Scale correlation between vegetation and soil in larch forest, NE China

ＩｎｔｒｏｄｕｃｔｉｏｎＶｅｇｅｔａｔｉｏｎ ｅｎｖｉｒｏｎｍｅｎｔｒｅｌａｔｉｏｎｓｈｉｐｉｓａｎｉｍｐｏｒｔａｎｔａｓｐｅｃｔｎｅｅｄｔｏｂｅａｄｄｒｅｓｓｅｄａｎｄｈａｓｂｅｅｎｓｔｕｄｉｅｄｆｏｒａｌｏｎｇｔｉｍｅｉｎｖｅｇｅｔａｔｉｏｎｅｃｏｌｏｇｙ (Ｇａｕｃｈ ,1982 ) .Ａｗｅｌｌｋｎｏｗｎｍｅｔｈｏｄｏｌｏｇｉｃａｌｆｒａｍｅｗｏｒｋｆｏｒｄｅｓｃｒｉｂｉｎｇｔｈｉｓｒｅｌａｔｉｏｎｓｈｉｐｉｓｔｈｅ ｇｒａｄｉｅｎｔａｎａｌｙｓｉｓ (Ｗｈｉｔｔａｋｅｒ,1978;Ｐｉｅｌｏｕ ,1985) ,ｉｎ…     

规模化养猪场的废水污染及综合治理措施

介绍了规模化养猪场的废水来源,废水产生量及污染物浓度.分别对养猪场废物综合利用的栽体、废水治理设施工艺设计方案等内容进行了分析.针对规模化养猪场废水对环境的污染及危害,提出了有效可行的养猪场废水综合治理措施,其中包括养猪场废水在冬季和夏季采取不同的治理措施.     

两段活性污泥法处理味精废水的中试研究

采用两段活性污泥法处理味精废水 ,试验规模 0 5m3/h ,当进水CODCr浓度 16 80～ 70 30mg/L,NH3 N浓度 2 0 6～ 1999mg/L时 ,经石灰中和 ,空气吹脱对离交废水的预处理后 ,出水CODCr<10 0 0mg/L。试验中 ,兼氧池和一段好氧池污泥浓度保持在 6 0 0 0～ 80 0 0mg/L之间 ,二段好氧池保持在 40 0 0～ 6 0 0 0mg/L之间。生物处理总停留时间 5 0h。在离交废水预处理中 ,pH中和至 9 5～ 10 ,鼓气量在 10 0m3/h左右 ,水温加至 5 5℃左右 ,经 8h ,可将原水NH3 N从12 0 0 0mg/L左右 ,脱除 6 5 %以上 ,出水氨氮可达 40 0 0mg/L左右。     

间歇曝气A2/C氧化沟工艺处理城市污水中试研究

为降低氧化沟工艺的运行成本,研究了连续进水间歇曝气缺氧(Anoxic)-厌氧(Anaerobic)-Carrousel氧化沟(A2/C)工艺.采用A2/C氧化沟模型运用连续进水间歇曝气模式对城市污水处理进行了研究.结果表明,增强外源反硝化是提高脱氮效率的关键.在一定范围内加大回流比,能够提高间歇频率,减小各污染指标在反应系统中的积累.在曝气1 h,停止曝气3 h,回流污泥比200%的模式下(模式Ⅱ),出水CODcr,NH4 -N和TN分别为40～50 mg·L-1、3.0～5.7 mg·L-1和10.2～12.5 mg·L-1.3个模式在1个周期内平均曝气量分别为连续曝气过程的66%、50%、44%.模式Ⅱ中在线监测仪表数据分析显示,曝气过程中出现NH4 -N氧化的终点--在pH曲线上表现为出现"氨谷",若利用在线监测仪表在曝气阶段采用自动控制,则可避免过量曝气.采用实际城市污水,应用中试试验模型,能够为实际生产提供重要技术参数,为原有氧化沟工艺技术改造提供支持.     

自然保护区学研究与景观生态学基本理论

本文尝试把景观生态学思想融于自然保护区理论中，较系统地论述了以景观结构与功能原理、景观异质性理论、景观格局理论、等级—尺度理论、干扰学说、生物多样性原理以及景观稳定性理论等景观生态学的基本理论为基础的自然保护区学的研究     

Alternative Non-market Value-Elicitation Methods: Are the Underlying Preferences the Same?

We advocate a more formal structural approach for comparing WTP for non-market or pre-test-market goods conveyed by fundamentally different preference elicitation mechanisms. Seven independent samples of respondents were asked to value the identical good. Elicitation methods include one actual purchase and six widely used hypothetical choice formats. Using a common underlying indirect utility function (and stochastic structure) allows data for different elicitation methods to be used independently, compared pair-wise (as in much of the earlier literature) or pooled across all samples in one unified model with heteroscedasticity across elicitation methods. Our differences in estimated WTP for the individual models are typical of earlier findings. However, pooled-data models that allow for heteroscedasticity reveal that while there are substantial differences in the amount of noise in the different samples, a common underlying systematic component of the preference structure cannot be rejected for at least four (and possibly five) of these seven elicitation methods.     

Sensitivity of Systematic Reserve Selection to Decisions about Scale, Biological Data, and Targets: Case Study from Southern British Columbia

Abstract:  The identification of conservation areas based on systematic reserve-selection algorithms requires decisions related to both spatial and ecological scale. These decisions may affect the distribution and number of sites considered priorities for conservation within a region. We explored the sensitivity of systematic reserve selection by altering values of three essential variables. We used a 1:20,000–scale terrestrial ecosystem map and habitat suitability data for 29 threatened vertebrate species in the Okanagan region of British Columbia, Canada. To these data we applied a reserve-selection algorithm to select conservation sites while altering selection unit size and shape, features of biodiversity (i.e., vertebrate species), and area conservation targets for each biodiversity feature. The spatial similarity, or percentage overlap, of selected sets of conservation sites identified (1) with different selection units was ≤40%, (2) with different biodiversity features was 59%, and (3) with different conservation targets was ≥94%. Because any selected set of sites is only one of many possible sets, we also compared the conservation value (irreplaceability) of all sites in the region for each variation of the data. The correlations of irreplaceability were weak for different selection units (0.23 ≤ r ≤ 0.67), strong for different biodiversity features ( r = 0.84), and mixed for different conservation targets ( r = 0.16; 0.16; 1.00). Because of the low congruence of selected sites and weak correlations of irreplaceability for different selection units, recommendations from studies that have been applied at only one spatial scale must be considered cautiously.     

Linking on-farm dairy management practices to storm-flow fecal coliform loading for California coastal watersheds

How and where to improve water quality within an agricultural watershed requires data at a spatial scale that corresponds with individual management decision units on an agricultural operation. This is particularly true in the context of water quality regulations, such as Total Maximum Daily Loads (TMDLs), that identify agriculture as one source of non-point source pollution through larger tributary watershed scale and above and below water quality investigations. We have conducted a systems approach study of 10 coastal dairies and ranches to document fecal coliform concentration and loading to surface waters at the management decision unit scale. Water quality samples were collected on a storm event basis from loading units that included: manure management systems; gutters; storm drains; pastures; and corrals and lots. In addition, in-stream samples were collected above and below the dairy facilities and from a control watershed, managed for light grazing and without a dairy facility or human residence and corresponding septic system. Samples were analyzed for fecal coliform concentration by membrane filtration. Instantaneous discharge was measured for each collected sample. Storm runoff was also calculated using the curve number method (SCS, 1985). Results for a representative dairy as well as the entire 10 dairy data set are presented. Fecal coliform concentrations demonstrate high variability both within and between loading units. Fecal coliform concentrations for pastures range from 206 to 2,288,888 cfu/100 ml and for lots from 1,933 to 166,105,000 cfu/100 ml. Mean concentrations for pastures and lots are 121,298 (SE=62,222) and 3,155,584 (SE=1,902,713) cfu/100 ml, respectively. Fecal coliform load from units of concentrated animals and manure are significantly more than units such as pastures while storm flow amounts were significantly less. Compared with results from earlier tributary scale studies in the watershed, this systems approach has generatedwater quality data that is beneficial for management decisions because of its scale and representation of current management activities. These results are facilitating on-farm changes through the cooperative efforts of dairy managers, regulatory agency staff, and sources of technical and financial assistance.     

地铁十字换乘车站全尺寸实验研究:I.站厅火灾

为了全面了解在不同通风模式下地铁十字换乘车站站厅火灾发展规律,通过在8A编组地铁十字换乘车站公共站厅层开展1 MW规模的全尺寸火灾实验,对不同通风模式下换乘地铁车站站厅层公共区火灾场景下的烟气前锋到达时间、烟气扩散与沉降范围和楼扶梯处温度等参数进行分析研究。研究结果表明:在换乘线路A线站厅层发生火灾时,受到出入口自然风以及站厅层空间结构的影响,站厅内形成了由站厅北侧向南侧方向的风压,有效抑制了烟气向B线站厅扩散;通风排烟系统能够有效降低烟气扩散速率,控制烟气扩散范围和沉降高度;针对此类结构车站站厅的防排烟设计,应综合考虑通风、出入口位置和空间构筑物对火灾烟气扩散的影响,确保火灾过程中人员疏散路径和楼扶梯处烟气层高度和烟气温度处于安全水平。     

“中尺度系统串”和洪涝的关系

在本文中，我们引入了“中尺度系统串”的概念，并通过７个例证讨论了它与洪涝之间的关系。