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Issue No.6

Land Cover Change and its Causes in Yulin District

LI Zhongfeng , CAI Yunlong
(Department of Resources, Environment and Geography, the Centre for Land Study;
Peking University, Beijing 100871)

Abstract：Yulin district is located in the most Northern part of Shaanxi province, between 36°57′and 39°34′N, and 107°28′and 111°15′E. Yulin district is one of the areas of the most serious soil erosion in the world and receives a lot of attention from the Chinese government and international societies. After the establishment of the People’s Republic of China, the desertification intensity declined because of rehabilitation measures. However, there is lack of knowledge concerning the dynamics of land cover and the complex role of factors in inducing changes in land cover. In the study，by usage of normalized difference vegetation index(NDVI) as an indicator of vegetation activity， seasonal trends of vegetation activity and their dynamic responses to climate changes in Yulin district were explored based on remotely sensed data (NOAA-AVHRR and VEGETATION) from 1981 to 2004. As a result，spatially averaged seasonal NDVI in Yulin showed a pronounced increase during the last two decades. The average autumn NDVI indicated the most significant increase. By analyzing inter-annual changes in seasonal NDVI，it was found that the advance of growing season was a major way for response of vegetation activity to climate changes and that the way exhibited a large regional heterogeneity. From the southeast to the northwest, change amplitude showed a declining trend.

Key words: land cover; NDVI; Yulin district；regional heterogeneity

Water Quality Purification of Urban Lakes and
Rivers with Floating Phytoremediation System

HUANG Tinglin, DAI Dongchao, WANG Zhen, XIE Yue, ZHONG Jianhong
(School of Environmental and Municipal Engineering, Xi’an University of Architecture
and Technology; Key Laboratory of Northwest Water Resource, Environment
and Ecology of Ministry of Education, Xi’an 710055，China)

Abstract:The technological principle, characteristics and composition of floating phytore medi-ation systems for water quality restoration were described and analyzed. The growth and effect of Canna generalis and Cyperus alternifolius on TN and TP removal from urban water bodies were also investigated based on experiments. And a new bio-plant technology for water quality restoration of urban water bodies, which combined floating cultivation system with biological contact oxidation, was utilized to purify polluted water of an urban river and a lake in Xi’an City of China. The experimental results showed that Canna generalis and Cyperus alternifolius had better effects on water body purification, and more than 90% of nitrogen was removed by the both systems. And the bio-plant system composed of floating cultivation and soft bio-media could not only remove TN and TP effectively, but also greatly degrade organic pollutants from the water bodies, with a high removal rate of 46% of CODMn obtained.

Key words: floating phytoremediation system; purification; biological contact oxidation; urban
lakes and rivers

Water Quality Purification of Urban Lakes and
Rivers with Floating Phytoremediation System

HUANG Tinglin, DAI Dongchao, WANG Zhen, XIE Yue, ZHONG Jianhong
(School of Environmental and Municipal Engineering, Xi’an University of Architecture
and Technology; Key Laboratory of Northwest Water Resource, Environment
and Ecology of Ministry of Education, Xi’an 710055，China)

Abstract:The technological principle, characteristics and composition of floating phytore medi-ation systems for water quality restoration were described and analyzed. The growth and effect of Canna generalis and Cyperus alternifolius on TN and TP removal from urban water bodies were also investigated based on experiments. And a new bio-plant technology for water quality restoration of urban water bodies, which combined floating cultivation system with biological contact oxidation, was utilized to purify polluted water of an urban river and a lake in Xi’an City of China. The experimental results showed that Canna generalis and Cyperus alternifolius had better effects on water body purification, and more than 90% of nitrogen was removed by the both systems. And the bio-plant system composed of floating cultivation and soft bio-media could not only remove TN and TP effectively, but also greatly degrade organic pollutants from the water bodies, with a high removal rate of 46% of CODMn obtained.

Key words: floating phytoremediation system; purification; biological contact oxidation; urban
lakes and rivers

Study on Land Use/ Cover Change in Mountain Areas of
Southern Ningxia Based on RS Technology

DU Lingtong
(Research Center for Western Development of Ningxia University, Yinchuan Ningxia 750021)

Abstract: With the integrated technology of Remote Sensing(RS) and Geographic Information System(GIS), the status of LUCC in the mountain areas of southern Ningxia Hui Autonomous Region is thoroughly studied by statistics and conversion matrix based on the remote sensing imagery date of 1975, 1985 and 2001. The main results are as follows. (1) The main styles of LUCC in the study area is farmland, and the following is grassland and woodland. The area of farmland reaches its maximum in 1987, with 790 312.06 hm2, taking 70.03% in the total land area. (2) The study results from conversion matrix indicate that there is 370 770.52 hm2 grassland and 39 813.57 hm2 woodland that had changed to farmland from 1975 to 1987. But from 1987 to 2001, there are 316 865.89 hm2 farmland that had changed to grassland and 50 729.16 hm2 farmland changed to woodland. The main reason that leads to this variation is that the local economy development was based on construction of farmland from 1975 to 1987. In this period, the development policy encouraged farmer to cultivate wasteland. But after 1990, the national exploitation policy changed greatly and carried out some zoology project, especially Returning Farmland to Forests and Grassland Project. Such policies and projects play an important role in the recovery process of grassland and woodland.

Key words: land use and land cover change; RS; GIS; Ningxia; image

Computation Method of Topographic Wetness Index
in Low Relief Area

QIN Chengzhi1，YANG Lin1，ZHU A-Xing1，2， LI Baolin1，PEI Tao1， ZHOU Chenghu1
(1. State Key Laboratory of Resources and Environmental Information System, Institute of
Geographical Sciences and Natural Resources Research, CAS, Beijing 100101, China;
2. Department of Geography, University of Wisconsin-Madison, Madison, WI 53706, USA)

Abstract: Topographic wetness index, which is designed for modeling the status (“dry” or “wet”) of the soil moisture quantitatively, is an important index for both predictive soil mapping and distributed hydrological modeling in a catchment. Current methods for calculating topographic wetness index have evident problems when applied in low relief area. Outside the positions of narrow accumulation line with high topographic wetness index, the topographic wetness index dramatically jumps down in other parts of wide valley area. This is unreasonable because the soil moisture should be comparatively average and high in the wide and flat valley, and the value of topographic wetness index should be high. This problem is caused by both the flow accumulation algorithm and the slope gradient used during computing the topographic wetness index. A new method for computing topographic wetness index is proposed in this paper to address this problem. Firstly, flow accumulation is calculated by a multiple flow direction algorithm(MFD-fg). Topographic wetness index is then computed by the flow accumulation and maximum downslope. The maximum downslope used in the computation of topographic wetness index is matched with the idea of both MFD-fg and topographic wetness index. Furthermore, a post-processing method is also proposed to compute the topographic wetness index in valley area. The topographic wetness index in the valley area is interpolated by a Gaussian function based on the value of the topographic wetness index on the nearest position on extracted flow accumulation line. The application in a small watershed shows that the method proposed in this paper can get a comparatively reasonable distribution of topographic wetness index for not only the hillslope but also the wide valley area. The value of topographic wetness index in valley area is averagely high and with a smooth transition, which reflects the natural status of the soil moisture in application area. In the future research, the method proposed in this paper will be evaluated by both artificial surfaces and the real applications.

Key words: topographic wetness index; low relief area; digital elevation model (DEM); multiple
flow direction algorithm; maximum downslope; interpolation

Grain-size Variation on a Transverse Dune and Response to
Wind Direction Changes on Southern Edge of Mu Us Desert
　　
HASI Eerdun1, ZHUANG Yanmei1, WANG Lei2, WANG Zhi1
(1. College of Resources Science and Technology, MOE Engineering Center of Desertification
and Blown-sand Control, Beijing Normal University. Beijing 100875;
2. College of Resource Environment and Tourism, Capital Normal University, Beijing 100037 )
　　
Abstract: The transect data of morphology and grain-size samples has been obtained from a transverse dune with 8m high and 48m long in the south edge of Mu Us Sandy Land in the period of wind direction transitions. The results show that there exist temporal changes in grain-size and its spatial pattern on transverse dune responding to different wind directions and magnitudes. These changes are more obvious in the creastal zone of dune with more sand activity. Great temporal changes take place in the grain size frequency distribution, mean grain size and skewness among the grain-size parameters. This suggests that these parameters are most susceptive to the wind, and so their changes can be used to explain the difference of dunes in the influence of different wind. The evidences of the wind direction, dune morphology and grain-size characteristics identified there not only have seasonal but daily changes in grain-size patterns on the dune when wind direction changes. It further confirms the conclusion that the time of sampling is as important as the site.
　　
Key words: Mu Us sandy land; transverse dune; Grain-size; Morphology wind direction

Research of Changes in Cultivated Land Around
the Reservoir Area of Three Gorges

CAO Yingui1,2, WANG Jing1, CHENG Ye1，2, FU Meichen2, RAO Caixia2, XU Ning1,2
（1. Key Laboratory of Land Use, China Land Survey and Planning Institute；
2. Department of Land Science and Technology, China University of Geosciences, Beijing 100083)

Abstract: Three Gorges Project is the great project in the world, which accelerates economic development in the reservoir area of Three Gorges Project. In the process of development in the reservoir area of Three Gorges Project, cultivated land has become an important resource, and a lot of cultivated land has been occupied and become constructing land. At the same time, a lot of cultivated land has been flooded because of the rising of the water level. This paper uses the cultivated land areas and social economic indicators of reservoir area of Three Gorges for 1990~2004, takes the statistic analyses and example research in order to analyze the process of cultivated land, gets the driving forces of cultivated land change, finds the new methods to stimulate and forecast the cultivated land areas in the future, and serves for the cultivated land protection and sustainable development in reservoir area of Three Gorges. The results indicate that, firstly, in the past 15 years, the cultivated land area has decreased by 200 142 hm2, and the decreasing quantity per year is 13343 hm2. The whole reservoir area is divided into three different areas: upper reach area, belly area and lower reach area. The trends of cultivated land change in different reservoir areas are similar to the whole reservoir area. Secondly, the curve of cultivated land areas and per capita GDP takes on a reverse U, and the paces between the change rate of cultivated land and the change rate of GDP are different in some years, which indicates that change of cultivated land and change of GDP is decoupled; besides that, change of cultivated land is in connection with the development of urbanization and the policy of returning forestry greatly. Lastly, the precision of multi-regression is lower than the BP neural network in the simulation of cultivated land. We then use the BP neural network to forecast the cultivated land areas for 2005, 2010 and 2015, and the forecasting results are reasonable.
Key words: change in cultivated land; driving forces; theory of decoupling; BP neural network;
Reservoir Area of Three Gorges

Parameterization of Leaf Phenology for
the Terrestrial Ecosystem Models

GU Fengxue1,2
(1. Institute of Geographical Sciences and Natural Resources Research, Synthesis Research Center of
CERN, Chinese Academy of Sciences, Beijing 100101, China;
2. Graduate Unviersity of Chinese Academy of Sciences，Beijing 100039, China)

Abstract: The seasonal phenology of the leaf area index (LAI) is a major determinant of net ecosystem production in deciduous forest ecosystems. In the simplest case, the effect of leaf phenology on energy and CO2 fluxes is represented by prescribing leaf onset and offset times or the seasonal evolution of LAI. Leaf phenology remains one of the most difficult processes to be parameterized in terrestrial ecosystem models because the understanding of the physical processes that initiate leaf onset and senescence is incomplete. At present, to describe phenology, the terrestrial models generally use one of two different approaches. One approach uses empirical formulations to estimate the timing of crucial phonological events like leaf-on/off dates only based on abiotic variables, especially temperature or growing degree-days (GDDs). The other approach is a carbon-gain-based scheme. In this approach, the phonological stages are directly determined from the current carbon balance. A carbon-gain-based parameterization of phenology in ecosystem models offers the possibility of reduced empiricism, general applicability, and increased robustness; and it is more suitable for being used in climate change models. In the future, while the mechanisms of processes controlling leaf phenology are clarified with progress being made at the physiological and molecular level, ecosystem models have to set up process-based model of leaf phenology and LAI to promote the robust of simulation results.

Key words: ecosystem models; phenology; LAI; parameterization

Regional Impaction and Evolution of
Express Way Networks in China

WANG Chengjin
（Institute of Geographic Sciences and Natural Resources Research，CAS，Beijing 100101，China）

Abstract：With the development of express ways, they has became the main transport model of road system, affecting the development of social-economy and urban region. In this paper, based on the research history and progress in China, the author analyzed the spatial evolution course of express way networks in China, which have the slowness development（1988~1997） and quick development stage（1997）, and discussed their spatial organization models, including regional access, urban circle road, access between hub cities, urban interior road, and travel road. Furthermore, by designing the shortest time model and O-D matrix, the author analyzed the regional impaction of express way networks in detail. Firstly the evolution of traffic flow structure in China was discussed, which enlarged the transport distance of road system and actuated the traffic to concentrate in the East region of China. Secondly, the author analyzed traffic flow structure of urban regions and its region system, which emerged as the main traffic flow access and hub-and-spoken system in Yangze delta and Pear river delta urban regions and Thirdly, the express transport circle of 30M and 1H around province cities were discussed and drew the conclusion that express way enhanced their service scope and accelerated concentrating speed of population and products to province cites.

Key words： express way networks； traffic flow； urban region； traffic circle； region impaction

Spatial-temporal Changes of Urban Spatial Morphology
at the Northern Slope of the Tianshan Mountains

ZHANG Yufang1,2, YANG Degang1, ZHANG Xiaolei1, MA Wenhong1,2, ZHANG Hongyuan1,2
(1. Xinjiang Institute of Ecology and Geography, CAS, Urumqi, Xinjiang 830011, China;
2. Graduate School, CAS, Beijing 100039, China)

Abstract: Urban spatial morphology is an important aspect in the huge and complex urban system. The essential rule of urban development and change cannot be understood via qualitative description, so quantitatively researching urban spatial characteristic has significant practice meaning for urban management and planning． Based on remote sensing, GIS and Landsat TM/ETM digital images, this paper analyzes the spatial-temporal changes of urban spatial morphology at the northern slope of the Tianshan Mountains in Xinjiang during the period from the late 1980s to the late 1990s by computing compact rations and fractal dimensions of the urban form as well as the types of urban land expansion. The results are as follows:
(1) The spatial-temporal changes of urban spatial morphology at the northern slope of the Tianshan Mountains belong mostly to compact and regular ones. (2) The average compact rations are 0.541 and 0.525, and the mean fractal dimensions are 1.2399 and 1.25 respectively for 1990 and 2000. The type of urban land expansion of 7 cities out of the 8 in the study area is ‘extension’ from 1990 to 2000. It was found that the shapes of cities in the study area tended to be less compact and more fragmentized. Generally, a more compact city has more advantages than a less one; so changes in the forms of the study area are considered being in a bad way. Shapes of several cities have been drastically changed during the period from 1990 to 2000. Fukang, Miquan and Shihezi are cities with high increment in fractal dimensions and high decrease in compact rations. Urban spatial morphology of them is more compact and regular. However, it is another case in Kelamayi, Kuytun and Urumqi. And (3) Another important finding is that there is a power function relationship between the compact and the fractal dimension of urban spatial morphology, which is only a qualitative deduction before.
Key words: urban spatial morphology; fractal dimension; compact ratio; type of urban land
expansion; the northern slope of the Tianshan Mountains

Study on Temporal-Spatial Processes of Farmland Conversion
and Its Control Mechanisms in Beijing, China, 1996～2004

SUN Qiang，CAI Yunlong，WANG Wenbo
(Department of Resources, Environment and Geography & The Center for Land Study, Peking University;
Laboratory for Earth Surface Processes, The Ministry of Education, Beijing 100871, China)

Abstract: Study on farmland non-agriculturalization and its control mechanisms is becoming an important issue in the framework of LCS ( Land Change Science), a new developing conception by IGBP. LCS stresses not only research on LUCC itself but also other relevant social-economic problems and pays much attention to high-speed change areas all over the world. China, a fast developing country, is facing many land use problems brought by fast economic growth, urbanization and industrialization with fast farmland losing as a core. Taking the capital of China, Beijing, as a case, the temporal-spatial processes of farmland conversion and its control mechanisms are discussed. It is found that（1）Farmland losing is the main character of land use in Beijing from 1996 to 2004; （2）Among various factors threatening the sustainability of farmland, the most outstanding and the most serious one is the occupation on farmland for urban development;（3）The lost farmland is mostly those high quality land in the plain area; and （4）Farmland losing is driven by population increase, economic growth, some local governments’ acts for short-term benefits from farmland conversion and so on. In order to moderate the conflicts between farmland conservation and urban development in Beijing and other fast developing districts in China, the authors claim that the following points should be emphasized in land management:（1）Importance should be especially placed on the quality of farmland; （2）Policies on farmland conservation, such as “keeping quantity balance”, should be reviewed; and （3） It is necessary to make appropriate control mechanisms for farmland conservation, including: to provide a reasonable threshold of farmland conservation, to establish appropriate legislation, institutions and mechanisms, and to avoid illegal occupation on farmland for urban development, etc.

Key words: farmland losing; LCS (Land Change Science); control mechanisms; Beijing, China

Theories, Methods and Progress of Energy-Environment Research

LIU Gang1,2，SHEN Lei1
（1. Institute of Geographic Sciences and Natural Resources Research，CAS，Beijing，100101，China；
2. Graduate School of CAS，Beijing，100049）

Abstracts: Both abundance of energy and cleanness of environment are of paramount importance to guaranteeing the national energy security and sustainable development. Considering coal’s important place in the energy supply and consumption structure, the big population in rural area and the sustainable development plan in the future, there are special practical significances to carry out energy-environment researches in China. This article summarized the concept, the analysis frame and theory base, and the usual methods and models in the energy-environment field. An energy-environment cube analysis frame was also given to conclude the main research aspects such as different kinds of energy utilization on environment, effects of fossil energies on global environment, and influences of rural energy and biomass energy on eco-environment which is less studied at present and especially from the viewpoints of geographical scale. After some reviews and comments on the research advances in economic, technical, political and regional demonstration fields of both domestic and international communities, the future trends and some perspectives on the energy environments are put forward at the end of the article.

Key words: energy; energy-environment; energy-environment cube; scenarios analysis

Spatial Analysis on Differences of Recycling Enterprises Distribution Among China’s Provinces

LIU Chuang1,2, YU Bohua1,2, LIU Xiangqun3
(1. Collage of Resources Science & Technology; Beijing Normal University, Beijing 100875, China；
2. Institute of Geographical Science and Natural Resources Research, CAS, Beijing 100101, China；
3. The Resources Recycle and Reuse Society of China, Beijing 100801, China）
　　
Abstract：Reduce-recycle-reuse becomes more active in China in natural resource development and uses. With the high pressure on natural resources in China’s socio-economic development, 3R industry experiences a new milestone during the last ten years. By the end of 2005, 23 512 enterprises are engaged in the 3R industry in China. In order to find the differences of the 3R industry development among the provinces in China, a statistic methodology with 14 socio-economic indicators linked with the 3R Industry GIS Database of China has been applied in the analysis of 3R industry in China’s provinces. Guangdong province is at the top level in 3R industry development in China, which has 4 996 enterprises. Jiangsu(2 267), Zhejiang (2 259) and Shandong(2 217) provinces run the second level 7 provinces, Hebei, Shanghai, Fujian, Liaoning, Hubei, Hunan and Henan, run the third level, with the number of the enterprises in each province ranging from 600~2000. The provinces of Tianjin, Beijing, Sichuan, Anhui, Jiangxi, Helongjiang, Guanxi, Shanxi, Chongqing, Jilin and Hong Kong run the fourth level, with the number of the enterprises in each ranging 200~600. And other provinces are lower than 200. The spatial pattern of the 3R industry in China is that it declines from eastern to western in the terms of changes in population, economic development and the local policies. Based on the analysis above, recommendations have been provided in this paper, including: (1) the official statistics agency of China should pay more attention to the statistics in the 3R industry development in China, and as a more practical action, a survey on 3R industry census in China is necessary; (2) The national guidance and management policy for 3R development and spatial distribution should be made available; and (3) the standards for 3R industry development and the 3R industry monitoring systems in the national level should be established as soon as possible.

Key words：resources; reduce-recycle-reuse; enterprise; spatial analysis; China

A Review of Research on Road Erosion

XU Xianli1,4，ZHANG Keli2, LIU Xianchun3
(1. State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-environmental Sciences,
the Chinese Academy of Sciences, Beijing 100085, China;
2. School of Geography and Remote Sensing Science, Beijing Normal University, Beijing 100875, China;
3. The Monitoring Center of Soil and Water Conservation Ministry of Water Resource, Beijing 100053, China；
4. Graduate School of the Chinese Academy of Sciences, Beijing 100039, China)

Abstract: Road construction would accelerate soil erosion, which in turn would deteriorate natural ecology. To reduce or control road erosion, we should grasp road erosion characteristics and its mechanics, and then find the effective control measures. Landform would be changed to some extent in road construction processes. Different micro-topography would be formed on the original geomorphology, which produces different erosion characteristics. Meanwhile, the erosion mechanics and processes are different among these parts of a road. The existing researches on road erosion have no agreement on the erosion intensity for the respective part of the road. Compared with other land use types, road would significantly change the physical and hydrological properties of soil surface, and furthermore accelerate runoff and soil erosion. Especially for a watershed, the linear feature of a road helps to easily converge and conduct runoff. However, few research on this aspect until present. At present, the statistical model of road erosion prediction is still predominating. Due to the limitation of the statistical model itself, it can’t reflect the erosion mechanics; so physical models should be the emphasis in the further researches. Especially, we should try our best to introduce the existing physical model on farmland. The control measures on road erosion mainly include the engineering ones, the biology ones and their combinations. All of them have different effectiveness in controlling soil loss, dependent on the local natural and economic factors. This paper reviewed the previous researches and pointed out some emphasis on road erosion in further study. It is significant for road erosion control and watershed environment protection.
Key words: road construction; road erosion; road erosion prediction; road erosion control

The Methods of Simulating Vegetation Growing
Season Based on NOAA NDVI

WANG Hong，LI Xiaobing，YING Ge, WANG Dandan，LONG Huiling
( College of Resources Science and Technology, Beijing Normal University, Key Laboratory of Environmental Change and Natural Disaster, Ministry of Education, Beijing 100875 , China )

Abstract: In recent years, estimating vegetation growing season on large scale has become a significant scientific field in global climate change studies. NOAA/AVHRR NDVI provides important means of research on temporal and spatial variability of vegetation growing season. This paper has summarized, compared and analyzed methods of estimating beginning, end, length of vegetation growing season on the basis of NDVI: NDVI threshold, NDVI time series analysis, combination of frequency distribution pattern of plant phenology with NDVI, principal component analysis，curves fitting model and so on. Influenced by different factors, each method has different limitations in application. Therefore, it is necessary to seek better methods for determining interannual and regional distribution variability of vegetation growing season. And on the basis of previous studies, growing season of grassland in Xilinhaote from 1991 to 1999 is estimated by NDVI threshold method, smoothed moving average, the greatest change slope, and curves fitting model. Then the results were verified with grassland greenup by field survey. Results shows that, combining with field surveying data, grassland greeup with better accuracy is acquired with NDVI threshold method, and curves fitting model can be applied to monitoring vegetation growing season on large scale. However, it is difficult for actual curves to match the simulated curves. Therefore, it is very important to choose appropriate fitting curves for subsequent studies. Furthermore, it is necessary to carry out further research on interannual variability of vegetation growing season.

Key words: vegetation growing season; NDVI; temporal and spatial variability

Effects of Drought on Ecosystem Carbon and Water Processes:
a Review at Different Scales

HU Zhongmin1,2, YU Guirui1, FAN Jiangwen1, WEN Xuefa1
(1. Key Laboratory of Ecosystem Network Observation and Modeling, the Center for Synthesis Research,
Chinese Ecosystem Research Network Institute of Geographic Sciences
and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China;
2. Graduate University of Chinese Academy of Sciences, Beijing 100039, China)

Abstract: In the background of global climate change, the effect of drought on ecosystem structure and function has been paid more and more attention to. In this paper, for the purpose of presenting approaches to elucidate the mechanism of drought effects on ecosystem processes, we reviewed the effects of drought on carbon/water processes at individual level and community level. At the individual level, drought can make plant change its physiological and morphological traits to conserve water, such as decreasing stomata conductance, increasing solute content, changing stomata density and size, increasing specific leaf area and belowground biomass allocation, etc. In addition, different plants have different water-use strategies. Their physiological and morphological traits responding to drought are apparently distinct. At the community level, similarly, drought can change vegetations physiology and structure, such as photosynthesis, respiration, transpiration, water use efficiency, biodiversity, productivity et al. Despite that most aspects of drought effects on ecosystem are included in current studies, they are isolated from each other. To fully understand how ecosystem responds to drought, it is essential to combine all methods available, to synthetically study the processes coupling with each other (e.g. carbon cycle, water cycle and nitrogen cycle), and to construct a theoretical system to connect different time scales ( from minute to decade) and levels (from leaf to ecosystem).

Key words: global climate change; water cycle; carbon cycle; water use efficiency; water stress

A Realism Scenario Analysis of Land-use Change at a Local Level

WANG Cheng1, WEI Chaofu1,　SHAO Jingan1,　LI yangbing2, JIANG Wei3
(1. College of Resource and Environment, Southwest University, Chongqing 400716, China；
2. Institute of Geographic Science and Natural Resource Research, CSA, Beijing 10010, China;
3. School of Geographic and Biologic Sciences, Guizhou Normal University, Guiyang 550001, China；
4. Land Surveying and Planning Academy, Chongqing 400020, China)

Abstract: Land-use change represents an implication of short-scheduling, better spatial orientation and anthropogenic compelling disturbance at the local level. Its processes and results are the most efficient approach for regional-level responses and national-and global-level feedbacks. Urbanization, agrarian structure transformation and land arrangement are presently the driving forces resulting in land-use change at the local level in China. Urbanization is an irreversible process. This process will result in the transformation from county’s landscape to city’s landscapes, accelerate the change of the characters of underlying surfaces such as surface albedoes and surface roughness, and in crease varieties of the habitat types and species diversities. Consequently, a new patterns of human homogenized landscape will be formed at the local level. Farmer’s microcosmic choices of land-use styles are a kind of motility, which results in agrarian structure transformation. The differences in farmer’s investment, production and management will lead to the changes of soil quality and environment. Land arrangement is a complex systematic engineering. Its implementation will change the local landscape structure, soil quality and hydrological process. Moreover, these results will influence correspondingly local ecologic environment. Thus, in order to profoundly understand local land use change, conceiving the theoretic frames of “human-land harmonious system”, simulating land use change and evaluating ecologic benefit of land-use change will be the orientation of future research in land-use change at the local level.

Key words: land-use change; realistic scenario; at the local level; prospect

Issue No.5

The Study on Pattern of International Trade Geography

YU Liang1,2, JIN Fengjun1, WANG Chengjin1,2
（1. Institute of Geographic Sciences and Natural Resources Research， Beijing 100101, China;
2. Graduate School of Chinese Academy of Sciences, Beijing 100039, China）

Abstract：This study reviews the related researches about the international trade flow and globalization. With the main merchandise trade data of one hundred and three countries in year 2002, the paper researches on global and regional patterns of international trade flow and clusters with principal components analysis and primary export destiny analysis. In addition, the hierarchy of multi-layers, including core nations and trade clusters, is specially pointed out. The first-class cores are United States and Europe Union; the second-class cores are China and Japan; and the third-class cores include Russian, Korea, India, Brazil, Singapore and Saudi Arabia. The compositions of trade clusters represent the effects of several factors, such as geography, culture, economy and politics. The trade system of China Bloc is a classical system of double stars with two cores: China mainland and China Hongkong. China Hongkong plays a quite important transfer role in the trade network of China. China Taiwan area doesn’t have a corresponding important status with its competitive economic capability. And a few predictions are also given on the trend of world merchandise trade system.
Key words: trade flow; cluster; pattern; globalization

Research on Evolution Process and Driving Factors
of Forest Landscape in Nujiang Basin

ZOU Xiuping1,2, QI Qingwen2, JIANG Lili2, LI Jin3
（1. Institute of Policy and Management, CAS, Beijing 100080, China；
2. Institute of Geographical Sciences and Natural Resources Research, CAS, Beijing 100101,China;
3. National Marine Data and Information Service, Tianjin 300171, China）

Abstract: Forest ecosystem, the main terrene ecosystem, plays a key role in balancing the carbon budget and keeping the water and soil in global climate change. Nujiang basin, located in Yunnan Province in southwestern China, is the main passageway and refuge for migrating species in Eurasia and is famed for its rich biodiversity. The data used in this paper is 1∶100000 scale land use and land cover maps in 1985, 1995 and 2000, which are provided by Resource and Environment Database of Chinese Academy of Science. According to natural attributes, the forest was classified to four kinds, which are forestland, shrubbery, woodland, and orchard. By using spatial intersect analysis of ARCGIS 9.0, the index of relative change degree of forest land and transition matrix of forestland change type was calculated.
The researches found out: the forestland landscapes of Nujiang basin have taken great changes. The rate of forest decrease during 1995 to 2000 was much more than the rate of forest increase during 1985 to 1995, and there were 35.6% forest land which had transferred into cultivated land, glass land and construction land. Further analysis shows that the forestland change in Nujiang basin is restricted by social economy factor.

Key words: forestland; landscape change; driving forces; Nujiang basin

Cultivated-land Transition and Land Consolidation and Reclamation in China: Research Progress and Frame

LONG Hualou, LI Xiubin
( Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China)

Abstract: Land use transition is a new integrated approach of land-use and land-cover change (LUCC) study. Land use transition is also one of the major research contents of Global Land Project (GLP), a joint research agenda of the International Geosphere-Biosphere Programme (IGBP) and the International Human Dimensions Programme on Global Environmental Change (IHDP) to improve the understanding of land system dynamics. This paper develops a research frame for cultivated-land transition and land consolidation and reclamation in China, after reviewing the research on land use transition, the theories and models of land-change science, cultivated-land change and land consolidation and reclamation. The frame may include: (1) analyzing the spatial pattern of cultivated-land change in China; (2) understanding the influential factors of cultivated-land transition trajectory; (3) putting forward the theoretical hypothesis on cultivated-land transition; (4) modeling the spatio-temporal changes of cultivated land in China and defining the regional types of cultivated-land transition and the phases where they are in; and (5) providing theoretical and scientific basis for land consolidation and reclamation, an important way to conserve cultivated land in China.

Key words: land use transition; land-change science; cultivated land; land consolidation and
reclamation; China

Research on the Characters of Space and Time of Marine
Economic Areal System in China

ZHANG Yaoguang，LIU Kai，WANG Shengyun
(Research Center for Marine Economy and Sustainable Development of
Liaoning Normal University, Dalian, 116029)

Abstracts: The research on marine economic area system is the most important part in man-earth relationship area system in China. This paper discussed the characters of marine economic area system from the point of man-earth relationship area system. Firstly the paper analyzed the marine resources, marine industry and the development process of China. Then the author analyzed the developing condition of marine economy based on space and time changing. What’s more, this paper evaluated comprehensive strength of marine economy over years by using some econometric methods such as principal component analysis, and drew the smooth curves between the total value of marine economy and marine industries, which gave the linear trend of the increase of marine industries. According to the development of marine industries, the author analyzed the character of marine industries and drew a tri-axial map to analyze the developing process of marine industry. At last, in order to reflect the differences between different area systems of Chinese marine economy, the author used the method of principal component analysis to give an evaluation and classification of comprehensive strength of coastal province and cities. Based on this result, some marine economic regions are classified according to the comprehensive strength.

Key words: man-earth relationship ; man-ocean relationship; marine resources; marine
industries; marine economic areal system

Main Progress and Prospects of Land Resource
Ecological Security Research

ZHANG Hongbo, LIU Liming
(Department of Land Resource Management， Institute of Resource and Environment，
China Agricultural University， Beijing 100094）

Abstract：Ecological security is critical to sustainable development of human society, which includes resource security, biological security, environmental security and etc. And land resource ecological security is an important aspect of resources security. However， the ecological problems of land resource are increasingly serious in such terms as soil erosion, land pollution and desertification, which are threatening regional eco-security and sustainable development. Therefore, the research of land resource ecological security has become the forefront topic in the field of sustainable utilization of land resource. This article interpreted the concept of land resource ecological security firstly, and then summarized the main progress and achievements in land ecological security research, which include the relationship between land resource ecological security and land use/land cover changes, assessment of land resource eco-security and design of land resource eco-security. Finally this article put forward that special attention should be paid to following aspects in the future study of land resource eco-security. Firstly, there is an tendency to integration of the research on mechanism of land resource eco-security, land ecological security assessment and land resource eco-security design. Secondly, study of land eco-security assessment method as well as determination of the threshold of land resource eco-security index should be further discussed. And finally, construction of land use security pattern is still an exploratory work.

Key words： land resource；ecological security；sustainable development

Applications of SWAT model in Zhang Wei River Basin

ZHU Xinjun1， WANG Zhonggen2， LI Jianxin1， YU Lei1， WANG Jingui1
(1. Haihe River Commission，Ministry of Water Resources， Tianjin, 300181 China;
2. Key Laboratory of Water Cycle and Related land Surface Processes， IGSNRR， CAS, Beijing 100101,China)

Abstract: Zhang Wei River Basin lies on the south of Hai River Basin， and it is one of the typical areas in north china that experiencing water shortage and water environment deterioration. Based on SWAT (Soil and Water Assessment Tool)， Zhang Wei River Basin distributed hydrological model is established. Based on DEM(100m×100m) ， considering location of hydrologic stations and four Large reservoirs， Zhang Wei River Basin was delineated into 74 sub basins and 940 Hydrological Response Unit(HRU). Topographic characteristics of each sub basin including slop and river networks are extracted automatically from DEM. The basic data including DEM， soil data， rainfall， weather data， land use and reservoir out flow data of Zhang Wei River Basin are collected and processed for the model. The soil and land use data are reclassified for the model and the soil physical properties database is created. The distributed hydro-process is simulated by using the hydro meteorological data from 2000 to 2004. SWAT model is calibrated with observed data from six principal hydrologic stations in Zhang Wei River Basin and the important parameters sensitivity is analyzed and the laws that changing some important parameters how to affect model results are discovered. The reliability of the SWAT model is validated by comparing the model outputs with Water Resource Reports. The mean relative error is less than 10%. The study results in this paper make a good demonstration for applying SWAT model in China， and lay a good foundation for establishment of whole Hai River basin distributed hydrological model.

Key words: SWAT model; Zhang Wei River Basin; parameter calibration; sensitivity analysis

A Conceptual Analysis of Karst Ecosystem Fragility

LI Yangbing1,5, SHAO Jingan2, WANG Shijie3, WEI Chaofu4
(1. School of Geography and Biology Science, Guizhou Normal University, Guiyang 550001, China;
2. Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China;
3. National key laboratory of environmental geochemistry, geochemistry institute of Chinese Academy of Science, Guiyang 550002, China; 4. Resources and Environment College, Southwest University, Chongqing 400716;
5. Geography Science Institute of Chongqing Normal University, Chongqing 400047, China )

Abstract: Assessing the fragility of ecosystem has an important role to sustainable ecosystem management. Karst environments, unique from other environments, is one kind of typical fragile ecosystem and key eco-region in China. Based on a critical review of current research about karst ecohydrological processes, soil fragility, vegetation characteristics, and the reciprocity of water, soil and plant in karst ecosystem, we developed an indicator system for assessing the fragility of degraded karst ecosystems, which including ecological structure fragility, ecological processes fragility, ecological function fragility and artificial menace fragility of karst ecosystem.. Therefore, the evaluation indicator should explain the change and diversity of ecological structure, ecological process and ecological function. According to this principle, some index such as structure stability, diversity of microhabitat type, energy utility and accumulation, direct use value, the degree and speed of karst rocky desertification was chosen. Furthermore, the fragility of degraded karst ecosystems was divided into four levels by this assessment system as follows: slight fragility, medium fragility, severe fragility and ecosystem collapse compared with the ecological baseline of undisturbed karst nature ecosystem.
Key words: karst; ecosystem, fragility; assessment

Progress and Prospect of study on Socio-culture
Impact of Tourism on Destination Area

XIE Ting1,2, ZHONG Linsheng1, CHEN Tian1，YUAN Hong1,2
(1. Institute of Geography Sciences and Resources Research, CAS, Beijing 100101 China;
2. Graduate School of the Chinese Academy of Sciences，Beijing 100049 China)
　　
Abstract: The substantial growth in tourism during the past few decades and projected growth in future decades have been widely documented. The tourist destination changed greatly with the development of tourism and the transformation of society, which can be found in every aspect of the social life in the destination. Since the 1970s, the socio-cultural impacts of tourism have appeared in more and more studies. And being a hot topic, it is still being discussed in recently years. Integrating the views of anthropology in this field, this paper summarized the domestic and international research progress in theories, perspectives, methods, practices and models of the socio-cultural impacts of tourism, in which tourism is perceived to contribute to changes in value systems, individual behavior, resident attitude and perceive, collective lifestyles, moral conduct, traditional ceremonies, and community organizations. Finally, the author pointed out the weak sides of the current studies, and the main research directions in the future are given. Studies show that the main problems include: the scholars generally paid much more attention to case study than theory building; the study emphasized quality over quantity; some studies focused too much on the negative impact of tourism, neglecting the positive side; and there was shortage of a normative index system, resulting in weak comparability within studies. The future main directions are as follows: to tightly combine the needs of actual tourism development and management with academic studies; to complete the theory building and technical method improving; to merge multiple disciplinaries; and so on.

Key words: tourism impacts; socio-culture; research progress

Countermeasures on Adjustment of Regional Industry Structures Under Climatic Drying Change——A Case Study of Yulin City

LIU Xiaoqiong1,2, LIU Yansui2
(1. College of Tourism and Environment, Shaanxi Normal University, Xi’an 710062, China；
2. Institute of Geographic Sciences and Natural Resources Research， CAS， Beijing, 100101, China)

Abstracts: Yulin city is an important national base of heavy-chemical engineering, and an extremely vulnerable area as well. Based on the analysis of annual and seasonal climatic change in Yulin city by using climatic data during 1974~2004 years, the author finds that the climate in Yulin city is becoming more warm and droughty, the annual temperature increased at 0.0438℃/a, and annual precipitation decreased at 0.678mm/a. Climatic drying changes intimidate the industrial development badly. Thus how to realize the sustainable resources exploration, and to ensure sustainable development in this base of heavy-chemical engineering around the leading factor－－water resource, is critical for the development in this base and national energy safety. Hereby, the author puts forward some harmonious countermeasures doing well to agricultural development and resources exploration based on the analysis of the regional climatic change and the various problems with regional industrial sustainable development. The main countermeasures are as the following: (1) to transform the agricultural polices of government should enhance the level of regional labor force by generalizing all kinds of agricultural technologies, carrying out new strategy such as self-support in foodstuff, preferential stock raising development; (2) the commercial base of regional agriculture must be offer food safeguard，consolidating the basic status of agriculture, and developing the second and third industry in county level, forcing the capacity of agriculture to resist climatic change; (3) for energy industry, the critical factor --water resource should be reasonably utilized and protected in order to realize the harmonious development of regional eco-economy by neatening small factory and reducing the water consumption of production in the future.
Key words: climatic drying change; resources exploration; industrial development; harmonious
countermeasures; Yulin city

Analysis Basic Situation of China’s Energy Security
　　　　　　　　　　　　　　
CAI Guotian1,2, ZHANG Lei1
（1. Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China;
2. Graduate School of Chinese Academy of Sciences, Beijing 100039, China)
Abstract: As one of the largest energy consumers and producers in the world, China has faced great challenge in energy security on the way of modernizing itself. Energy security mainly includes reliable energy provision and safe energy use. Reliable energy provision cares about whether a country’s energy supply could meet its demand for population and economic development. Safe energy use tells us that we should reject the pattern of energy use at the cost of polluting environment.
　　The paper analyzes the situation of China’s energy security based on the analysis of energy resource base, balance between energy production and consumption, energy transportation and side effect of energy consumption. Owing to the pressure of economic development, China has placed much more emphasis on the security of energy provision than safe energy use, though it realized the importance of the latter in the past years. While it built its energy provision system, it polluted the environment greatly at the same time in such ways as lots of CO2 emissions, which contribute to the global warming, and the sinking of the earth's surface caused by coal mining. So it is time to rethink the goal of energy security.
Energy security, as a determinant factor to the modern society, will become an increasingly sensitive issue in China when the country makes great strides in modernizing itself; and it could become even more sensitive in the next twenty to thirty years when China’s population growth and economic development imposes more pressure on the national energy supply system continuingly. Based on the basic situation of China’s energy security, this paper suggests that a new energy policy, including reliable energy provision and safe energy use, be needed for China’s sustainable development in the future.

Key words: energy security; energy resource base; energy production and consumption;
energy transportation

Landscape Assessment on Impacts of the Hydroelectric
Development in the Valley Region
——Case Study of Nujiang River

LIU　Hailong1,2， Li Dihua2， Huang Gang2,3
（1 Department of Landscape Architecture, Tsinghua University, 100084;
2 Graduate School of Landscape Architecture, Peking University, 100871;
3 Urban Construction Agency, High-Tech Development Area of Chengdu, 610041）

Abstract：The understanding of hydroelectric construction is becoming comprehensive from eco-environmental and socio-economic perspectives. Positive influences occur on one hand and negative on the other hand. Hydroelectric development can cause great changes to valley landscape but landscape assessment on its impacts is weak in past studies. Many arguments have emerged concerning the planned 13 multilevel hydroelectric constructions in Nujiang River of China, called “the last natural big river in China without dams”. These arguments have had impacts not only on the environment issues but also on the landscape ones, thus becoming extremely important. After briefly summarizing the significance and relative concepts of landscape impact assessment, this paper explores theories and methods at this point and designs a series of landscape impact assessment parameters such as the View Shed Loss, the Visual Disturbance Scope of dams, the Altitude Loss, the Sight Spots Loss and the Rush Flow Loss. Based on the concept of different levels of landscape impact of Nujiang River Valley, this paper classifies the landscape impacts into holistic and partial types, then utilizes GIS simulation and calculation of parameters to analyze alterations before and after the rising of water level for the whole valley and individual sites, and demonstrates the suitability of each dam site. Finally, this paper indicates that the hydroelectric power development in valley region such as Nujiang River should be especially circumspect, its decision-making should be based on comprehensive environmental impact assessment in which landscape assessment is included, and rigorous legislation also should be established gradually.

Key words: valley region; hydroelectric development; dams; landscape impact assessment;
the Nujiang River

Principles and Systems of Landscape
Ecological Regionalization

LI Zhengguo1, WANG Yanglin1,2, Chang Hsiaofei2, WU Jiansheng1,2
(1. College of Environmental Sciences, Peking University, Beijing 100871, China
2. Graduate School of Shenzhen, Peking University, Shenzhen 518055, China)

Abstract: Landscape ecological system is composed of ordered horizontal levels. The relationships of landscape structures and functions are distinct in different temporal and spatial scales, and it is useful to integrate hierarchy and components of landscape by regionalization concept. In this paper, the background and concept of the delineation of ecosystems were advanced. The principle of landscape heterogeneity on which the delineation is operated was also addressed. It was pointed out that the change from a framework based on a single natural indicator to another based on the integrated ecosystem approach reflects the progress in the understanding of human-nature reconciliation and the balance between biodiversity conversation and sustainable use of natural resources. On the basis of ecosystem integrity, a framework for the landscape ecological regionalization systems was recommitted, which followed the principles of hierarchy, multi-scale, origin-coherence, interdependence between landscape pattern and function, interaction among landscape functions and integrality of delineation units.
　　Under these principles, the main scientific issues to be discussed were as follows: (1) the theory and system of comprehensive regionalization; (2) the changing processes, patterns and their interactions of the main elements in regional system; (3) the identification of the boundaries between the regional systems; and(4) the construction of the organizational levels of the system. Then, the differences and relationships among the landscape ecological regionalization and the natural regionalization, economical regionalization and the ecological regionalization were given. Finally, the paper assumed the application of landscape ecological regionalization theory in national, regional and watershed levels.

Key words: landscape ecological regionalization; landscape heterogeneity; landscape function

The Characteristics of Landscape Patterns in
Karst Area of Chongqing, China

SHAO Jing’an1,2, LI Yangbing3, WEI Chaofu2, XIE Deti2
(1. Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101;
2. College of Resource and Environment, Southwest University, Chongqing 400716;
3. School of Geography and Biology Science, Guizhou Normal University, Guiyang, 550001)

Abstract: There is an even poorer understanding of the characteristics of landscape in southwestern karst area, China, particularly in Chongqing. The objective of this paper was to measure the framework of landscape patterns in karst area of Chongqing, and to determine the factors to drive the changes in landscape patterns. The results showed that landscape types presented unevenness tendencies, and several dominated preferably. Landscape mosaic patches had complex geological shape, lower isolation, unobvious fragment, and fragmentation. And further their spatial heterogeneities were much lower. The value of landscape diversity all distributed at average position of maximum landscape diversity 2.81 in each karst subarea of Chongqing. Similarly, one or several landscape types controlled landscape patterns of each subarea. Disturbance index and relative richness were the increasing tendencies associating with the decrease of landform along the rank of I, II and III, while the reverse results occurred in heterogeneity, unevenness and dominance. There was significantly difference between fractal dimensions, and higher fluctuation between shape indexes in each subarea. Thus, the geological shape among different landscape mosaic patches was very complex, and the differences between them were very pronounced. The density and isolation of landscape mosaic patches increased along the rank of I, II and III, while the contrary results were detected in cropland, orchard land and residential and mining land. Except for water body with 63.03 edge density in III, the rest all ranged from 1.82 to 9.14. Similar landscape characteristics were observed between I and II, but the obvious differences were witnessed, when they compared with that of III. In karst area, internal geological function, under the big environmental background, controls the basic trends and processes of landscape patterns, while external dynamics, at short-term spatial-temporal scale, has become a major force in shaping the environment. This study will be useful to supply fine ground and knowledge for establishing appropriate landscape practices and evaluating ecological security in karst area.

Key words: landscape patterns; environmental heterogeneity; drivers; karst area; Chongqing

Emergy Evaluation of Miyun County as the Area
of Watershed Conservation for Beijing

ZHOU Liandi1, HU Yanxia1, YAN Maochao2,3, DONG Xiaobin4，
WU Zhiqiang5， WEI Changshan5
(1. Institute for Studies of Comprehensive Development, Beijing Academy of Agiculture & Forestry, 100089;
2. College of Agronomy and Biotechnology, China Agricultural University,100094; 3. Institute of Geographical Science and Natural Resource Researches, CAS, Beijing 100101; 4. Institute of Resource, Beijing Normal University, Beijing 100875; 5. Scientific Committee of Miyun County in Beijing，101500)

Abstract: As economies and ecological support system become more interdependent, new disciplines are needed to “bridge the gap” of understanding between societies and nature. It is now clear that neither ecology nor economics alone can address the problems of our global commons. New measures of wealth, of value, of contributions and production are needed that acknowledge the "natural capital" and "ecosystem services" provided from healthy environments. In order to study and view eco-economic system from a new visual angle, new tools are being invested to measure wealth, services and production fairly and equitably. Systems analysis approach is powerful to study the combined eco-economic systems of many scales. Diagramming is done with energy system symbols. The symbols each have rigorous energetic and mathematical meanings. We use an alternative measure of value, based on real contributions to system performance, termed "emergy". It is a concept which quantifies “energy memory” in products and processes. It is a new accounting unit of total contributions, direct and indirect, used in generation of a product or service. This broader approach could help us to investigate resource utilization and potentionalities and exchange in eco-conomic systems. Emergy analysis allows comparison and incorporation of environmental costs and benefits to provide a more comprehensive perspective for public policy directives. An emergy analysis of Miyun system of economy and nature was performed in order to study its sustainability and emergy use. Indices of thermodynamic and economic vitality of Miyun were evaluated and a comparison with indices of other developed and developing areas was performed. The results show that in Miyun County the total emergy use in 2003 was 2.49×1021sej, which was worth of 6.55 ×108US$, and the emergy-dollar ratio was 2.99×1012sej /$， lower than the average emergy-dollar ratio of China. The emergy use per capita is 5.885.88×1015 sej/person/a, much lower than that of Beijing(17.89×1015sej/person/a). The developed carrying capacity of population is about 51×104 persons. At present, the population reaches 42×104, so it is important to make right policies to control population. The emergy-based sustainability index was 0.52, which means the economic increase is based on large resource consumption, so enhancing the resource utilization efficiency and establishing rational industry structures are very important for sustainable development in future.

Key words: emergy evaluation; eco-economic system; policies and suggestions; Miyun county