2017 Vol. 27, No. 3

Display Method:
Regional Variation in Carbon Sequestration Potential of Forest Ecosystems in China
XU Li, WEN Ding, ZHU Jianxing, HE Nianpeng
2017, 27(3): 337-350. doi: 10.1007/s11769-017-0870-1
Enhancing forest carbon (C) storage is recognized as one of the most economic and green approaches to offsetting anthropogenic CO2 emissions. However, experimental evidence for C sequestration potential (Csp) in China's forest ecosystems and its spatial patterns remain unclear, although a deep understanding is essential for policy-makers making decisions on reforestation. Here, we surveyed the literature from 2004 to 2014 to obtain C density data on forest ecosystems in China and used mature forests as a reference to explore Csp. The results showed that the C densities of vegetation and soil (0-100 cm) in China's forest ecosystems were about 69.23 Mg C/ha and 116.52 Mg C/ha, respectively. In mature forests, the Csp of vegetation and soil are expected to increase to 129.26 Mg C/ha (87.1%) and 154.39 Mg C/ha (32.4%) in the coming decades, respectively. Moreover, the potential increase of C storage in vegetation (10.81 Pg C) is estimated at approximately twice that of soil (5.01 Pg C). Higher Csp may occur in the subtropical humid regions and policy-makers should pay particular attention to the development of new reforestation strategies for these areas. In addition to soil nutrients and environment, climate was an important factor influencing the spatial patterns of C density in forest ecosystems in China. Interestingly, climate influenced the spatial patterns of vegetation and soil C density via different routes, having a positive effect on vegetation C density and a negative effect on soil C density. This estimation of the potential for increasing forest C storage provided new insights into the vital roles of China's forest ecosystems in future C sequestration. More importantly, our findings emphasize that climate constraints on forest C sequestration should be considered in reforestation strategies in China because the effects of climate were the opposite for spatial patterns of C density in vegetation and soil.
Influence of Climate on Soil Organic Carbon in Chinese Paddy Soils
WANG Dandan, YAN Yechao, LI Xinhui, SHI Xuezheng, ZHANG Zhongqi, David C WEINDORF, WANG Hongjie, XU Shengxiang
2017, 27(3): 351-361. doi: 10.1007/s11769-017-0868-8
Soil organic carbon (SOC) is a major component of the global carbon cycle and has a potentially large impact on the greenhouse effect. Paddy soils are important agricultural soils worldwide, especially in Asia. Thus, a better understanding of the relationship between SOC of paddy soils and climate variables is crucial to a robust understanding of the potential effect of climate change on the global carbon cycle. A soil profile data set (n = 1490) from the Second National Soil Survey of China conducted from 1979 to 1994 was used to explore the relationships of SOC density with mean annual temperature (MAT) and mean annual precipitation (MAP) in six soil regions and eight paddy soil subgroups. Results showed that SOC density of paddy soils was negatively correlated with MAT and positively correlated with MAP (P < 0.01). The relationships of SOC density with MAT and MAP were weak and varied among the six soil regions and eight paddy soil subgroups. A preliminary assessment of the response of SOC in Chinese paddy soils to climate indicated that climate could lead to a 13% SOC loss from paddy soils. Compared to other soil regions, paddy soils in Northern China will potentially more sensitive to climate change over the next several decades. Paddy soils in Middle and Lower Yangtze River Basin could be a potential carbon sink. Reducing the climate impact on paddy soil SOC will mitigate the positive feedback loop between SOC release and global climate change.
Spatial Patterns of Irrigation Water Withdrawals in China and Implications for Water Saving
JU Hongrun, ZHANG Zengxiang, WEN Qingke, WANG Jiao, ZHONG Lijin, ZUO Lijun
2017, 27(3): 362-373. doi: 10.1007/s11769-017-0871-0
By considering numerical features, spatial variation, and spatial association, the spatial patterns of China's irrigation water withdrawals in 2001 and 2010 were explored at the regional, provincial, and prefectural scales. In addition, an overlay analysis was used to develop specific water-saving guidance for areas under different levels of water stress and with different degrees of irrigation water withdrawals. It was found that at the regional scale, irrigation water withdrawals were highest in the Middle-Lower Yangtze River region in both years, while at the provincial scale, the largest irrigation water withdrawals occurred in Xinjiang. During 2001-2010, the total of irrigation water withdrawals decreased; however, in the Northeast region, especially in Heilongjiang Province, it experienced a dramatic increase. The spatial variation was largest at the prefectural scale, with an apparent effect. The spatial association was globally negative at the provincial scale, and Xinjiang was the only significant high-low outlier. In contrast, the association displayed a significant positive relationship at the prefectural scale, and several clusters and outliers were detected. Finally, it was found that the water stress in the northern part of China worsened and water-saving irrigation techniques urgently need to be applied in the Northeast region, the Huang-Huai-Hai Plain region, and Gansu-Xinjiang region. This study verified that a multi-scale and aspect analysis of the spatial patterns of irrigation water withdrawals were essential and provided water-saving advice for different areas.
China's Wetland Databases Based on Remote Sensing Technology
YAN Fengqin, LIU Xingtu, CHEN Jing, YU Lingxue, YANG Chaobin, CHANG Liping, YANG Jiuchun, ZHANG Shuwen
2017, 27(3): 374-388. doi: 10.1007/s11769-017-0872-z
Wetland databases can provide the basic data that necessary for the protection and management of wetlands. A large number of wetland databases have been established in the world as well as in China. In this paper, we review China's wetland databases based on remote sensing (RS) technology after introducing the background theory to the application of RS technology in wetland surveys. A key conclusion is that China's wetland databases are far from sufficient in fulfilling protection and management needs. Our recommendations focus on the use of the hyper-spectral imagery, microwave data, multi-temporal images, and automatic classifications in order to improve the accuracy and efficiency of wetland inventory. Further, attention should also be paid to detect major biophysical features of wetlands and build wetland databases in years after the 1980s in China. Considering that great gap exists between RS experts and wetland experts, further cooperation between wetland scientists and RS scientists are needed to promote the application of RS in the foundation of wetland databases.
A New Method Based on Association Rules Mining and Geo-filter for Mining Spatial Association Knowledge
LIU Yaolin, XIE Peng, HE Qingsong, ZHAO Xiang, WEI Xiaojian, TAN Ronghui
2017, 27(3): 389-401. doi: 10.1007/s11769-017-0873-y
Association rule mining methods, as a set of important data mining tools, could be used for mining spatial association rules of spatial data. However, applications of these methods are limited for mining results containing large number of redundant rules. In this paper, a new method named Geo-Filtered Association Rules Mining (GFARM) is proposed to effectively eliminate the redundant rules. An application of GFARM is performed as a case study in which association rules are discovered between building land distribution and potential driving factors in Wuhan, China from 1995 to 2015. Ten sets of regular sampling grids with different sizes are used for detecting the influence of multi-scales on GFARM. Results show that the proposed method can filter 50%-70% of redundant rules. GFARM is also successful in discovering spatial association pattern between building land distribution and driving factors.
Reconstructing Environmental Changes of a Coastal Lagoon with Coral Reefs in Southeastern Hainan Island
ZHOU Liang, GAO Shu, GAO Jianhua, ZHAO Yangyang, HAN Zhuochen, YANG Yang, JIA Peihong
2017, 27(3): 402-414. doi: 10.1007/s11769-017-0867-9
Coastal lagoons with small catchment basins are highly sensitive to natural processes and anthropogenic activities. To figure out the environmental changes of a coastal lagoon and its contribution to carbon burial, two sediment cores were collected in Xincun Lagoon, southeastern Hainan Island and 210Pb activities, grain size parameters, total organic carbon (TOC), total nitrogen (TN), total inorganic carbon (TIC) and stable carbon isotopes (δ13C) were measured. The results show that in 1770-1815, the decreasing water exchange capacity with outer open water, probably caused by the shifting and narrowing of the tidal inlet, not only diminished the currents and fined the sediments in the lagoon, but also reduced the organic matter of marine sources. From 1815 to 1950, the sedimentary environment of Xincun Lagoon was frequently influenced by storm events. These extreme events resulted in the high fluctuation of sediment grain size and sorting, as well as the great variation in contributions of terrestrial (higher plants, soils) and marine sources (phytoplankton, algae, seagrass). The extremely high content of TIC, compared to TOC before 1950 could be attributed to the large-scale coverage of coral reefs. However, with the boost of seawater aquaculture activities after 1970, the health growth of coral species was severely threatened, and corresponding production and inorganic carbon burial flux reduced. The apparent enhanced inorganic carbon burial rate after 1990 might result from the concomitant carbonate debris produced by seawater aquaculture. This result is important for local government long-term coastal management and environmental planning.
An Object-based Approach for Two-level Gully Feature Mapping Using High-resolution DEM and Imagery: A Case Study on Hilly Loess Plateau Region, China
LIU Kai, DING Hu, TANG Guoan, ZHU A-Xing, YANG Xin, JIANG Sheng, CAO Jianjun
2017, 27(3): 415-430. doi: 10.1007/s11769-017-0874-x
Gully feature mapping is an indispensable prerequisite for the motioning and control of gully erosion which is a widespread natural hazard. The increasing availability of high-resolution Digital Elevation Model (DEM) and remote sensing imagery, combined with developed object-based methods enables automatic gully feature mapping. But still few studies have specifically focused on gully feature mapping on different scales. In this study, an object-based approach to two-level gully feature mapping, including gully-affected areas and bank gullies, was developed and tested on 1-m DEM and Worldview-3 imagery of a catchment in the Chinese Loess Plateau. The methodology includes a sequence of data preparation, image segmentation, metric calculation, and random forest based classification. The results of the two-level mapping were based on a random forest model after investigating the effects of feature selection and class-imbalance problem. Results show that the segmentation strategy adopted in this paper which considers the topographic information and optimal parameter combination can improve the segmentation results. The distribution of the gully-affected area is closely related to topographic information, however, the spectral features are more dominant for bank gully mapping. The highest overall accuracy of the gully-affected area mapping was 93.06% with four topographic features. The highest overall accuracy of bank gully mapping is 78.5% when all features are adopted. The proposed approach is a creditable option for hierarchical mapping of gully feature information, which is suitable for the application in hily Loess Plateau region.
Factors Acquisition and Content Estimation of Farmland Soil Organic Carbon Based upon Internet of Things
WU Qiulan, LIANG Yong, LI Ying, WANG Xizhi, YANG Lei, WANG Xiaotong
2017, 27(3): 431-440. doi: 10.1007/s11769-017-0875-9
Aiming at the shortage of sufficient continuous parameters for using models to estimate farmland soil organic carbon (SOC) content, an acquisition method of factors influencing farmland SOC and an estimation method of farmland SOC content with Internet of Things (IOT) are proposed in this paper. The IOT sensing device and transmission network were established in a wheat demonstration base in Yanzhou Distict of Jining City, Shandong Province, China to acquire data in real time. Using real-time data and statistics data, the dynamic changes of SOC content between October 2012 and June 2015 was simulated in the experimental area with SOC dynamic simulation model. In order to verify the estimation results, potassium dichromate external heating method was applied for measuring the SOC content. The results show that: 1) The estimated value matches the measured value in the lab very well. So the method is feasible in this paper. 2) There is a clear dynamic variation in the SOC content at 0.2 m soil depth in different growing periods of wheat. The content reached the highest level during the sowing period, and is lowest in the flowering period. 3) The SOC content at 0.2 m soil depth varies in accordance with the amount of returned straw. The larger the amount of returned straw is, the higher the SOC content.
Use of Intensity Analysis to Measure Land Use Changes from 1932 to 2005 in Zhenlai County, Northeast China
YANG Yuanyuan, LIU Yansui, XU Di, ZHANG Shuwen
2017, 27(3): 441-455. doi: 10.1007/s11769-017-0876-8
Analyzing spatiotemporal dynamics of land use and land cover over time is widely recognized as important to better understand and provide solutions for social, economic, and environmental problems, especially in ecologically fragile region. In this paper, a case study was taken in Zhenlai County, which is a part of farming-pastoral ecotone of Northeast China. This study seeks to use multi-temporal satellite images and other data from various sources to analyze spatiotemporal changes from 1932 to 2005, and applied a quantitative methodology named intensity analysis in the time scale of decades at three levels: time interval, category, and transition. The findings of the case study are as follows: 1) the interval level of intensity analysis revealed that the annual rate of overall change was relatively fast in 1932-1954 and 1954-1976 time intervals. 2) The category level showed that arable land experienced less intensively gains and losses if the overall change was to have been distributed uniformly across the landscape while the gains and losses of forest land, grassland, water, settlement, wetland and other unused land were not consistent and stationary across the four time intervals. 3) The transition level illustrated that arable land expanded at the expense of grassland before 2000 while it gained intensively from wetland from 2000 to 2005. Settlement targets arable land and avoids grassland, water, wetland and other unused land. Besides, the loss of grassland was intensively targeted by arable land, forest land and wetland in the study period while the loss of wetland was targeted by water except for the time interval of 1976-2000. 4) During the early reclamation period, land use change of the study area was mainly affected by the policy, institutional and political factors, followed by the natural disasters.
Industrial Agglomeration Externalities, City Size, and Regional Economic Development: Empirical Research Based on Dynamic Panel Data of 283 Cities and GMM Method
ZHU Huayou, DAI Zejuan, JIANG Ziran
2017, 27(3): 456-470. doi: 10.1007/s11769-017-0877-7
Local governments have long been ardently pursuing the industrial specialization effect (MAR externalities) and industrial diversification effect (Jacobs externalities). Such a pursuit has resulted in severe distortion of resource allocation and negative effect on sustainability of local economic development. Regarding the effect from both MAR and Jacobs externalities on local economic development existing literature records notable disputes. Therefore, for local economic development, one important issue is which externality (MAR or Jacobs) can better bring the effect into play. By studying a panel data of 283 Chinese cities from 2003 to 2012 and applying dynamic plane data GMM method, this paper conducted a regression analysis of the relationship among industrial agglomeration externalities, city size, and regional economic development. The result indicates that with regard to the whole nation, MAR externalities are conducive to regional economy development whereas Jacobs externalities will, to an extent, restrain regional economic development. As regards eastern, middle, and western regions, MAR externalities are conducive only to the economic development of the eastern region; their effects on middle and western regions are insignificant. Moreover, the interaction item between MAR externalities and city size has a significant negative synergistic effect on national economic development and a certain acceleration effect on eastern region as well as a strong negative synergistic effect on the middle region and an insignificant effect on the western region. The interaction item between Jacobs externalities and city size has a positive synergistic effect on only the middle region and has an insignificant synergistic effect on both eastern and western regions. Capital stock and labor input have significant accelerating effects on GDP growth per capita of Chinese cities, whereas material capital and labor input remain primary driving forces for Chinese local economic development. Furthermore, human capital contributes to accelerating urban economic development, whereas government intervention restrains urban economic development.
Conceptualizing and Measuring Economic Resilience of Resource-based Cities: Case Study of Northeast China
TAN Juntao, ZHANG Pingyu, LO Kevin, LI Jing, LIU Shiwei
2017, 27(3): 471-481. doi: 10.1007/s11769-017-0878-6
This paper develops a conceptual model and an indicator system for measuring economic resilience of resource-based cities based on the theory of evolutionary resilience and the related concepts of persistence, adaptation, and transformation. Nineteen resource-based cities in Northeast China were analyzed using the indicator system. The results showed that Liaoning and Jilin provinces had higher economic resilience than Heilongjiang Province. Panjin, Benxi, and Anshan in Liaoning Province were the top three cities, while Shuangyashan and other coal-based cities in Heilongjiang Province ranked last. Metals- and petroleum-based cities had significantly higher resilience than coal-based cities. The differences in persistence, adaptability, transformation, and resilience among resource-based cities decreased since the introduction of the Northeast Revitalization Strategy in 2003. Forestry-based cities improved the most in terms of resilience, followed by metals-based and multiple-resource cities; however, resilience dropped for coal-based cities, and petroleum-based cities falling the most. The findings illustrate the importance and the way to develop a differentiated approach to improve resilience among resource-based cities.
An Evolutionary Economic Geography Perspective on Types of Operation Development in West Lake, China
YANG Xingzhu, ZHA Yanyan, LU Lin, YANG Yang
2017, 27(3): 482-496. doi: 10.1007/s11769-017-0855-0
The types of operation play a key role in facilitating tourism consumption and economic development in a tourism destination. By adopting evolutionary economic geography theory, the paper analyzes the types of operation in West Lake Scenic Area from 1978 to 2013. First, an evolution process consisting of four stages is underpinned, and they are: the new establishment stage, the preliminary development stage, the speedup development stage, and the stabilized maturity stage. Specifically, the distinct characteristics associated with operation types are compared and evaluated at different stages throughout the process. The evolution trees are introduced to scrutinize types of operation development. The results of evolution trees demonstrate the substantial increase in both numbers and types. Second, by applying GIS spatial analysis, the paper also analyzes the spatial evolution characteristics on the types of operation, and the results unveil the co-existence of centripetal and centrifugal forces: the processes of spatial agglomeration and spatial dispersion. More specifically, we recognize the spatial process includes the emergence of node and concentration (1978-1995), the sparse distribution and intensity reduction (1996-2002), the patchy distribution and spatial agglomeration intensification (2003-2008), the dispersed distribution and core area agglomeration (2009-2013). Lastly, path dependence on resource endowment, government and market innovation, knowledge learning and spillover can reasonably explain the types of operation evolution. In conclusion, the evolutionary economic geography theories provide new theoretical and empirical perspectives for tourism policy analysis. At the same time, our comprehensive evidences impart more comprehensive insights and offer useful managerial and policy implications.
Spatial Agglomeration of Exhibition Enterprises on a Regional Scale in China
FANG Zhongquan, ZHANG Ying, WANG Zhangjun, ZHANG Lifeng
2017, 27(3): 497-506. doi: 10.1007/s11769-017-0879-5
During the past two decades, the exhibition industry in China has been developing rapidly and has become an important part of the modern service industry, particularly the agglomeration characteristics of exhibition enterprises highlighted on the regional scale. Although the development of theoretical research on the western exhibition industry has taken place over time, the spatial perspective has not been at the centre of attention so far. This paper aims to fill this gap and report on the agglomeration characteristics of exhibition enterprises and their influential factors. Based on data about exhibition enterprises in the Pearl River Delta (PRD) during 1991-2013, using the Ripley K function analysis and kernel density estimation, this research identifies that: 1) the exhibition enterprise on the regional scale is significantly characterized by spatial agglomeration, and the agglomeration density and scale are continuously increasing; 2) the spatial pattern of agglomeration has developed from a single-center to multi-center form. Meanwhile, this paper profiles the factors influencing the spatial agglomeration of exhibition enterprises by selecting the panel data of nine cities in the PRD in 1999, 2002, 2006 and 2013. The results show that market capacity, urban informatization level and exhibition venues significantly influence the location choice of exhibition enterprises. Among them, the market capacity is a variable that exerts a far greater impact than other factors do.