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Evapotranspiration of a Populus euphratica forest during the growing season in an extremely arid region of northwest China using the Shuttleworth–Wallace model

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Journal of Forestry research 2016年第4期27卷 879-887页

作者： Guanlong Gao Xiaoyou Zhang Tengfei Yu Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences

Thus far, measurements and estimations of actual evapotranspiration（ET） in extremely arid areas are still insufficient. Based on successive observations from June–September 2014, we simulated ET of a Populus euphratica Oliv. forest during the growing season in an extremely arid region of northwest China using the Shuttleworth–Wallace（S–W） model. Simulated ET values were compared to those of the eddy-covariance（EC） method on a 1 h interval. With a root mean square error（RMSE）,relative error（RE） and mean absolute error（MAE） of0.192, 3.100 and 0.165 mm h-1, respectively, model performance was not satisfactory. In particular, on days with strong winds（Sep. 11–13）, deviations between simulated and observed ET values increased to 0.275, 0.878 and0.251 mm h-1, RMSE, RE and MAE respectively. These values were significantly greater than those in other study periods and were most likely owing to sharp increases in wind speed. As a result, there were substantial advective effects, which is not consistent with the assumption of the S–W model that there are no advective effects or mesoscale circulation patterns induced by surface discontinuities.

关键词： Wallace extremely satisfactory northwest absolute season successive insufficient sharp assumption

Comparison of three evapotranspiration models with eddy covariance measurements for a Populus euphratica Oliv.forest in an arid region of northwestern China

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Journal of arid Land 2016年第1期8卷 146-156页

作者： GAO Guanlong ZHANG Xiaoyou YU Tengfei LIU Bing Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences

The accurate estimation of evapotranspiration (ET) in arid regions is important for improving the water use efficiency of vegetation. Based on successive observations from May to October of 2014, we estimated the ET of a Populus euphratica Oliv. forest during the growing season in an extremely arid region using the PM (Penman-Monteith), SW (Shuttleworth-Wallace) and SSW (an improved canopy transpiration model) models. Estimated ET values were compared with those of the eddy covariance measurements. Results indicated that the actual ET of the P. euphratica forest was always overestimated by the PM model. The accuracy of the SW model was higher than that of the PM model. However, some data were not easily obtained because of the complicated structure of the SW model. The newly proposed SSW model gave the most accurate ET values, and its accuracy was higher at hourly than at daily time scale. In conclusion, the SSW model is more suitable for sparse vegetation system at large scales in extremely arid regions.

关键词： evapotranspiration Penman-Monteith model Shuttleworth-Wallace model SSW model

Experimental study on location accuracy of a 3D VHF lightning-radiation-source locating network

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Science China Earth Sciences 2015年第10期58卷 2034-2048页

作者： ZHANG GuangShu LI YaJun WANG YanHui ZHANG Tong WU Bin LIU YanXiu Key Laboratory of Land Surface Process and Climate Change in cold and arid regions Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences

This paper reports the investigation of the location accuracy of a three-dimensional(3D) lightning-radiation-source locating system using sounding balloon measurements. By comparing the information from the balloon-borne VHF transmitter flight path and locations using simple geometric models, the location uncertainties of sources both over and outside the network were estimated. For radiation sources inside the network and below an altitude of 7 km, the horizontal uncertainty was 12–48 m and the total mean value was 21 m(rms), and the vertical uncertainty was 20–78 m and the total mean value was 49 m(rms). Outside the network, the location uncertainties increased with distance. The geometric model showed that range and altitude errors increased as a function of the range squared whereas the range errors increased parabolically with distance, and that was confirmed by the covariance calculation results. The standard deviation was used inside the network and covariance was used outside the network. The results indicated that location errors from a simple geometric model exhibited good agreement with standard experimental data. The geometry of the network, set of measurements, and calculation method were verified as suitable. The chi-square values of the least squares goodness of fit algorithm were verified and the timing error(?trms) of the fitting formula was estimated. The distribution of the chi-square values was less than 5, corresponding to a timing error of 50–66 ns(rms).

关键词：辐射源定位外部网络定位精度三维实验闪电 VHF 位置精度

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Integrated study of the water–ecosystem–economy in the Heihe River Basin

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National Science Review 2014年第3期1卷 413-428页

作者： Guodong Cheng Xin Li Wenzhi Zhao Zhongmin Xu Qi Feng Shengchun Xiao Honglang Xiao Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences

The ecological water diversion project in the Heihe River Basin is the irst successful case in China in which the ecological systems in a river basin have been rescued. his project serves as a valuable example for the management of ecosystems in other inland river basins. his paper reviews the integrated studies of the water–ecosystem–economy relationship in the Heihe River Basin and concludes that sustainable development in inland river basins requires the basin to be considered as a whole, with the relationships between the upstream, midstream and downstream areas of the basin coordinated appropriately. Successful development in these basins will be relected in an improved output per cubic meter of water and the implementation of integrated river basin management practices.

关键词： Heihe River Basin water–ecosystem–economy integrated study climate change human activity ecological water diversion

Estimation of the quantity of aeolian saltation sediments blown into the Yellow River from the Ulanbuh Desert,China

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Journal of arid Land 2014年第2期6卷 205-218页

作者： HeQiang DU Xian XUE Tao WANG Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences

The Ulanbuh Desert borders the upper reach of the Yellow River. Every year, a mass of aeolian sand is blown into the Yellow River by the prevailing wind and the coarse aeolian sand results in serious silting in the Yellow River. To estimate the quantity of aeolian sediments from the Ulanbuh Desert blown into the Yellow River, we simulated the saltation processes of aeolian sediments in the Ulanbuh Desert. Then we used a saltation submodel of the IWEMS （integrated Wind-Erosion Modeling System） and its accompanying RS （Remote Sensing） and GIS （Geographic Information System） modules to estimate the quantity of saltation sediments blown into the Yellow River from the Ulanbuh Desert. We calibrated the saltation submodel by the synchronous observation to wind ve- locity and saltation sediments on several points with different vegetation cover. The vegetation cover, frontal area of vegetation, roughness length, and threshold friction velocity in various regions of the Ulanbuh Desert were obtained using NDVI （Normalized Difference Vegetation Index） data, measured sand-particle sizes, and empirical relation- ships among vegetation cover, sand-particle diameters, and wind velocity. Using these variables along with the observed wind velocities and saltation sediments for the observed points, the saltation model was validated. The model results were shown to be satisfactory （RMSE less than 0.05 and IRel less than 17%）. In this study, a subdaily wind-velocity program, WlNDGEN, was developed using this model to simulate hourly wind velocities around the Ulanbuh Desert. By incorporating simulated hourly wind-velocity and wind-direction data, the quantity of saltation sediments blown into the Yellow River was calculated with the saltation submodel. The annual quantity of aeolian sediments blown into the Yellow River from the Ulanbuh Desert was 5.56x106 t from 2001 to 2010, most of which occurred in spring （from March to May）; for example, 6.54x10~ tons of aeolian sand were blown into the Yellow River on 25 April, 2010. However,

关键词： aeolian sand sediments integrated wind-erosion modeling system NDVI WlNDGEN Ulanbuh Desert

Impact of sand burial on maize(Zea mays L.)productivity and soil quality in Horqin sandy cropland,Inner Mongolia,China

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Journal of arid Land 2016年第4期8卷 569-578页

作者： WANG Shaokun ZHAO Xueyong ZHAO Halin LIAN Jie LUO Yongqing YUN Jianying Naiman Desertification research Station Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of Sciences Laboratory of Stress Ecophysiology and Biotechnology Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of Sciences

Croplands are often suffering from sand burial in dry regions of northern China. For studying this phenomenon, we carried out a case study of field experiment including four sand burial levels, i.e. shallow （1-3 cm）, moderate （8-12 cm） and deep （15-20 cm） sand burials, and no sand burial （control, CK）, in a typical agro-pastoral transitional zone in Naiman Banner of eastern Inner Mongolia. The aim of this study was to assess the impacts of sand burial on maize （Zea rnays L.） productivity and the soil quality along a gradient of burial depths. Results showed that there was a strong negative effect of sand burial on maize productivity and soil quality, which significantly declined （P〈0.05） under moderate and deep sand burial treatments. In comparison with the CK, the maize yield and above-ground biomass reduced by 47.41% and 39.47%, respectively. The soil silt and clay, soil water, soil organic carbon and total nitrogen contents under deep sand burial decreased by 67.85%, 40.32%, 86.52% and 82.11%, respectively, while microbial biomass carbon, microbial abundance and enzyme activity decreased by 89.78%, 42.28%-79.66% and 69.51%-97.71%, respectively. There was no significant effect on crop productivity and soil quality with shallow sand burial treatment. The correlations analysis showed that there was significant positive correlations of both maize yield and above-ground biomass with soil silt and clay, soil organic carbon and total nitrogen contents, pH, electrical conductivity, soil water content, microbial abundance and biomass and all tested soil enzyme activities. Stepwise regression analysis indicated that soil water and total nitrogen contents, urease, cellobiohydrolase and peroxidase activities were key determining factors for maize productivity. This combination of factors explains reason of the decreased maize productivity with deep sand burial. We found that degradation of cropland as a result of sand burial changed soil physical-chemical properties and soil enzyme activities in the plow layer, and decrea

关键词： sand burial soil quality enzyme activity maize productivity sandy cropland

First comprehensive fine-resolution global land cover map in the world from China—Comments on global land cover map at 30-m resolution

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Science China Earth Sciences 2015年第8期58卷 1677-1678页

作者： RAN YouHua LI Xin Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences

Land cover maps are of fundamental importance in studies of the complex interactions between human activities and global change.Mapping land cover using remote sensing is a traditional but still very active field.In the past 45 years,nearly 30000 papers about land cover mapping were published worldwide,including approximately 10000

关键词：土地覆盖世界范围覆盖图分辨率中国评论相互作用全球变化

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Effect of traffic restriction on atmospheric particle concentrations and their size distributions in urban Lanzhou, Northwestern China

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Journal of environmental Sciences 2014年第2期26卷 362-370页

作者： Suping Zhao Ye Yu Na Liu Jianjun He Jinbei Chen Key Laboratory of Land Surface Process and Climate Change in cold and arid regions Cold & Arid Regions Environmental & Engineering Research Institute Chinese Academy of Sciences University of Chinese Academy of Sciences

During the 2012 Lanzhou International Marathon, the local government made a significant effort to improve traffic conditions and air quality by implementing traffic restriction measures. To evaluate the direct effect of these measures on urban air quality, especially particle concentrations and their size distributions, atmospheric particle size distributions （0.5-20μm） obtained using an aerodynamic particle sizer （model 3321, TSI, USA） in June 2012 were analyzed. It was found that the particle number, surface area and volume concentrations for size range 0.5-10 μm were （15.0±2.1） cm-3, （11.8±2.6） μm2/cm3 and （1.9±0.6） μm2/cm3, respectively, on the traffic-restricted day （Sunday）, which is 63.2%, 53.0% and 47.2% lower than those on a normal Sunday. For number and surface area concentrations, the most affected size range was 0.5-0.7 and 0.5-0.8 μm, respectively, while for volume concentration, the most affected size ranges were 0.5-0.8, 1.7-2.0 and 5.0-5.4 μm. Number and volume concentrations of particles in size range 0.5-1.0μm correlated well with the number of non-CNG （Compressed Natural Gas） powered vehicles, while their correlation with the number of CNG-powered vehicles was very low, suggesting that reasonable urban traffic controls along with vehicle technology improvements could play an important role in improving urban air quality.

关键词： traffic restriction particle concentration size distribution urban air quality

青藏高原东部高寒草原地表能量交换特征(英文)

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Science Bulletin 2015年第4期60卷 435-446,M0003页

作者：尚伦宇张宇吕世华王少影 Key Laboratory of Land Surface Process and Climate Change in cold and arid regions Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of Sciences

青藏高原是世界上面积最大、海拔最高的高原,其独特的地形地貌特征对东亚乃至全球大气环流有重要影响.由于地表特征不同,高原不同区域地表热力特征也有显著差异.高原的东部边缘地表、植被和气象特征与高原其他区域明显不同,因此这一区... 详细信息

青藏高原是世界上面积最大、海拔最高的高原,其独特的地形地貌特征对东亚乃至全球大气环流有重要影响.由于地表特征不同,高原不同区域地表热力特征也有显著差异.高原的东部边缘地表、植被和气象特征与高原其他区域明显不同,因此这一区域地表热力作用也与高原其他区域不同.本文研究了青藏高原东部玛曲草原地表能量交换的季节变化特征.玛曲草原冬季净辐射占入射太阳辐射的比例小于雨季,其差异主要由2个季节的地表反照率和湿度状况的差异引起.全年来看,净辐射大部分用水汽蒸发所需的热量.冬季由于土壤冻结加之降水稀少,净辐射主要用于加热地表和大气.雨季由于相对较高的气温、充足的降水及植被茂盛的生长力,净辐射主要用于水汽蒸发.在这一区域,降水的季节分布以及土壤的冻融状况对地表能量分配有重要影响.

关键词：能量交换青藏高原高山草原季节变化表面反射率叶面积指数相关测量季节分配