This article calculates and compares synthetical strength of the 15 cities in the Changjiang River Delta through principle component analysis by setting up a series of indexes, including 5 stratums, 16 aspects, 34 indexes total. On the analysis, by normalizing the indexes with Statistical Software SPSS10.0, rotating them by the method of varimax, analyzing the component matrix, six components were draw. And then, by multiplying each component score and orresponding component proportion, summing the consequences, the synthetical strength of the cities was calculatecd. From high to slow, they are Shanghai, Nanjing, Hangzhou, Suzhou, Wuxi, Ningbo, Zhenjiang, Shaoxing, Changzhou, Nantong, Yangzhou, Taizhou,Zhoushan, Jiaxing and Huzhou. According to the level of the synthetical strength, the cities were classifies into one core and three circles. In the development of the future, Shanghai should be put in a central position in the Changjiang River Delta and Nanjing, Hangzhou, Suzhou in important pivot positions, and regional divisio n to enhance common prosperity and collaboration be strengthend.

In order to evaluate, monitor and examine the level, process and efficiency of developmental sustainability of ecological demonstration area, a set of quantified indicator system and three types of mathematical methods (such as indices weighed coupling method, efficacy target value method and fuzzy comprehensive evaluation method)are constructed in this paper. Yuexi County, one of the 3rd national ecological demonstration areas is taken as a case study. The values of developmental sustainability for the integrated system and three subsystems (economic, natural and social) in datum year (2000), near future year (2005) and long-term target year (2010) by above indicator system and mathematic models are dovetailed to the present condition and future trend of this study area. As a result, this pilot research will be valuable in enriching the quantified theory of ecological demonstration area and guiding construction practices of Yuexi County's ecological demonstration area.

The spatial morphology of out area of a city is the exterior exhibition of its spatial organization. The rational spatial morphology is valuable for the development of urban elements and resources. There is an inherent evolutional rule for the fractal dimension of spatial morphology in different temporal sizes, and there is a linear relationship between the fractal dimensions and the population, and also the area. Taking Wuhan as an example, the outer spatial dimensions, populations and areas are calculated, and there is a consanguineous functional relationship between urban size and the outer morphological fractal dimension. The describing morphological function can be constructed based on abovementioned research. It is considered that the fractal dimension can be regarded as the indicator to forecast the urban spatial expansion and evolvement, and the developing mechanism of urban spatial morphology can be analyzed using the correlation between the fractal dimension and social and economical factors.

Ecosystem security is associated with sustainable development, the function of ecosystem security lies in supplying ecological service for human being. An attempt is made to assess the sustainability of ecosystem in various aspects of environmental degradation during the next few decades. Ecological appropriation as a tool for ecosystem security and sustainability assessment is widely used. The ecological appropriation presents a sample framework for national or regional natural capital accounting. In this paper, security and carrying capacity of ecosystem in Xichang, Sichuan, China was analyzed based on the theory of Ecological Appropriation. Analysis illustrates that the carrying capacity of ecological footprint is only 0.8 hm\+2, ecological deficit is per capita 0.6 hm\+2, the security of ecosystem is threatened due to resource exploitation dependence on local resource absolutely in Xichan; sensitivity analysis shows that the ecological footprint per capita will decrease 2.21%, ecological deficit per capita decrease 5.32%, while energy consumption decrease 10%; biocarrying capacity per capita will increase 9.92%, ecological deficit per capita will decrease \{14.01%,\} while agricultural output increase 10%. In this context, the goal of enhancing ecosystem health and stability through ecoindustry development forms effective and important measure. Development of ecoindustry is an essential tool for decreasing ecological deficit from the local level to regional level.

Resourcebased cities, which developed on the basis of resources exploitation, are one principal type of cities in China. This paper discusses the shortage of assessing ecological economic system of resourcebased city by emergy and currency, and then introduces the theory of emergy founded by H.T.Odum, the main steps and indices of the methods. At last, taking Tongchuan city as an example, whose ecological economic system is analyzed and evaluated. The result shows: During 1949 and 2000, Tongchuan have contributed wealth worthy of 254.1 billion Yuan; the primary driving forces of the system is local nonrenewable resources, the other includes the resources and products from outside region and local renewable resources; The emergy dollar ratio is decreasing, while the emergy density is increasing, but both are still at a less developed level; Stress on the environment is getting greater and greater, which are blocking the sustainable development; the ratio of emitted waste to GDP is decreasing, which leads to the improvement of environment.

The length of the classified riverbank resources along Suzhou reaches of the Changjiang River is figured out using remote sensing and geography information system. The exploitation condition of the riverbank resources along Suzhou reaches of the Changjiang River is evaluated through selecting indeces such as water depth, riverbank stability and water route width. The results indicate that although the ratio of the eminent riverbank resources is not very high， the exploitation condition of the riverbank resources along Suzhou reaches of the Changjiang River is very preponderant because of the centralized distribution of the eminent riverbank resources，the contiguity to towns，the good traffic condition and developed hinterland economy. The status of Suzhou Port among the lower Changjiang River Port Group is evaluated through calculating the port comprehensive strength index. Thus the function orientation and the developing way are confirmed——the assembled and assorted core port of Shanghai international Shipping Center， the international container main stem port of the Changjiang basin， the transferring port for staple bulk cargo and grocery of the middle and upper Changjiang River， and the assorted port of the fundamental industry strip along the Changjiang River. Then the strategies and suggestions on the exploitation of the riverbank resources and the development of Suzhou Port are put forward.

Using Landsat TM imageries (taken in 1987, 1993 and 1999) and GIS method, the spatial and temporal changes in land use of a typical urban lake watershed, Donghu Lake of Wuhan, were analyzed between 1987 and 1999. The satellite images were classified into seven land use/cover categories: water body, broadleaf forest, coniferous forest, shrubgrass land, bare land, cropland and urban land. Overall classification accuracy on satellite imagery for three period was all above 85%. Our results showed that urban land expansion (from 9.1% to 29.6% of study area) and farmland increase (from 7.0% to 13.9%), at the cost of reduction of water body (from 30.4% to 23.8%) and forestland (from 33.6% to 24.3%), are main characteristics of land use change in the watershed. At the same time, landscape diversity of the watershed decreased, as dominance increased during the study period. While degree of fragmentation changed differently between dominant landscape components and others. Because forestland becomes major source of the increment of the urban land and farmland, the ecological impact of urbanization on this urban lake watershed is remarkable. Several physical and economical factors contribute to land use pattern and its change in the study area.

The cultivated land per capita in Jiangxi Province touches the cordon of cultivated land per capita enacted by FAO. The decrease of cultivated land has accelerated over the last a few years. The main components of decreased cultivated land, and were occupied by national building, returned to forests and lakes, and damaged by natural disasters, etc. Different regions in Jiangxi show various characters in change of cultivated land during the last decade. Decreasing rate is lower in regions with higher GDP per capita than with lower GDP per capita because Jiangxi is on the special stage of development. The regions with high GDPPC are on the period of industrial transformation, so they occupy less cultivated land than others. The regions with low GDPPC are on the starting period of industry, and they occupy more cultivated land than others.This paper analyzes the main factors of driving forces in cultivated land change by the Principal Component Analysis. The results show that economic development and population increase, and natural disasters and technological advance in agriculture are the four main factors. This paper proposes some basic strategies for the protection of cultivated land in Jiangxi, such as controlling population, implementing quantity balance of cultivated land, reclaiming land, improving ecological circumstance, etc.

With the increasing serious water crisis in the world, water resource management of large river basins has show its importance. This paper analyses the hotspot in international water resources research, summaries the conversion and progress in water resources management of large river basins in China. The existing problems resulted in that importance were not attached to the relationship between human and nature, ecological evolution law, ecological function of rivers and wetland, integer governess of basins, ecological measures, and water ecological protection. Based on ecology theory, the paper brings forward measures to ensure sustainable development of water resources and ecological protection of large river basins, such as improving harmonious behavior of human and nature, inhensing sound development of social, economic and environment systems, adjusting integrated management to local river basin, and building ecological culture etc.

Catchment area is a basic，integral and relatively independent geoecological unit of hilly landscape in red soil regions. Taking three geomorphic integral catchment areas in Taoyuan County of Hunan Province as a case study，three kinds of plantation models were set including types of cropland intensive，halfintensive (cropland intensive plus about 50% noncropland intensive) and all intensive (cropland intensive plus noncropland intensive). The changing feature of soil fertility，potential，evolving tendency and developing mechanism of soil exploitation were then studied. Fixed observation over 11 years showed that three kinds of plantation models were at the approximate same inputoutput level，while the inputoutput level of noncropland had great deviation，with different evolving feature of soil fertility，biomass productivity and economic results. Soil erosion modulus in intensive management catchment areas was apparently decreased，which was equal or lower than soil loss tolerace(500 t/rm\+2). Soil organic matter and total nitrogen were steadily increased (increment scope >20%) in sloping land and cropland. Water conservation capacity could increase more than 20% in surface soil in sloping land and dryland in waterlack seasons. Productivity of crops was greatly improved (increment scope > 20%). Amount of tree，fruit，tea，fish and soil productivity were geminated. Three kinds of plantation models represented three developing steps in exploiting catchment areas. Soil development in catchment area should be along from cropland intensive to halfintensive，then to all land intensive. And developing speed was decided by the effect mechanism of essential factor, capacity of productivity of the dominant industry or items，relative interest，improvement of science and technology. More studies showed that the potential in developing catchment area was water surface > sloping land > dryland > paddy field. The potential was great with the rationality in development of hilly sloping land and water surface.

The research on nutrient balance is the premise to study agricultural activities and environmental pollution of agroecosystem. This paper, choosing a typical agroforestry ecosystem located in Sichuan hilly area in upper reaches of Three Gorges, discussed the nitrogen balances and appraised their reasonability wit h the way of inspection in farmlands and forestry lands, and of modeling experiments in basins and arable lands and participatory rural appraisal. The results showed that there was a little nitrogen surplus in croplands and in the whole farming system, with balance of 56.1 kg/hm2·a and 42 kg/hm2·a，actual balance rates of 10.4% and 8.2%；contrarily, a little deficit in paddies and in the catchments, with balance of -13.21 kg/hm2·a and -37.5 kg/hm2·a ，actual balance rates of -3.2% and -7.8% respectively. However, the forest showed more deficit with a balance of -165.9 kg/hm\+2·a and with actual balance rate of -39.2%. The allowable rates (23.4% for croplands and -37.2% for paddy) calculated out by mathematical appraisal model showed that, the nitrogen balances of croplands and paddies were relatively reasonable. Comparing nowadays' nitrogen balance with that of 1960s, it is clear that much more attention should be paid to the forest because it plays a great pole in reducing soil and water loss and changing the nitrogen cycling way in ecosystem.

Based on the situation in China, this paper discussed the use of organic manure and its role in agricultural production in China. The effect of fertilization on the quality of agricultural product, on the contribution of soil fertility, effect of organic and inorganic fertilization on atmosphere and water environment were also discussed. It is pointed out that there is some misunderstanding on the use of chemical fertilizer. This misunderstanding is that using chemical fertilizer will pollute environment, and only using organic manure can solve the problem. It is indicated that as a country with large population, China will need chemical fertilizers for agriculture in a long period in the future. Chemical fertilizer supplies sufficient, reasonable and balanced condition for the requirement of people to quantity but also to the quality of agricultural products. Reasonable chemical fertilizer application will improve crop quality, improve soil fertility, reduce greenhouse gas and water pollution. Chemical fertilizer is hurtless. The problem of the fertilization comes from unreasonable use. For the issues of fertilizers and fertilization in the future, we should pay more attention to produce high quality and high efficienct chemical fertilizers, try to extend scientific fertilization techniques and increase fertilization efficiency.

The rural cooperative economic organization bridges the farmers and the market and the competition. It is one of the factors that promote rural economic development and increase farmers' income. This article analyzes the marketdemand induced impetus of the development of rural cooperative organization from three aspects, which are the scale management of land, saving of the market transaction fare and the protection of farmers' interest, using the new institutional economics. And then it analyses the defects in external institution supply from the following aspects: the institutional environment and situation, the present accumulation of scientific knowledge, the present institutional arrangement, the transferring cost of organizational institution and the informal institutional arrangement, as well as in the internal institution from the property rights and organizational institution. At last, the article puts forward policy advice to promote the development of cooperative economic organization, including two pieces of advice. One is that the government, aiming at serving for “rural areas, agriculture and farmers”, should allow and guide the cooperative organization to innovate the property rights institution and carry out various kinds of organizational innovation. The other is that the government should provide institutional service for the cooperative organization as much as possible.

Total suspended matter plays an important role in internal loading release and water environment. Total suspended matter determines the transparency of water and the distribution of underwater light, which ultimately determines the lake primary productivity. Based on longterm and two times fixedpoint field observations of total suspended matter, wind and wave, the composition, temporal and spatial variations, vertical variation and the relationship between total suspended matter and wind and wave are analyzed. The results show: Organic suspended matter accounts for 30% of total suspended matter; Total suspended matter is characterized by regional variation, with the highest value in Lake Center and the lowest value in East Taihu Lake; Obvious seasonal variations of total suspended matter are characterized in Lake Center and East Taihu Lake; Vertical variations are characterized by the increase of concentration of the total suspended with depth; The critical wind speed of sediment resuspension is between 5 and 6.5 m/s; Increase of total suspended matter results in decrease of transparency and increase of beam attenuation coefficient.

Six PCB congeners were studied in 43 samples collected in February and August 2000 from Taihu Lake. Most of PCBs for six congeners are detectable in the sediment samples. Among them the concentration of PCB52 is the highest (average 0.983 ng/g), and that of PCB138 is the lowest (average 0.104 ng/g). No pattem was found in the distribution of PCBs in different areas of the lake. PCBs in the sediment samples collected from the center of the lake are not lower than that in other parts of the lake, suggesting that atmospheric transport and deposition can be the major input of PCBs to the lake. PCBs in sediments has nearly no correlations with the organic carbon and nutrient elements in the lake. Based on the sediment quality criteria, PCBs from all samples are lower than the low range of effects. But its potential hazard can not be neglectable as they enrich in organisms through benthic feeder.

The water environment of Lake Donghu is polluted heavily as a result of population growth and economy development, and the problem of eutrophication is serious. Authors make the eutrophication evaluation in ten sections of Lake Donghu, and the results show that eutrophicated water are constitutes 62.21% of total water area, while the area of moderate eutrophication is 37.9%. Phosphorus is the principal factor of eutrophication in Lake Donghu, and spot pollution is the main source of the enrichment of phosphorus in water body; on the base of these, the authors analyze the current measures and existent problems of Lake Donghu. The remedy of Lake Donghu eutrophication should be different with sections. Firstly spot pollution source should be controlled thoroughly, and then the surface pollution source by artificial wetland; to the seriously eutrophicated sections, the bottom deposit should be dredged up to cut internal pollution. At the same time, the management of Lake Donghu must be strengthened, the environmental legislation enforced, and the environmental supervision intensified.

Mechanisms for hydrological factors causing algal bloom in Hanjiang River are studied. First, the hydrological factors relative to algal bloom in Hanjiang River and their relation are generalized. Then the river continuous reactor model for algae growth is created and moreover mathematics model describing relation between concentration of algal and flow velocity is built up according to continuous reactor principle and Monod Function—— a = m exp(k/ν ). Parameters in this model are determined by measuring data in Hanjiang River—m=8.975 9、k=0.905 4，the relative coefficient r=0.924 4. In the end, the influence of flow velocity, flux and water level of the Changjiang River is discussed. In addition, the model is extensively adaptive to eutrophic rivers and it can be studied progressively because the parameters have clear physical signification.

The ecosystems in Three Gorges Area are very frangile with complex and diverse terrain. Many kinds of extremely degraded ecosystems (wasteland) occurred for the longterm disturbance from human and nature. The wasteland type, cause of its formation and the vegetation recover pattern were reported in this paper, then some suggestions were put forward for revegetating the waselands in this area based on the local geographic and ecological condition and the development in restoration ecology. The stabilization and restoration of soil and substrate, the construction of pioneer community and the biodiversity enrichment in management were regarded as the key approaches of wasteland vegetation restoration in Three Gorges Area.

Napahai, located in Jinshajiang Watersheds of northwestern Yunnan Plateau with low latitudes and high elevation, is a unique and seasonal marsh wetland. Developed from limestone in Hengduan Mountain of the upstream of Yangtze River, Napahai bears dissolved snow and controls water level of the down streams. The over years explorations on and cultivation on its marsh soils caused significant ecological and environmental deteriorations. Those deteriorations include wetland shrinking, type of marsh alternation, aridity and sandification, retrogressive ecological succession, mesophytes and xerophytes instead of helophytes, biodiversity decline, soil subsidence, water quality decline and soil enzymes activities changes. Among the analyzed causes of natural water drainage leaching from limestone and human interferences such as over pasture, wetland reclamation and cultivation, the human interferences are the main factor causing the degradation of the ecological environment of Napahai Wetland.

The “natural forest protection” and “returning farmland to forestry” projects are two ecological projects launched by Chinese government to greatly adjust the production scale of both afforestation and the forest industry within the whole land area of the China. It has made a primary progress after fouryear implementation. The paper discussed the relationship of the projects and environmental development, and indicated some aspects which pushed the projects:(1)constructing ecological civilization; (2)sticking to the principle of ecological benefit first; (3)strengthening research of ecological restoration, framing the standard of evaluation and inspection; (4)seting up and consummating ecological compensation mechanism; (5)perfecting the projects institution;(6)erecting the law and regulation.