Dynasty, the stationed troops reclaimed wasteland in Hami. Hami Garrison was founded in Ming Dynasty, and the oases were enlarged to some extent. The oases in Hami were sharply expanded in Qing Dynasty. Karezs, the special irrigation systems, were constructed in the oases in the Republic of China, on which the oases were further expanded on the basis of old ones. After the founding of new China, a lot of new oases were opened up. Geographically, the oases in Hami were developed from the fluvialpluvial finesoil plains where springs flew out to the areas and lowhill regions irrigated by Karezs, spring water or rgroundwater, and then to the fluvialpluvial gravel plains and winderoded plains. Such results were formed under the effects of both natural and human factors. Natural factors were dominant before Qing Dynasty. Human factors played an important role from Qing Dynasty to the republic of China. Human factors were dominant after the founding of new China. Related Articles | Metrics

Select

Estimation of Carbon Dioxide Emission in Xinjiang SONG Mei ,SHI Jia 2014, 31 (1):  188-191.  Abstract ( 1401 )   PDF (1453KB) ( 965 )   Carbon dioxide has become as one of the main greenhouse effect gases due to its long life span and enormous emission. In this paper, the emission amounts of carbon dioxide produced by energy consumption in Xinjiang during the period of 2003-2011 were calculated using the methods based on the topdown firstorder estimate in the IPCC (2006). The results indicated that the carbon dioxide emission in Xinjiang was increased rapidly year by year due to the rapid emission increase of carbon dioxide produced by burning solid fuels, and the rapidlyincreased carbon dioxide emission was mainly produced by the high energyconsuming industries, such as the chemical, electric power, steel and cement industries. Therefore, it is suggested to promote the development of lowcarbon economy in Xinjiang, which includes the development of market access mechanism and carbon trading mechanism, optimization of industrial structure, improvement of energy efficiency, etc. based on the current situation of energy, economy and environment in Xinjiang.   Related Articles | Metrics