Loading...

Table of Content

    20 May 2011, Volume 26 Issue 5 Previous Issue    Next Issue
    Resources Utilization and Management
    Preliminary Assessment on Pressure and Threat of Protected Area in Northeast China
    LUAN Xiao-feng, XI Yan, CHEN Chen, YAO Li, LI Di-qiang, ZHU Chun-quan
    2011, 26 (5):  725-732.  doi: 10.11849/zrzyxb.2011.05.001
    Abstract ( )   PDF (885KB) ( )   Save
    The methodology of Rapid Assessment and Prioritization of Protected Areas Management (RAPPAM) recommended by World Commission on Protected Areas (WCPA) and World Wide Fund for Nature (WWF) was used in investigating and analyzing pressures, threats and trends of the protected areas in Northeast China. The results showed that the following six factors had broader sphere of influence, affecting at higher degree and lasting a longer time in the 14 threatening factors: fires, deforestation, poaching, non-timber forest products (NTFP), tourism and grazing. Protected areas should focus on control of these threatening factors. Therefore, the future management of protected areas should strengthen monitoring of fires, deforestation, poaching, NTFP, etc. Meanwhile, protected areas should develop relevant policies and take appropriate measures to effectively control and reduce the negative impact of eco-tourism to improve the effectiveness of management.
    References | Related Articles | Metrics
    The Rationality Evaluation of Land Use Changes in the Middle and Low Mountain Basin and Valley Area of Southwest Yunnan Province Driven by the National Project of Converting Farmland to Forest: A Case Study in Luxi City
    YANG Zi-sheng, HAN Hua-li, ZHU Yu-bi, ZHAO Qiao-gui
    2011, 26 (5):  733-745.  doi: 10.11849/zrzyxb.2011.05.002
    Abstract ( )   PDF (974KB) ( )   Save
    In present study on land use/land cover change (LUCC), rationality analysis and evaluation of land use change has not been taken seriously. In particular, there is hardly any study on the theory and method system for evaluating rationality of land use change. By taking Luxi City as an example, which is located in the middle and low mountainous basin and valley area in southwest Yunnan, this paper has discussed the concept and connotation of rational degree of land use change and constructed the evaluation target, estimation method, and grading standard system for studying rational degree of land use change. Then, based on these, it has quantitatively analyzed and evaluated the rational degree of the change in every land use type and rational degree of the overall land use change driven by the nearly-eight-year Program of Converting Farmland to Forest in Luxi City. It aims to provide basic foundation for promoting the sustainable use of land resources in mountainous areas and scientific implementation of the Program of Converting Farmland to Forest.The evaluation results reveal the following facts: 1) During recent eight years, the whole city witnessed land use type changes in a total area of 77602.80 hm2. Rational degree (RD value) of the change was only 48.98% while the irrational degree (ID value) was 51.02%, making the change at the "moderately rational" level. 2) Among all land use types, farmland, forest and waste grassland had the largest changes. Farmland was mainly changed into forest, garden plot and waste grassland, a result driven by the Program of Converting Farmland to Forest. During recent eight years, the whole city had 19661.07 hm2 of farmland converted to ecological uses. Of which, 18886.09 hm2 were the farmland suitable for cultivation (farmland that "should not have been converted") and only 774.98 hm2 were the farmland not suitable for cultivation (farmland that "should be converted"). The nearly-eight-year Program of Converting Farmland to Forest (grassland) had a rational degree of only 3.94%, but an irrational degree of 96.06%. This means that the project is "highly irrational". 3) Waste grassland was changed mainly into forest, which was caused largely by the forestation efforts in waste hills and closed mountains to match the "conversion of farmland". 4) Forest was mainly changed into farmland. Such change had a rational degree (RD value) of only 44.62% and an irrational degree (ID value) of 55.38%, making it "moderately irrational". 5) By and large, the land use change in Luxi City during recent eight years driven by the Program of Converting Farmland to Forest had some rational elements. For example, some farmlands on steep slopes were converted to ecological uses, forestation. However, the general land use change showed extremely obvious irrationality, which was demonstrated by the following facts. About 96% of the converted farmlands were the farmland suitable for cultivation that "should not have been converted. " Some 5595.54 hm2 of good-quality flat field, flat dry land, terraced field and terraced land were converted, accounting for 28.46% of the total converting amount. In addition, when the Program of Converting Farmland to Forest was implemented, large scale deforestation for farmland was carried out (amounting to 12634.25 hm2). Of the deforested land, over 3/4 is on steep slopes of over 25° or becomes farmland on slopes of below 25° without any soil and water conservation measures. These outstanding problems made the land use change of Luxi City during recent eight years have an extremely low rationality degree.
    References | Related Articles | Metrics
    Cultivated Land Soil Nutrient Precision Management Zoning and Prescription Fertilization at Town Scale
    LI Wen-lu, ZHAO Geng-xing, XU Zhi-wei
    2011, 26 (5):  746-754.  doi: 10.11849/zrzyxb.2011.05.003
    Abstract ( )   PDF (972KB) ( )   Save
    Cultivated land soil nutrients precision management zoning is a significant measurement to properly protect and utilize farmland and implement variable fertilization. This study took Dingzhuang Town in Guangrao County of Shandong Province as a case, overlay method between soil map and land use map was adopted to produce zoning units, the zoning factors were chosen synthetically by Hierarchical Cluster Analysis and principal component analysis, the weight of indicators were determined by degree of membership method of Analytic Hierarchy Process (AHP), and the amounts of management zoning were decided by K-Means Cluster Analysis. Using the method mentioned above, the model of cultivated land soil nutrients management zoning at town scale was built. The cultivated land in Dingzhuang Town was divided into three different management zones. On this basis, the prescription fertilization in different zones and for different field crops were calculated by the objective yield model. The result showed that the fertilizer amount needed for different field crops varied greatly. Compared with summer crops, autumn crops need more nitrogen fertilizer, less phosphate fertilizer, potash fertilizer flat; the fertilizer amount needed for different management zones differed also greatly, gradually increased from the first zone to the third zone; the prescription fertilization in different management zones was characterized by the variances of potash fertilizer ratio, the proportion of N, P and K for summer crops was about 1 ∶0.38 ∶0.68-0.71, for autumn crops, 1 ∶0.33 ∶0.66-0.68. The study proposes the method of cultivated land soil nutrient precision management that is compatible with the dispersed and extensive management in our country, which has a positive reference value to soil nutrient and fertilizing management in small regions.
    References | Related Articles | Metrics
    Resources Ecology
    Impact of Grain for Green Project on Ecosystem Service Values in the Hilly Region in Sichuan Basin: A Case Study of Hongya County
    LAI Yuan-chang, LI Xian-wei, FENG Shuai, WANG Peng, TANG Jiao-ping, ZHAO An-jiu, LAI Jia-ming
    2011, 26 (5):  755-768.  doi: 10.11849/zrzyxb.2011.05.004
    Abstract ( )   PDF (1396KB) ( )   Save
    Grain for Green Project is the most critical forestry ecological program of China. In this paper, a case study of the Hongya County in the hilly region in Sichuan Basin by using RS-GIS techniques and referencing the table ecosystem service value per unit area of Chinese terrestrial ecosystem, and combining with the local grain yield and grain purchasing price, this paper analyzed the changes of ecosystem service value between 1994-1999 and 1999-2007, two stages before and during the implementation of Grain for Green Project, and explored the impact of Grain for Green Project on ecosystem service values. The results show that the land use has been declining by the reason of Grain for Green Project; the magnitude of land use exhibited a decreasing trend of the study area. The ecosystem service values changed slightly in 1994-1999, but the ecosystem service values changed tremendously in 1999-2007, the total ecosystem service values increased by 2.90×108 yuan, the possible reason was farmland ecosystem service value decreased and wood land ecosystem service value increased. Each ecosystem service value was increased except food production, and the water supply value increased most, the water supply value increased by 0.78×108 yuan. Sensitivity analysis indicated that the estimated total ecosystem services value in the study area was inelastic to the services value coefficients change, and the results shown in this study were stable.
    References | Related Articles | Metrics
    Response of Water Levels to Precipitation Changes and Regional Urbanization in the Core Regions of the Taihu Lake Basin
    YIN Yi-xing, XU You-peng
    2011, 26 (5):  769-779.  doi: 10.11849/zrzyxb.2011.05.005
    Abstract ( )   PDF (1101KB) ( )   Save
    The water level of river network significantly increased and flood disasters occurred frequently in the Taihu Lake Basin at the end of the 20th century under the influence of climatic and anthropogenic factors. This paper makes a classification analysis of precipitation and water level series and explores the trends of their changes based on daily rainfall and water level data. A two-parameter elasticity analysis is adopted to investigate the sensitivity of water level to precipitation changes and urbanization which is representative of human activities. The main results are as follows: First, the contribution of low ranks (Ranks 1-3) of precipitation in flood and non-flood seasons to the total precipitation in the same period is on the decrease while the contribution of the high ranks (Ranks 8-10) is on the increase, thus the concentration of precipitation increases. The characteristics of water level are similar to those of the precipitation. However, the concentration of high rank water levels increases much more significantly than that of the rainfall. Second, the elasticity of urbanization during baseline period (1954-1985 for flood season and 1954-1987 for non-flood season) is not significant at the 5% level, while it is significant during the comparison period and the contribution of urbanization is near that of the precipitation. The paper draws a conclusion that human activities characterized by fast urbanization have played an important role in the changes of water level in the core region of the Taihu Lake Basin since the 1980s. The results of the paper may provide support for flood control and urban planning and management in the study area.
    References | Related Articles | Metrics
    Species Composition and Quantitative Distribution of Copepods in Zhoushan Fishing Ground and Adjacent Waters
    QIN Tao, YU Cun-gen, CHEN Xiao-qing, ZHENG Ji, WANG Jie-yu, NING Ping
    2011, 26 (5):  780-789.  doi: 10.11849/zrzyxb.2011.05.006
    Abstract ( )   PDF (1187KB) ( )   Save
    Based on four seasonal data of the comprehensive survey of marine ecosystem in August 2006, January, May and November 2007, this paper deals with the changes of species composition and quantitative distribution of copepods in Zhoushan fishing ground and adjacent waters (29°30'N-31°30'N, west of 124°30'E). The result shows that there are 65 species of copepods having been identified in the survey area. Ten species found in four seasons accounted for 15.38%. There were 10 dominant species appearing in four seasons, among them Calanus sinicus, Euchaeta concinna, Canthocalanus paupe and Scolecithrix nicobarica were the main dominants. In accordance with the results of dominance and regression analysis, it is clear that the four seasonal abundance distributions were mainly determined by the distribution of Calanus sinicus, Euchaeta concinna, Scolecithrix nicobarica and Canthocalanus paupe. And the seasonal variation of dominant species was remarkable. The areas of high abundance located in mix zone of water masses intersection. The trend of average abundance is the highest in spring(567.4 ind·m-3), then in summer(104.12 ind·m-3)and autumn(97.23 ind·m-3), and the lowest in winter(72.45 ind·m-3).
    References | Related Articles | Metrics
    Temporal and Spatial Response of Vegetation Net Primary Productivity to Climate Change in Buryatiya Republic, Russia
    REN Zheng-chao, ZHU Hua-zhong, ZHANG De-gang, LIU Xiao-ni
    2011, 26 (5):  790-801.  doi: 10.11849/zrzyxb.2011.05.007
    Abstract ( )   PDF (1241KB) ( )   Save
    As a critical index for monitoring the terrestrial ecosystem responding to climate change, net primary productivity(NPP) is widely used to reflect the productivity of vegetation community under natural conditions. Little work has been carried out on vegetation NPP in Buryatiya Republic of Russia in China. As Baikal Lake is located in Buryatiya, it would affect the vegetation growth in this area through changing the atmospheric circulation. Moreover, Buryatiya borders on Northern China. It would be of great importance for natural resource security and ecological value evaluation in Northern China to examine the vegetation growth there. In order to fully understand temporal and spatial variations in vegetation NPP and its response to climate change, satellite images of Moderate-resolution Imaging Spectroradiometer (MODIS) NDVI products in conjunction with ground-based observations of climatology were jointly used to estimate the vegetation NPP in Buyatiya Republic during the period 2000-2008. Meanwhile, observed values of vegetation NPP and MODIS NPP products were jointly utilized to verify simulations of vegetation NPP in this area. Data of MODIS NDVI and MODIS NPP were obtained from the United States Geological Survey (USGS), and the ground observations of climatology were gained from the United States National Centers for Environmental Prediction (NCEP). In addition, observations of vegetation NPP were obtained in August 2008 and September 2009 in Buryatiya. In particular, the Carnegie Ames Stanford Approach (CASA) was improved by simplifying its parameters so as to be suitable for large-scale estimation of vegetation NPP. Bio-temperature instead of monthly average temperature was applied to the sub-model of soil water content. Subsequently, the reliability of the model was tested with the observed vegetation NPP. Variation in vegetation NPP and its relationship with climatic factors were analyzed in detail. Results showed that: 1) The modified CASA model can be used to estimate vegetation NPP in Buryatiya Republic, and the accuracy of the model was generally high with a correlation coefficient of 0.91 (P<0.01). 2) The vegetation average annual NPP was 542.45 gC·m-2·a-1 and the total NPP was estimated as 1.91×1014 gC·a-1. Vegetation NPP exhibited an increasing trend at a rate of roughly 0.39 gC·m-2·a-1 from 2000 to 2008. As for monthly variation, vegetation NPP increased significantly from April to July, decreased rapidly from August to November, and maintained steady from December to March of the next year. Its monthly increasing rate was found to be approximately 9.93 gC·m-2·month-1. Vegetation NPP revealed fluctuation change in different regions with effect of terrain and human factors. However, it raised with increasing longitude and decreased with raising latitude. The NPP value of different vegetations embodied trend with meadow and swamp>forest>forest and steppe>steppe>high mountainous vegetation. 3) Temperature and precipitation were found to be the primary factors limiting vegetation NPP over this area. In short, this study results can be taken as reference for vegetation NPP estimation in Northern China or cross-border ecological research.
    References | Related Articles | Metrics
    Resources Evaluation
    Variations of Mteorological Factors Concerning Icing and Comprehensive Assessment in Southwest China
    ZHAO Xiao-meng, LI Dong-liang, XIONG Hai-xing, JIN Xi-ping
    2011, 26 (5):  802-813.  doi: 10.11849/zrzyxb.2011.05.008
    Abstract ( )   PDF (1570KB) ( )   Save
    The configuration of main meteorological elements was studied based on fuzzy information distribution method of probability by using daily meteorological elements data for the period of 1960-2009 from 96 stations in Southwest China, to the number of icing consecutive days mainly constructing icing comprehensive evaluation index. The results show that when satisfying the conditions that daily minimum temperature in the context of -10 ℃ and 1 ℃, relative humidity greater than or egual to 80%, sunshine duration less than or equal to 2 hours at the same time, the probability of formation icing will increase. The most severe icing area is at the border of Yunnan, Guizhou, Sichuan and Yunnan-Guizhou Plateau. There is obvious interdecadal variability in annual icing intensity in Southwest China.
    References | Related Articles | Metrics
    Trends and Determining Factors of Energy Consumption Carbon Footprint —An Analysis for Suzhou-Wuxi-Changzhou Region Based on STIRPAT Model
    LU Na, QU Fu-tian, FENG Shu-yi, SHAO Xue-lan
    2011, 26 (5):  814-824.  doi: 10.11849/zrzyxb.2011.05.009
    Abstract ( )   PDF (1111KB) ( )   Save
    Improving the understanding of the impact of socio-economic development on energy consumption carbon footprint is of great importance for developing low-carbon economy. This paper calculated and analyzed the trend of energy consumption carbon footprint of Suzhou-Wuxi-Changzhou region during the period of 1991—2008. Applying ridge regression method, the STIRPAT model was estimated to explore the relationships between population, per capita GDP, technological development and energy consumption carbon footprint. The decoupling index was adopted to further analyze the relationship between economic growth and energy consumption carbon footprint. Results indicated that: 1) For Suzhou-Wuxi-Changzhou region, energy consumption carbon footprint has increased from 0.05 hm2 per capita in 1991 to 0.58 hm2 per capita in 2008. The annual average increasing rate was 15.30%. Coal consumption accounted for the largest share in energy consumption carbon footprint. The share in 2008 was 96.18%. Petroleum consumption fluctuated and showed a downward trend, the share decreased from 18.71% to 3.42% from 1991 to 2008. Different from petroleum, natural gas consumption rose very fast. Even though the share was only 0.40% in 2008, the annual average increasing rate was 45.40% since the extension of natural gas in 2002. The value of carbon footprint showed an overall fluctuating downward tendency, indicating a large space for energy efficiency improvement. 2) Economic development was the main driving factor for energy consumption carbon footprint. 1% increase of per capita GDP has resulted in 0.73% increase in energy consumption carbon footprint. The relationship between per capita GDP and energy consumption carbon footprint, however, did not prove the environmental Kuznets curve (EKC), indicating that with the socio-economic development, environmental pressure caused by energy consumption will continuously increasing. 3) The decoupling index was fluctuating, either in the state of relative decoupling or in re-coupling, indicating that economic growth was highly dependent on energy consumption, and verifying that EKC hypothesis does not exist. Compared with Suzhou and Wuxi, Changzhou has displayed a decoupling state between economic growth and energy consumption carbon footprint since 1998.
    References | Related Articles | Metrics
    Characteristics of Variation in Sunshine Duration and Wind Speed in the Last 50 Years in Northwest China
    HUANG Xiao-yan, ZHANG Ming-jun, WANG Sheng-jie, XIN Hong, HE Jin-yun
    2011, 26 (5):  825-835.  doi: 10.11849/zrzyxb.2011.05.010
    Abstract ( )   PDF (1374KB) ( )   Save
    Based on the data of sunshine duration, wind speed and temperature collected at 112 stations from 1960 to 2009 in Northwest China (covering Gansu, Ningxia, Qinghai, Shaanxi and Xinjiang), spatial and temporal (for annual, seasonal and monthly) variations of sunshine duration and wind speed, as well as the correlation coefficients between wind speed and temperature were analyzed. The result showed that the sunshine duration displays a marked decreasing tendency in the last 50 years with a decreasing rate of 13.6 h (10 a)-1, while a sudden change is found in 1981. A distinct decreasing occurs in central Xinjiang, Guanzhong Plain and Qinling-Daba Mountains in spatial distribution, and it is most prominent in seasonal distribution in summer and winter. The annual average wind speed is decreasing at a rate of 0.09 m s-1(10 a)-1. The decrement rate in the western part of the study area is higher than that in the eastern part, especially in most part of Xinjiang and Qinghai, as well as Hexi Corridor. Wind speed showed a relevance, to some degree, with average temperature, average maximum temperature and average minimum temperature.
    References | Related Articles | Metrics
    Monitoring Glacial Lake Variations Based on Remote Sensing in the Lhozhag District,Eastern Himalayas,1980-2007
    LI Zhi-guo, YAO Tan-dong, YE Qing-hua, LI Chao-liu, WANG Wei-cai
    2011, 26 (5):  836-846.  doi: 10.11849/zrzyxb.2011.05.011
    Abstract ( )   PDF (1138KB) ( )   Save
    Based on the datasets of topographic maps of 1980, Landsat TM of 1988/1990, Landsat ETM+of 2000, and ALOS AVNIR-2 of 2007 as well as 42 years (1967-2008) temperature and precipitation data in the Lhozhag District of the eastern Himalayas, the characteristics of glacial lake change and its reason were investigated. The results show that: 1) The total area of 53 glacial lakes (with an area larger than 0.02 km2 in 1980) increased from 9.97 km2 in 1980 to 13.05 km2 in 2007. The overall increase was 3.08 km2, which was 30.9% of the total glacial lake area in 1980. Compared with the non-glacial-fed lakes, the area of glacial lakes in 1980 was found larger than the latter, and was distributed in more grades and elevation gradients. Moreover, area expansion during 1980-2007 of glacial lakes was as large as 102.7 times that of the non-glacial-fed lakes, much larger than the latter. It shows that the distribution and change of glacial lakes were affected deeply by glacier-meltwater supply. 2) During the period of 1980-2007, the average annual temperature of Cona Station increased significantly, which was in agreement with the trend of global warming elsewhere. The annual precipitation in Cona Station increased a little during 1980-2007. Therefore, the increase of glacial meltwater caused by rising temperature and increasing precipitation in the study area jointly determined the expansion of glacial lakes. Increased annual temperature acted as the most significant factor for recent glacial lake expansion in the Lhozhag District, while increased precipitation made some contributions, too. 3) The risk assessment of outburst probability for 32 recognizable glacial lakes larger than 0.1 km2 in 2007 shows that Cuogalongpu, Jialangka, Angge and Bailang lakes were in the highest rank of outburst in the study area.
    References | Related Articles | Metrics
    Dryness/Wetness Climate Variation Based on Standardized Precipitation Index in Northwest China
    ZHAI Lu-xin, FENG Qi
    2011, 26 (5):  847-857.  doi: 10.11849/zrzyxb.2011.05.012
    Abstract ( )   PDF (1117KB) ( )   Save
    Drought is one of the main natural disasters in Northwest China, even in the whole country. In this article, the standardized precipitation index (SPI) was applied to reconstruct the drought at the different time scales in recent 50 years in Northwest China. Then the frequency and the spatial distribution were calculated and analyzed for the severely dryness and extremely dryness. The results show that SPI used as a drought reconstruction index, is suitable in Northwest China, and may also be taken as the monitor index of the climate change. The trend of increase of the precipitation in western part and decrease in eastern part is corresponding to the trend of drought frequency, which is upward in southeastern part and downward in northwestern part of Northwest China. That is to say, the climatic change alleviated drought in northern Xinjiang and western Qinghai, but aggravated drought in southeastern part of Gansu and southern and central Shaanxi. Corresponding with the climatic change, the drought frequency of the entire Northwest China has an overall trend of downward, although the drought region continues to change.
    References | Related Articles | Metrics
    Spatial and Temporal Structure of Water Deficitover Northeast China during the Period of 1951-2008
    ZENG Li-hong, SONG Kai-shan, ZHANG Bai
    2011, 26 (5):  858-870.  doi: 10.11849/zrzyxb.2011.05.013
    Abstract ( )   PDF (1533KB) ( )   Save
    Based on measured meteorological data obtained from 106 stations located in Northeast China, potential evapotranspiration was calculated by applying Penman-Monteith equation, and water deficit was expressed as the difference of precipitation and potential evapotranspiration at the same period. Finally, spatial and temporal variation characteristics of water deficit over Northeast China were analyzed by using Kendall rank-related trend analysis, Morlet wavelet function and Mann-Kendall abrupt test. The results showed that: 1) during the period from 1951 to 2008, multi-year average water deficit over Northeast China varied between -850 mm and 650 mm with the spatial variation pattern of decreasing gradually from east to west, from north to south and from northeast to southwest. 2) Among all the 106 meteorological stations located in Northeast China, there were 97 stations showed declining trends in yearly water deficit, and the declining trends of 28 stations could even pass the significance test at the level of P<0.05. 3) Yearly water deficits of the whole region, Hailar, Changchun and Kuandian fluctuated obviously with the multi-year average water deficit for each were -283.60 mm, -427.25 mm, -362.58 mm and 334.91 mm, and monthly water deficit of them was uneven with the minimum value appearing in May and the maximum value in July or August. 4) Yearly water deficit had periodic characteristic, water deficit of the whole region, Hailar, Changchun and Kuandian showed "higher period", "lower period" alternately with the main period of 26, 28, 25 and 9 years, respectively. Moreover, water deficit also had abrupt property as other meteorological factors, water deficit of the whole region showed an abrupt decrease in 1999, while Changchun showed two abrupt decrease events which happed in 1958 and 1998.
    References | Related Articles | Metrics
    Study on Land Use/Cover in Mountain Area Based on the DEM —Taking the Qinghai Lake Basin as an Example
    CUI Bu-li, LI Xiao-yan, JIANG Guang-hui, ZHANG Si-yi, HUANG Yang-kui
    2011, 26 (5):  871-880.  doi: 10.11849/zrzyxb.2011.05.014
    Abstract ( )   PDF (942KB) ( )   Save
    Study on the influence of terrain upon land use pattern is necessary. This would help us to have a better understanding of the effects of human activity and the physical geography on the processes of land use/cover change, and is of practical significance in regional development and environmental protection. Based on the 1 ∶50000 DEM (Digital Elevation Model) and the multi-temporal remote sensing data of TM image extracted in 2004, this study, taking the Qinghai Lake Basin as an example, analyzed the difference between projected area and true surface area and the relationship between the terrain (elevation, slope and aspect) and the spatial distribution pattern of land use/cover. The conclusions of the study can be drawn as follows: 1) The true surface area is larger than projected area by 754.79 km2. 2) There were different land use types associated with different elevations, slope gradients and aspects. The main distributions of different land use types are listed as: cropland, habitation, water area and sandy land (below 3500 m and 2°, S and S-W aspects), woodland (3500-4000 m and 6°-25°), grassland (below 4500 m and 25°), swamp (3500-4500 m, below 25°, N and N-E aspects) and unused land (4000-4500 m, above 15°). 3) With the rise of elevation and slope, the index of land use intensity showed a gradual decreasing tendency, and the index of land use intensity decreased in the order of flat land, sunny slope and shady slope. These also showed that the terrain features are the foundation of regional land use pattern in the Qinghai Lake Basin. The reason was the terrain factor determines the redistribution of rainfall, heat and other natural resource, which finally affect the land use type and degree of human being. Compared the index of land use intensity with other typical regions, human activity had little effect on the land use/cover in this study area, so the related researches on environmental and ecological problems should pay more attention to the natural driving factors.
    References | Related Articles | Metrics
    Resources Research Methods
    Estimating Soil Total Nitrogen Content Based on Hyperspectral Analysis Technology
    ZHANG Juan-juan, TIAN Yong-chao, YAO Xia, CAO Wei-xing, MA Xin-ming, ZHU Yan
    2011, 26 (5):  881-890.  doi: 10.11849/zrzyxb.2011.05.015
    Abstract ( )   PDF (1015KB) ( )   Save
    Quantitative relationships between soil total nitrogen content (TN) and hyperspectra in visible and near-infrared region (VIS-NIR) (350-2500 nm) were studied for five soil types (paddy soil, fluvo-aquic soil, salinized fluvo-aquic soil, saline soil, dark soil with lime concretion) collected from central and East China. Based on three different methods of spectral index, partial least square (PLS) and back propagation neural network (BPNN), the models were developed for estimating TN content in soil. The results showed that the newly developed PLS and BPNN models for estimating TN content based on the corrected first derivative spectra of 500-900 nm and 1350-1490 nm regions with Norris smoothing filter performed well, with R2 of calibration as 0.81 and 0.98, respectively. The R2, RMSE and RPD of validation were 0.81, 0.219 g·kg-1 and 2.28 for the method of PLS, and were 0.93, 0.149 g·kg-1 and 3.36 for the method of BPNN, respectively. In addition, DI (NDR872, NDR1482) composed of the corrected first derivative spectra of 872 nm and 1482 nm with Norris smoothing algorithm also had a good correlation with soil TN content. Testing of the estimating model based on DI(NDR872, NDR1482) with independent datasets from different types of soil samples resulted in R2, RMSE and RPD as 0.66, 0.53 g·kg-1 and 1.60, respectively. Comparison of the above three methods, the sequence of prediction accuracy was PLS-BPNN model>PLS>DI(NDR872, NDR1482), which indicated that the newly developed BPNN and PLS models were reliable for estimating soil TN content with high prediction accuracy, and DI(NDR872, NDR1482) maybe a good indicator of soil TN content.
    References | Related Articles | Metrics
    Special Forum
    Progress in the Study of Wind Energy Utilization in the Built Environment
    YUAN Xing-fei, ZHANG Yu
    2011, 26 (5):  891-898.  doi: 10.11849/zrzyxb.2011.05.016
    Abstract ( )   PDF (966KB) ( )   Save
    According to wind characteristics in the built environment, the possibility of wind energy utilization was represented, and then the main way of wind energy utilization were introduced which includes natural aeration and exhaust, and electricity generation by wind power. The research status and application examples of wind energy utilization in the built environment were summarized systematically, from four aspects such as simulation of wind in the built environment, performances of wind energy augmented in the built environment, suitable wind turbines designs and the benefit evaluation of wind power in the built environment, also their shortages were analyzed simply. On this basis, some pending problems are proposed, which can be a reference to the promotion and application of wind energy utilization technology in the built environment.
    References | Related Articles | Metrics
Share: