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  • 2012 Volume 27 Issue 11
    Published: 20 November 2012
      

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  • CHENG Wei-ming, CHAI Hui-xia, FANG Yue, ZHOU Cheng-hu, TIAN Chang-yan, WU Shi-xin, TANG Qi-cheng
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    Based on the method and technology of geographic information system (GIS) and statistical analysis, this paper quantitatively analyzes the spatial and temporal distribution and change characteristics of the cultivated land resources from 1995 to 2008 in Xinjiang. The dataset used includes land use data, water resources regionalization, and SRTM-DEM with a horizontal resolution of 90 m.
    This paper firstly calculates the quantities and variation of cultivated land area in different periods in order to reflect the distribution and change characteristics of the cultivated land within 26 water resources regions possessed cultivated land area. The results show that: 1) The spatial distribution of cultivated land of every region in different periods slightly changed, and the whole pattern of cultivated land remained unchanged; the area of cultivated land of every region is increased or reduced, but the total area of all regions represents the trend of continuous growth from 1995 to 2008, the increased value is 126.39×104 hm2. And the increased rate of cultivated land in three periods is different, especially it is the highest from 2000 to 2005. 2) Through comparing the quantities, variation, rising and falling numerical differences of cultivated land of 26 water resources regions in different stages, variation mode of cultivated land can be grouped into four categories, namely the rising class, firstly falling-then rising class, firstly rising-then falling, rising-falling fluctuation class. 3)There are regional differences in the cultivated land change among water resources regions in Xinjiang. The Yarkand River Basin possesses the highest increased area of cultivated land from 1995 to 2008, the value is 17.36×104 hm2. And the area reduction of Emin River Basin is higher than other regions; the area of cultivated land reduced 3.15×104 hm2. 4) The cultivated land resources are distributed in low and middle elevation regions below the 2000 m, among which the most widely distributed is in 500-2000 m regions. The biggest change is observed in regions whose elevation is below 1500 m. The cultivated land area is increased both in plain terrain and hilly region, the new additional cultivated land is mainly distributed in plain landform. The piedmont plain area of fluvial landform types is mainly cultivated land resources from landform genetic types in Xinjiang.
    There are observably spatial differences of the cultivated land in Xinjiang. The reclamation and desolation of the land become the main and marked characteristics in Xinjiang. Consequently, it is necessary to effectively control the reclamation speed of cultivated land in Xinjiang. To ensure that food safety, the decision maker in Xinjiang should consider how to stand out the local distinguishing feature and realize the sustainable development of oasis agricultural economy. The farmland distribution on the basis of local watershed water resources and geomorphologic characteristic should be reasonably planned.

  • LI Peng, PU Li-jie
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    There is a close relationship between construction land expansion and economic growth, which in developed region have their own particularity besides the commonness. In order to analyze the particular relationship between construction land expansion and economic growth in Jiangsu Province, the linear regression basing on AR model and the co-integration are used basing on the research of Zhao Ke et al. Results show that: 1) The correlation coefficient between construction land and economic growth in Jiangsu Province is 0.992 which is comparatively high. The result of regression shows that when the GDP grows 1%, the area of construction land will grows 0.1359% in response which is lower than the average of the whole country. 2) The speed of construction land expansion driven by economic growth in southern Jiangsu Province is smaller than that of the whole country, but bigger than that of the whole Jiangsu Province. This perhaps is related to the concentration of population and the development of rural industry. 3) There existed a long-term stable equilibrium between construction land area and economic growth. The adjusted coefficient of constriction land to the short-time fluctuate is -0.4469, that of economic growth is 2.2360, which is higher than the average of whole country researched by Zhao Ke et al. 4) The economic growth is the Granger reason for the construction land expansion, but not the reverse, which is the same to the conclusion of Zhao Ke et al. Finally, the author brings forward the conclusion that when the governors and decision-makers are trying to find methods to hold back construction land expansion, they should give up the thought or attempt that construction land expansion can accelerate economic growth drastically. At the same time, developing small city which can attract more people who want to go to big city is a good way to prevent construction land expansion.

  • LI Hai-yan, CAI Yin-ying
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    In this paper, we focus on the trend of the farmer’s perceived value after the land expropriation. Taking the factor of the farmer’s perceived value and the evaluated index as measurement tools, we draw the relationship between the farmers’ perceived value and their land requisition willingness by the structure equation model (SEM). We show that the farmer’s perceived value after the land expropriation reflected by the changes of his financial condition, farmland fund, basic public service, social public service and the farmland landscape and surrounding. We further give the financial condition, farmland fund, basic public service and farmland landscape and surrounding generated positive effect on farmers’willingness of land requisition. However, social public service does have weaker effect compared by others. Finally, we rank of the factors which produced more positive effect on the farmer land requisition. The outstanding factor is farmland fund which is followed by the financial revenue, basic public service and farmland landscape and surrounding in order. Obviously farmer land requisition willingness is directed by their perceived value. So taking this into consideration and making good use for government to draft an effective compensatory land expropriation policy, will guide the farmer to adapt to the sudden changes and provide a basis to solve the conflict in land expropriation.

  • CHEN Gui-yue, LI Hai-tao, LIANG Tao
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    Based on the unrestricted VAR method, the dynamic interactions between economic growth and environmental pollution was investigated through the variable stationary characterization and cointegration test, Granger causality test, impulse response functions and variance decomposition analysis according to the time series data of six kinds of pollution indices and per capita GDP in Inner Mongolia from 1986 to 2009. The results were as follows: 1) There are long-term relationships among the release rate of industrial dust, solid wastes, sulfur dioxide, soot, industrial gas, waste water and the per capita GDP. When the release rate of industrial dust, solid wastes, sulfur dioxide and soot increased by 1%, the per capita GDP would decrease by 0.068%, 0.411%,0.380% and 0.418%,respectively; when the release rate of industrial gas and waste water increased by 1%, the per capita gross domestic production would increase by 1.305% and 1.601% individually. 2) The per capita GDP Granger caused industrial solid wastes and gas emissions, while it was not true vice versa. This was consistent with the fact that Inner Mongolia was at a middle industrialization stage during the study period. 3) The response of economic growth to environmental quality was almost zero in the first period while there was negative relationship between per capita GDP and dust, waste water emissions for a long time. The function graph of response of per capita GDP to industrial gases represented "increasing-decreasing-increasing" trend in the first four periods while the impact decreased gradually. The response of per capita GDP to industrial solid wastes and sulfur dioxide was not apparent, almost reaching zero and the response of per capita GDP to soot was the biggest in the second period. 4) The variance decomposition results of per capita GDP show that besides per capita GDP itself, the variation of all environmental factors makes the least contribution to the changes of per capita GDP, and their contribution rates are almost zero in the first period and rise unobviously afterwards; while the variation of per capita GDP contributes more to the changes of environmental factors. Among all the environmental factors, per capita GDP makes the biggest contribution to the changes of dust emissions, reaching 57.62% steadily. Per capita GDP makes the least contribution to the changes of soot emissions, reaching 12.7% steadily from the first to the tenth periods. It was further explaining that the pollutant emissions could not promote the economy heavily while the increase of per capita GDP can lead to pollutants emission.

  • WU Wei, LU Ping-shan
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    Resource major portion has the key function to the sustainability and the security of local land ecosystem, which is a critical part of local ecological networks. The main purpose of this paper is to promote an approach, which is suitable for the characteristics of land ecosystem of the Yangtze River Delta Area, with collected coarse ecological data and precise land use data to identify resource major portion. Firstly, a set of indices, 21 indicators, is proposed to identify the importance of different sub-municipal units within the objective, Wuxi municipal city. Then, a set of ecological contribution ratios of different land use is applied with GIS technology to identify the importance of different patches of land use within the sub-municipal units. Lastly, the total area of Wuxi municipal city is classified into six groups: resource major portion (RMP), RMP buffer, common zone, interference portion (IP), IP buffer, and overlapped zone of buffers (OB). The research result presents that these six groups of zones sharing the proportions of total area are 19.70%, 12.03%, 39.62%, 16.36%, 12.28% and 6.35% respectively. The patches of RMP are small in size and in an unbalanced spatial arrangement. 85.26% of all the RMP patches are in Yixing sub-municipal unit due to local physiogeographic factors and less human activities interference. The IP patches in average size are bigger and more spatially concentrative compared with those of RMP patches, especially for the IP patches in Binhu Built-up Area, the combination of seven sub-municipal units and the city centre of Wuxi municipal city. The spatial arrangement of IP patches has a close relation with those of the urban built-up areas and regional infrastructures. The characteristics of spatial arrangements of the OB patches in different sub-municipal units are different due to their different causes. At last, the authors recommend that there are 50.48% of the RMP buffer patches in Binhu Built-up Area, 40.91% in Jiangyin, and 33.63% in Yixing which have potential possibility of being interfered along with coming rapid urbanization.

  • ZHAO Jun, SHI Yin-fang, WANG Da-wei
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    Daily average temperature and precipitation observations during 1985-2009 are collected from 94 meteorological stations in Inner Mongolia and its surrounding areas. On the basis of Integrated Orderly Classification System (IOCS), the net primary productivity (NPP) of potential vegetation types in Inner Mongolia are simulated with the model of classification indices. Then the spatial distribution characteristics and the relationships between NPP and climatic factors are analyzed, and the results are shown as follows: 1) The NPP of Inner Mongolia shows nearly meridional distribution; the mean NPP is from 0 to 366.5 gC·m-2·a-1, and the bigger value region is located in the northeast of Greater Hinggan Mountains. 2) The potential vegetation type of the largest NPP is cool temperate perhumid mixed coniferous broad-leaved forest and its value is 231.8 gC·m-2·a-1; the second is warm temperate-subhumid forest steppe and its value is 222.8 gC·m-2·a-1; besides the minimum is warm temperate-extrarid warm temperate zonal desert, the value of which is only 0.6 gC·m-2·a-1. 3) For all the potential vegetation types, the maximum contribution to carbon sequestration potential is cool temperate-semiarid temperate typical steppe, the value of which is 23.6%; the minimum is cold temperate-semiarid montane steppe and the value is close to zero. 4) Each potential vegetation NPP has a higher partial correlation with moisture-humidity than annual cumulative temperature; by the IOCS, which is based on a moisture index, expressed as the ratio between annual precipitation and >0℃ annual cumulative, we can confirm that precipitation is the main factor, which impacts the NPP of potential vegetation types. 5) In Inner Mongolia, the NPP of potential vegetation types show the characteristics of wet-dry and latitude zonality obviously, and the NPP increases gradually as the change is with cold temperate→cool temperate→warm temperate and the diversification is with semiarid→subhumid→humid→perhumid; however, warm temperate-extrarid warm temperate zonal desert and warm temperate-arid warm temperate zonal semidesert do not comply with this law; the main reason is that higher temperature and less precipitation cannot meet the needs of vegetation growth.

  • YAO Xiao-ying, LI Xiao-wei, WANG Yu-xi, WANG Ning-zhen
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    Based on the experiment data of maize on the Xifeng Agrometeorological Experiment Station and meteorological data on Xifeng National Base Climate Station from 1994 to 2008, the characteristics of LAI (Leaf Area Index) and influence of accumulated temperature and PAR (Photosynthetically Active Radiation) on LAI, influence of LAI on total water storage in depth of 50 cm in soil, biomass and yield factors have been analyzed. The results showed that the LAI in three leaves period to milky mature period presented "S-shape" curves with the days in which LAI increased slowly in 8 to 28 days after emerging then increased rapidly at a rate of 0.7/10 days in 28 to 74 days after emergence and at last decreased slowly at a rate of 0.1/10 days in 74 to 103 days after emerging and water ratio of leaves decreased by 0.9% every 10 days. During the experiment years, the different values of precipitation was bigger which the variation coefficients were 31% to 92%; next was effective accumulated temperature ≥10℃ with the variation coefficients 15% to 58% and PAR was the stable factor in which the variation coefficients were 6% to 18%. The meteorological factors in all experiment years tended to be average value from sowing to milky maturation period. LAI and effective accumulated temperature and PAR varied with power function that turning point of values of LAI were in 500℃ of effective accumulated temperature and 250 MJ/m2 of PAR. Total water storage in depth of 50cm in soil decreased by 11 mm with LAI increased by 1. Biomass of maize turned to be power function described by LAI in which the most optimum value is 3.5. The most optimum planting density was 60000 plants per hectare. Relevance between yield factors and LAI in seven leaves to jointing period was not notability but notability in tasseling to milky maturation period. LAI in tasseling period within the specific limits was favorable to improve economic outputs.

  • XU Li-li, WANG Qiu-bing, ZHANG Xin-yu, ZOU Jing-dong, DAI Xiao-qin, WANG Hui-min, SUN Xiao-min, DONG Wen-yi
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    Supported by Qianyanzhou Ecological Experiment Station, this study aimed to discuss the effects of different fertilizer treatments on paddy soil elements including carbon and other nutrients by using the long-term fertilization trial on paddy soil established in 1998. The results showed as follows: 1) Application of organic manure was beneficial to increase the contents of soil carbon, nitrogen and phosphorus. Specifically, the content of soil organic carbon (SOC) reached 16.8 g·kg-1, total nitrogen (TN) reached 1.5 g·kg-1, available nitrogen (AN) reached 153.8 mg·kg-1, available phosphorus (AP) reached 43.3 mg·kg-1, while the content of available potassium (AK) was only 23.0 mg·kg-1 which was lower than the chemical fertilizer treatments. 2) The application of chemical fertilizer could alleviate soil acidification tendency to some extent in red paddy soil and significantly increase the contents of AP (12.3-47.1mg·kg-1) and AK (22.3-54.5 mg·kg-1). 3) Application of straw returning enhanced the content of SOC (10.8 g·kg-1) and TN (1.1 g·kg-1). 4) In conclusion, it was recommended to apply the organic manure and straw returning with K fertilizer to increase the soil carbon and satisfy the nutrient demand of rice. Meanwhile, the application rate of organic manure and chemical fertilizer should consider the potential risk of nitrogen and phosphorus pollution.

  • ZHANG Sheng-ying, ZHANG De-gang, CHEN Jian-gang, XU Chang-lin, LIU Xiao-ni, ZHANG Hu
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    The Achnatherum splendens tussock fertile island was studied in Qilian Mountains. The results showed that: 1) The soil nutrient in the crown width of Achnatherum splendens tussock was more than that in the tussock gap. 2) A common variation pattern was found that the some soil nutrient contents, including organic matter, total nitrogen, total phosphorus, available nitrogen, available phosphorus, available potassium, available zinc, available manganese and available iron, decreased firstly and then increased along with the distance from the centre of tussock to the edge of tussock. 3) Other soil indices showed their own variation pattern: Total potassium content varied in different soil layers; pH value increased within 0-10 cm and 10-20 cm layers, and decreased within 20-30cm layer. Available copper content continuously decreased within 0-10 cm and 10-20 cm layers, and firstly decreased and then increased in 20-30 cm. Generally, the variation pattern of soil nutrient in Achnatherum splendens tussock varied in terms of different nutrients or properties.

  • LI Yun-gang, HE Da-ming, HU Jin-ming, LIU Jiang
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    The temporal and spatial variations of extreme precipitation were studied by using extreme precipitation indices Based on the daily precipitation data of 23 meteorological stations over the Red River Basin in China from 1960 to 2007. The intensity and frequency of extreme precipitation gradually reduces from southeast to northwest, high value area was distributed along the south of the Jiangcheng-Lüchun-Jinping-Hekou while low value area existed along the north of Weishan-Nanjian-Midu and the middle reaches of the Yuanjiang River Valley. The peak of extremely heavy precipitation occurred in July, while extreme precipitation occurrence frequency in flood season accounted for 91.48% of the annual total. In the past 48 years, an increasing trend was observed in indices such as the total wet day precipitation (PRCPTOT), the maximum 1-day precipitation amount (Rx1d), the maximum 5-day precipitation amount (Rx5d), the number of heavy precipitation days (R95N), the percent of total precipitation from heavy precipitation (R95T) and the simple daily intensity index (SDII), among which R95T and SDII increased significantly at the rates of 0.68%·(10 a)-1 and 0.17 mm·d-1·(10 a)-1 respectively. The trends of these indices exhibited spatial differences except for SDII, regions with the increasing trends are distributed mostly in the upstreams of the Lixianjiang and Yuanjiang rivers, as well as Tengtiao River Basin, while those of the decreasing trends were found in the downstreams of the Lixianjiang and Yuanjiang rivers, and Panlong River Basin as well.

  • LI Xue-mei, LI Lan-hai, BAI Lei, ZHANG Fei-yun, SHANG Ming, WANG Xi-xi
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    The 20th century was probably believed as the warmest period during the last one thousand years. However, the lack of observed climatic data during the first half of the 20th century in China, especially in the arid land of Northwest China led to great uncertainty in climate change assessment of the 20th century. Reconstruction of climatic data for the first half of the 20th century could improve the reliability of climate change assessment of the 20th century. Choosing the observed monthly temperature and precipitation of three meteorological stations from Central Asia during the 20th century and the observed monthly temperature and precipitation of four meteorological stations from Kaidu River Basin during 1961-1990, this paper reconstructed the monthly temperature and precipitation during 1901-1960 in Kaidu River Basin using Delta and Canonical Correlation Analysis (CCA) methods and analyzed the performance of reconstruction and applicability of those two methods. The results showed that: the performance of reconstructed monthly temperature using Delta method was better than that using CCA method, while the performance of reconstructed monthly precipitation using CCA method was better than that using Delta method. The inter-annual variation of monthly temperature time series during 1901-1960 reconstructed by Delta method was large. It was smooth and steady of monthly temperature time series during 1901-1960 reconstructed by CCA method. The inter-annual variation was large for monthly precipitation time series during 1901-1960 reconstructed by both Delta and CCA methods.

  • LIU Xin-hua, XU Hai-liang, ZHANG Qing-qing, BAI Yuan, FU Jin-yi, DAI Yue
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    Based on the runoff data of two hydrological stations and the climate data of two meteorological stations during the period of approximate 50 years in the headstream areas of Aksu River Basin, the periodicity and trends of climate change and runoff were investigated by nonparametric test and an extrapolation method of variance analysis, and then the future change trend and runoff volumes of the annual runoff were predicted by the periodic trend superposition model and R/S analysis. In succession, the impact volumes of climate change on the annual runoff were separated from the observation values of the annual runoff in the Aksu River. the results showed that: the temperature, precipitation and annual runoff of Aksu River Basin increased significantly, and the mutations of which are at 1989, 1985 and 1993, respectively; the Hurst coefficients of both climate factors and the annual runoff were bigger than 0.5, and indicated that they would still keep an increasing trend; the relative highest and lowest volumes of the annual runoff will be 91.822×108 m3 in 2014 and 83.430×108 m3 in 2011 during the period of 2010-2014; the annual runoff holds a quasi-25 years’period from 1957 to 2007, but the primary period of 17 years was proved before shifting change; the increased volume of the annual runoff in the headstream due to climate change is 224.97×108 m3 after shifting change, and the highest value and lowest value of the affecting volume are in 2003 and 2004, respectively.

  • WEI Wei, SHI Pei-ji, FENG Hai-chun, WANG Xu-feng
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    The paper selects slope, aspect, relief degree of land surface, vegetation index, hydrology, transportation and climate as evaluation indexes and sets up the Human Settlements Environment Index (HEI) model to evaluate the environment suitability for human settlements in Shiyang River Basin. Through using spatial analysis technique of GIS such as spatial overlay analysis, buffer analysis and density analysis to establish the spatial situation of nature suitability and spatial pattern for human settlement. The results showed that: the index of nature suitability for human settlement in the Shiyang River Basin was between 17.13 and 84.32. In general, nature suitability for human settlement decreased from southwest to northeast. Considering area, the suitable region was mainly distributed in Minqin oasis, Wuwei oasis and Changning basin, which accounted for about 1080.01 km2, 2.59% of the total area. Comparatively suitable region was mainly distributed around the county in Gulang, Yongchang and north of Tianzhu County, which accounted for about 1100.30 km2. The common suitable region was mainly distributed outside of the county in Yongchang, Jinchuan and most part of Minqin county, which accounted for about 23328.04 km2, 56.08% of the total area. The non-suitable region was mainly distributed upstream and north of the river, which accounted for about 9937.60 km2, 23.89% of the total area. Meanwhile, the most non-suitable region was distributed around the Qilian Mountain which covered by snow and cold desert and the intersecting area between Tengger Desert and Badain Jaran Desert. The total area was about 6154.05 km2, which accounted for 14.79% of the total area. Suitable regions for human inhabitance were distributed mainly around rivers in the form of ribbons and batches, while others are scattered. Their distribution was identical with the residential spatial pattern. There was a clear logarithm correlation between situation of residential environment and population, that is, the coefficient of determination between evaluation value of residential environment and population density reached 0.851 2. There was also positive correlation between situation of residential environment and economics, which reached 0.845 4 between evaluation value of residential environment and GDP. Result also shows the environment is difficult to support the existing population in the Shiyang River Basin. Spatial distribution of population was profoundly affected by severe environment such as the expanded deserts, the wavy terrains, and the changeful climate. Surface water shortage and slow economic growth was the bottleneck of nature suitability for human settlement in the Shiyang River Basin. So according to these problems and various planning, some of the residential parts need to relocate in order to improve situation of residential environment.

  • WANG Jiao-e, HU Hao
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    Medium- and small-sized cultural tourist cities are an important component part of regional tourism. Besides the attraction of scenic spots, enhancing accessibility and perfecting infrastructure construction in scenic spots are very important for their tourism development. Therefore, the research on accessibility of medium- and small-sized cultural tourist cities is meaningful. First, there are 113 cultural cities which are proved by the State Council of the People’s Republic of China. The medium- and small-sized cities are defined with non-agricultural people less than 500000 in 2008. Therefore, the paper gets 34 medium- and small-sized cultural tourist cities as research objects. Second, the paper researches the accessibility of 34 medium- and small-sized cultural tourist cities from the perspective of Euclidean distance and time cost based on GIS with countiec as the basic unit. The Euclidean distance is measured by 50 km, 100 km, and 200 km respectively and the time cost is calculated by 1 hour, 2 hours, and 3 hours based on the road transport network since most tourists are distributed in 250 km from the attractions. Results indicate that: the accessibility of the 34 medium- and small-sized cultural tourist cities shows disequilibrium in spatial distribution, and the blank areas and overlapped areas from attractions for enjoying tourism resources exist together. For example, Northeast China, South China, Inner Mongolia Plateau and Tibetan Plateau can’t access medium- and small-size cultural tourist cities in 200 km or 3 hours. Conversely, the market areas of cultural tourist cities in the Yangtze River, Chengdu-Chongqing region, Southwestern Shandong, and West of the Taiwan Strait are overlapped in 200 km or 3 hours, and the tourism resources of these areas have the potential for regional cooperation. Finally, this paper calculates the correlation coefficient of tourism income, tourism population of the 34 cities and the socio-economic indices in accessed areas by distance and time, and the result shows that the GDP in 1 hour has the highest correlation coefficient with the tourism income and the GDP in 50 km having the highest correlation coefficient with the tourism population. In a word, how to perfect the infrastructure construction of medium- and small-sized cities and enhance their accessibility has great function to expand their tourism market.

  • LI Xiao-dong, XIAO Jian-she, LI Feng-xia, XIAO Rui-xiang, XU Wei-xin, WANG Li
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    The meteorological and MODIS data in recent 10 years were used to analyze change of the area of water surface, water level, annual average temperature and annual rainfall, and reveal trend of the area of water surface of the Qinghai Lake. Results of the analysis of remote sensing monitoring data of the Qinghai Lake and climate factors around it showed that the annual average temperature increased significantly in recent 10 years, the average increase per year for the annual average temperature about 0.12℃. The annual rainfall showed an increasing trend in fluctuation. It is found that water level of the Qinghai Lake showed a continued declining trend in recent 50 years, but enhanced from 2001 to 2010 and the increasing trend was remarkable. The results indicated that area of water surface monitoring show significant increase in the Qinghai Lake from MODIS data in April and September in the past 10 years, and area of water surface was significantly correlated with water level,the correlation coefficients are 0.818 and 0.875 respectively(P<0.05). As a result of climate change, rainfall increased or climate changed wet in some areas of northern Qinghai. Because of warm-wet climate leading to rainfall increase, this may cause water level rising and such a trend of climate change made area of water surface enlarged in the nearly 10 years.

  • LI Min, ZHAO Geng-xing, CAI Ming-qing, ZHAO Qian-qian, TANG Jian
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    Precision management of cotton information is an objective need to improve the management of cotton production and promote digital agricultural development. This article took Xiajin County of Shandong Province as a study area and selected remote sensing images of HJ-1 satellite in four different cotton growing seasons. The best phase to identify cotton was determined by analyzing phonological calendar and spectral characteristics of major crops. An extraction model was established to acquire cotton planting area information. Combining characteristic spectral index established at flower and boll stage with five kinds of main soil nutrients measured, cotton management zones were divided by correlation analysis, principal component analysis and K-means cluster analysis. The significant differences of the partition results were analyzed to evaluate the reasonableness. The results showed that the best phase to extract cotton area was bud stage and extraction accuracy was more than 93%. The OSAVI could reflect cotton growth information well and was significantly correlated with soil nutrients. Cotton field of the study area was divided into three management zones using principal component partition indicators. The first management zone accounted for 24.67% of the total area with the highest content of soil organic matter and N,P,K, and its cotton grew well. The second management zone accounted for 47.02% with medium soil nutrients and general cotton grew. The third management zone accounted for 28.31% with the lowest soil fertility and poor cotton grew. In each management partition, coefficient variation of soil nutrients decreased significantly. There were significantly statistical differences between mean soil nutrients and spectral data in different defined management zones, which showed the partition’s high reasonableness. This research provides scientific basis of real-time and accurate cotton cultivation management for decision-making.

  • TAN Yong-zhong, CHEN Jia, WANG Qing-ri, MOU Yong-ming, LIU Yi, SHI Ya-juan
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    A comprehensive understanding and scientific assessment of the value of prime farmland is an important prerequisite for building the economic compensation for the protection of prime farmland. This paper proposes the initial attempt of the introduction of choice experiment model to the study of non-market value of prime farmland, and makes a case study taking Deqing County, Zhejiang Province as an example. Based on face-to-face interview, it discusses the cognitive differences of urban and rural residents for the protection of prime farmland, and analyses the cognitive preferences and its possible sources of heterogeneity of urban and rural residents for the non-market value of prime farmland by applying choice experiment model. Finally, urban and rural residents’ willingness to pay for the non-market value of prime farmland is evaluated and compared, and the non-market value of prime farmland in Deqing County is obtained.
    Based on it, this paper concludes that: 1) both urban and rural residents had known the non-market value of prime farmland to some extent, and recognized the need and importance for continuing the protection of prime farmland, however, the urban residents’ cognition of non-market value of prime farmland is more comprehensive and profound compared with that of rural residents. 2) Urban and rural residents paid more attention to the social value of prime farmland, and the cognitive preferences of urban and rural residents for the non-market value of prime farmland are influenced by age, education, family size, income, behavior and attitude variables. 3) Urban residents’ willingness to pay is generally higher than rural residents’, urban residents’ willingness to pay per year is 143.04 yuan per household while rural residents’ is 27.47 yuan per household, and gender, age, family size, income and attitude variables have a major impact on their willingness to pay. Besides, the income of urban and rural residents significantly affects the level of their payment. 4) Mixed Logit model reveals individuals’ heterogeneity of preferences and its possible source, and it also shows higher degree of model fit and better explanation than MNL model. However, the estimated results were different in the application of assessing willingness to pay for the property by MNL model and Mixed Logit model. 5) The results show that, in 2009, non-market value of prime farmland in Deqing County is 2.58×108 yuan, and non-market value per unit is 1.27×104 yuan/hm2, accounting for 54.17% of the total value of prime farmland.