水源区生态补偿机制理论框架研究

建立和完善水源区生态补偿机制,对保护水源区生态环境以及地区之间的协调可持续发展至关重要。在总结前人研究成果的基础上,从生态保护成本(或效益)外部性问题内部化,依据"公平、公开、公正"和"谁受益谁补偿、谁破坏谁治理"的原则,提出了水源区生态补偿概念;从生态补偿主客体的划分,补偿标准,补偿模式与补偿方式,补偿保障措施等方面提出了水源区生态补偿机制理论框架,为建立和完善水源区生态补偿机制提供理论参考。     

黑龙江黑河市小麦和大豆的灌溉计划

以黑河市典型农作物大豆和小麦为研究对象,利用气象数据和相关研究成果,计算了黑河地区大豆和小麦的需水规律和需水量,并和降水分布和有效降水量进行对比。研究发现在小麦生长阶段内,小麦需水量和降水量基本同步,但是6月-7月份亏水量约72 mm。在大豆整个生育期内,各月有效降水量均不能满足大豆的需水量,6月份缺水量最大为88 mm,生育期内共缺水量182 mm。考虑到当地矮杆作物灌水技术一般采用喷灌,建议灌水定额采用40 mm,小麦需在6月份喷灌一次,大豆在整个生育期内喷灌4~5次,以实现小麦和大豆的高产稳产。     

南水北调中线小南河串流片防洪水位计算

传统的多河流串流计算主要采用水库联调的方法,把串流的各条河流概化为静态水库,库水位水平且不考虑横向流动。为解决串流区水流的横向流动及水面线并不总像库水位一样水平的问题,采用二维非恒定流数学模型计算串流区洪水演进。通过概化地形、考虑入流、糙率、边界条件和水流的横向流动等因素,计算出了整个串流区域的水面线、水深、流速、出流等水力要素,并给出洪水演进模拟图,为确定河流与总干渠交叉建筑物的规模、总干渠左岸沿线水面线和对沿线村庄、农田的防洪影响提供了可靠的依据。     

Correcting for the influence of frozen lakes in satellite microwave radiometer observations through application of a microwave emission model

The spatial resolution of passive microwave observations from space is of the order of tens of kilometers with currently available instruments, such as the Special Sensor Microwave/Imager (SSM/I) and Advanced Microwave Scanning Radiometer (AMSR-E). The large field of view of these instruments dictates that the observed brightness temperature can originate from heterogeneous land cover, with different vegetation and surface properties.In this study, we assess the influence of freshwater lakes on the observed brightness temperature of AMSR-E in winter conditions. The study focuses on the geographic region of Finland, where lakes account for 10% of the total terrestrial area. We present a method to mitigate for the influence of lakes through forward modeling of snow covered lakes, as a part of a microwave emission simulation scheme of space-borne observations. We apply a forward model to predict brightness temperatures of snow covered sceneries over several winter seasons, using available data on snow cover, vegetation and lake ice cover to set the forward model input parameters. Comparison of model estimates with space-borne observations shows that the modeling accuracy improves in the majority of examined cases when lakes are accounted for, with respect to the case where lakes are not included in the simulation. Moreover, we present a method for applying the correction to the retrieval of Snow Water Equivalent (SWE) in lake-rich areas, using a numerical inversion method of the forward model. In a comparison to available independent validation data on SWE, also the retrieval accuracy is seen to improve when applying the influence of snow covered lakes in the emission model.     

Plumes of discolored water of volcanic origin and possible implications for algal communities. The case of the Home Reef eruption of 2006 (Tonga, Southwest Pacific Ocean)

The Home Reef volcano (Tonga, Southwest Pacific Ocean) erupted in August 2006. Initially a submarine eruption it quickly evolved into a subaerial event upon the formation of an ephemeral island.Remote sensing data from different sensors including MODIS, ASTER, EO-1 ALI and Landsat-7 ETM+ were used to analyze the event, focusing on the plumes of discolored water, ocean chlorophyll-a concentration (OCC) and sea surface temperature.An early classification system for the plumes was devised based on spectral properties and point of origin. Plumes originated at the volcano were named Type-I and those associated to the pumice rafts Type-II.Anomalies in ocean chlorophyll-a concentration, measured using MODIS data, were analyzed and a large bloom, presumably dominated by Trichodesmium sp. was identified. The bloom, which contributed to OCC values 17 times higher than the background, was spatially and temporally coincident with a Type-I plume of discolored water. The OCC increase appears to have been caused by a combined effect of both ocean fertilizations by the subsurface volcanic plume and rising sea surface temperatures.The Home Reef event offers a good candidate for a case of ocean enrichment by a submarine volcano and highlights the need for continuous monitoring of the eruptions even after the end of the explosive, more spectacular stages.     

SODA: A new method of in-scene atmospheric water vapor estimation and post-flight spectral recalibration for hyperspectral sensors: Application to the HyMap sensor at two locations

A new method of estimating per-pixel atmospheric column water vapor (ACWV) and potential differences in the reported band center wavelengths of the HyMap sensor has been developed. The new method uses variations of a second order derivative algorithm (SODA) to assess the impact of atmospheric residual features on calculated surface reflectance spectra after atmospheric compensation. The SODA method provides an alternative to the current band ratio techniques of ACWV estimation and also allows the same form of algorithm to be used for the estimation of possible band shifts. A comparison of in-situ measured surface reflectance at two field sites in Western Australia demonstrates improvement in the resulting spectra when post-flight updates are made to the reported HyMap band center wavelengths and applied during the atmospheric compensation process. The same SODA methodology was varied to estimate the ACWV on a per-pixel basis and found to significantly reduce the appearance of the underlying surface structure on the resulting ACWV images as well as improve the overall accuracy of the estimation. The ACWV estimated from the HyMap imagery at the two field sites was found to agree with in-situ atmospheric ACWV measurements to within 2% and represented a two fold increase in accuracy over a 3 band ratio Continuum Interpolated Band Ratio (CIBR) technique of ACWV estimation.     

模糊控制在循环水加酸控制系统中的应用

以火电厂循环水加酸控制系统为研究对象,分析了影响循环水耗水量的主要因素.根据循环水加酸控制系统对象难以建立、非线性和大滞后的特点,采用了模糊控制算法.设计了模糊控制器,利用了离线计算在线查表的控制策略,并用PLC加以实现,该方法减少了在线运行的计算量.实际运行结果表明,该系统能够克服环境温度带来的干扰,使循环水pH值被...     

高层二次供水泵站远程监控系统的设计与实现

近几年,各级政府开始要求城市供水企业将高层建筑二次供水纳入日常管理范围,为了达到科学高效的管理目标,提出采用计算机、网络和自控技术对二次供水泵站进行远程监控,并详细介绍了系统的建设目标、建设原则、网络结构、中心端硬软件配置、现场端数据采集和地址分配。该系统实现了不同型号设备跨平台的集成,在实践中具有推广价值。     

锅炉水温度和压力专家PID分段控制系统

原有锅炉温度和压力调节系统性能不能满足生产需求,结合专家控制和PID控制的优点,根据误差的变化范围提出了专家PID分段控制方案.从控制结果可以看出,该方法对水温及水压实现了有效的闭环恒值控制.     

冷喂料胶管生产线的自动控制系统

The current status of colloidal tube production in China and the technique process of the tube prod uction are described in brief． The funct ions and the implementation of the control system, the mathematical model of the PID operation and the block diagram of program are introduced in detail．