黑河流域生态系统服务的价值

生态系统服务的价值评估研究是可持续发展评估研究的关键内容和焦点 ,是生态经济学、环境经济学和生态学的前沿研究领域 ,是开展环境 经济综合核算的基础工作 .以黑河流域 1987年和 2 0 0 0年的 1∶10 0 0 0 0LandsatTM图像解译数据为基础 ,在分析黑河流域土地利用和土地覆盖变化状况的同时 ,对黑河流域生态系统服务的价值进行了评估 ,结果表明 :按当前价计算 ,1987年黑河流域生态系统服务的年价值为 2 1.6 2 3× 10 8＄ ,相当于 178.82 2× 10 8元人民币 ;2 0 0 0年黑河流域生态系统服务的年价值为 17.6 74× 10 8＄ ,相当于 146 .16 4× 10 8元人民币 .与 1999年黑河流域的国内生产总值 (GDP) 10 2 .5 4× 10 8元人民币相比 ,2 0 0 0年黑河流域生态系统服务的年价值相当于GDP的 1.42 5倍 .由于缺乏对盐碱地、永久积雪 /冰川、建筑用地、沙丘 /戈壁、裸岩 /裸土地等服务价值的相关研究信息 ,该结果是对流域生态系统服务价值的保守估计 .     

在气候影响研究中引入随机天气发生器的方法和不确定性

通过采用不同的随机天气发生器生成一定气候背景下各种气候变率情景，许多学者在最近的研究中已经认识到气候变率对农作物生长发育影响的重要性。传统的气候影响评估方法直接以大气环流模式的模拟试验结果作为未来气候情景，这样不可能理解如上的重要性。本文着重评述将随机天气发生器应用于气候变化影响研究的一般方法框架，以及作者的具体个例研究方法。文中最后分析了目前该领域研究中还存在的一些不确定性。 在当前的气候变化影响研究中，有不同的方法用来研制一种称为WGEN的典型随机天气发生器的参数化方案及其随机试验方法。不同的研究者也有不同的参数调控方法。通常的思路是通过气候控制试验和2×CO2试验之间的气候变量平均值和方差的变化来扰动随机天气发生器的参数，以生成未来逐日气候变化情景。本文作者根据短期气候预测模式的输出产品建立了一套WGEN的参数化方案及其随机试验方法，并且在时间和空间两个尺度上检验和评估了此参数化方案下WGEN的模拟能力。另外，作者由未来降水的变化，调试随机天气发生器参数，生成了气候变率变化情景。这些参数调节可以产生各种不同类型和定性大小的气候变率变化，用于气候影响评估的敏感性分析。通过如上方法，作为一个个例，文中评估了未来气候变率变化     

海南岛山区土地的持续利用评价——以琼中、通什为例

土地持续利用就是要达到生态合理性、经济有效性和社会可接受性。本文以琼中县和通什市为例，通过土地利用现状分析、土地持续利用评价，提出了实现其土地持续利用的对策措施。     

西藏自治区生态环境问题及对策

以青藏高原生态环境构成和社会经济发展。分析了西藏自治区存在的生态环境问题及生态环境发展趋势，提出生态环境建设分区及区域生态环境建设对策。     

贡嘎山东坡亚高山森林系统植被光合作用——双裂蟹甲草（Cacalia davidii）净光合速率对生态因子的响应

以双裂蟹甲草(Cacaliadavidii)为材料，研究其净光合速率对生态因子的响应。结果表明，双裂蟹甲草净光合速率(P     

The impacts of urbanization on soil erosion in the Loess Plateau region

1 IntroductionThe Loess Plateau region covers an area of 62.4(104 km2 and lies in the center of northern China. Urbanization and economic development have been quickened in recent decades. Both the number of towns established and scale of cities have increased. Although the pace of urbanization has been accelerated, the eco-environmental control in urban areas still lags behind relatively. Moreover, the construction and development of cities damaged the already vulnerable eco-environment to …     

人地关系调控与生态环境 --以长江洪灾为例

以长江洪灾为例，分析了人地相互作用的内容与方式，人地关系系统调控的任务与措施。认为洪灾频发的重要原因是人类对地质资源的不合理开发利用而导致生态系统的严重破坏。并认为要培植生态系统的抗干扰能力，应及时调整人地关系，改善农村的经济方式与经济条件，把生态建设作为国家长治久安的根本大事长期坚持下去。     

Environmental mitigation and the Upper Yazoo Projects

The US Army Engineer District, Vicksburg (CELMK), evaluated an array of flood control alternatives, which included up to 167 water control structures, 52 confined disposal facilities, and 47 borrow pits as part of a major flood control effort known as the Upper Yazoo Projects (UYP). Many of these project features are capable of ponding water and thus can be managed to mitigate for aquatic, terrestrial, waterfowl, and wetland resource losses expected to occur as a result of the UYP. The benefits to be derived will depend upon the land uses and management of the ponded areas. The US Army Engineer Waterways Experiment Station developed procedures to quantify the cost and habitat benefits of the many management options for these sites. The mitigation strategy was derived by optimizing various combinations of land acquisition, reforestation, land-use change, and site hydrology so that the least-cost mitigation plan could be selected.     

Potential impacts of global warming on the frequency and magnitude of heavy precipitation

It is now widely recognised that the most significant impacts of global warming are likely to be experienced through changes in the frequency of extreme events, including flooding. This paper reviews physical and empirical arguments which suggest that global warming may result in a more intense hydrological cycle, with an associated increase in the frequency and/or magnitude of heavy precipitation. Results derived from enhanced-greenhouse experiments using global climate models (GCMs) are shown to be consistent with these physical and empirical arguments. Detailed analysis of output from three GCMs indicates the possibility of substantial increases in the frequency and magnitude of extreme daily precipitation, with amplification of the effect as the return period increases. Moreover, return period analyses for locations in Australia, Europe, India, China and the USA indicate that the results are global in scope. Subsequent discussion of the limitations of GCMs for this sort of analysis highlights the need for caution when interpreting the precipitation results presented here. However, the consistency between physically-based expectations, empirical observations, and GCM results is considered sufficient for the GCM results to be taken seriously, at least in a qualitative sense, especially considering that the alternative seems to be reliance by planners on the fundamentally flawed concept of a stationary climate.