2012 Vol. 22, No. 1

Display Method:
Regional Differences of China’s Urban Expansion from the Late 20th to the Early 21st Century -- Based on Remote Sensing Information
Jiyuan Liu Qian Zhang Yunfeng Hu
2012, 22(1): 1-14.
This study investigates the regional differences of China’s urban land expansion from the late 1980s to the year of 2008, based on the spatial and temporal analysis of CLCD datasets which were mainly produced from remote sensing imagery data. A newly defined urbanization level index (UI), based on urban land area, is proposed to describe Chinese urban expansion process at 1 kilometer, provincial, regional, and national scales, together with the absolute urban expansion area index (UXa) and the relative urbanization intensity index (UXr). The results indicate that the percentages of total land area occupied by urban in the late 1980s, 1995, 2000, 2005, and 2008 were approximately 0.25%, 0.32%, 0.33%, 0.43% and 0.52%, respectively. Between the late 1980s and 2008, the total urban expansion in mainland China was 26.45×103 km2, resulting in an annual urban expansion area (UXa) of about 1322.7 km2 per year, with an urban expansion intensity (UXr) of 111.9%. This study also points that there has been an obvious spatial gradient of urbanization ratio running from the east coast to the west inland, and the urbanization gaps among different regions have persisted over the past two decades. The study also reveals obvious temporal variations of the urbanization rates. There was very little urban growth during the period of 1995-2000.
Nitrogen Biological Cycle Characteristics of Seepweed (Suaeda salsa) Wetland in Intertidal Zone of Huanghe (Yellow) River Estuary
2012, 22(1): 15-28.
Abstract: From April 2008 to November 2009, the nitrogen (N) cycling of plant-soil system in Suaeda salsa wetland in the intertidal zone of the Yellow River estuary was studied with a compartment model. Results showed that the N in soil had significantly seasonal fluctuations and vertical distribution, and the net N mineralization rates in topsoil were significantly different in growing season (p<0.01). The N contents in root and stem of S. salsa generally decreased, while those in leaf fluctuated significantly. The N/P ratio (9.87±1.23) of S. salsa was less than 14, indicating that the growth of plant was limited by N. The litter production and the N content in litter changed significantly, and the change trends were just the opposite. The mass loss and N content increased at all times during litter decomposition, and the C/N ratio controlled the N dynamics of S. salsa litter. The N accumulated in S. salsa litter at all times, which was ascribed to the N immobilization by microbes from the decomposition environment. The N in the plant subsystem was mainly stored in aboveground living body. Soil organic N was the main N stock of plant-soil system, accounting for 97.35% of the total N stock. The N absorption and utilization coefficients of S. salsa were very low (0.0145 and 0.3844, respectively), while the N cycling coefficient was high (0.7108). The N turnovers among compartments of S. salsa wetland showed that the N uptake amount of aboveground part and root were 7.764 and 4.332g/m2, respectively. The N translocation amounts from aboveground part to root and from root to soil were 3.881 and 0.626g/m2, respectively. The N translocation amount from aboveground living body to litter was 3.883g/m2, the annual N return amount from litter to soil was larger than 0.125(-)g/m2 (minus expressed immobilization), and the net N mineralization amount in topsoil (0-15cm) in growing season was 1.190g/m2. The assessment of N cycling status of S. salsa wetland indicated that the N was a very important limiting factor, and the ecosystem was situated in unstable and vulnerable status. The S. salsa seemed to be well adapted to the low-nutrient status and vulnerable habitat, and the N quantitative relationships in the compartment model might provide some scientific bases for us to reveal the special adaptive strategy of S. salsa to the vulnerable habitat in the following studies.
Simulating the net carbon budget of forest ecosystems and its response to climate change in Northeast China using the improved forest carbon budget model FORCCHN
2012, 22(1): 29-41.
As dominant biomes, forests play an important and indispensable role in adjusting the global carbon balance under climate change. Therefore, there are scientific and political implications in investigating the carbon budget of forest ecosystems and its response to climate change. Here we synthesized the most recent research progresses on the carbon cycle in terrestrial ecosystems, and applied an individual-based forest ecosystem carbon budget model for China (FORCCHN) to simulate the dynamics of the carbon fluxes of forest ecosystems in the northeastern China. The FORCCHN model was further improved and applied through adding variables and modules of precipitation (rainfall and snowfall) interception by tree crown, understory plants and litter. The results showed that the optimized FORCCHN model had a good performance in simulating the carbon budget of forest ecosystems in the northeastern China. From 1981 to 2002, the forests played a positive role in absorbing carbon dioxide. However, the capability of forest carbon sequestration had been gradually declining during the the same period. As for the average spatial distri-bution of net carbon budget, a majority of the regions were carbon sinks. Several scattered areas in the Heilongjiang Province and the Liaoning Province were identified as carbon sources. The net carbon budget was apparently more sensitive to an increase of air temperature than change of precipitation.
Perturbed Solving Method for Interdecadal
2012, 22(1): 42-47.
A coupled system of the interdecadal sea-air oscillator model is studied. The El Ni?o-southern oscillation (ENSO) atmospheric physics oscillation is an abnormal phenomenon involved in the tropical Pacific ocean-atmosphere interactions. The oscillator model is involved with the variations of both the eastern and western Pacific anomaly pat-terns. This paper proposes an ENSO atmospheric physics model using a method of the perturbation theory. The aim is to create an asymptotic solving method for the ENSO model. Employing the perturbed method, the asymptotic solution of corresponding problem is obtained, and the asymptotic behaviour of the solution is studied. Thus we can obtain the prognoses of the sea surface temperature anomaly and related physical quantities.
Grain-size Characteristics and Climate Variability in TMS5e Sequence of Tumen Section in Southern Tengger Desert, Northwestern China
2012, 22(1): 48-62.
The TMS5e sequence from the Tumen section, at the southern edge of China's Tengger Desert, is synchronous with Marine Isotope Stage 5e (MIS5e). It consists of 16 layers of aeolian dune sands, 11 layers of lacustrine loess-like facies, and 5 layers of lacustrine facies. Our grain-size analysis showed that the palaeo-mobile dune sands, palaeo-fixed to semi-fixed dune sands and loess-like sandy loams are mainly composed of sands, ranging from 70 to 96%; their silt contents ranged from 4 to 20%, and their clay contents ranged from 1 to 5%; the climate under which the aeolian dune sands were deposited is similar to that under which modern mobile dune sands form, which is caused by the dominance of the cold, dry East Asian winter monsoon. In contrast, the lacustrine loess-like facies and lacustrine facies had a lower sand contents than those the three aeolian dune sands,but have higher silt and clay contents, most of their sand content ranged from 30 to 60%, their silt contents ranged from 35 to 55%, and their clay contents ranged from 6 to 20%.The lacustrine loess-like facies and lacustrine facies formed under the influence of the warm, humid East Asian summer monsoon based on their similarity with modern sediments. The grain-size indicator Mz (mean grain diameter) and the SC/D value in the TMS5e sequence indicate climatic instability at the southern edge of the Tengger Desert during MIS5e, with at least 14 fluctuations between a warm, humid climate and a cold, dry climate, divided into five stages: TMS5e5 (139 to 129.30 ka B.P.), TMS5e4 (129.30 to 124ka B.P.), TMS5e3 (124 to 119.50 ka B.P.), TMS5e2 (119.5 to 116.5 ka B.P.), and TMS5e1 (116.5 to 113.70 ka B.P.). These correspond roughly to MIS5e5, MIS5e4, MIS5e3, MIS5e2, and MIS5e1, respectively, in the GRIP ice core data.
Estimating Fraction of Photosynthetically Active Radiation of Corn with Vegetation Indices and Neural Network from Hyperspectral Data
2012, 22(1): 63-74.
The fraction of photosynthetically active radiation (FPAR) is a key variable in the assessment of vegetation productivity and land ecosystem carbon cycles. Based on ground-measured corn hyperspectral reflectance and FPAR data over Northeast China, the correlations between corn-canopy FPAR and hyperspectral reflectance were analyzed, and the FPAR estimation performances using vegetation index (VI) and neural network (NN) methods with different two-band-combination hyperspectral reflectance were investigated. The results indicated that the corn-canopy FPAR retained almost a constant value in an entire day. The negative correlations between FPAR and visible and shortwave infrared reflectance (SWIR) bands are stronger than the positive correlations between FPAR and near-infrared band re-flectance (NIR). For the six VIs, the normalized difference vegetation index (NDVI) and simple ratio (SR) performed best for estimating corn FPAR (the maximum R2 of 0.8849 and 0.8852, respectively). However, the NN method esti-mated results (the maximum R2 is 0.9417) were obviously better than all of the VIs. For NN method, the two-band combinations showing the best corn FPAR estimation performances were from the NIR and visible bands; for VIs, however, they were from the SWIR and NIR bands. As for both the methods, the SWIR band performed exceptionally well for corn FPAR estimation. This may be attributable to the fact that the reflectance of the SWIR band were strongly controlled by leaf water content, which is a key component of corn photosynthesis and greatly affects the absorption of photosynthetically active radiation (APAR), and makes further impact on corn-canopy FPAR.
Trends in temperature and precipitation extremes over Circum-Bohai-Sea region during 1961-2008
2012, 22(1): 75-87.
Using daily temperature and precipitation data of 63 meteorological stations, trends in extreme temperature and precipitation during 1961-2008 were studied over Circum-Bohai-Sea region. The results showed that at most stations, there was a significant increase in the annual frequency of warm days and warm nights and a significant decrease in the annual frequency of cold days, cold nights, frost days, and annual diurnal temperature range (DTR). Their regional averaged changes were 2.06 days/decade, 3.95 days/decade, -1.88 days/decade, -4.27 days/decade, -4.21 days/decade and 0.20℃/decade respectively. The seasonal changes had similar trend patterns to the annual results, but there was a large seasonal difference. For cold days and cold nights, winter had the most significant changes. Whether at the annual or seasonal scales, a significant warming trend was detected from trends of six extreme temperature indices, which was contributed more by changes in the indices defined by daily minimum temperature than those defined by daily maximum temperature. For precipitation indices, the regional annual extreme precipitation displayed a weak decreasing trend in terms of magnitude and frequency (RD95p, RINTEN, RPROP and CWD) but a slight increasing trend in CDD, which was all consistent with the decrease of annual total precipitation (PRCPTOT). Seasonally, the total precipitation and RD95p all exhibited an increase in spring and a decrease in other seasons with the largest decrease occurring in summer, although their trends were generally non-significant. Overall, this study showed a tendency toward warmer and drier climate conditions over Circum-Bohai-Sea region, which would have great negative effects on regional economic development and ecological protection.
Spatial Structure Characteristics Detecting of Landform based on Improved 3D Lacunarity Model
2012, 22(1): 88-96.
The spatial structure characteristics of landform are the foundation of geomorphologic classification and recognition. This paper proposed a new method on quantifying spatial structure characteristics of terrain surface based on improved 3D Lacunarity model. Lacunarity curve and its numerical integration are used in this model to improve traditional classification result that different morphological types may share the close value of indexes based on global statistical analysis. Experiments at four test areas with different landform types show that improved 3D Lacunarity model can effectively distinguish different morphological types per texture analysis. Higher sensitivity in distinguishing the tiny differences of texture characteristics of terrain surface shows that the quantification method by 3D Lacunarity model and its numerical integration presented in this paper could contribute to improving the accuracy of landform classifica-tions and relative studies.
Peripheral Challenge in Container Port System: A Case Study of Pearl River Delta
2012, 22(1): 97-108.
The growth of peripheral ports to dominant hubs has been well documented in North America and Europe, and has led to the elaboration of several theoretical models. However, although changes in containerization growth have been taking place in the South and East Asia in recent years, particularly in China, only a few studies have focused on this region. The Pearl (Zhujiang) River Delta (PRD) has a typical port system with hub and peripheral ports, and provides an excellent case for studying the Peripheral Challenge. This paper introduces the theoretical evidence of the Hayuth model and analyzes the evolution of the container port system in the PRD with five phases: 1) phase I: preconditions for change and phase II: initial container port development in the 1970s and early 1980s; 2) phase III: diffusion, consolidation, and port concentration in the middle and late 1980s; 3) phase IV: the load center in the 1990s; and (4) phase V: the Peripheral Challenge since the late 1990s. The results illustrate that the Shenzhen port presents mounting challenges to the Hong Kong port, descending from a transshipment hub of China to a regional load center of Southeast China. Furthermore, this paper explores five points that have led to the evolution of the port system in the PRD: 1) competition in the regional port systems; 2) different interested parties; 3) shift of investment strategies of in-ternational terminal operators; 4) integration of shipping networks and reorganization of carriers; and 5) cost-based competition.
Industrial Arrangement of Large-scale, Non-grid-connected Wind Power Industrial Zones in Coastal Areas of China
ping binJIN
2012, 22(1): 109-118.
Constructing an industrial system for a large-scale, non-grid-connected wind power industry is a key step towards the diverse utilization of wind power. However, wind power exploitation is not only a technical challenge but an industrial problem as well. The objective of this study is to introduce a concept of large-scale, non-grid-connected wind power (LSNGCWP) industrial zones and establish an evaluation model to assess their industrial arrangement. The data of wind energy, industry, nature resources and socio-economy were collected in this study. Using spatial overlay analysis of geographic information system, this study proposes a spatial arrangement of the LSNGCWP industrial zones in the coastal areas of China, which could be summarized as the ′one line and three circles′ structure, which will contribute to the optimization of the industrial structure, advance the wind power technology, coordinate the multi-industrial cooperation, and upgrade the industrial transformation of China′s coastal areas.
Eco-compensation of Wetlands in Yellow River Delta of Shandong Province, China
2012, 22(1): 119-126.
Wetlands play an important ecological role and provide many functions for people, yet wetlands are currently decreasing and deteriorating. The ability to calculate an economic value for the loss of wetlands is becoming in-creasingly important for policy makers. In this study, remote sensing, field investigations, department visits, and other methods were used to survey wetland types, assess wetland area changes, and calculate wetland economic value. Mar-ket value loss and ecological function value loss, caused by reduction of wetland area and environmental pollution were calculated using commonly accepted methods of market valuation, ecological valuation, environmental protec-tion investment cost analysis, and outcome parameters. According to market value loss and ecological function value loss, preliminarily fund allocation for wetland and ecological compensation was calculated. This will provide an im-portant reference for future Yellow River Delta eco-compensation studies.