2017 Vol. 27, No. 1

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Global Water Vapor Content Decreases from 2003 to 2012: An Analysis Based on MODIS Data
MAO Kebiao, CHEN Jingming, LI Zhaoliang, MA Ying, SONG Yang, TAN Xuelan, Yang Kaixian
2017, 27(1): 1-7. doi: 10.1007/s11769-017-0841-6
Water vapor in the earth's upper atmosphere plays a crucial role in the radiative balance, hydrological process, and climate change. Based on the latest moderate-resolution imaging spectroradiometer (MODIS) data, this study probes the spatio-temporal variations of global water vapor content in the past decade. It is found that overall the global water vapor content declined from 2003 to 2012 (slope b=-0.0149, R=0.893, P=0.0005). The decreasing trend over the ocean surface (b=-0.0170, R=0.908, P=0.0003) is more explicit than that over terrestrial surface (b=-0.0100, R=0.782, P=0.0070), more significant over the Northern Hemisphere (b=-0.0175, R=0.923, P=0.0001) than that over the Southern Hemisphere (b=-0.0123, R=0.826, P=0.0030). In addition, the analytical results indicate that water vapor content are decreasing obviously between latitude of 36°N and 36°S (b=0.0224, R=0.892, P=0.0005), especially between latitude of 0°N and 36°N (b=0.0263, R=0.931, P=0.0001), while the water vapor concentrations are increasing slightly in the Arctic regions (b=0.0028, R=0.612, P=0.0590). The decreasing and spatial variation of water vapor content regulates the effects of carbon dioxide which is the main reason of the trend in global surface temperatures becoming nearly flat since the late 1990s. The spatio-temporal variations of water vapor content also affect the growth and spatial distribution of global vegetation which also regulates the global surface temperature change, and the climate change is mainly caused by the earth's orbit position in the solar and galaxy system. A big data model based on gravitational-magmatic change with the solar or the galactic system is proposed to be built for analyzing how the earth's orbit position in the solar and galaxy system affects spatio-temporal variations of global water vapor content, vegetation and temperature at large spatio-temporal scale. This comprehensive examination of water vapor changes promises a holistic understanding of the global climate change and potential underlying mechanisms.
Potential Renaturalisation of Lakes as An Element Building Up Water Re-sources: An Example of Mosina Lake, Poland
2017, 27(1): 8-12. doi: 10.1007/s11769-017-0842-5
Water deficits observed in many regions of the world make it necessary to implement measures intended to improve this situation. Poland is one of the countries with the poorest water resources in Europe due to its natural conditions and human impact. As a result of land reclamation carried out over decades, many elements of its hydrographic system have been changed, and some of them, like lakes, have disappeared altogether. In the days of the socio-economic transformation and more frequent extreme events, what seems worth considering is the renaturalisation of non-existing lakes, an idea presented in this paper on a selected example.
Impacts of Land-use and Land-cover Changes on River Runoff in Yellow River Basin for Period of 1956-2012
WANG Fang, GE Quansheng, YU Qibiao, WANG Huaxin, XU Xinliang
2017, 27(1): 13-24. doi: 10.1007/s11769-017-0843-3
River runoff is affected by many factors, including long-term effects such as climate change that alter rainfall-runoff relationships, and short-term effects related to human intervention (e.g., dam construction, land-use and land-cover change (LUCC)). Discharge from the Yellow River system has been modified in numerous ways over the past century, not only as a result of increased demands for water from agriculture and industry, but also due to hydrological disturbance from LUCC, climate change and the construction of dams. The combined effect of these disturbances may have led to water shortages. Considering that there has been little change in long-term precipitation, dramatic decreases in water discharge may be attributed mainly to human activities, such as water usage, water transportation and dam construction. LUCC may also affect water availability, but the relative contribution of LUCC to changing discharge is unclear. In this study, the impact of LUCC on natural discharge (not including anthropogenic usage) is quantified using an attribution approach based on satellite land cover and discharge data. A retention parameter is used to relate LUCC to changes in discharge. We find that LUCC is the primary factor, and more dominant than climate change, in driving the reduction in discharge during 1956-2012, especially from the mid-1980s to the end-1990s. The ratio of each land class to total basin area changed significantly over the study period. Forestland and cropland increased by about 0.58% and 1.41%, respectively, and unused land decreased by 1.16%. Together, these variations resulted in changes in the retention parameter, and runoff generation showed a significant decrease after the mid-1980s. Our findings highlight the importance of LUCC to runoff generation at the basin scale, and improve our understanding of the influence of LUCC on basin-scale hydrology.
Spatial-temporal Changes of Vegetation Cover in Guizhou Province, Southern China
TIAN Yichao, BAI Xiaoyong, WANG Shijie, QIN Luoyi, LI Yue
2017, 27(1): 25-38. doi: 10.1007/s11769-017-0844-3
Guizhou Province is an important karst area in the world and a fragile ecological area in China. Ecological risk assessment is very necessary to be conducted in this region. This study investigates different characteristics of the spatial-temporal changes of vegetation cover in Guizhou Province of Southern China using the data set of SPOT VEGETATION (1999-2015) at spatial resolution of 1-km and temporal resolution of 10-day. The coefficient of variation, the Theil-Sen median trend analysis, and the Mann-Kendall test are used to investigate the spatial-temporal change of vegetation cover and its future trend. Results show that:1) the spatial distribution pattern of vegetation cover in Guizhou Plateau is high in the east whereas low in the west. The average annual normalized difference vegetation index (NDVI) from west to east is higher than that from south to north. 2) Average annual NDVI improved obviously in the past 17 years. The growth rate of average annual NDVI is 0.028/10 yr, which is slower than that of vegetation in the country (0.048/10 yr) from 1998 to 2007. Average annual NDVI in karst area is lower than that in non-karst area. However, the growing rate of average annual NDVI in karst area (0.030/10 yr) is faster than that in non-karst area (0.023/10 yr), indicating that vegetation coverage increases more rapidly in karst area. 3) Vegetation coverage in the study area is stable overall, but fluctuates in the local scales. 4) Vegetation coverage presents a continuous increasing trend. The Hurst exponent of NDVI in different vegetation types has an obvious threshold in various elevations. 5) The proportion of vegetation cover with sustainable increase is higher than that of vegetation cover with sustainable decrease. The improvement in vegetation cover may expand to most parts of the study area.
Using Fuzzy Theory and Variable Weights for Water Quality Evaluation in Poyang Lake, China
LI Bing, YANG Guishan, WAN Rongrong, ZHANG Lu, ZHANG Yanhui, DAI Xue
2017, 27(1): 39-51. doi: 10.1007/s11769-017-0845-2
Achieving water purity in Poyang Lake has become a major concern in recent years, thus appropriate evaluation of spatial and temporal water quality variations has become essential. Variations in 11 water quality parameters from 15 sampling sites in Poyang Lake were investigated from 2009 to 2012. An integrative fuzzy variable evaluation (IFVE) model based on fuzzy theory and variable weights was developed to measure variations in water quality. Results showed that:1) only chlorophyll-a concentration and Secchi depth differed significantly among the 15 sampling sites (P<0.01), whereas the 11 water quality parameters under investigation differed significantly throughout the seasons (P<0.01). The annual variations of all water quality variables except for temperature, electrical conductivity, suspended solids and total phosphorus were considerable (P<0.05). 2) The IFVE model was reasonable and flexible in evaluating water quality status and any possible ‘bucket effect’. The model fully considered the influences of extremely poor indices on overall water quality. 3) A spatial analysis indicated that anthropogenic activities (particularly industrial sewage and dredging) and lake bed topography might directly affect water quality in Poyang Lake. Meanwhile, hydrological status and sewage discharged into the lake might be responsible for seasonal water quality variations.
Spatial Distribution and Seasonal Variations of Heavy Metal Contami-nation in Surface Waters of Liaohe River, Northeast China
WANG Hui, SUN Lina, LIU Zhe, LUO Qing
2017, 27(1): 52-62. doi: 10.1007/s11769-017-0846-1
Heavy metal pollutants are a worldwide concern due to slow decomposition, biocondensation, and negative effects on human health. We investigated seasonal and spatial variations of the five heavy metals and evaluated their health risk in the Liaohe River, Northeast China. A total of 324 surface water samples collected from 2009 to 2010 were analyzed. Levels (high to low) of heavy metals in the Liaohe River were:zinc (Zn) > chromium (Cr) > copper (Cu) > cadmium (Cd) > mercury (Hg). Spatial and seasonal changes impacting concentrations of Cu and Zn were significant, but not significant for Cr, Cd and Hg. The highest concentrations of heavy metals were:Hg at Liuheqiao, Cu at Fudedian, Zn at Tongjiangkou, Cr at Mahushan, and Cd at Shenglitang. The highest concentrations of Hg and Cr were found in the wet period, Cu and Cd in the level period, and Zn in the dry period. The surface water of a tributary was an important accumulation site for heavy metals. Health risks from carcinogens and non-carcinogens increased from upstream to downstream in the mainstream of the Liaohe River. The total health risk for one person in the Liaohe River exceeded acceptable levels. The total health risk was the greatest during the wet period and least in the dry period. Among the five heavy metals in the Liaohe River, Cr posed the greatest single health risk.
Using Geochemistry of Rare Earth Elements to Indicate Sediment Provenance of Sand Ridges in Southwestern Yellow Sea
LI Lei, SU Jinbao, RAO Wenbo, WANG Yigang
2017, 27(1): 63-77. doi: 10.1007/s11769-017-0847-0
The Jianggang Harbour-centered radial sand ridge (RSR) is the largest sand body in the Yellow Sea. Its formation and evolution are of interest for scientists of various fields; however, the sediment provenance is uncertain. In this study, rare earth element (REE) geochemical compositions of the RSR sediments together with their potential sources are investigated to identify the provenance of the RSR sediments. The typical parameters ((La/Yb)N, (La/Sm)N and (Gd/Yb)N) as well as the upper continental crust-normalized patterns of REEs can only be associated with source rocks, and thus can be used as effective tracers for the origin and sources of sediments. However, the REE contents of sediments are affected by many factors, such as particle sorting and chemical weathering. Onshore RSR sediments are different in REE geochemical composition from offshore RSR sediments to some extent, suggesting that not all of the offshore RSR sediments have the same sources as the onshore RSR sediments. Meanwhile, the sediments adjacent to the northeast of Cheju Island and at Lian Island near the Lianyun Harbour were not the source of the RSR sediments due to their distinctive REE patterns, δEu, (La/Yb)N, (Gd/Yb)N and (La/Sm)N. The Korean river sediments could be dispersed to the Jiangsu Coast slightly impacting the fine fractions of the RSR sediments, particularly the offshore RSR sediments. Additionally, geochemical comparisons show that the modern Yellow River was responsible for the onshore RSR sediments, whereas the sediment loads from the Yangtze River could serve as a major contributor to the RSR, particularly the offshore RSR. In addition, the offshore RSR could also be partly fed by an unknown source due to some high values of (La/Yb)N, (La/Sm)N and La contents differing from those of the Chinese and Korean river sediments.
Gully Erosion Regionalization of Black Soil Area in Northeastern China
YANG Jiuchun, ZHANG Shuwen, CHANG Liping, LI Fei, LI Tianqi, GAO Yan
2017, 27(1): 78-87. doi: 10.1007/s11769-017-0848-z
Gully erosion is the frequent and main form of soil erosion in the black soil area of the northeastern China, which is one of the most important commodity grain production bases in China. It is encroaching upon the fertile farmland there. Regionalization of gully erosion can reveal the spatial distribution and regularity of the development of gully erosion. Based on the eco-geographical regional background features of the black soil area, this study combined the regionalization with influencing factors of the development of gully erosion. GIS spatial analysis, geostatistical analysis, spatial statistics, reclassification, debris polygon processing and map algebra methods were employed. As a result, the black soil area was divided into 12 subregions. The field survey data on type, length, volume and other characteristics indicators of gully erosion were used to calibrate the results. Then the features of every subregion, such as where the gully erosion is, how serious it is, and why it happens and develops, were expounded. The result is not only an essential prerequisite for gully erosion surveys and monitoring, but also an important basis for gully erosion prevention.
Distributed Estimation and Analysis of Precipitation Recharge Coefficient in Strongly-exploited Beijing Plain Area, China
PAN Yun, GONG Huili, SUN Ying, WANG Xinjuan, DING Fei
2017, 27(1): 88-96. doi: 10.1007/s11769-016-0839-5
The precipitation recharge coefficient (PRC), representing the amount of groundwater recharge from precipitation, is an important parameter for groundwater resources evaluation and numerical simulation. It was usually obtained from empirical knowledge and site experiments in the 1980s. However, the environmental settings have been greatly modified from that time due to land use change and groundwater over-pumping, especially in the Beijing plain area (BPA). This paper aims to estimate and analyze PRC of BPA with the distributed hydrological model and GIS for the year 2011 with similar annual precipitation as long-term mean. It is found that the recharge from vertical (precipitation + irrigation) and precipitation is 291.0 mm/yr and 233.7 mm/yr, respectively, which accounts for 38.6% and 36.6% of corresponding input water. The regional mean PRC is 0.366, which is a little different from the traditional map. However, it has a spatial variation ranging from -7.0% to 17.5% for various sub-regions. Since the vadose zone is now much thicker than the evaporation extinction depth, the land cover is regarded as the major dynamic factor that causes the variation of PRC in this area due to the difference of evapotranspiration rates. It is suggested that the negative impact of reforestation on groundwater quantity within BPA should be well investigated, because the PRC beneath forestland is the smallest among all land cover types.
Stable Isotopes in Precipitation and Atmospheric Moisture of Pailugou Catchment in Northwestern China's Qilian Mountains
FENG Fang, FENG Qi, LIU Xiande, WU Jinkui, LIU Wei
2017, 27(1): 97-109. doi: 10.1007/s11769-017-0849-y
Hydrogen and oxygen isotopes in precipitation have been widely used as effective traces to investigate hydrological processes such as evaporation and atmospheric moisture source. This study analyzed δD and δ18O of precipitation in continuous event-based samples at three stations of Pailugou Catchment from November 2012 to December 2013. The δ18O and δD values ranged from -32.32‰ to +3.23‰ and from -254.46‰ to +12.11‰, respectively. Results show that the δ18O displayed a distinct seasonal variation, with enriched values occurring in summer and relatively depleted values in winter, respectively. There was a statistically significant positive correlation between the δ18O and δD values and local surface air temperature at all the three stations. The nearest Global Network of Isotopes in Precipitation (GNIP) station (Zhangye), compared to the Meteoric Water Lines for this study, showed the obvious local evaporation effects with lower intercept and slope. Additionally, d-excess (δD -8δ18O) parameter in precipitation exhibited an anti-phase seasonal variability with the δ18O. The 96-h back trajectories for each precipitation event using Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model indicated a dominant effect of westerly air masses in summer and the integrated influence of westerly and polar air masses in winter.
New Perspectives on Restructuring of Old Industrial Areas in China: A Critical Review and Research Agenda
HU Xiaohui, Robert HASSINK
2017, 27(1): 110-122. doi: 10.1007/s11769-015-0784-8
The restructuring of old industrial areas has been receiving much attention in regional development studies both in industrialized and emerging economies. Although ample Chinese-speaking studies have been published on the topic, most of them suffer from paying too little attention to dynamic multi-scalar interactions between firms, institutions, policies and places, as well as a too strong focus on individual cases. They also mostly disregard internationally recognized concepts and theories in the field. Based on these internationally recognized modern concepts, this paper therefore puts forward some potential avenues for future research on the evolution of old industrial areas in China, which should overcome existing deficits in the Chinese-speaking literature. It suggests that some evolutionary economic geography concepts such as path dependence, lock-in, path creation, relatedness, as well as multi-scalar institutional and leadership ap-proaches have useful potentials to better understand the evolutionary processes and mechanisms of old industrial areas in China.
Permanence of Economic Potential of Cities Based on Sector Develop-ment
2017, 27(1): 123-136. doi: 10.1007/s11769-017-0850-5
The paper attempts to answer the following key question:how will a city's world rank change in the face of crisis in its main economic sector? Crisis is defined here as a decline in financial performance in the given sector, which leads to the decline of its constituent firms and corporations on the world economic scene. The World Economic Center Index (WECI) has been created in order to rank cities based on the value of their resident corporations by sector and show their level of stability upon the removal of the most important sector. This provides information on the potential of each analyzed city as well as on its advanced features or area of specialization. Research has shown that nearly half the World Economic Centers are dominated by the financial and materials sectors of the economy. Different sectors dominate different regions of the world. For example, consumer staples and materials were dominant in North America, while information technology and financials were dominant in Europe. In Asia, several sectors tend to dominate the economy. Research has shown that the ability of a principal economic sector to resist economic crisis largely depends on the strength of the command and control function of a city. Finally, a high globalization level of a city is a key determinant of its susceptibility to economic crisis.
Spatio-temporal Fragmentation of Leisure Activities in Information Era: Empirical Evidence from Nanjing, China
XI Guangliang, ZHEN Feng, Puel GILLES, Fernandez VALERIE
2017, 27(1): 137-150. doi: 10.1007/s11769-017-0851-4
Activity fragmentation provides a new approach for understanding the transformation of urban space and function in the information era. Numerous theoretical and empirical studies have been conducted on activity fragmentation, but few studies have focused on the fragmentation of leisure activities. This study was intended to extend the extant literature by:1) analysing the spatio-temporal fragmentation of physical and virtual leisure activities by using a dataset collected in Nanjing, China, and 2) evaluating the reasons of leisure activity fragmentation, as well as the potential spatial effect of activity fragmentation. The results indicated that virtual leisure activities are more fragmented than physical leisure activities, but the fragmentation of physical and virtual leisure activities varies on weekday and weekend, as well as in various locations and urban districts. In addition, the results suggested that sociodemographic factors and information and communication technology (ICT) variables distinctly affect the fragmentation of leisure activities. Meanwhile, the fragmentation of virtual leisure activities may enhance the transformation of traditional urban space by reallocating leisure activity times and locations.
Urban Redevelopment, Gentrification and Gentrifiers in Post-reform Inland China: A Case Study of Chengdu, China
HUANG Xing, YANG Yongchun
2017, 27(1): 151-164. doi: 10.1007/s11769-017-0852-3
Since its process evolved in recent years, the definition of gentrification has expanded to cover different forms of social upgrading, new spaces and new actors around the world. Studies on gentrification in Chinese cities began to take off in the 2000s. However, they all mainly focused on the newly emerging global cities and there has been a lack of investigation on provincial cities. Furthermore, discussions on gentrifiers' profiles and their motivations for housing choice are absent from literature on Chinese gentrification. Therefore, this paper aims to assess the relevance of the broad definition of gentrification in provincial Chinese cities through empirical research on urban redevelopment projects in Chengdu, and to examine the characteristics of gentrifiers (as new incoming residents) in it. The results show the rationality of gentrification processes as urban redevelopment in Chengdu, and reveal original outcomes on the corresponding gentrifiers' profiles and the motivations behind their housing choice, which are different from the general features of gentrifiers in standard Western gentrification research.