Degradation of Soil Properties due to Erosion on Sloping Land in Southern Jiangsu Province,China

Soil erosion accelerates soil degradation. Some natural soils and cultivated soils on sloping land in southern Jiangsu Province, China were chosen to study soil degradation associated with erosion. Soil erosion intensity was investigated using the 137Cs tracer method. Soil particle-size distribution, soil organic matter (OM), total nitrogen (TN) and total phosphorus (TP) were measured, and the effects of erosion on soil physical and chemical properties were analyzed statistically using SYSTAT8.0. Results indicated that erosion intensity of cultivated soils was greater than that of the natural soils, suggesting that cultivation increased soil loss. Erosion also led to an increase of coarser soil particle proportion, especially in natural soils. In addition, silt was the primary soil particle lost due to erosion. However, in cultivated fields, coarser soil particles over time were attributed not only to soil erosion but also to mechanical eluviation as a result of farming activities. Moreover, erosion caused a decrease in soil OM, TN and TP as well as thinning of the soil layer.

A New Fusion Technique of Remote Sensing Images for Land Use/Cover

In China,accelerating industrialization and urbanization following high-speed economic development and population increases have greatly impacted land use/cover changes,making it imperative to obtain accurate and up to date information on changes so as to evaluate their environmental effects. The major purpose of this study was to develop a new method to fuse lower spatial resolution multispectral satellite images with higher spatial resolution panchromatic ones to assist in land use/cover mapping. An algorithm of a new fusion method known as edge enhancement intensity modulation (EEIM) was proposed to merge two optical image data sets of different spectral ranges. The results showed that the EEIM image was quite similar in color to lower resolution multispectral images,and the fused product was better able to preserve spectral information. Thus,compared to conventional approaches,the spectral distortion of the fused images was markedly reduced. Therefore,the EEIM fusion method could be utilized to fuse remote sensing data from the same or different sensors,including TM images and SPOT5 panchromatic images,providing high quality land use/cover images.

Satellite remote sensing for urban growth assessment in Shaoxing City, Zhejiang Province

Urban growth represents specific response to economic, demographic and environmental conditions. Rapid urbanization and industrializations have resulted in sharp land cover changes. The present investigation was carried out from Shaoxing City to quantify satellite-derived estimates of urban growth using a three-epoch time series Landsat TM data for the years 1984, 1997 and ETM 2000. The methodology used was based on post classification comparison. The use of GIS allowed spatial analysis of the data derived from remotely sensed images. Results showed that the built-up area surrounding Shaoxing City has expanded at an annual average of 7 km2. Analysis of the classified map showed that the physical growth of urban area is upsetting the other land cover classes such as farming, water resources, etc. The study conclusion mainly emphasized the need for sustainable urban capacity.

ENVIRONMENTAL CHANGE AND ITS IMPACTS ON HUMAN SETTLEMENT IN THE CHANGJIANG RIVER DELTA IN NEOLITHIC AGE

Dating data, altitude of Neolithic sites, climatic changes from sedimentary records and previous research results were collected and analyzed to detect possible connections between climatic changes and human activities in the Changjiang River Delta in the Neolithic Age. The results indicated that hydrological changes greatly impacted the human activities in the study region. Low-lying geomorphology made the floods and sea level changes become the important factors affecting human activities, especially the altitude change of human settlements. People usually moved to higher places during the periods characterized by high sea level and frequent floods to escape the negative influences from water body expansion, which resulted in cultural hiatus in certain profiles. However, some higher-altitude settlements were not the results of climatic changes but the results of social factors, such as religious ceremony and social status. Therefore, further research will be necessary for the degree and types of impacts of climatic changes on human activities in the study area at that time.

SPATIAL-TEMPORAL DYNAMICS OF REGIONAL CONVERGENCE AT COUNTY LEVEL IN JIANGSU

The dynamics of regional convergence include spatial and temporal dimensions. Spatial Markov chain can be used to explore how regions evolve by considering both individual regions and their geographic neighbors. Based on per capita GDP data set of 77 counties from 1978 to 2000, this paper attempts to investigate the spatial-temporal dynamics of regional convergence in Jiangsu. First, traditional Markov matrix for five per capita GDP classes is constructed for later comparison. Moreover, each region’s spatial lag is derived by averaging all its neighbors’ per capita GDP data. Conditioning on per capita GDP class of its spatial lag at the beginning of each year, spatial Markov transition probabilities of each region are calculated accordingly. Quantitatively, for a poor region, the probability of moving upward is 3.3% if it is surrounded by its poor neighbors, and even increases to 18.4% if it is surrounded by its rich neighbors, but it goes down to 6.2% on average if ignoring regional context. For a rich region, the probability of moving down ward is 1.2% if it is surrounded by its rich neighbors, but increases to 3.0% if it is surrounded by its poor neighbors, and averages 1.5% irrespective of regional context. Spatial analysis of regional GDP class transitions indicates those 10 upward moves of both regions and their neighbors are unexceptionally located in the southern Jiangsu, while downward moves of regions or their neighbors are almost in the northern Jiangsu. These empirical results provide a spatial explanation to the "convergence clubs" detected by traditional Markov chain.

Analysis and assessment of land desertification in Xinjiang based on RS and GIS

The land desertification in Xinjiang was monitored and analyzed based on RS and GIS techniques. Satellite data interpretation was adopted to obtain the general situation of Xinjiang’s land desertification in assistance with the sampling method and on-the-spot investigations. Related monitoring and investigations showed that Xinjiang was facing with severe wide range land desertification, and its desertified area made up 77.08% of the total monitoring area. As for land types, the desertified farmland accounted for 1.92% of the total monitoring area, desertified woodland 4%, desertified grassland 45%, and unused land 49%. Accordingly, as for desertification degrees, non-desertified land occupied 22.92%, weak desertified land 5.69%, medium-degree desertified land 16.58%, severe desertified land 33.19% and super severe desertified land 21.61%. Finally, as for inducing factors, wind-eroded desertification made up 58.23%, water-eroded desertification 8.69%, salinization desertification 6.52% and frozen-melt eroded desertification 3.64%. Xinjiang’s land desertification tended to get worse and the harnessing mission remained hard.

SOIL EROSION AND ITS IMPACTS ON ENVIRONMENT IN YIXING TEA PLANTATION OF JIANGSU PROVINCE

Soil erosion on sloping field has led to a lot of environmental prob lems. In order to reveal the seriousness of the damage of soil erosion on slopin g fields 137Cs tracer method was used to estimate soil erosion rate. 137Cs refer ence inventory of 2200Bq/m2 in Yixing, southern Jiangsu Province, was estimated and a model for estimating erosion of cultivated soil was established in order t o avoid overestimating soil erosion rates. Then based on the soil erosion rates and measured soil physical and chemical properties, direct and indirect impacts of soil erosion on environment were further discussed. Direct impacts of erosion on environment included on-site and off-site impacts. The on-site impacts we re that soil layer became thin, soil structure was deteriorated and soil nutrien ts decreased. The off-site impacts were that water bodies were polluted. The in direct impacts of soil erosion on environment were the increase of fertilizer ap plication and energy consumption, and change of adaptability of land uses. Altho ugh erosion intensity was not serious in the study area, its environmental impac ts should not be ignored because of great soil nutrient loss and coarseness of s oil particles.

PRELIMINARY STUDY ON THE FLOODING AND DROUGHT CLAMITY DURING PAST 1500 YEARS IN THE HAI′AN REGION，JIANGSU PROVINCE

Collection and arrangement of the historical records of climatic changes and environment evolution,espectial-lyin the aspect of calamities,are made on the history documents of past 1500 years about Haiˊan region,Jiangsu Province.There existed two obvious flooding-drought frequently-occurring periods:one was from 1550 AD to 1850 AD and another was 100 AD to 1200AD.The period of 1550 AD to1850 AD is interrupted by two relatively arid and cold climatic periods:one was from 1630 AD to 1700 AD and another was 1750 AD to 1820 AD.The main characteristic of the calamity periods is that they occurred by turns,and sometimes,both drought and flooding occurred in the same year.The instability of the climatic changes in the Little Ice Age may be the main reason of the frequently-occurring flooding and drought in Haiˊan region.Research results also show that the frequently-occurring periods of flooding and drought is in close relationship with the solar activity,and therefore,occurrence of the flooding and drought may be in relation with the intensity of the solar activity.This hypothesis may need further study in the future.

ESTIMATE OF METHANE EMISSIONS FROM RICE FIELDS IN CHINA BY CLIMATE-BASED NET PRIMARY PRODUCTIVITY

Rice fields provide food for over half of the world population but are also an important source of atmospheric CH4. Using the climate-based GIS empirical model and the meteorological data collected from 600 meteorological stations in China, with county as the basic unit, the net primary productivity (NPP) of rice fields in China in 1990, 1995, 1998, and 2000 were estimated to be in the range from 202.19×1012g C in 1990 to 163.46×1012g C in 2000. From the measured data of the factors affecting CH4 emission and NPP, the conversion ratio of the NPP into CH4 emission for the rice fields of China was determined to be 1.8%. Using this ratio and estimated NPP, the CH4 emissions from rice fields of China in 1990, 1995, 1998, and 2000 were estimated to be 7.24×1012, 6.31×1012, 6.77×1012 and 5.85×1012g CH4, respectively.

AN ILLUSTRATIVE STUDY ON LOCAL LANDSCAPE AND ITS LONG-TERM CHANGES BASED ON IKONOS AND HISTORICAL AERIAL PHOTO

Nowadays, the research works on landscape at fine scales using high-resolution images are uncommon.This research is based on the analysis of the combination of remote sensing data (IKONOS imagery acquired in 2002and historical aerial photo taken in 1942). In the paper, the ecotopes in Qiujiadou and Xishao villages in Yixing City of Jiangsu Province in 1942 and 2002 were compared and landscape changes as well as the causes of the considerable changes were analyzed. It was found that the ecotope changes were at greater level in some aspects such as water surface and perennial vegetation coverage etc. This study at fine scale is globally significant for the rural areas, especially for the subsistence agricultural land, which occupies larger percentage in the earth. And it analyzes the structure of landscape based on a new landscape classification system-stratifications method.

RS AND GIS-BASED FOREST FIRE RISK ZONE MAPPING IN DA HINGGAN MOUNTAINS

The Da Hinggan Mountains is one of the most important forest areas in China, but forest fire there is also of high frequency. So it is completely necessary to map forest fire risk zones in order to effectively manage and protect the forest resources. Two forest farms of Tuqiang Forest Bureau (53°34′-52°15′N,124°05′-122°18′E) were chosen as typical areas in this study. Remote sensing (RS) and Geographic Information System (GIS) play a vital role and can be used effectively to obtain and combine different forest-fire-causing factors for demarcating the forest fire risk zone map. Forest fire risk zones were described by assigning subjective weights to the classes of all the coverage layers according to their sensitivity to fire, using the ARC/INFO GIS software. Four classes of forest fire risk ranging from low to extremely high were generated automatically in ARC/INFO. The results showed that about 60.33% of the study area were predicted to be upper moderate risk zones, indicating that the forest fire management task in this area is super onerous. The RS and GIS-based forest fire risk model of the study area was found to be highly compatible with the actual fire-affected sites in 1987. Therefore the forest fire risk zone map can be used for guidance of forest fire management, and as basis for fire prevention strategies.

KARST ENVIRONMENT AND ECO-POVERTY IN SOUTH-WESTERN CHINA:A CASE STUDY OF GUIZHOU PROVINCE

Guizhou Province is one of the least developed areas with the largest number of counties in poverty and the widest coverage of karst landscape in China. The vulnerability of its karst eco-environment seriously threatens the survival of local residents and the development of local economy. Rapid population growth results in higher demand of various resources, which leads to more intensive development activities. For example, the blindfolded development on steep slopes has caused rock desertification of local rare soil in this karst area. It has induced a vicious circle in the poverty→population growth→ecosystem degradation and so on. About 3.13×106 people belong to the absolute impoverished population in Guizhou Province and most of them are living in rock-desertification areas. The essential reasons for destitution are the atrocious eco-environment and the huge population stress. Degradation of mountain ecosystems in southwestern China has continued at unprecedented speed and scale in recent decades. It is necessary to control population growth strictly and prevent further expansion of rock-desertification in order to develop local economy and better living conditions for local people. The only way to ensure a sustainable, stable and harmonious development of human, nature and economy is to restore a good condition of eco-environment and resolve the conflicts between human and land use.

LAND-COVER DENSITY-BASED APPROACH TO URBAN LAND USE MAPPING USING HIGH-RESOLUTION IMAGERY

Nowadays, remote sensing imagery, especially with its high spatial resolution, has become an indispensable tool to provide timely up-gradation of urban land use and land cover information, which is a prerequisite for proper urban planning and management. The possible method described in the present paper to obtain urban land use types is based on the principle that land use can be derived from the land cover existing in a neighborhood. Here, moving window is used to represent the spatial pattern of land cover within a neighborhood and seven window sizes (61m×61m, 68m×68m, 75m×75m, 87m×87m, 99m×99m, 110m×110m and 121m×121m) are applied to determining the most proper window size. Then, the unsupervised method of ISODATA is employed to classify the layered land cover density maps obtained by the moving window. The results of accuracy evaluation show that the window size of 99m×99m is proper to infer urban land use categories and the proposed method has produced a land use map with a total accuracy of 85%.

MEASUREMENT OF AGGLOMERATION ECONOMIES AT COUNTY LEVEL IN JIANGSU PROVINCE

Agglomeration economies are the important factors for the regional development. However, the common indicators to measure them, such as Gini Coefficients neglect the spatial ingredient of data, leading to a-spatial estimates. In order to assess spatial neighbor effects of agglomeration economies, this study makes the new attempts by applying a series of techniques of spatial autocorrelation analysis, specifically, measuring the economies of urbanization and localization at the county level in the secondary and tertiary industries of Jiangsu Province in 1999 and 2002. The conclusions in this study reveal that on the whole, the localization effects on the economies of the secondary industry might be stronger than urbanization effects for that period, and highly agglomerative economies were limited within the southern Jiangsu and parts of middle along the Changjiang (Yangtze) River. Moreover, the tertiary industry has been strong urbanization rather than localization economies in the whole Jiangsu. Unlike the secondary industry, the tertiary industry held the high levels of agglomeration economies can be also found in the poor northern Jiangsu, and then the spatial clusters of trade and services might be basically seen in each of urban districts in 13 cities. All in all, spatial autocorrelation analysis is a better method to test agglomeration economies.

APPROACH OF DETERMINISTIC GEOMORPH OLOGIC INSTANTANEOUS UNIT HYDROGRAPH TO HYDROLOGICAL PROCESSES' SIMULATION IN KARST AREA

In order to analyze the condition of s pecial landform and regularity of sp ecial hydrological movement in karst area,the method of Geomorphologic Instantaneous Unit Hydrograph(GIUH)has been used to divide the river net-works into three grades in the research area and the karst hydrologic processes were simulated with Nash insta ntaneous u-nit hydrograph(NIUH).The combination of the GIUH and NIUH fully considers the moving path of wa ter particles in drainage and the regional composition of runoff at the end of the drainage,resulting in a rational combinatio n of probabili-ty of GIUH and NIUH and geomorphologic parameters which could reflect the complexity of the landform structur e of karst drainage.The results showed t hat the combined method of GIUH and NI UH has clear physical concept and acc ept-able precision,which can be widely a pplied on hydrological studies of karst area.

COMPARATIVE STUDY ON RESIDENTS′ PERCEPTION OF TOURISM IMPACT AT TOURIST PLACES——A Case Study of Xidi, Zhouzhuang and Jiuhua Mountain

Based on the questionnaire investigation, the authors make a comparative study on local residents′ perception of tourism impacts in Xidi, Zhouzhuang and Jiuhua Mountain. The result shows that residents of the three places tend to have strong and consistent perception of its positive economic, socio-cultural and environmental impacts, but distinctly diverse ones of its negative impacts. Residents in Xidi and Zhouzhuang also have noticeable perception of its negative environmental impacts while those in Jiuhua Mountain have weaker perception of them. The research confirms the fact that residents are more liable to have positive perceptions at the early stage of the life cycle of the tourist places. The authors conclude that there exists a nonlinear relationship between residents′ perception and tourism development stages, and that tourism socio-cultural impact may appear at an early stage of tourism development instead of being no universal.

An Approach to Reasoning Topological Relations Between Areal Objects Under Randomness

This paper describes the geometric and statistical properties of areal object under randomness. In order to describe formally such a uncertain topological relation, a new formal model (i.e. 4ID model) is proposed. On the basis of this, the effects of positional uncertainty on topological relations between areal objects are investigated in detail. Some possibility functions for the determination of relations are constructed based on the assumption that randomness of point location complies with a normal distribution, and the concept of uncertain sets of topological relations under randomness is introduced.

ASSESSMENT OF INDIRECT USE VALUES OF FOREST BIODIVERSITY IN YAOLUOPING NATIONAL NATURE RESERVE, ANHUI PROVINCE

Direct use values of forest ecosystem have been recognized apparently due to its easy and convenient assessment, while indirect use values are usually neglected because they are not easy to be recognized by the public. For a nature reserve with forest ecosystem, the most important economic values are the indirect use values, which provide human beings and other living things with beneficial services through ecological processes and functions. In this case study, a quantifying framework to estimate the annual indirect use values of forest ecosystem has been established in Yaoluoping National Nature Reserve based on alternative cost method and opportunity cost method. The ecological functions assessed in the study relate to six aspects: soil protection, water conservation, CO2 fixation, nutrient cycling, pollutant decomposition and disease and pest control. These ecological functions provide an economic value of 86.1×106 yuan (RMB) per year (US$10.37×106 ), which is 25 times higher than the opportunity cost for regular timber production. This study can contribute to the monetary assessment of indirect use values of forest biodiversity and to the conservation and sustainable use of nature reserves.

INFLUENTIAL FACTORS COMBINATION AND COMPETITIVE ADVANTAGES IN STAGES OF URBAN COMPETITIVENESS——Case Study of Suzhou in China

The urban competitive advantages rely on the combination and interaction of influential factors. As a dynamic progressive process, the city at different time has different competition influential factors combination. Because of this, the urban competitive advantages take on time-series characteristics. Stages of urban competition can be summed up into three ones, the basic factor-driven, the investment-driven and the innovation-driven. The finding of the study on the stages of urban competitive advantages in Suzhou is that in the current stage of Suzhou its competitive advantage is the investment-driven. The investment, especially FDI, plays remarkable functions for Suzhou competition with other cities.

EXTERNAL SOURCES OF URBAN COMPETITIVE ADVANTAGES IN CHINA

Urban competition refers to capacities of cities for attracting, capturing, controlling, dominating and transforming certain resources during urban development, and capacities for wealth creating, life-standard improving and sustainable development maintenance. This paper first analyzes the external sources of urban competitive advantages: the global network-based advantages and the location-based ones. Then with the aid of method of principal component analysis in SPSS 10.0 for Windows, the Chinese urban global and local competitive advantages are explored. The finding is that the global network-and location-based advantages are remarkable for the cities in the eastern China. While for those in the western and the middle regions, affected by much lower regional competitive advantages and lower degrees of urban-regional integration, the urban competitive advantages are deeply influenced and weakened.