Carrying capacity of water environment in public tourism resources based on matter-element model

When water environmental carrying capacity of public resource tourist attraction is studied, the two action subjects of tourists and local residents should be discussed, and comprehensive consideration must be given to the influence of these two on water environment. On the basis of water resource carrying capacity and water quality carrying capacity, water environmental carrying capacity index of public resource tourist attraction was constructed, the model for the water environmental carrying capacity of public resource tourist attraction was established on the basis of matter-element model and analytical hierarchy process. By applying this method, water environmental carrying capacity situation of a certain public resource tourist attraction can be gained, moreover, situations about several aspects of water environmental carrying capacity can be evaluated.

Linking Numerical Water Quality Models in an Environmental Information System for Integrated Environmental Assessments

Decision makers involved in prevention of water contamination often lack the technical knowledge of water quality evaluation or the comprehension of complex software for environmental information management required to make effective decisions. Providing information about the environment is not an easy task due to its complex structure, relationships, and dynamic processes. Because environmental models play an important role in environmental decision support systems, the integration of models into user-friendly integrated information systems is a key factor in the support of such users. This paper presents an environmental information system which supports water protection of Coatzacoalcos River in Mexico, having as a main building block water quality assessments supported by mathematical modeling through the two-dimensional Saint Venant and Advection-Diffusion-Reaction equations to calculate the river hydrodynamics and the contaminant transport, respectively. The mathematical modeling solution yields appropriate results representing the river contaminant distribution when compared with field measurements. But the direct use of these models by decision makers is difficult at best, meaning they are not likely to be used in making practical decisions. The system described in this paper integrates these models, and several other tools, into a seamless, user-centered application, improving model usability, initial configuration, and results visualization.

The 3D simulation and optimized management model of groundwater systems based on eco-environmental water demand

Through the study of mutual process between groundwater systems and eco-environmental water demand, the eco-environmental water demand is brought into groundwater systems model as the important water consumption item and unification of groundwater抯 economic, environmental and ecological functions were taken into account. Based on eco-environmental water demand at Da抋n in Jilin province, a three-dimensional simulation and optimized management model of groundwater systems was established. All water balance components of groundwater systems in 1998 and 1999 were simulated with this model and the best optimal exploitation scheme of groundwater systems in 2000 was determined, so that groundwater resource was efficiently utilized and good economic, ecologic and social benefits were obtained.

Modeling the fate of paddy field pesticide in surface water and environmental risk assessment

The risk of drinking water is greatly concerned because of the large amount of pesticide applied to paddy field and the contamination of drinking water sources due to the runoff. A mathematical model is developed, based on the mass balance, to predict the fate of paddy field pesticides from application, runoff and mixing in a river, taking account of the physical chemical properties and processes of volatilization, degradation, adsorption and desorption. The model is applied to a river basin in Japan to estimate the contaminant level of several popularly used pesticides at the water intakes. The health risk in drinking water induced by each pesticide concerned is estimated and evaluated by comparing with the acceptable daily intake values(ADI) and with that induced by trihalomethanes. An index to evaluate the total risk of all pesticides appearing in water is proposed. The methods for risk management are also discussed.

Modelling of water quality of Minjiang estuary

In order to establish economic development region at Mawei districtwhich is nearby downstream of Minjiang river and to answer the question of impact of economic development on water quality of Minjiang estuary, the analyses of hydrologic and hydraulic characteristics of Mawei reach of Minjiang tidal river, a two-dimensional mathematical model has been established and simulation of water quality was studied. The results show that the flushing time of a conservative pollutant during dry and raining period are 12 and 7 days respectively from Mawei to Minjiang mouth, the decay rate constants of BOD and NH3-N are 0.1 to 0.4 and 0.18 to 0.45 d-1 respectively. The capacity of dilution and assimilation for pollutants is larger.

Environmental Risk Imposed by Diverted Flood Waters on Water and Soils in Emergency Retention Basins

Emergency retention basins (ERB) are diked enclosures alongside rivers into which water from the main river channel is diverted during extreme floods. If the basins are operated during extreme flooding, two negative environmental impacts may occur: 1) contamination of the soils due to their transport by suspended sediments to the basin and 2) depletion of dissolved oxygen in the basin water. A computer-based methodology is presented which was used to assess the environmental risk exhibited by the operation of an ERB system proposed for the Elbe River in Germany. The August 2002 extreme flood event was used as a test case. For such a flood, the results showed that there is a 77% risk that dissolved oxygen levels fall below 2 mg/L in the water and a 48% chance of exceeding the inspection value of 500 mg zinc/kg in the soil.

长江经济带水污染、环境规制与高质量经济发展关系研究

基于2009—2021年长江经济带11个省(市)面板数据,通过构建高质量经济发展评级指标体系,利用熵值法对高质量经济发展水平进行测度;基于环境库兹涅茨曲线理论进行基准回归,以水污染为门槛变量分析了环境规制对高质量经济发展的影响,并探讨了长江经济带上游、中游、下游3个区域水污染和环境规制的空间异质性。结果表明:随着水污染程度的加剧,环境规制对高质量经济发展表现出抑制作用,且抑制作用先增大后减小;水污染与高质量经济发展之间呈倒“U”形关系,且存在“环境库兹涅曲线”;长江经济带水污染与环境规制对高质量经济发展具有空间异质性。

基于水环境容量的污染物总量控制研究

目前有关水环境容量和污染物总量控制的理论研究已经非常成熟,我国污染物总量控制正在由目标总量控制向理想状态的容量总量控制过渡。本文将污染物总量控制与水环境容量的研究发展相结合,阐述了污染物总量控制的具体方法,并以水环境数学模型为例详细介绍了污染物控制总量的确定及总量分配。根据研究进展和工作实际指出,当地方经济发展与环境保护处于对立面时,现有的目标总量控制以及总量分配难免会有失偏颇,建议探索出一条适合我国国情的中国特色容量总量控制和总量分配方法。

河北省水资源与经济社会、环境耦合协调度研究——基于再生水利用视角

再生水是传统水资源的重要补充,开发利用再生水可以缓解河北省水资源短缺和供需矛盾.基于再生水利用视角研究河北省水资源利用与经济社会、环境的相互影响关系,构建了再生水-经济社会-传统水资源-环境(RETE)系统评价指标体系,运用熵值法对RETE系统的发展水平进行综合评价,并采用耦合协调度模型和灰色关联分析探究了RETE系统的耦合协调程度及其影响因素.结果表明:河北省再生水、经济社会、传统水资源、环境子系统的发展水平呈上升趋势,且存在一定的区域差异性;RETE系统的耦合协调度逐年上升,并且除保定、沧州和衡水濒临失调外,其他城市均处于耦合协调阶段;此外,RETE系统耦合协调度的主要影响因子为城镇化率、污水处理率、建成区绿化覆盖率、城镇居民人均可支配收入、人均GDP.

基于自适应PID的智能建筑供热系统节能控制方法

由于客观环境温度波动,建筑供热系统在统一输出模式下的能耗相对较高。因此,提出基于自适应PID的智能建筑供热系统节能控制方法。在构建建筑供热系统运行逻辑模型的基础上,结合实际环境温度,引入PID对回水循环过程的温度进行控制,并根据环境的实际温度与管理要求之间的温度差,差异化选择阀门开度调节方式、水温调节方式以及温补动态调节方式。结果表明,设计的控制方法具有良好的节能效果。

Physical Hydrography and Algal Bloom Transport in Hong Kong Waters

In sub-tropical coastal waters around Hong Kong, algal blooms and red tides are usually first sighted in the Mirs Bay, in the eastern waters of Hong Kong. A calibrated three-dimensional hydrodynamic model for the Pearl River Estuary （Delft3D） has been applied to the study of the physical hydrography of Hong Kong waters and its relationship with algal bloom transport patterns in the dry and wet seasons. The general 3D hydrodynamic circulation and salinity structure in the partially-mixed estuary are presented. Extensive numerical surface drogue tracking experiments are performed for algal blooms that are initiated in the Mirs Bay under different seasonal, wind and tidal conditions. The probability of bloom impact on the Victoria Harbour and nearby urban coastal waters is estimated. The computations show that： i） In the wet season （May - August）, algal blooms initiated in the Mirs Bay will move in a clockwise direction out of the bay, and be transported away from Hong Kong due to SW monsoon winds which drive the SW to NE coastal current; ii） In the dry season （November- April）, algal blooms initiated in the northeast Mirs Bay will move in an anti-clockwise direction and be carried away into southern waters due to the NE to SW coastal current driven by the NE monsoon winds; the bloom typically flows past the east edge of the Victoria Harbeur and nearby waters. Finally, the role of hydrodynamic transport in an important episodic event -- the spring 1998 massive red tide -- is quantitatively examined. It is shown that the strong NE to E wind during late March to early April, coupled with the diurnal tide at the beginning of April, significantly increased the probability of bloom transport into the Port Shelter and East Lamma Channel, resulting in the massive fish kill. The results provide a basis for risk assessment of harmful algal bloom （HAB） impact on urban coastal waters around the Victoria Habour.

The Use of Imitation Models at Developing and Introducing Information-Control Systems

Imitation models for computing the environmental water pollution level depending on the intensity of pollution sources created by the author over the years are presented. For this purpose, an additive model of a non-stationary random process is considered. For the modeling of its components, models that consider only dilution and self-purification processes are proposed for waste water and three-dimensional turbulent diffusion equations for river waters, and multidimensional Gaussian Markov series are proposed for modeling the random component. The purpose, the capabilities and the peculiarities of such imitation models are discussed taking into account the peculiarities of the water objects. The modular principle of creating imitation models is proposed to facilitate their development and use.

基于MIKE11的合流制截流倍数优化

文章以安徽阜阳地区界首市界临河为例,以化学需氧量(chemical oxygen demand,COD)和氨氮为指标,按照排放的污水水质、污染物质量浓度差异,将研究区域划分为工业区、居民区、城中村3个区域,采用取最值法,将区域内溢流口概化为连续恒定的污染源,并设计分质截流倍数,建立MIKE11水动力水质模型;从降低河流中污染物质量浓度、提升动态水环境容量2个方面,对比分质截流与传统截流的截流效果。结果表明:采用传统截流倍数时,界临河中河长制断面处,ρ_(COD)、ρ(NH_(3)-N)分别降低28%、25%;采用分质截流倍数时,ρ_(COD)、ρ(NH_(3)-N)分别降低39%、32%;在COD和氨氮的动态水环境容量方面,分质截流比传统截流分别提升30%、16%,可见分质截流对河流水质改善效果优于传统截流。研究结果可为老城区截流式合流制排水系统改造提供参考。

长江经济带环境规制对水资源利用效率的影响——基于技术创新中介效应的视角

高效利用水资源是当前水资源可持续利用的关键,环境规制是影响水资源利用效率的重要因素。为分析环境规制对水资源利用效率的影响,特别是探讨存在技术创新时两者之间的作用关系,选取2004~2019年间长江经济带108个地级市的面板数据作为研究样本展开分析。利用Super-SBM模型测算长江经济带各城市的水资源利用效率,分析技术创新视角下环境规制对水资源利用效率的影响机制,实证检验环境规制对水资源利用效率的影响程度。结果表明:长江经济带水资源利用效率偏低;环境规制对长江经济带水资源利用效率具有显著的提升作用,其中,对长江经济带下游的作用力度最高,中游次之,上游最低;技术创新作为中介变量,在环境规制与水资源利用效率之间起到部分中介效应,环境规制可以通过技术创新间接影响水资源利用效率。研究成果可为促进长江经济带水资源保护及区域高质量发展提供参考。

基于QUAL2K模型的滦河流域动态水环境容量研究

传统的水环境容量核算一般以一定保证率下的设计枯水流量为计算条件,存在水文计算条件单一、水环境容量不易管控等不足。本文通过滦河流域污染排放调查核算,基于QUAL2K模型建立水质模型,对流域水质进行逐日模拟,并根据模拟结果计算滦河流域主要河流逐日COD、氨氮和总磷的水环境容量。本研究计算的动态水环境容量能够较为客观地反映水文条件变化下的动态水环境容量,给出满足河道水质目标前提下逐日入河污染物允许阈值,为流域水环境保护与精细化管理提供数据支撑。

基于一维水动力-水环境耦合模型的长兴港生态流量研究

【目的】长兴港是太湖流域重要的城市河流,对其开展生态流量研究并确定合理的生态流量管控值,对保障长兴港水生态环境健康、提高当地人民群众幸福指数具有重要意义。【方法】以长兴港新塘断面2016—2020年的逐月水生态监测数据为对象,明确了长兴港非汛期、汛期的水环境约束指标;并基于MIKE 11软件,构建了一维水动力-水环境耦合模型;从保障水生态环境质量、缓解水华爆发的营养条件的角度出发进行了生态流量研究。【结果】结果显示:长兴港非汛期约束指标为NH_(3)-N、COD_(Mn)和BOD,汛期约束指标为NH_(3)-N、TP和COD_(Mn);通过对比实测数据与模拟数据可知,水位、流量的模拟值与实测值间的Re均小于10%,R^(2)和Nash-Suttcliffe系数分别大于0.6和0.9,各时期的水环境主要管控指标的模拟值与实测值间的Re均小于17%;最终计算得到长兴港非汛期和汛期合理的生态流量管控值分别为2.59 m^(3)/s和2.63 m^(3)/s。【结论】结果表明:研究构建的一维水动力-水环境耦合模型符合长兴港的实际情况,能够应用于长兴港生态流量研究,可以解决水动力和水环境模块单独使用不能表征河流特点的问题,为河流生态流量的研究和管控提供了更为科学、高效的工具;研究提出的生态流量管控值具有可达性,可切实有效地改善长兴港水生态环境、抑制水华爆发并为长兴港的生态流量管控和“幸福河”构建等工作提供理论与技术支撑。