滇池流域主要农业产品水足迹空间格局及其环境影响测度

科学合理的评估农业产品水资源消耗及其环境影响对保护区域农业生产安全和水资源合理配置具有重要意义.本文以滇池流域为例,耦合水足迹和生命周期评价方法,对流域内2005—2011年主要农业产品水足迹空间格局进行分析,并对其环境影响进行测度.结果显示:滇池流域主要农作物和动物产品年平均水足迹分别为4.88×108m3·a-1和8.97×108m3·a-1,动物产品总水资源消耗大于农作物产品.动物产品水足迹的人类健康和生态系统质量总环境影响高于农作物,但资源消耗总环境影响要低于农作物,各区县产品水足迹环境影响值最大的为猪肉、水稻和玉米.各区县主要产品水足迹及其环境影响空间差异显著,嵩明县和晋宁县的产品水足迹环境影响最高,城区则较低.本文最后提出:评价一种产品对区域水资源的可持续性影响时,不仅要考虑产品耗水量也应考虑产品对水资源产生的潜在环境影响大小,应从水资源管理和生命周期角度综合考虑.水资源量少的地区,应侧重选择水资源消耗量小的产品,水量充沛地区则应选择对人类和生态产生影响小的产品.     

Gas–Liquid Two-Phase Flow in a Mini-Channel with Water Infiltration Continuously Along the Flow Direction

Characteristics of air–water two-phase flow pattern in a square-mini-channel were investigated experimentally. One sidewall of the flow channel was made of a permeable porous media. Air was fed into the channel from its inlet, while liquid water was injected uniformly into the channel along the permeable sidewall. Based on the results of visualization, the typical flow patterns encountered in the conventional co-current gas–liquid two-phase flow were not observed in the present work. Flow patterns of this special gas–liquid two-phase flow were catalogued, and the influence of gas flow rate and liquid infiltration rate on flow patterns was also analyzed. The results also indicate that the channel differential pressure on both sides brings obvious fluctuations when the liquid is infiltrated. The frequency of this fluctuation depends not only on the amount of liquid infiltration but also relies on the gas flow rate significantly. However, the amount of liquid infiltration barely affects the fluctuation in the amplitude of the pressure differential.     

资源型城市转型效率时空格局及影响因素探析：以陕甘宁能源富集区为例

基于数据包络分析、标准差椭圆和地理探测器方法，引入产业多样化指数和产业专业化指数，综合探讨陕甘宁资源型城市的转型效率、时空格局及其影响因素，得到2011—2020年陕甘宁资源型城市转型绩效综合得分及分布、不同发展阶段资源型城市转型绩效以及三省区各自资源型城市的转型绩效。结果表明：（1）2011—2020年陕甘宁资源型城市转型效率具有显著的时间和空间差异。（2）研究期内陕甘宁资源型城市转型效率空间分布格局基本保持稳定，仍以东西方向为主导。（3）地方财政一般预算内支出、城市建设用地面积、地区生产总值是影响资源型城市转型效率空间分异的主导因子。揭示了研究区资源型城市转型效率的发展演变态势及驱动因素，可为其持续优化转型提供决策依据。     

The Urbanization Pattern of China in the 21st Century

Abstract

This paper begins by analysing the mutual influence between international trade and the environment, and then proceeds to explore the environment and trade conflicts. On the basis of sustainable development theories and the above discussion, the article suggests taking sustainable trade as a solution to the existing conflicts. This paper aims to find the way to strike a balance between international trade and environment based on the present situation in China.     

Waterfowls habitat modeling: Simulation of nest site selection for the migratory Little Tern (Sterna albifrons) in the Nakdong estuary

This paper aims to find patterns in nest site selection by Little Terns Sterna albifrons, in the Nakdong estuary in South Korea. This estuary is important waterfowl stopover and breeding habitat, located in the middle of the East Asia-Australasian Flyway. The Little Tern is a common species easily observed near the seashore but their number is gradually declining around the world. We investigated their nests and eggs on a barrier islet in the Nakdong estuary during the breeding season (May to June, 2007), and a pattern for the nest site selection was identified using genetic programming (GP). The GP generated a predictive rule-set model for the number of Little Tern nests (training: R² = 0.48 and test: 0.46). The physical features of average elevation, variation of elevation, plant coverage, and average plant height were estimated to determine the influence on nest numbers for Little Tern. A series of sensitivity analyses stressed that mean elevation and vegetation played an important role in nest distribution for Little Tern. The influence of these two variables could be maximized when elevation changed moderately within the sampled quadrats. The study results are regarded as a good example of applying GP to vertebrate distribution patterning and prediction with several important advantages compared to conventional modeling techniques, and can help establish a management or restoration strategy for the species.     

Do biodiversity indices behave as expected from traits of constituent species in simulated scenarios?

It is believed that diversity of plant communities has a positive effect on their productivity. The benefits of diversity are described by “biodiversity indices”, comparing yield of mixtures with yields of monocultures of constituent species. These indices are supposed to capture also the main mechanisms leading to increased yield. We have constructed a spatially explicit individual based model, simulating even-aged stand development, and compared the behaviour of selected biodiversity indices (overyielding, selectivity and complementarity) with expectations based on life history traits of constituent species. The results are based on comparisons of two species mixtures with corresponding monocultures. We designed three scenarios of changes in the two species life history differentiation, and compared the behaviour of the indices with expectation based on it. In the first scenario, selectivity was driven by increasing size inequality of the two species, mostly in accordance with expectations. The second scenario presents increasing shade tolerance of the smaller species that increased complementarity, again mostly as expected. In the last scenario, shortening of length of stress tolerance of the weaker species surprisingly increased values of the biodiversity indices. For each setting, we varied sowing density and spatial pattern of the constituent species. The behaviour of the indices was influenced by both factors, but the effect of density was more pronounced. In particular, at high sowing densities, the most important interactions happened in the very early stages of mixture development, and the behaviour of the indices was often counter-intuitive.     

Effects of habitat and landscape fragmentation on humans and biodiversity in densely populated landscapes

Landscape fragmentation has often been seen as an only ecological problem. However, fragmentation also has a societal perspective, namely, in how humans perceive landscape fragmentation and in how landscape fragmentation potentially influences human well-being. These latter aspects have rarely been addressed so far. The inter-relationship of ecological and human dimensions of landscape fragmentation becomes especially evident when looking at the landscape where most people in industrial countries live, namely in suburban and urban areas. In these areas, landscape planners and environmental managers are confronted with the problem that landscapes should fullfil various functions, often with conflicting goals, e.g. nature reserves to enhance species richness vs. recreational areas for city-dwellers. We reviewed the ecological and sociological literature relevant for fragmentation in suburban and urban landscapes. In an interdisciplinary approach, we evaluated whether there are similarities and dissimilarities between the ecological and the human aspects of landscape fragmentation. We found important similarities. An example is that for both, humans and biodiversity, the loss of semi-natural areas has more drastic effects than the fragmentation of these areas per se. However, there are also relevant differences. We concluded that in densely populated landscapes a shift from responsive planning to an intentional design of environments is therefore needed.     

水湿生经济植物开发及涝渍地农业模式研究

简要阐述了利用水生和湿生植物开发涝渍地的必要性，报导了四湖地区涝渍地进行水生和湿生经济植物引种栽培和优化农业模式试验方面的研究结果，还讨论了在平原湖区涝渍地水湿生经济作物优化农业模式的优越性和生态效益。     

秦淮河流域城镇用地增长格局及其演化机制

利用四期遥感TM数据和GIS技术，通过分析20年秦淮河流域城镇用地增长格局及其演化机制，为流域综合管理和模拟提供重要参数，研究结果表明：①城镇用地增长显示阶段性和空间的不均匀性，增长拐点发生在1994年和2000年，空间上表现出增长“热极”与“热带”；②城镇用地增长阶段性是经济社会过程及驱动因子演化阶段的反映，回归分析显示城镇用地增长与城镇人口、经济总量及开发区发展相关系数高，这归于1992年开发区创建、投资增加与2000年撤县设区驱动的结果；③城镇用地增长格局变化是社会经济物质载体演化的体现，1992年后开发区成为城镇用地增长首要来源，2000年后东山新市区与大学城成为其增长核心和新形式，机场与高速公路网强化对城镇用地的空间导向。研究结果较客观地刻画了城市化格局与过程的演化规律，参数应用与数据精度的提高是今后研究的重点.     

OPTIMUM CROPPING AND GROUND WATER MANAGEMENT1

ABSTRACT: A decision model for optimum cropping pattern and ground water manaement alternatives in canal irrigated areas is pre sented. Various ground water management alternatives in conjunction with optimum cropping pattern and based on water production functions are compared. The model developed also ensures optimum utilization of surface and poor quality ground water and proper soil conditions for plant growth.