103 research outputs found

    Time tracking of different cropping patterns using Landsat images under different agricultural systems during 1990-2050 in Cold China

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    Rapid cropland reclamation is underway in Cold China in response to increases in food demand, while the lack analyses of time series cropping pattern mappings limits our understanding of the acute transformation process of cropland structure and associated environmental effects. The Cold China contains different agricultural systems (state and private farming), and such systems could lead to different cropping patterns. So far, such changes have not been revealed yet. Based on the Landsat images, this study tracked cropping information in five-year increments (1990-1995, 1995-2000, 2000-2005, 2005-2010, and 2010-2015) and predicted future patterns for the period of 2020-2050 under different agricultural systems using developed method for determining cropland patterns. The following results were obtained: The available time series of Landsat images in Cold China met the requirements for long-term cropping pattern studies, and the developed method exhibited high accuracy (over 91%) and obtained precise spatial information. A new satellite evidence was observed that cropping patterns significantly differed between the two farm types, with paddy field in state farming expanding at a faster rate (from 2.66 to 68.56%) than those in private farming (from 10.12 to 34.98%). More than 70% of paddy expansion was attributed to the transformation of upland crop in each period at the pixel level, which led to a greater loss of upland crop in state farming than private farming (9505.66 km(2) vs. 2840.29 km(2)) during 1990-2015. Rapid cropland reclamation is projected to stagnate in 2020, while paddy expansion will continue until 2040 primarily in private farming in Cold China. This study provides new evidence for different land use change pattern mechanisms between different agricultural systems, and the results have significant implications for understanding and guiding agricultural system development

    Classifying Ingestive Behavior of Dairy Cows via Automatic Sound Recognition

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    Determining ingestive behaviors of dairy cows is critical to evaluate their productivity and health status. The objectives of this research were to (1) develop the relationship between forage species/heights and sound characteristics of three different ingestive behaviors (bites, chews, and chew-bites); (2) comparatively evaluate three deep learning models and optimization strategies for classifying the three behaviors; and (3) examine the ability of deep learning modeling for classifying the three ingestive behaviors under various forage characteristics. The results show that the amplitude and duration of the bite, chew, and chew-bite sounds were mostly larger for tall forages (tall fescue and alfalfa) compared to their counterparts. The long short-term memory network using a filtered dataset with balanced duration and imbalanced audio files offered better performance than its counterparts. The best classification performance was over 0.93, and the best and poorest performance difference was 0.4–0.5 under different forage species and heights. In conclusion, the deep learning technique could classify the dairy cow ingestive behaviors but was unable to differentiate between them under some forage characteristics using acoustic signals. Thus, while the developed tool is useful to support precision dairy cow management, it requires further improvement

    Annual accumulation for Greenland updated using ice core data developed during 2000-2006 and analysis of daily coastal meteorological data

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    An updated accumulation map for Greenland is presented on the basis of 39 new ice core estimates of accumulation, 256 ice sheet estimates from ice cores and snow pits used in previous maps, and reanalysis of time series data from 20 coastal weather stations. The period 1950-2000 is better represented by the data than are earlier periods. Ice-sheetwide accumulation was estimated based on kriging. The average accumulation (95 confidence interval, or ±2 times standard error) over the Greenland ice sheet is 30.0 ± 2.4 g cm -2 a-1, with the average accumulation above 2000-m elevation being essentially the same, 29.9 ± 2.2 g cm-2 a -1. At higher elevations the new accumulation map maintains the main features shown in previous maps. However, there are five coastal areas with obvious differences: southwest, northwest, and eastern regions, where the accumulation values are 20-50 lower than previously estimated, and southeast and northeast regions, where the accumulation values are 20-50 higher than previously estimated. These differences are almost entirely due to new coastal data. The much lower accumulation in the southwest and the much higher accumulation in the southeast indicated by the current map mean that long-term mass balance in both catchments is closer to steady state than previously estimated. However, uncertainty in these areas remains high owing to strong gradients in precipitation from the coast inland. A significant and sustained precipitation measurement program will be needed to resolve this uncertainty. Copyright 2009 by the American Geophysical Union

    Real-time Monitoring for the Next Core-Collapse Supernova in JUNO

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    Core-collapse supernova (CCSN) is one of the most energetic astrophysical events in the Universe. The early and prompt detection of neutrinos before (pre-SN) and during the SN burst is a unique opportunity to realize the multi-messenger observation of the CCSN events. In this work, we describe the monitoring concept and present the sensitivity of the system to the pre-SN and SN neutrinos at the Jiangmen Underground Neutrino Observatory (JUNO), which is a 20 kton liquid scintillator detector under construction in South China. The real-time monitoring system is designed with both the prompt monitors on the electronic board and online monitors at the data acquisition stage, in order to ensure both the alert speed and alert coverage of progenitor stars. By assuming a false alert rate of 1 per year, this monitoring system can be sensitive to the pre-SN neutrinos up to the distance of about 1.6 (0.9) kpc and SN neutrinos up to about 370 (360) kpc for a progenitor mass of 30M⊙M_{\odot} for the case of normal (inverted) mass ordering. The pointing ability of the CCSN is evaluated by using the accumulated event anisotropy of the inverse beta decay interactions from pre-SN or SN neutrinos, which, along with the early alert, can play important roles for the followup multi-messenger observations of the next Galactic or nearby extragalactic CCSN.Comment: 24 pages, 9 figure

    Transforming the Loess Plateau of China

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    This paper aims to show the importance of land consolidation in transforming the Loess Plateau of China. The paper comprehensively analyzes how over recent decades the Grain for Green Project and Gully Land Consolidation Project jointly transformed the ecology and landscape of the Loess Plateau and the livelihood of its residents. The findings show that these two projects have achieved a balance between green protection, new land creation, and improved food security and livelihood of local people in the hilly areas of China. The paper points out that the successful transformation of the Plateau lies in a holistic approach incorporating various components of the human and natural systems. Finally, the paper highlights the necessity of retaining these two land consolidation projects as part of an ongoing policy in the mountain and hilly areas of China, changing agricultural management to suit the new relationship between humans and the land

    Effects of Topographic Factors on Cultivated-Land Ridge Orientation in the Black Soil Region of Songnen Plain

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    Topographic factors are essential to the spatial distribution of ridge orientation, yet the literature shows limited exploration of the mechanisms underlying the effects of terrain on cultivated-land ridge orientation in a black soil region. To better understand this subject, interpretation, statistical analyses and field verification were carried out in Songnen Plain, a typical Mollisol area. The results revealed that inclined-ridge cultivation was the most common farming method in the study area. When the slope gradient of cultivated land was greater than 13°, the influence of slope on ridge orientation was obvious, and the residual ridge angle increased with the increase in slope. There was a strongly significant negative correlation between the residual ridge angle and the azimuth angle, and the proportion curves of all ridge orientations with respect to different slope aspects were axisymmetric with respect to azimuth angles of 0°–180°. The relationship among indices such as slope gradient, slope aspect and ridge orientation could be modeled using a Poly2D function. This study indicates that topographic factors are the dominant factor in ridge-orientation selection, and provides a scientific basis for block-scale cultivated-land protection and utilization in black soil region; however, the scientific configuration of ridge orientation requires further research

    GIS-Based Niche Hybrid Bat Algorithm for Solving Optimal Spatial Search

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    Complex nonlinear optimization problems are involved in optimal spatial search, such as location allocation problems that occur in multidimensional geographic space. Such search problems are generally difficult to solve by using traditional methods. The bat algorithm (BA) is an effective method for solving optimization problems. However, the solution of the standard BA is easily trapped at one of its local optimum values. The main cause of premature convergence is the loss of diversity in the population. The niche technique is an effective method to maintain the population diversity, to enhance the exploration of the new search domains, and to avoid premature convergence. In this paper, a geographic information system- (GIS-) based niche hybrid bat algorithm (NHBA) is proposed for solving the optimal spatial search. The NHBA is able to avoid the premature convergence and obtain the global optimal values. The GIS technique provides robust support for processing a substantial amount of geographical data. A case in Fangcun District, Guangzhou City, China, is used to test the NHBA. The comparative experiments illustrate that the BA, GA, FA, PSO, and NHBA algorithms outperform the brute-force algorithm in terms of computational efficiency, and the optimal solutions are more easily obtained with NHBA than with BA, GA, FA, and PSO. Moreover, the precision of NHBA is higher and the convergence of NHBA is faster than those of the other algorithms under the same conditions

    Efficiency Analysis of Land Use and the Degree of Coupling Link between Population Growth and Global Built-Up Area in the Subregion of West Africa

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    The main challenge for land use efficiency is population growth. Using a coupling coordination model and the Sustainable Development Goal 11.3.1 (Land Consumption Rate to Population Growth Rate, LCRPGR), the present study unravels the evolution of land use types and efficiency of land use in the Economic Community of West African States (ECOWAS) from 2003 to 2019. We interpreted the temporal land use types based on the long-time series Moderate Resolution Imaging Spectroradiometer (MCD12Q1-V6) land use images in 2003, 2007, 2011, 2015, and 2019. The World Bank data on population and socioeconomics were used to support the investigation on the coupled link. Our results showed that from 2003 to 2019, the total area of agricultural land decreased by −1.4%, while the built-up area expanded by 25.80%. Globally, the LCRPGR was 0.82, of which Cabo-Verdi and Niger had the highest (1.69) and lowest index (0.58), respectively. Correspondingly, the coupled coordination model indicated an overall value of 6.81, in which the highest and lowest value occurred in Liberia (29.78) and Niger (0.31), respectively. Furthermore, a rapidly growing population had become one of the most important factors causing inefficient land use in the study area. In summary, the ECOWAS was confronted with a lack of management to improve land use efficiency. Thus, future land use policies should pay more attention to balancing the coupled relationship between urban expansion and socio-economic interests

    A Quantitative Study on the Identification of Ecosystem Services: Providing and Connecting Areas and Their Impact on Ecosystem Service Assessment

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    The spatial location relations between service-providing areas and service-demand areas determine the effective provision level of ecosystem services. Some scholars use the term ecological service flow to conceptualize the transmission path, transmission characteristics, and service benefits of the provision-oriented service type between service-providing areas and service-demand areas. A few scholars have characterized the transmission range and spatial unit characteristics of single or several ecosystem service types, such as production services and regulation services between the providing area and demand area based on landscape, region and global scale. The current literature lacks quantitative studies on the spatial location relations between providing areas and demand areas of ecosystem services and the actual level of ecosystem service provision at the municipal scale based on the demand for ecosystem services faced by cities. This study takes Jinan, China, as the research area, quantifies the providing areas, connecting areas and demand areas of seven services—namely, the air purification service, climate regulation service, flood prevention service, water pollution prevention service, water supply service, soil erosion prevention service, and habitat supply service—and analyzes the spatial relation characteristics of each element. On this basis, the Hellwig model is used to quantitatively analyze the impact of service-providing area and service-connecting area on regional overall ecosystem service assessment. The results prove that service-providing areas and service-connecting areas are the key units that affect the level of regional ecosystem service provision. The evaluation of regional ecosystem service provision level is inseparable from the identification of service-providing areas and service-connecting areas and the study of their attributes, characteristics, and spatial relations. Service-providing areas and service-connecting areas should be differentiated when developing strategies to optimize and improve the level of regional ecosystem service provision. Different optimization measures should be formulated according to the differences in unit attributes and service barriers in different areas. The results provide guidance for the optimization of ecosystem services to ensure the efficient and sustainable provision of regional ecosystem services and improve the actual benefits of service-demand groups or service-demand areas

    Efficiency Analysis of Land Use and the Degree of Coupling Link between Population Growth and Global Built-Up Area in the Subregion of West Africa

    No full text
    The main challenge for land use efficiency is population growth. Using a coupling coordination model and the Sustainable Development Goal 11.3.1 (Land Consumption Rate to Population Growth Rate, LCRPGR), the present study unravels the evolution of land use types and efficiency of land use in the Economic Community of West African States (ECOWAS) from 2003 to 2019. We interpreted the temporal land use types based on the long-time series Moderate Resolution Imaging Spectroradiometer (MCD12Q1-V6) land use images in 2003, 2007, 2011, 2015, and 2019. The World Bank data on population and socioeconomics were used to support the investigation on the coupled link. Our results showed that from 2003 to 2019, the total area of agricultural land decreased by −1.4%, while the built-up area expanded by 25.80%. Globally, the LCRPGR was 0.82, of which Cabo-Verdi and Niger had the highest (1.69) and lowest index (0.58), respectively. Correspondingly, the coupled coordination model indicated an overall value of 6.81, in which the highest and lowest value occurred in Liberia (29.78) and Niger (0.31), respectively. Furthermore, a rapidly growing population had become one of the most important factors causing inefficient land use in the study area. In summary, the ECOWAS was confronted with a lack of management to improve land use efficiency. Thus, future land use policies should pay more attention to balancing the coupled relationship between urban expansion and socio-economic interests
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