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10 December 2015, Volume 7 Issue 6 Previous Issue    Next Issue
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Brief Communication
Spatial variability of glacial changes and their effects on water resources in the Chinese Tianshan Mountains during the last five decades
WANG Puyu, LI Zhongqin, HUAI Baojuan, WANG Wenbin, LI Huilin, WANG Lin
Journal of Arid Land. 2015, 7 (6): 717-727.   DOI: 10.1007/s40333-015-0086-0
Abstract ( 1841 )     PDF (475KB) ( 1876 )  
Changes in glaciers in the Chinese Tianshan Mountains have been analyzed previously. However, most pre-vious studies focused on individual glaciers and/or decentralized glacial basins. Moreover, a majority of these studies were published only in Chinese, which limited their usefulness at the international level. With this in mind, the authors reviewed the previous studies to create an overview of glacial changes in the Chinese Tianshan Mountains over the last five decades and discussed the effects of glacial changes on water resources. In response to climate change, glaciers in the Tianshan Mountains are shrinking rapidly and are ca. 20% smaller on average in the past five decades. Overall, the area reduction of glacial basins in the central part of the Chinese Tianshan Mountains is larger than that in the eastern and western parts. The spatial differentiation in glacial changes are caused by both differences in regional climate and in glacial factors. The effects of glacial changes on water resources vary in different river basins due to the differences in glacier distribution, char-acteristics of glacial change and proportion of the glacier meltwater in river runoff.
A framework of numerical simulation on moraine-dammed glacial lake outburst floods
ZHANG Xiujuan, LIU Shiyin
Journal of Arid Land. 2015, 7 (6): 728-740.   DOI: 10.1007/s40333-015-0133-x
Abstract ( 1439 )     PDF (239KB) ( 1645 )  
Glacial outburst floods (GLOFs) in alpine regions tend to be relatively complicated, multi-stage catastrophes, capable of causing significant geomorphologic changes in channel surroundings and posing severe threats to infrastructure and the safety and livelihoods of human communities. GLOF disasters have been observed and potential hazards can be foreseen due to the newly formed glacial lakes or the expansion of existing ones in the Poiqu River Basin in Tibet, China. Here we presented a synthesis of GLOF-related studies including trig-gering mechanism(s), dam breach modeling, and flood routing simulation that have been employed to re-construct or forecast GLOF hydrographs. We provided a framework for probability-based GLOFs simulation and hazard mapping in the Poiqu River Basin according to available knowledge. We also discussed the un-certainties and challenges in the model chains, which may form the basis for further research
Drought analysis in Antakya-Kahramanmara? Graben, Turkey
Murat KARABULUT
Journal of Arid Land. 2015, 7 (6): 741-754.   DOI: 10.1007/s40333-015-0011-6
Abstract ( 1603 )     PDF (802KB) ( 2100 )  
The most parts of the Earth experience precipitation variability as a part of their normal climates over both short- and long-time periods. These variations of precipitation will have unpredictable and perhaps unex-pectedly extreme consequences (such as drought and flood) with respect to frequency and intensity for many regions of the Earth. Because of high precipitation fluctuations, the Mediterranean region is also the areas of the world sensitive to precipitation changes which often involve frequent drought conditions in Turkey. In this study, drought conditions at annual, seasonal and monthly time scales over the period of 1975–2010 were examined for Antakya-Kahramanmara? Graben which is located in the eastern part of the Mediterranean region of Turkey. Application of appropriate measures to analyze and monitor droughts is recognized as a major challenge to scientists involved in atmospheric studies. Standardized Precipitation Index (SPI) and cumulative deviation curve techniques were used to determine drought conditions. Results indicated that the study area presented a cyclic pattern of variations with alternating drier and wetter years. From analyses of annual, seasonal and monthly drought series it can be seen that precipitation characteristic of the area is changing. By the results, apparent wet and dry periods can be distinguished. This study also indicated that precipitation totals of winter, spring and summer seasons were slightly decreased during the study period. Drought fre-quency was increased especially for the northern part of the area in the last ten years. Drought periods were divided into 1982–1985, 1999–2002 and 2004–2008, respectively. According to our analyses, the time scale of 1999–2002 was the driest period in the most of the graben area. The study area, which covers agriculturally important fertile alluvial plains, will experience increasing pressure on its water resources because of its growing population and industry, ever-larger demands for intensive agricultural activities, and frequent drought events.
Changes in wind activity from 1957 to 2011 and their possible influence on aeolian desertification in northern China
LI Jinchang, LIU Haixia, SU Zhizhu, FAN Xiaohui
Journal of Arid Land. 2015, 7 (6): 755-764.   DOI: 10.1007/s40333-015-0050-z
Abstract ( 1475 )     PDF (372KB) ( 1416 )  
Wind activity is proved to have significant impacts on aeolian desertification. Clarifying the fluctuations and change trend of wind velocity is important for understanding their influence on aeolian desertification. In this study, we used a dataset of wind velocities collected from 93 meteorological stations across northern China from 1957 to 2011 to analyze the changes in wind activity during this period. We tested the monotonic and step (abrupt) trends for annual and seasonal data of mean wind velocity by using Mann-Kendall and Mann-Whitney tests, respectively. The results indicated that the annual mean wind velocity decreased by 0.83 m/s from 1957 to 2011. The decreasing trends were also significant (P<0.01) for each season. The magnitude of the decrease was smallest in the east of northern China and largest in the west of northern China, and the most remarkable decrease occurred in the northwest of northern China. Abrupt decreases in annual and seasonal mean wind velocities occurred in the mid-1980s, which was consistent with the changes in aeolian desertification since the mid-1980s in northern China. As revealed by our study, although both modern aeolian desertification and ecosystem rehabilitation are affected by human activities to some extent, they are also likely to be strongly controlled by climate change, especially by wind activity.
Re-evaluating the vertical mass-flux profiles of aeolian sediment at the southern fringe of the Taklimakan Desert, China
XUE Jie, LEI Jiaqiang, LI Shengyu, GUI Dongwei, MAO Donglei, ZHOU Jie
Journal of Arid Land. 2015, 7 (6): 765-777.   DOI: 10.1007/s40333-015-0134-9
Abstract ( 1783 )     PDF (556KB) ( 1574 )  
Reliable estimation of the mass-flux profiles of aeolian sediment is essential for predicting sediment transport rates accurately and designing measures to cope with wind-erosion. Vertical mass-flux profiles from seventeen wind-erosion events were re-evaluated using five typical models based on observed data obtained from a smooth bare field at the southern fringe of the Taklimakan Desert, China. The results showed that the expo-nential-function model and the logarithmic-function model exhibited the poorest fit between observed and predicted mass-flux profiles. The power-function model and the modified power-function model improved the fit to field data to an equivalent extent, while the five-parameter combined-function model with a scale constant (σ) of 0.00001 m (different from the σ value proposed by Fryear, which represented the height above which 50% of the total mass flux occurred) was verified as the best for describing the vertical aeolian sediment mass-flux profiles using goodness of fit (R2) and the Akaike Information Criterion (AIC) values to evaluate model performance. According to relationships among model parameters, the modified power model played a prominent explanatory role in describing the vertical profiles of the observed data, whereas the exponential model played a coordinating role. In addition, it was found that the vertical profiles could not be extrapolated using the five selected models or easily estimated using an efficient model without field observations by a near-surface sampler at 0 to 0.05 m.
Planar morphology and controlling factors of the gullies in the Yuanmou Dry-hot Valley based on field investigation
DENG Qingchun, MIAO Fang, ZHANG Bin, LUO Mingliang, LIU Hui, LIU Xiaojiao, QIN Fachao, LIU Gangcai
Journal of Arid Land. 2015, 7 (6): 778-793.   DOI: 10.1007/s40333-015-0135-8
Abstract ( 1389 )     PDF (724KB) ( 1312 )  
The plane form of a gully can provide a basis for evaluating the gully volume and erosion rate, acting process, and evolutionary stage. For describing the planar characteristics of a permanent gully and understanding their controlling factors, this study, utilizing a total station and GPS RTK, measured the shoulder lines and channel curves of 112 gullies in six sites of the Yuanmou Dry-hot Valley and then mapped them by ArcGIS software and calculated nine parameters. The results showed that the channel lengths range from 10.88 to 249.11 m; the widths range from 6.20 to 40.99 m; the perimeters range from 54.11 to 541.67 m; the gully areas range from 153.02 to 6,930.30 m2; the left-side areas range from 92.93 to 4,027.20 m2; and the right-side areas range from 63.65 to 3,539.77 m2. The slightly sinuous and straight gullies account for 73.21% of the total gullies; the quantity of the right skewed gullies is 8.93% greater than that of the left skewed ones based on the symmetry ratio; the shape ratios range from 1.12 to 1.40 and the morphology ratios from 0.038 to 1.294; the fractal dimension is 1.192. Gullies in different sites have diverse planar characteristics. Except for the symmetry index, which was close to a negatively skewed distribution, all of the other parameters had the characteristic of positively skewed distribution. The gully area is related to the length and width, but the gully length has a weak correlation with the width. The evolutionary stage, topographic conditions, strata, soil properties, and piping erosion played very important roles in the gully planar morphology. This study could provide useful infor-mation for controlling gully erosion and safeguarding human habitation and engineering buildings.
Soil salinity prediction in the Lower Cheliff plain (Algeria) based on remote sensing and topographic feature analysis
Ibrahim YAHIAOUI, AbdelKader DOUAOUI, ZHANG Qiang, Ahmed ZIANE
Journal of Arid Land. 2015, 7 (6): 794-805.   DOI: 10.1007/s40333-015-0053-9
Abstract ( 1716 )     PDF (890KB) ( 1902 )  
Soil salinity and ground surface morphology in the Lower Cheliff plain (Algeria) can directly or indirectly impact the stability of environments. Soil salinization in this area is a major pedological problem related to several natural factors, and the topography appears to be important in understanding the spatial distribution of soil salinity. In this study, we analyzed the relationship between topographic parameters and soil salinity, giving their role in understanding and estimating the spatial distribution of soil salinity in the Lower Cheliff plain. Two satellite images of Landsat 7 in winter and summer 2013 with reflectance values and the digital elevation model (DEM) were used. We derived the elevation and slope gradient values from the DEM corresponding to the sampling points in the field. We also calculated the vegetation and soil indices (i.e. NDVI (normalized dif-ference vegetation index), RVI (ratio vegetation index), BI (brightness index) and CI (color index)) and soil salinity indices, and analyzed the correlations of soil salinity with topography parameters and the vegetation and soil indices. The results showed that soil salinity had no correlation with slope gradient, while it was sig-nificantly correlated with elevation when the EC (electrical conductivity) values were less than 8 dS/m. Also, a good relationship between the spectral bands and measured soil EC was found, leading us to define a new salinity index, i.e. soil adjusted salinity index (SASI). SASI showed a significant correlation with elevation and measured soil EC values. Finally, we developed a multiple linear regression for soil salinity prediction based on elevation and SASI. With the prediction power of 45%, this model is the first one developed for the study area for soil salinity prediction by the combination of remote sensing and topographic feature analysis.
Changes in soil organic carbon and nitrogen after 26 years of farmland management on the Loess Plateau of China
ZHOU Zhengchao, ZHANG Xiaoyan, GAN Zhuoting
Journal of Arid Land. 2015, 7 (6): 806-813.   DOI: 10.1007/s40333-015-0051-y
Abstract ( 1433 )     PDF (180KB) ( 1694 )  
Soil carbon (C) and nitrogen (N) play a crucial role in determining the soil and environmental quality. In this study, we investigated the effects of 26 years (from 1984 to 2010) of farmland management on soil organic carbon (SOC) and soil N in abandoned, wheat (Triticum aestivum L.) non-fertilized, wheat fertilized (mineral fertilizer and organic manure) and alfalfa (Medicago Sativa L.) non-fertilized treatments in a semi-arid region of the Loess Plateau, China. Our results showed that SOC and soil total N contents in the 0–20 cm soil layer increased by 4.29 (24.4%) and 1.39 Mg/hm2 (100%), respectively, after the conversion of farmland to alfalfa land. Compared to the wheat non-fertilized treatment, SOC and soil total N contents in the 0–20 cm soil layer increased by 4.64 (26.4%) and 1.18 Mg/hm2 (85.5%), respectively, in the wheat fertilized treatment. In addition, we found that the extents of changes in SOC, soil total N and mineral N depended on soil depth were greater in the upper soil layer (0–30 cm) than in the deeper soil layer (30–100 cm) in the alfalfa land or fertilizer-applied wheat land. Fertilizer applied to winter wheat could increase the accumulation rates of SOC and soil total N. SOC concentration had a significant positive correlation with soil total N concentration. Therefore, this study suggested that farmland management, e.g. the conversion of farmland to alfalfa forage land and fertilizer application, could promote the sequestrations of C and N in soils in semi-arid regions.
Variation in soil organic matter accumulation and metabolic activity along an elevation gradient in the Santa Rosa Mountains of Southern California, USA
Amitava CHATTERJEE, George D JENERETTE
Journal of Arid Land. 2015, 7 (6): 814-819.   DOI: 10.1007/s40333-015-0085-1
Abstract ( 1296 )     PDF (253KB) ( 1598 )  
Variations in soil organic matter accumulation across an elevation can be used to explain the control of substrate supply and variability on soil metabolic activity. We investigated geographic changes in soil organic matter and metabolic rates along an elevation gradient (289–2,489 m) in the Santa Rosa Mountains, California, USA from subalpine and montane pine forests through chaparral to desert. From base (289 m) to summit (2,489 m), 24 sites were established for collecting soil samples under canopies and inter-canopy spaces, at 0–5 and 5–15 cm soil depths increments. Soil organic matter (SOM) content was determined using weight loss on ignition at 550°C and soil CO2 efflux (R) was measured at day 5 (R5) and day 20 (R20) of incubation. Changes in SOM content along the elevation gradient showed a significant relationship (P<0.05) but R5 and R20 were not related to either elevation or SOM content. However, the ratio of R and SOM (R5/SOM) showed a strong relationship across the mountains at both soil depths. R5/SOM, as an indicator of carbon use efficiency, may be applicable to other semi-arid transects at larger scale modeling of soil metabolic processes.
Identifying the influence of urbanization on soil organic matter content and pH from soil magnetic characteristics
YANG Han, XIONG Heigang, CHEN Xuegang, WANG Yaqi, ZHANG Fang
Journal of Arid Land. 2015, 7 (6): 820-830.   DOI: 10.1007/s40333-015-0052-x
Abstract ( 1548 )     PDF (494KB) ( 1528 )  
Soil magnetic characteristics are correlated with soil pH and organic matter content. Analyzing soil magnetic characteristics, organic matter content and pH can indirectly evaluate soil pollution caused by human activities. This study analyzed the soil magnetic characteristics, organic matter content and pH in surface soil samples from different land use types in Shihezi city, a newly and rapidly developing oasis city in Xinjiang of China. The aims of this study were to explore the possible relationships among the soil magnetic parameters and thereby improve the understanding of influence of urbanization on soil properties. Eighty surface soil samples at the depth of 0–10 cm were collected from 29 July to 4 August 2013. The results showed that the magnetic minerals in surface soil were dominated by ferromagnetic minerals. Spatially, the magnetic susceptibility (χLF), anhys-teretic remanent magnetization susceptibility (χARM), saturation isothermal remanent magnetization (SIRM) and “soft” isothermal remanent magnetization (SOFT) were found to be most dominant in the new northern urban area B (N-B), followed by built-up areas (U), suburban agricultural land (F), and then the new northern urban area A (N-A). The values of χLF, χARM, SIRM and SOFT were higher in the areas with high intensities of human ac-tivities and around the main roads. Meanwhile, the property “hard” isothermal remanent magnetization (HIRM) followed the order of U>N-B>F>N-A. Built-up areas had an average pH value of 7.93, which was much higher than that in the new northern urban areas as well as in suburban agricultural land, due to the increased urban pollutant emissions. The average value of soil organic matter content in the whole study area was 34.69 g/kg, and the values in the new northern urban areas were much higher than those in the suburban agricultural land and built-up areas. For suburban agricultural land, soil organic matter content was significantly negatively correlated with χLF, and had no correlation with other magnetic parameters, since the soil was frequently ploughed. In the new northern urban areas (N-A and N-B), there were significant positive correlations of soil organic matter contents with χARM, SIRM, SOFT and HIRM, because natural grasslands were not frequently turned over. For the built-up areas, soil organic matter contents were significantly positively correlated with χLF, χARM, SIRM and SOFT, but not significantly correlated with frequency-dependent susceptibility (χFD, expressed as a percentage) and HIRM, because the soil was not frequently turned over or influenced by human activities. The results showed that soil magnetic characteristics are related to the soil turnover time.
Canopy interception loss in a Pinus sylvestris var. mongolica forest of Northeast China
LI Yi, CAI Tijiu, MAN Xiuling, SHENG Houcai, JU Cunyong
Journal of Arid Land. 2015, 7 (6): 831-840.   DOI: 10.1007/s40333-015-0013-4
Abstract ( 1489 )     PDF (313KB) ( 1957 )  
Pinus sylvestris var. mongolica is one of the main species to be afforested in deserts of China. But little work has been carried out on the canopy interception loss of this plant species. For researching the canopy in-terception loss of a natural P. sylvestris forest, we observed the gross precipitation, gross snowfall, throughfall and stemflow in a sample plot at the Forest Ecosystem Research Station of Mohe in the Great Khingan Mountains of Northeast China from July 2012 to September 2013. Considering the spatial variability of the throughfall, we increased the area rather than the number of collector and randomly relocated them once a week. The results demonstrated that the throughfall, stemflow, and derived estimates of rainfall and snowfall interception loss during the main rainy and snowy seasons were 77.12%±5.70%, 0.80%, 22.08%±5.51% and 21.39%±1.21% of the incident rainfall or snowfall, respectively. The stemflow didn’t occur unless the accu-mulated rainfall reached up to 4.8 mm. And when the gross precipitation became rich enough, the stemflow increased with increasing tree diameters. Our analysis revealed that throughfall was not observed when rainfall was no more than 0.99 mm, indicating that the canopy storage capacity at saturation was 0.99 mm for P. sylvestris forest.
Changes of forest fire regime and landscape pattern under different harvesting modes in a boreal forest of Northeast China
CHEN Hongwei, HU Yuanman, CHANG Yu, BU Rencang, LI Yuehui, LIU Miao
Journal of Arid Land. 2015, 7 (6): 841-851.   DOI: 10.1007/s40333-015-0015-2
Abstract ( 1620 )     PDF (288KB) ( 1516 )  
Forest management such as timber harvesting shapes fire regimes and landscape patterns, and these patterns often differ significantly from those under natural disturbances. Our objective was to examine the effects of timber harvesting modes on fire regimes and landscape patterns in a boreal forest of Northeast China. We used a spatially explicit landscape model, LANDIS, to simulate the changes of forest landscape in the Hu-zhong forest region of the Great Khingan Mountains under no-cutting, clear-cutting, gradual-cutting and se-lective-cutting modes. Results showed that: (1) the fine fuel loadings generally decreased while the coarse fuel loadings increased with the increase of timber harvesting intensity; (2) the potential burn area significantly varied among different cutting modes, but the potential fire frequency had no obvious difference. Moreover, timber harvesting generally increased the potential fire risk; (3) clear-cutting mode significantly decreased the mean patch size and the aggregation of larch forests and increased the mean patch size and the aggregation of white birch forests. Therefore, clear-cutting mode should be abandoned, and selective-cutting mode be recommended for the sustainable forest management in the Great Khingan Mountains.
Impact of great gerbils (Rhombomys opimus) on desert plant communities
XU Wenxuan, LIU Wei, YANG Weikang, WANG Muyang, XU Feng, David BLANK
Journal of Arid Land. 2015, 7 (6): 852-859.   DOI: 10.1007/s40333-015-0084-2
Abstract ( 1263 )     PDF (197KB) ( 1522 )  
Great gerbil (Rhombomys opimus) colonies, with bare soil and herbaceous plants, are conspicuous to the background environment throughout their range area. In order to quantify the engineer role of great gerbils, we investigated the plant communities of 20 active colonies in the Junggar Basin, Xinjiang, China. In areas without disturbance, desert plant communities were dominated by the shrubs with low level species richness. In burrow areas and surrounding intermediate areas, which were disturbed by great gerbils, the shrubs were suppressed with the decrease of vegetation cover and aboveground biomass. As a result, “niche gaps” were created in disturbed areas and worked as a refuge for herbaceous annuals and perennials. So the existence of great gerbils increased the overall species richness of the desert. Furthermore, herbaceous annuals and perennials are the major food source for great gerbils in spring, indicating that great gerbils have a mutually beneficial relationship with herbaceous plants.
Food habits of striped hyena (Hyaena hyaena) in a semi-arid conservation area of India
M Shamshad ALAM, Jamal A KHAN
Journal of Arid Land. 2015, 7 (6): 860-866.   DOI: 10.1007/s40333-015-0007-2
Abstract ( 1287 )     PDF (129KB) ( 2458 )  
Striped hyena (Hyaena hyaena) is a near-threatened large carnivore known to occur in arid and semi-arid landscapes in many parts of the world. Its population is declining globally and ecological information is re-quired urgently to meet their conservation needs. We studied the diet pattern of the striped hyena in the semi-arid Gir National Park and Sanctuary (GNPS), western India. Prey items eaten by the striped hyena were identified from scats. Around 44.4% scats represented single to three mammalian preys while 55.6% of them represented four preys to seven preys. A variety of food items were identified including mammals, birds, insects and vegetable matters. Scats analysis showed that 63.91% diet of striped hyena was contributed by wild prey items, 20.94% by domestic prey and 3.31% by birds, whereas vegetable and insects contributed 9.92% and 1.93%, respectively. Diet diversity of the striped hyena computed by the Shannon-Weiner Index (H) was found to be 2.64. The presence of domestic mammals in the scat remains implied that the striped hyena might frequently visit human habitation in search for food and hence, a potential conflict between human and wildlife might arise. Reducing the dependence of hyena on domestic livestock is a challenge to ensure the survival of striped hyena outside the protected area.