基于遥感影像的木兰溪水质参数反演

水质监测对水环境评价及污染预防至关重要,但地面监测成本高、监测面积有限等,难以满足实时、大范围监测的要求。为了更好地解决该问题,基于遥感影像的空中监测技术越来越得到研究人员的青睐。以木兰溪为研究区,利用和地面监测数据同步的Landsat-8卫星遥感影像数据,对木兰溪的典型水质参数总磷、总氮、溶解氧、高锰酸盐指数的反演问题进行研究。首先,根据Landsat-8的水体敏感波段,分别选取总磷、总氮、溶解氧、高锰酸盐指数的反演特征波段组合为(b1-b2)/(b2+b3),(b1-b2)/(b3-b4),b2/(b1+b4),b1/b2;其次,利用反演特征波段组合分别构建总磷、总氮、溶解氧、高锰酸盐指数浓度的SVR(Support Vector Regression)反演模型,通过IPSO算法对SVR模型的参数进行优选;然后,将IPSO-SVR反演模型和统计回归反演模型、广义回归神经网络(GRNN)反演模型在验证集上进行评估,以平均绝对误差和均方根误差作为评价指标进行对比分析,结果表明IPSO-SVR反演模型的平均绝对误差和均方根误差最小,说明IPSO-SVR反演模型具有较高的精度和较好的实用性...     

Planning process influences on sustainability in Ohio township plans

This study examines planning process influences on plan sustainability scores for 46 township plans in Central Ohio, in the Midwestern Region of the United States. Townships face many similar development challenges as exurban communities along with cultures and economies which straddle urban and rural perspectives. The empirical analysis shows that participation breadth is positively related to sustainability scores, while the use of the sustainability concept in the planning process is negatively related to sustainability scores. Based on the findings, we suggest that communities preparing a comprehensive plan should encourage participation by a variety of groups in the planning process. Future research should examine the manner in which the sustainability concept is incorporated into the planning process to better assess its influence.     

A stochastic approach for the operation of a wind and pumped storage plant under a deregulated environment

To improve the competiveness in the energy market, it is necessary that the wind power plants provide guaranteed power generation, although, it is not possible to forecast power availability from wind power plant accurately. This paper presents a stochastic model and solution technique for the combined operation of wind and pumped storage power plants to improve the power availability and increasing the profit considering uncertainties of wind power generation. In this model, uncertainties in wind data have been forecasted for grid connected day-ahead market using Weibull distribution model. The imbalances in the forecasted wind data and the market demand have been reduced by operating the pumped storage power plant. In this stochastic mixed integer problem, pumped storage plant can take the supply either from the grid or from the wind power plant for the pumping operation to store the energy in order to utilize this energy during peak hours for increasing the overall revenue. The reliability of the pumped storage is improved by replacing the conventional unit with the adjustable speed type pumped storage unit. In order to prove the optimality of the solution, two case studies were considered. In case study–I, scheduling is provided by operating the conventional pumped storage unit, whereas in case study–II, adjustable speed pumped storage unit has been used. It has been found that the adjustable speed pumped storage unit has further reduced the imbalance between generated power and demand. The complete approach has been formulated and implemented using AMPL software.     

基于城市总规的基本农田空间优化调整研究——以乌鲁木齐市高新区(新市区)为例

随着"三化"进程的推进,有限的土地资源供给与日趋上升的用地需求矛盾日益凸现。农地非农化的现象日趋严峻。耕地和基本农田的保护难度加大。城郊作为城市建成区与乡村衔接的特殊经济地理区位,土地利用受城市化进程和农业用地制约的双重影响,基本农田保护面临更为突出的问题。本文以乌鲁木齐市高新区(新市区)为研究靶区,充分利用高新区(新市区)二轮土地调查、土地总体规划、基本农田划定等数据和图库资料,以GIS技术作为分析工具和手段,在综合考虑耕地的质量与立地条件,结合高新区(新市区)社会经济、城市发展方向与定位、产业用地划定及布局等条件因素,对高新区(新市区)已划定的基本农田与产业空间布局结构衔接进行调整提供科学依据和参考,为区域协调耕地保护寻求路径。     

基于系统动力学—投入产出分析整合方法的江苏省产业用水综合效用分析

产业用水结构的欠合理一定程度上制约着社会的发展,如何科学评价产业用水情况,取得在经济效益、水资源和环境资源约束下的协调发展已成为目前区域社会经济发展面临与亟待解答的科学问题。以江苏省为例,提出了系统动力学—投入产出分析整合方法,在构建反映产业结构、用水结构和排污结构的互动反馈的水资源综合利用系统动力学模型基础上,通过敏感性分析确定对系统影响较大的关键变量,运用投入产出分析技术,对江苏省各部门用水特性、排污特性和经济效益特性进行计算测度,由此构建了3种产业发展模拟方案。依据系统动力学模型输出结果,对2025年3种方案下的重点产业部门用水综合效用情况进行对比分析,进而优选出"节水治污型"方案,并最后提出保障方案实施的对策建议,为江苏省产业和用水结构调整提供决策依据。     

一种兼顾水质目标和成本投入的流域减排措施优化方法

综合考虑断面水质及治污成本,构建流域治污减排措施优化模型,分析单位污染物去除成本与断面水质改善间的关系,并以承德市武烈河流域治污减排优化为例,绘制治污减排措施优化曲线,提出优化方案。结果表明,在达到流域水质要求的情况下,优化后,治污减排项目由34项缩减到22项,平均单位COD去除成本由1.44万元/t下降到0.65万元/t,同时实现了流域水质达标和降低投入成本的要求。     

改性黄麻制备及其对铜离子的吸附

从地表水突发污染应急处置实际需求的角度,考虑纤维材料的现场实用性,研究了均苯四甲酸二酐改性黄麻的制备过程及对重金属铜离子的吸附性能,吸附等温线、吸附动力学和吸附热力学。通过正交实验对改性条件进行了优化,结果表明,反应物(黄麻与酸酐)配比和反应温度对改性黄麻的吸附量有十分显著的影响;在室温,p H为5~7的条件下,改性黄麻对铜离子的吸附容量为43.56 mg/g,比原态黄麻提高了7倍多;改性黄麻对铜离子的吸附符合Langmuir模型,为单分子层吸附;吸附过程是符合假二级动力模型的自发吸热反应。     

新型活性焦干法脱硫脱硝脱汞反应塔流场的模拟与优化

在CFD软件Fluent中,选择k-ε湍流模型,多孔介质模型和SIMPLE算法,对新型脱硫脱硝脱汞反应塔内的三维流场进行数值模拟,结果发现,反应塔入口处烟气流场存在大漩涡。为消除漩涡,使穿过活性焦层的烟气均匀化,以充分利用活性焦层的空间来提高脱除效率,提出在入口处加装弯曲导流板,并通过相对标准偏差确定最优导流板长度。同时模拟了在最优喷氨位置处加装涡旋混合器时氨气和烟气的混合情况。结果表明,最优导流板长度(3.6 m)明显改善了烟气的均匀性,促使入口处的压降下降100 Pa左右。涡旋混合器形成的小漩涡,增强了烟气和氨气的混合。最后对照不同流量下实验值和模拟值的压降变化,验证了多孔介质模型的可行性。模拟结果对设备的优化设计和实际运行具有指导作用。     

城市生态保护红线与生态控制线协调性研究

生态保护红线与生态控制线是生态空间保护的两条主线,两线既有差别又紧密联系。生态保护红线是维护区域和城市生态安全的格局和数量底线,生态控制线是控制城市开发边界和保障生态安全划定的生态用地控制线。地市是两线划定的适宜尺度,本文在总结高、中、低不同开发强度城市两线探索实践的基础上,从两线联系与差异角度进行协调必要性分析。两线在概念内涵、法律地位、划定内容、技术方法、管控要求上的差异既是衔接的重点又是衔接的难点。然后,从空间、内容与管控等角度提出两线协调的思路,空间协调解决工作底图不统一、话语权不对等问题,内容协调解决生态用地保护目标不一致问题,管控协调解决部门管理准入条件不一致问题。最后,从工作机制角度,提出促进两线衔接的若干建议以及未来两线重点完善的内容和主要方向,为地市开展相关工作提供参考。     

Valuing environmental amenities through inverse optimization: Theory and case study

Amenity values of private forests are implicit but play a critical role in decision and policy making. This study presents an innovative valuation approach integrating techniques of operations research and economic theory of pricing environmental goods. A forest planning problem was inversed through altering its reward function of timber values so that the observed harvesting behavior became optimal. The discrepancy between the original and new rewards uncovered amenities values which were linked to forest attributes via hedonic models. This method was applied to a case study of the U.S. southern pine region. Depending on forest conditions, total economic values of amenities varied from zero to just under one thousand dollar per ha. At a discount rate of 3%, a typically managed forest generated on average $243 ha⁻¹ of amenities values per annum, more than twice of harvested timber values. Structural diversity and density of large pine trees were the key determinants to preserving forests for environmental amenities.