广西水源涵养型重点生态功能区生态状况变化

文章利用2010年、2018年生态环境监测与评价项目土地利用类型数据,通过生态功能指数、生态结构指数和生态胁迫指数综合反映重点生态功能区生态状况,分析 2010-2018年广西水源涵养型重点生态功能区的生态状况变化趋势。结果表明,广西水源涵养型重点生态功能区林地覆盖率明显提升,生态状况改善。其中疏林地及其他林地向有林地、灌木林地转变是水源涵养指数提升的主要原因,退耕还林、封山育林等措施对重点生态功能区生态状况改善发挥重要作用。     

Altitudinal Distribution of Meltwater and Its Effects on Glacio‐Hydrology in Glacierized Catchments,Central Asia

In glacierized catchments, elevation is correlated with meltwater through its association with temperature, precipitation, and glacier hypsometry. The revelation of the altitudinal distribution of meltwater, unattended and not fully understood in previous work, might provide a better understanding of climate change impacts on glacio‐hydrology. Here, critical zone approach was defined and applied in 12 glacierized catchments of the Tien Shan–Pamir–Karakorum Mountains, Central Asia using manually calibrated glacier‐enhanced Soil and Water Assessment Tool model over 1966–2005. The critical zone, a sequence of elevation bands with above‐average snow and glacier melt, contributes maximum meltwater to total runoff. The critical zone shared 37%–95% (average = 80%) of meltwater contributions to total runoff, although its size was only 13%–30% of the total elevational relief. The critical zone controlled 76% and 82% variability in relative changes of glacier area and total runoff at the catchment scale, respectively. The increase in temperature was identified as the dominant driver for variations in total runoff in all catchments except Vakhsh and Yurungkash, where precipitation change remained dominant. Overall, glacier hypsometry limited the first‐order control of meltwater distributions on glacio‐hydrology. It is concluded that critical zone approach can interpret the proxy role of elevation to affect water availability under climate and glacier area change in glacierized catchments.     

嘉陵江流域经济空间分异研究

认识流域经济空间分异特征是科学决策、促进流域经济可持续发展的关键。以嘉陵江流经的主要县市为研究单元,选取度量嘉陵江流域经济发展的10个指标,运用主成分分析揭示流域经济差异,并用Geoda软件提供的空间分析方法揭示流域经济差异的空间分异特征。分析结果表明：流域内经济发展水平差异显著,并在地理空间上存在集聚性;流域内基本形成了“点 轴”式空间结构,且存在两个明显的经济热点区--绵 渝“双核区”,以及一个较大的经济盲区,即陕西、甘肃、四川三省交界处的边缘区域。在此基础上分析了影响流域空间经济分异的主要原因,提出盲点区与热点区的发展策略,防止流域内“极化”效应加剧,为缩小流域经济差距,促进流域经济协调发展提供基础依据.     

Effects of Geomorphic Setting and Urbanization on Wood,Pools, Sediment Storage,and Bank Erosion in Puget Sound Streams1

Segura, Catalina and Derek B. Booth, 2010. Effects of Geomorphic Setting and Urbanization on Wood, Pools, Sediment Storage, and Bank Erosion in Puget Sound Streams. Journal of the American Water Resources Association (JAWRA) 46(5):972-986. DOI: 10.1111/j.1752-1688.2010.00470.x Abstract: Interrelationships between urbanization, the near-riparian zone, and channel morphology were examined in 44 lowland stream reaches in the Puget Lowlands of western Washington, United States. Both the degree of urbanization and channel type control channel response to a range of instream and riparian conditions. Some of these relationships are not evident in lumped datasets (i.e., with all channel types and/or degrees of urbanization) and highlight the importance of fluvial geomorphology in determining channel response. We found that in low-urbanized watersheds dominated by forced pool-riffle and plane-bed morphologies, the frequency and distribution of large woody debris (LWD), pool spacing, sediment storage, and bank erosion have a strong relationship with channel confinement and characteristics of near-riparian vegetation. In contrast, high-urbanized reaches dominated by simplified morphologies are substantially less sensitive to the condition of the near-riparian zone (e.g., size of the near-riparian vegetation and the level of channel confinement), due to the common disconnection of stream and floodplain caused by the placement of stabilizing structures in the banks. These structures are typically placed to prevent erosion; however, they also result in fewer LWD and pools, less sediment storage, and higher potential for incision.     

围填海对南通淤泥质海岸资源影响的综合评价研究

在系统分析淤泥质海岸围填海开发活动对海岸带资源影响的基础上,重点考虑岸滩冲淤变化特性、岸滩资源利用现状、利用潜力以及泥沙淤积对港口航道造成的资源损失,通过成本型、效益型两大类共16个指标,构建了适合淤泥质海岸资源状况评价的压力-状态-响应(PSR)模型,实现了围填海开发活动对海岸带资源影响的综合评估。利用该模型计算了江苏省南通市沿海的围填海活动对海岸带资源影响的评价系数,计算结果为0.596,表明南通当前的围填海开发活动已经对当地的海岸带资源造成了较大影响,在今后的沿海开发过程中,需要注重海岸带资源的节约与保护。     

A2O氧化沟缺氧区三维流场模拟及结构形式优化

以FLUENT软件为工具,选用三维RNG k-ε紊流数学模型对重庆井口污水厂A2O氧化沟缺氧区内的流场进行模拟,分析了缺氧区内流场分布不均匀及沉泥的原因,提出了水下推进器的合理设置位置与导流墙的合理设置方式,并对优化后的缺氧区进行了模拟计算。通过优化后模拟的结果可见,在相同的功率密度下,缺氧区内的流场得到了较均匀的分布,流速从原来的0.131 m/s提升到0.204 m/s,减少了能量的损失。底部的流速也从原来的0.140 m/s提升到0.226 m/s,有效的防止或减少了沟中的污泥沉积。优化的结果对实际工程的设计也有一定的指导意义。     

A2O氧化沟缺氧区三维流场模拟及结构形式优化

以FLUENT软件为工具,选用三维RNG k-ε紊流数学模型对重庆井口污水厂A²O氧化沟缺氧区内的流场进行模拟,分析了缺氧区内流场分布不均匀及沉泥的原因,提出了水下推进器的合理设置位置与导流墙的合理设置方式,并对优化后的缺氧区进行了模拟计算。通过优化后模拟的结果可见,在相同的功率密度下,缺氧区内的流场得到了较均匀的分布,流速从原来的0.131 m/s提升到0.204 m/s,减少了能量的损失。底部的流速也从原来的0.140 m/s提升到0.226 m/s,有效的防止或减少了沟中的污泥沉积。优化的结果对实际工程的设计也有一定的指导意义。     

植物床-沟壕系统的藻类捕获功能

采用原位实验验证植物床．沟壕系统的藻类捕获功能。结果表明：该系统能够有效拦截和捕获源水藻类。在水力梯度驱动下,约35％源水进入高位小沟流经植物床内部根孔结构而汇至低位小沟。低位小沟内叶绿素a（Chl-a）浓度显著低于高位小沟（P=0．0239）,其降低比例为11．1％。以植物床．沟壕系统为结构形式的根孔净化区其出水Chl-a浓度较源水整体下降了27．0％。估算该片根孔净化区捕获藻类鲜生物量约122kg／d。石臼漾湿地共含根孔净化区11片,按供水25万t／d计,估算捕获藻类鲜生物量约1100kg／d。     

一次雷暴天气发生发展的水汽图和红外云图特征分析

通过MTSAT的水汽图和红外云图,结合天气图、NCEP资料、地闪实况资料和探空数据对在高空急流影响下的暗区雷暴实例进行了对比分析。结果表明:暗区雷暴在卫星云图上表现为经过白天太阳辐射对晴空区(水汽图暗区)近地面的加热作用,大气不稳定能量增加,在一定条件下,午后强雷暴时常发生发展于高空急流左侧的晴空区中;而在水汽图上,高空急流与水汽图上的干区、湿区间有明显的联系,而这些联系又与强雷暴的发生发展有密切的关系,是雷暴发生发展的重要条件;在雷暴云发展过程中,地闪时空分布在卫星云图上有着明显的对应。     

福建龙岩可持续发展实验区规划探讨及实践

可持续发展实验区总体规划是区域规划的一种特殊类型。通过对可持续发展实验区及其总体规划的理解和认识,文章指出地方可持续发展实验区总体规划的编制思路应当回归到问题指向型的出发点上来。规划编制思路应当紧密结合宏观经济发展环境、社会事业新要求以及全球环境变化压力等背景,从地区人地关系的突出问题入手,制定实验区可持续发展战略,并通过重点项目落实到规划实施中,使可持续发展实验区总体规划体现实验、探索、示范、创新的作用。文章以福建龙岩可持续发展实验区总体规划编制的实践经验为例,对规划编制思路进行探讨。