Landscape ecological characteristics in temporal changes of riverside open space in urbanized area

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重点生态功能区环境污染源排放特征与空间管控模式——以藏东南为例

重点生态功能区以保持并提高生态产品供给能力为主体功能定位，区内自然环境敏感性和脆弱性突出，研究其人类活动过程中的环境污染源排放特征与空间管控模式，对科学协调保护与利用、切实加强重点生态功能区环境保护和治理水平具有重要意义.以青藏高原重要生态安全屏障区藏东南为例，基于环境污染源的固体废弃物、水体污染物和大气污染物排放强度的分类估算与空间特征解析，探讨面向污染源排放强度和多尺度管控精度的分级空间管控方案.研究结果表明：藏东南环境污染源的排放强度整体较低，雅鲁藏布江和雅尼河谷地因人类生产生活活动密度较大，其污染物排放量显著高于其他区域；在重点生态功能区应建立由7个二级类和21个三级类构成的环境污染源空间管控体系，重点管控以城镇居住区和工矿业生产空间为主的"点状"胁迫、以交通运输场所和人文游憩空间为主的"线状"胁迫、以农业种植区和畜禽养殖区为主的"面状"胁迫；针对藏东南各类环境污染源的空间耦合及交互特征，提出城乡生活集聚型、农牧业生产集聚型和休闲旅游集聚型3种典型区，依次制定"分级处理+资源利用"、"源头减排+就地消纳"、"实时动态监控+绿色设施营造+游憩利用规范"的差异化空间管控模式.     

深圳市观澜河流域水土流失规律研究

深圳市观澜河流域地处南亚热带,受自然因素和人为因素的影响,流域存在着严重的水土流失,改革开放以来,流域的大片土地被开发成了工业开发区。工业开发区在建设阶段,机械夷平土地所形成的各种松散的堆积坡,引起了新的水土流失类型。本文研究和探讨了该流域的水土流失规律及水土流失对流域水环境的影响。     

What Matters Most: Are Future Stream Temperatures More Sensitive to Changing Air Temperatures,Discharge, or Riparian Vegetation?

Simulations of stream temperatures showed a wide range of future thermal regimes under a warming climate — from 2.9°C warmer to 7.6°C cooler than current conditions — depending primarily on shade from riparian vegetation. We used the stream temperature model, Heat Source, to analyze a 37‐km study segment of the upper Middle Fork John Day River, located in northeast Oregon, USA. We developed alternative future scenarios based on downscaled projections from climate change models and the composition and structure of native riparian forests. We examined 36 scenarios combining future changes in air temperature (ΔT_air = 0°C, +2°C, and +4°C), stream discharge (ΔQ = ?30%, 0%, and +30%), and riparian vegetation (post‐wildfire with 7% shade, current vegetation with 19% shade, a young‐open forest with 34% shade, and a mature riparian forest with 79% effective shade). Shade from riparian vegetation had the largest influence on stream temperatures, changing the seven‐day average daily maximum temperature (7DADM) from +1°C to ?7°C. In comparison, the 7DADM increased by 1.4°C with a 4°C increase in air temperature and by 0.7°C with a 30% change in discharge. Many streams throughout the interior western United States have been altered in ways that have substantially reduced shade. The effect of restoring shade could result in future stream temperatures that are colder than today, even under a warmer climate with substantially lower late‐summer streamflow.     

济南市大气污染防治三区划定研究

根据《山东省区域性大气污染物综合排放标准》(DB37/2376-2013)实施要求,开展济南市市域范围大气污染防治三区划定。划定过程以地理信息系统空间分析技术为手段,根据各区域大气环境承载力、人口密度分布和生态环境敏感程度三个因素的空间分布差异,实现三区划分,形成划定初步方案。同时,结合相关规划和重点企业/工业园区空间布局状况,对初步划定方案进行调整,形成三区划定最终方案,并在此基础上提出各分区大气污染控制措施。     

基于城市规划的开封市地质环境风险评价

随着城市化进程的加快,城市地质环境风险评价作为缓解日益严峻的人地矛盾,科学合理地利用地质环境的有效措施,对城市的规划和可持续发展有着十分重要的指导意义。针对开封市的城市规划,将不同类型功能区作为评价对象,建立了地质环境危险性和社会经济易损性评价指标体系,并采用通用的风险评价模型对开封市地质环境风险进行了评价。评价结果显示:开封市高风险区面积占1.21%;次高风险区面积占11.89%;次低、低风险区面积占86.9%。根据评价分区结果,提出了功能优化和风险防控建议。     

风帘长度对采空区瓦斯体积分数及自燃“三带”分布的影响

采用Fluent软件,对工作面进风侧无风帘、风帘长度20 m、30m、40m四种情况下的采空区流场进行了数值模拟,分析了不同风帘长度下采空区瓦斯和自燃“三带”的分布情况.结果表明:随风帘长度增加,采空区瓦斯爆炸范围虽变化不明显,但距工作面越来越近;采空区自燃带逐渐向工作面靠近,能使窒息带在采空区走向方向上变宽,覆盖原本位于采空区自燃带中后部(靠近窒息带)的高温点,降低采空区自燃发火的危险性.     

Geomorphic and Ecological Consequences of Riprap Placement in River Systems

Riprap, consisting of large boulders or concrete blocks, is extensively used to stabilize streambanks and to inhibit lateral erosion of rivers, yet its effect on river morphology and its ecological consequences have been relatively little studied. In this paper, we review the available information, most of it culled from the “grey” literature. We use a simple one‐dimensional morphodynamic model as a conceptual tool to illustrate potential morphological effects of riprap placement in a gravel‐bed river, which include inhibition of local sediment supply to the channel and consequent channel bed scour and substrate coarsening, and downstream erosion. Riprap placement also tends to sever organic material input from the riparian zone, with loss of shade, wood input, and input of finer organic material. Available information on the consequences for the aquatic ecosystem mainly concerns effects on commercially and recreationally important fishes. The preponderance of studies report unfavorable effects on local numbers, but habitat niches created by openings in riprap can favorably affect invertebrates and some small fishes. There is a need for much more research on both morphological and ecosystem effects of riprap placement.     

三峡库区典型消落带土壤及沉积物中溶解性有机质(DOM)的紫外-可见光谱特征

溶解性有机质(DOM)是陆地生态系统的重要组成部分,在环境地球化学中扮演着重要角色.在测定三峡库区典型消落带土壤及沉积物DOM的紫外-可见光谱基础上,通过特征参数及光谱模型来获取DOM的地化特征和信息.紫外-可见光谱特征参数表明土壤DOM的芳香性、疏水组分及腐殖化程度都明显低于上层沉积物,与高程和土地利用类型无关;而所选择的4种吸收光谱模型中以模型2为最优.同时,不同模型和不同拟合波段均对DOM光谱曲线斜率(S)有影响:S值随波长增加而减小;而不同波段S值相关性存在差异,表明各波段S值仅反映DOM部分信息,而非全部.此外,特征斜率之比(SR)反映出表层沉积物所受降解程度(光漂白或生物降解)小于土壤和往年沉积物,其芳香性更高,分子量更大,参与降解的反应活性也更大;这表明DOM越新鲜,其受到的光照和生物作用相对较小,降解潜力越大.     

利用紫外-可见吸收光谱估算三峡库区消落带水体、土壤和沉积物溶解性有机质(DOM)浓度

溶解性有机质(DOM)是陆地和水生生态系统的重要物质,有色溶解性有机质(CDOM)是可用光谱测定的DOM组分.基于2012年7月采集的土壤和沉积物样品以及2012年11月采集的水体样品,通过单波长、双波长、吸收光谱斜率(S值)和三波长模型建立CDOM与DOM浓度之间的关系.结果表明,4种模型中三波长模型效果最佳,水体数据模型的决定系数为0.788,土壤数据模型的决定系数为0.933,沉积物模型的决定系数为0.856.同时,利用2013年随机采集的32个土壤样品和36个水体样品对模型精度进行检验,结果表明,土壤DOM浓度的相对均方根误差(RRMSE)和平均相对误差(MRE)分别为16.5%和16.9%,水体分别为10.32%和9.06%,相比土壤DOM而言,三波长模型对水体DOM的预测精度更高.