2013 Vol. 23, No. 1

Display Method:
Abrupt Climate Changes of Holocene
WANG Shaowu, GE Quansheng, WANG Fang, WEN Xinyu, HUANG Jianbin
2013, 23(1): 1-12.
This paper is a review of studies of abrupt climate changes (ACCs) during the Holocene published during the past ten years. North Atlantic cold events are indicators of ACCs. As indicated by North Atlantic ice-rafted debris (IRD), there were nine confirmed cold events during the Holocene, occurring at 11.1 kyr, 10.3 kyr, 9.4 kyr, 8.1 kyr, 5.9 kyr, 4.2 kyr, 2.8 kyr, 1.4 kyr, and 0.4 kyr respectively according to most representative results from Bond et al. (1997). However, the identification of chronology has been made with some uncertainties. Considerable climatic proxy data have shown that, during the cold events, substantial climate abnormalities have occurred widely across the globe, particularly in the areas surrounding the North Atlantic. These abnormalities were in the form of high-latitude cold in the both hemispheres, expansion of the Westerlies to low latitudes, drought in the monsoon regions, recession of summer monsoons, and intensification of the winter monsoons. Studies have indicated that the four ACCs occurring in the early Holocene may be related to freshwater pulses from ice melting in the northern part of the North Atlantic, and the other five ACCs that occurred during the middle and late Holocene may be related to the decreased solar activity.
Assessing Vulnerability to Drought Based on Exposure, Sensitivity and Adaptive Capacity: A Case Study in Middle Inner Mongolia of China
LIU Xiaoqian, WANG Yanglin, PENG Jian, Ademola K BRAIMOH, YIN He
2013, 23(1): 13-25.
In this paper, we proposed a framework for evaluating the performance of ecosystem strategies prepared for enhancing vulnerability reduction in the face of hazards due to climate change. The framework highlights the positive effects of human activities in the coupled human and natural system (CHANS) by introducing adaptive capacity as an evaluation criterion. A built-in regional vulnerability to a certain hazard was generated based upon interaction of three dimensions of vulnerability: exposure, sensitivity and adaptive capacity. We illustrated the application of this framework in the temperate farming-grazing transitional zone in the middle Inner Mongolia of the northern China, where drought hazard is the key threat to the CHANS. Specific indices were produced to translate such climate variance and social-economic differences into specific indicators. The results showed that the most exposed regions are the inner land areas, while counties located in the eastern part are potentially the most adaptive ones. Ordos City and Bayannur City are most frequently influenced by multiple climate variances, showing highest sensitivity. Analysis also indicated that differences in the ability to adapt to changes are the main causes of spatial differences. After depiction of the spatial differentiations and analysis of the reasons, climate zones were divided to depict the differences in facing to the drought threats. The climate zones were shown to be similar to vulnerability zones based on the quantitative structure of indexes drafted by a triangular map. Further analysis of the composition of the vulnerability index showed that the evaluation criteria were effective in validating the spatial differentiation but potentially ineffective because of their limited time scope. This research will be a demonstration of how to combine the three dimensions by quantitative methods and will thus provide a guide for government to vulnerability reduction management.
Storage and Density of Soil Organic Carbon in Urban Topsoil of Hilly Cities: A Case Study of Chongqing Municipality of China
LIU Yong, WANG Cheng, YUE Wenze, HU Yanyan
2013, 23(1): 26-34.
Rapid urbanization results in the conversion of natural soil to urban soil, and consequently, the storage and density of the soil carbon pools change. Taking Chongqing Municipality of China as a study case, this investigation attempts to better understand soil carbon pools in hilly cities. First, the vegetated areas in the study area were derived from QuickBird images. Then, topsoil data from 220 soil samples (0–20 cm) in the vegetated areas were collected and their soil organic carbon (SOC) densities were analyzed. Using the Kriging interpolation method, the spatial pattern of SOC was estimated. The results show that the SOC density exhibited high spatial variability in the urban topsoil of Chongqing. First, the SOC density in topsoil decreased according to slope in the order 2°–6° < 25°–90° < 0°–2° < 6°–15° < 15°–25°. Second, the newly developed areas during 2001–2010 had a lower SOC density than the areas built before 1988. Third, urban parks and gardens had a higher SOC density in topsoil, residential green land followed, and scattered street green land ranked last. For hilly cities, the variability of terrain affects the distribution of SOC. The Kriging results indicate that Kriging method combining slope with SOC density produced a high level of accuracy. The Kriging results show that the SOC density to the north of the Jialing River was higher than the south. The vegetated areas were estimated to amount to 73.5 km2 across the study area with an SOC storage of 0.192 Tg and an average density of 2.61 kg/m2.
Inference of Reference Conditions for Nutrient Concentrations of Chaohu Lake Based on Model Extrapolation
ZHOU Yuliang, JIN Juliang, LIU Li, ZHANG Libing, He Jun, WANG Zhesun
2013, 23(1): 35-48.
 In the mid-eastern China, there are few or no lakes which are in the absence of anthropogenic disturbances, or their sediments remain undisturbed. As a result, the reference lakes distribution and paleolimnological reconstruction approaches usually are inappropriate to estimate lake reference conditions for nutrients. This yields the necessity of using the extrapolation methods to estimate the lake reference conditions for nutrients within those regions. The lake reference conditions for nutrients could be inferred inversely from the law of mass conservation, current lake nutrient concentration, and the loadings from watershed. Considering the scarcity of hydrological and water quality data associated with lakes and watersheds in China, as well as the low requirement of the watershed nutrient loadings models for these data, the soil conservation service (SCS) distributed hydrological model and the universal soil loss equation (USLE) were applied. The SCS model simulates the runoff process of the watershed, thereby calculating dissolved nutrients annually. The USLE estimates the soil erosion and particulate nutrients annually in a watershed. Then, with the loadings from atmospheric deposition and point source, the previous annual average nutrient concentrations could be acquired given the current nutrient concentrations in a lake. Therefore, the nutrient reference conditions minimally impacted by human activities could be estimated. Based on the proposed model, the reference conditions for total nitrogen and total phosphorus of Chaohu Lake, Anhui Province, China are 0.031 mg/L and 0.640 mg/L, respectively. The proposed reference conditions estimation model is of clear physical concept, and less data required. Thus, the proposed approach can be used in other lakes with similar circumstances.
Mercury Distribution and Accumulation in Typical Wetland Ecosystems of Sanjiang Plain, Northeast China
WANG Qiang, ZHANG Zhongsheng1, ZHOU Xuehong, LU Xianguo
2013, 23(1): 49-58.
Total mercury in soil, water, plant, insects, fishes and bird feathers were determined to study mercury distribution and accumulation in typical wetland ecosystems in the Sanjiang Plain, Northeast China. Results show that total mercury concentrations in soils of Deyeuxia angustifolia wetland and Carex lascarpa wetland are 0.046 mg/kg and 0.063 mg/kg, respectively. Total mercury concentration in water bodies is 0.053 μg/L on average. Of four plants studied, total mercury in moss is the highest with the mean of 0.132 mg/kg. Of 10 terrestrial insect species studied, total mercury in centipede (Scolopendra spp.) is the highest with the mean of 0.515 mg/kg while total mercury in grasshopper (Oxya spp.) bodies is the lowest. Total mercury concentrations in the herbivorous, omnivorous and predatory insects are 10.18 ng/g, 16.47 ng/g and 213.35 ng/g on average, respectively. Total mercury concentrations of the adult feather (549.88 ± 63.04 ng/g), nestling feather (55.15 ± 23.53 ng/g), and eggshell (22.05 ± 5.96 ng/g) of the Grey heron (Ardea cinerea) are higher than those of the Great egret (Egretta alba) (adult feather: 446.57 ± 90.89 ng/g; nestling feather: 32.99 ± 17.15 ng/g; eggshell: 21.02 ± 3.17 ng/g) in the wetlands of the Sanjiang Plain. The bioconcentration factors decrease in the order of piscivorous fish muscle > omnivorous fish muscle > herbivorous fish > insect.
Magnetic Properties of Tree Leaves and Their Significance in Atmospheric Particle Pollution in Linfen City, China
YIN Gang, HU Shouyun, CAO Liwan, Wolfgang ROESLER, Erwin APPEL
2013, 23(1): 59-72.
 Fifty-one tree leaves were sampled in the industrial area, residential area, and Fenhe River ecological zone, for the purpose of a magnetic study on atmospheric pollution in Linfen City, Shanxi Province, China. Measurements of mass-specific magnetic susceptibility (χ) show a significant variation range (from 11.6 × 10–8 m3/kg to 129.7 × 10–8 m3/kg). Overall values of magnetic susceptibility decline in the following sequence: industrial area > residential area > Fenhe River ecological zone. The relatively elevated concentration-related magnetic parameters (saturation isothermal remanent magnetization, anhysteretic remanent magnetization and magnetic su¬sce¬ptibility) appear in the industrial area, with their highest values in the vicinity of Linfen Steel Mill. Magnetic particles are dominated by multidomain, magnetite-like minerals. Magnetic particle concentration and grain size both decrease with the increasing distance from industrial area, indicating the industrial area, especially Linfen Steel Mill, is the main source of atmospheric particle pollution. Residential area and Fenhe River ecological zone are also affected by industrial emission to a certain extent. The results of this study indicate that magnetic measurements of tree leaves are practicable for monitoring and determination of atmospheric pollution in Linfen City.
Evapotranspiration Estimation Based on MODIS Products and Surface Energy Balance Algorithms for Land (SEBAL) Model in Sanjiang Plain, Northeast China
DU Jia, SONG Kaishan, WANG Zongming, ZHANG Bai, LIU Dianwei
2013, 23(1): 73-91.
In this study, the Surface Energy Balance Algorithms for Land (SEBAL) model and Moderate Resolution Imaging Spectroradiometer (MODIS) products from Terra satellite were combined with meteorological data to estimate evapotranspiration (ET) over the Sanjiang Plain, Northeast China. Land cover/land use was classified by using a recursive partitioning and regression tree with MODIS Normalized Difference Vegetation Index (NDVI) time series data, which were reconstructed based on the Savitzky-Golay filtering approach. The MODIS product Quality Assessment Science Data Sets (QA-SDS) was analyzed and all scenes with valid data covering more than 75% of the Sanjiang Plain were selected for the SEBAL modeling. This provided 12 overpasses during 184-day growing season from May 1st to October 31st, 2006. Daily ET estimated by the SEBAL model was misestimaed at the range of –11.29% to 27.57% compared with that measured by Eddy Covariance system (10.52% on average). The validation results show that seasonal ET from the SEBAL model is comparable to that from ground observation within 8.86% of deviation. Our results reveal that the time series daily ET of different land cover/use increases from vegetation on-going until June or July and then decreases as vegetation senesced. Seasonal ET is lower in dry farmland (average (Ave): 491 mm) and paddy field (Ave: 522 mm) and increases in wetlands to more than 586 mm. As expected, higher seasonal ET values are observed for the Xingkai Lake in the southeastern part of the Sanjiang Plain (Ave: 823 mm), broadleaf forest (Ave: 666 mm) and mixed wood (Ave: 622 mm) in the southern/western Sanjiang Plain. The ET estimation with SEBAL using MODIS products can provide decision support for operational water management issues.
Simulation of Land-use Scenarios for Beijing Using CLUE-S and Markov Composite Models
HU Yecui, ZHENG Yunmei, ZHENG Xinqi
2013, 23(1): 92-100.
This study investigated and simulated land use patterns in Beijing for the year 2000 and the year 2005 from the actual land use data for the year 1995 and the year 2000, respectively, by combining spatial land allocation simulation using the CLUE-S model, and numerical land demand prediction using the Markov model. The simulations for 2000 and 2005 were confirmed to be generally accurate using Kappa indices. Then the land-use scenarios for Beijing in 2015 were simulated assuming two modes of development: 1) urban development following existing trends; and 2) under a strict farmland control. The simulations suggested that under either mode, urbanized areas would expand at the expense of land for other uses. This expansion was predicted to dominate the land-use conversions between 2005 and 2015, and was expected to be accompanied by an extensive loss of farmland. The key susceptible to land-use changes were found to be located at the central urban Beijing and the surrounding regions including Yanqing County, Changping District and Fangshan District. Also, the simulations predicted a considerable expansion of urban/suburban areas in the mountainous regions of Beijing, suggesting a need for priority monitoring and protection.
Pattern Dynamics of Thermal-environment Effect During Urbanization: A Case Study in Shenzhen City, China
XIE Miaomiao, WANG Yanglin, FU Meichen, ZHANG Dingxuan
2013, 23(1): 101-112.
The thermal-environment effect exists in the field of rapid urbanization. It has adverse effects on the urban atmosphere, regional climate, energy consumption, and public health. Shenzhen, a representative of rapidly urbanizing cities in China, was selected as a case for pattern dynamics analysis of the thermal environment. The surface temperature was acquired from the thermal infrared data of Landsat TM and ETM+ images in 1986, 1995, and 2005 by Jiménez-Muñoz and Sobrino′s generalized single-channel method, which was used in assessing the distribution and spatial patterns of the thermal environment. The relative thermal environment curve (RTC) was combined with Moran′s I analysis to assess the pattern dynamics of the thermal environment in different urbanization periods. Moran′s I index and the RTC represent a process of aggregation-fragmentation-aggregation, which shows the aggregation pattern of a decrease during the rapid urbanization period and then an increase during the steady urbanization period. High-tem¬pera¬ture areas gradually expanded to a uniform and scattered distribution in the rapid urbanization period; while the high thermal-environment effect was gra¬dually transformed into a steady spatial pattern in the stable urbanization period. To characterize the increasing development in this multiple- center city, we chose profiles along an urban-development axis. The results suggest that heat islands have expanded from internal urban to external urban areas. Four profiles were obtained showing differences in shape due to spatial differences in the process of development.
Spatial Process of Green Infrastructure Changes Associated with Rapid Urbanization in Shenzhen, China
CHANG Qing1, LI Shuangcheng2, WANG Yanglin2, WU Jiansheng3, XIE Miaomiao4
2013, 23(1): 113-128.
Through a case study of Shenzhen City, China, this study focused on a quantitative method for analyzing the spatial processes involved in green infrastructure changes associated with rapid urbanization. Based on RS, GIS and SPSS statistics software, the approach includes selection of the square analysis units and representative landscape metrics, quantification of the change types of landscape metrics in all analysis units through two indices and hierarchical cluster analysis of the above analysis units with different landscape metric change types (i.e. spatial attributes). The analyses verify that there is a significant sequence of continuous changes in green infrastructure in Shenzhen. They are the perforation, the segmentation, the fragmentation, the evanescence and the filling-in processes, which have a good spatio-temporal correspondence with urbanization and reflect the synthetic influence of urban planning, government policies and landforms. Compared with other studies on quantifying the spatial pattern, this study provides an alternative probe into linking the spatial pattern to spatial processes and the corresponding ecological processes in the future. These spatio-temporal processes offer many opportunities for identifying, protecting and restoring key elements in an urban green infrastructure network for areas in the early stages of urbanization or for non-urbanized areas.
International Conference on Land Use Issues and Policy in China under Rapid Rural and Urban Transformation
LONG Hualou, LIU Yansui
2013, 23(1): 129-130.
The International Conference on Land Use Issues and Policy in China under Rapid Rural and Urban Transformation was held in Beijing, China, from 20 to 23 October 2012, under the auspices of National Natural Science Foundation of China (NSFC) and the Institute of Geographic Sciences and Natural Resources Research (IGSNRR), Chinese Academy of Sciences (CAS). The Conference was mainly co-organized by the Journal of Land Use Policy (Elsevier); the Center for Regional Agriculture and Rural Development and Research Center for Land Use Engineering, IGSNRR, CAS; and the Key Laboratory of Degraded and Unused Land Consolidation Engineering, the Ministry of Land and Resources of China (MLRC). More than 120 scientists attended this Conference, and they came from nine countries including Australia, the United Kingdom, the United States of America, Sweden, Germany, Nepal, Iran, Netherlands and China. The Conference collected 115 abstracts or full papers, which covered all the predesigned seven themes. A selection process for the abstracts or full papers was employed, and 49 of them were invited to present full paper at the Conference.