水资源是制约社会经济发展的重要因素之一,以浙江省临海市为研究区域,分析城市水资源承载力的动态变化及引起变化的主要驱动因素.基于城市水资源承载力复合系统分析,采用模糊评判法和熵值法联合评价临海市2010-2015年水资源承载力水平,并采用单因素敏感性分析方法和情景分析法进一步分析临海市水资源承载力动态变化驱动因素.结果 表明:近年来临海市水资源承载力水平总体上呈波动上升趋势,社会经济发展是水资源承载力水平动态变化的主要驱动来源;城镇化率、第三产业占GDP比重、工业用水重复利用率为主要驱动因素,其中第三产业占GDP比重的驱动影响较为突出.研究为临海市实现城市水资源可持续利用提供决策参考.

生态修复对遏制城市湖泊生态系统的退化意义重大,寻找一种有效且简单的生态修复效果预测方法有利于进一步推动湖泊修复研究的发展.利用综合污染指数法、基于专家调查法的湖泊污染物浓度确定方法及水质提升贡献度分析了生态修复的水质响应,并采用基于污染负荷平衡的水质模型预测了生态修复措施作用下的潜龙渠水质.结果 表明:4种污染物浓度均有下降,潜龙渠水质提升显著,但各污染物对不同修复措施的响应程度不同,COD的浓度控制需要污染源控制与修复净化的共同支撑,TN对各项措施的敏感性接近,TP、NH3—N分别对污染源控制、生态补水敏感性最高.情景预测表明,依据水质响应关系制定的生态修复方案,能够稳定保持潜龙渠的生态修复效果.

River water system is an important resource and environmental carrier of the city. The contradiction between urban development and water environment protection is becoming more and more prominent in recent years,especially in the plain river network area. Due to geographical constraints,the improvement of urban river water environment is challenging. The sustainable development of urban water system will be directly related to the healthy development of cities and the whole society. Therefore implement modern water system management theory and promote water environment improvement through the interconnected river system has become an important step of urban water management. In this paper, the urban area of Changshu city is selected as the research area. The water transfer experiment and the hydraulic model areapplied as technical support to formulate river interconnected schemes for the sake of water environment enhancement. Based on the concept of structural connectivity and functional connectivity, the river network connectivity assessment method is proposed. In the water transfer experiment,flow exchange in major rivers is satisfied and water quality of indexes is increased 20%-30% in average. Yet the river connectivity inthe central downtown is limited which leads to less flow access. The improvement of river channel connectivity and the reasonable dispatching of water conservancy project have important influence on the connectivitysystem. Taking the scenario simulations in the paper as an example,channel regulation projects increase river connectivity and give rise to water quality about 30%-50%. The change of connectivity index also prove that structural connectivity greatly enhances water transfer efficiency,and promotes better flow distribution and water environment. The establishing methodology of interconnected water system to improve water environment can provide theoretical basis for water system connectivity decision,and provide reference for urban water system connectivity in China.

Freshwater shallow lakes of small-to-medium size are distributed across the eastern plain areas of China.Influenced by a high rate of urbanization and intense human disturbance due to rapid economic development,these lakes are facing such environmental problems as eutrophication and ecological service function loss. A case study was conducted on the lakes in the Wujiang District,in Suzhou City,to the southeast of Taihu Lake. Based on ecological characteristics of shallow lakes,a conceptual framework of lake ecosystem health was put forward to establish the lake ecosystem health evaluation system. Four factors and 12 indices were selected to describe the state of lake health. The factors include the ecological faltor,the environmental factor,human disturbance,and ecological construction. Results show that water quality degradation and extensive human exploitation are the critical causes of the imbalance of the lake ecosystem. Based on these results, ecological restoration and construction measures are formulated for a typical lake,Sanbaidang Lake,providing a scientific basis for lake ecosystem management and protection.

This study was carried out in a typical small watershed of the Taihu Basin. The aquifer calculation parameters were identified through systematic field experiments on near-surface geological features and analysis of near-surface soil and rock structural features. The three-dimensional groundwater numerical simulation method was used to generalize the hydrogeological conditions,and to identify and verify the model parameters. The results show that the surface water recharge to groundwater is approximately twice the groundwater recharge to the surface water,and the interaction between the surface water and groundwater in stream-type watersheds tends to be unidirectional.That is,the river water recharges groundwater. In terms of the change of water storage in the aquifer,in addition to evapotranspiration,water loss through the underground passage accounts for a large proportion of the total water amount,and the reduced groundwater storage is recharged mainly by rainfall infiltration. The established model can well reflect the actual hydrogeological conditions of the study area. It has been used to describe the change process of the interaction between the surface water and groundwater,and to quantitatively study the dynamic changes of the basin water balance. In addition,it can provide a basis for the prediction and analysis of groundwater protection in changing environments and groundwater undercurrent calculation of lake areas.

According to some problems of sponge city construction such as the practice of the construction of the sponge city is mostly confined to the city or the research area,lacking of co-ordination between internal and external drainage basins,overemphasizing low impact development,ignoring the fact of hardened city which is difficult to reform,this article focuses on the relationship between the sponge city and the watershed control as well as the basic measures of river basin control,and briefly expounds the main steps in the preparation of the implementation plan of the sponge city. It is considered that the construction of sponge city is a systematic project of multi branch and multi discipline,and related basic theory research and engineering construction should be strengthened.

Based on the principles of the Markov model dynamic evaluation was conducted to investigate the improvement of water quality after an experiment on prototype water diversion in Changshu City. Tthe water quality evaluation indices were selected for the dimensionless analysis,the division of the degree of membership,and the allocation of weights. The probability transfer matrix was established to obtain the degree of progress,and the change of concentrations of pollutants in the process of water diversion was analyzed,in order to evaluate the water quality. The results show that the water quality of all the sections have changed after the water diversion. The water quality of most of the sections improved,with the most significant improvement seen in the two sections nearest the water inlet. Meanwhile,the water quality of some sections deteriorated due to insufficient water diversion and pollution in the land area along the water diversion route.

A co-governance program for five waters (CPFW), including sewage treatment, flood prevention, drainage, water supply and saving, is an innovative concept in water resource management. It includes current and near future system projects and advanced management policies for water utilization and protection. In this paper, the scientific connotation of CPFW is explained by multidisciplinary theory. Based on current guidance and technology, evaluation targets and water management countermeasures are specified. Combining hydraulic engineering and their characteristics, operable approaches for CPFW are suggested for projects' designation and construction. These approaches of CPFW are applied in a typical area. Systematic projects are composed of sewage interception projects, efficient water supply projects and hydraulic projects with ecological engineering. With the guidance of CPFW, all projects are connected together and their integrated benefits are evaluated in water saving, sewage drainage, increase in environmental capacity and ensuring security. The results show the CPFW is valuable and available both in theory and in practice.

In view of the uncertainty of indexes for evaluating water resources carrying capacity, to resolve the incompatibility of the results of evaluating water resources carrying capacity, and to raise the distinguishment of the model of evaluating water resources carrying capacity, an effective and general model-Projection Pursuit Classification model is suggested. The density window breadth R is the window way radius that solves the partial density, it is determined by the characteristic of the sample datum, and it is mainly determined by trying to calculate or experience, which lacks theoretical basis, this article improves the density window breadth R of the model in theory, it deduces and acquires the empirical formula of calculation, making the model more scientific and stable. It adopts Real Coding based on Accelerating Genetic Algorithm to find the best projective direction, at the same time, uses the datum of the best projective direction to research the level of the influence of each factor to water resources carrying capacity, the classification results which accord with the fact are gained, which provide the decision proof of water resources carrying capacity.

The per capita ecological footprint (EF) is one of the most widely recognized measures of environmental sustainability. It aims to quantify the Earth's biological resources required to support human activity. In this paper, we summarize relevant previous literature, and present five factors that influence per capita EF. These factors are: National gross domestic product (GDP), urbanization (independent of economic development), distribution of income (measured by the Gini coefficient), export dependence (measured by the percentage of exports to total GDP), and service intensity (measured by the percentage of service to total GDP). A new ecological footprint model based on a support vector machine (SVM), which is a machine-learning method based on the structural risk minimization principle from statistical learning theory was conducted to calculate the per capita EF of 24 nations using data from 123 nations. The calculation accuracy was measured by average absolute error and average relative error. They were 0.004883 and 0.351078% respectively. Our results demonstrate that the EF model based on SVM has good calculation performance.

In view of the complexity of indexes for evaluating water-saving irrigation program, to resolve the incompatibility of the results of evaluating water-saving irrigation program, and to raise the distinguishment of the model of evaluating water-saving irrigation program, application of projection data distribution and normal distribution difference as projection index, an effective and general model, named as K-L absolute information dispersion clustering model was suggested. The Real Coding based on Accelerating Genetic Algorithm was used to find the best projective direction, and the data of the best projective direction to research the level of the influence of each factor to water-saving irrigation program, the classification results according with the fact were got, which provided the decision reference for water-saving irrigation program.

Agriculture is an important contributor to diffuse pollution in the aquatic environment system. The exact transfer of nitrogen (N) and phosphorus (P) in an agriculturally dominated area is still poorly understood. Export of pollutants shows significant spatial and temporal variation and the relevant factors are complex and nonlinear in nature. There has been a dramatic increase of synthetic fertilizer usage in southern China during recent decades due to decreasing farmland and increasing food demand. Massive N and P fertilizer application has led to many environmental problems, especially eutrophication. Research has shown that extreme rainstorms will increase in frequency with climate change. The objective of this study is to examine the diffuse agricultural pollution transfer at the watershed-scale and field-scale through event- based, on-site observation and sampling. Seven years of experiments carried out in Meilin watershed demonstrate the export of significant quantities of nutrients during high intensity rainstorms. Based on detailed field experiments, the N and P transfer in different seasons and land covers is described.

The Improved Back Propagation Neural Network (IBPN) model was developed to predict the longitudinal dispersion coefficient for natural rivers. The hydraulic variables [mean flow depth (H), flow velocity (u) and shear velocity (u*)] and geometric characteristic [channel width (B)] constituted inputs to the IBPN model, whereas the longitudinal dispersion coefficient (Kx) was the target model output. The model was trained and tested using 23 data sets of hydraulic and geometric parameters, of which first 20 data sets were used to train and validate the model, and the rest data to test. In this model, cross validation theory was applied. To overcome the shortage of the traditional BPN model, the network was designed to determine the optimal weights and thresholds by random sampling at the interval (−1,1) for 1000 times, which would generate an output as close as possible to the target values of the output. The training of the IBPN model was accomplished with the no error fitting and the prediction average relative error was 8.07%. The results indicated that both prediction accuracy and the generalization ability were significantly improved.

Water pollution is the main threat to sustainable environmental and social-economic development in Taihu basin, China. To resolve conflicts between population growth and food supply, high-efficiency agricultural practices were implemented with the benefit of the reduction of farming lands and an increase in food production. As a consequence, large amounts of fertilizers were consumed, which resulted in serious diffuse pollution from agriculture in the region. The fate of this diffuse agricultural pollution is closely related to hydrologic processes. The hydrologic response mechanisms are the basis for understanding diffuse pollutant transport. A distributed hydrologic model system (HMS) which couples various components of the watershed hydrologic cycle such as surface water, channel water, soil water and groundwater, as well their interactions, was used to simulate various hydrologic processes in the Meilin watershed. Driven by the distributed hydrologic model, the diffuse pollution forecasting model was established by simplifying nitrogen (N) and phosphorous (P) dynamics. The model showed good simulation results and obtained the distribution of the critical source areas of total nitrogen (TN) and total phosphorous (TP) export in the Meilin watershed. The research results provide a scientific basis for the effective control of agricultural diffuse pollution in the Taihu basin.

The per capita ecological footprint (EF) is one of the most-widely recognized measures of environmental sustainability. It tries to quantify the earth's biological capacity required to support human activity. This study at first summarize the previous literature, and then present the five factors which influenced the per capita EF, they are the nation's GDP, urbanization independent of economic development, the distribution of income measured with the Gini coefficient, Exports as percentage of total GDP, Service as the percentage of total GDP. On the base of it, an ecological footprint model based on improved BP network (IBPN) is conducted to predict the 24 nation's per capita EF used the 123 nation's data. The forecasting accuracy is measured by average absolute error and average relative error. They are 0.0022842 and 0.016206% respectively. The results demonstrate that the EF model based on IBPN has good forecasting performance.

The per capita ecological footprint (EF) is one of the most widely recognized measures of environmental sustainability. It tries to quantify the earth's biological capacity required to support human activity. This study first summarized the previous literature, and then presented the six factors which influenced the per capita EF, they are the nation's gross domestic product (GDP), urbanization independent of economic development, the distribution of income measured by the GINI coefficient, exports dependence as measured by the percentage of exports to total GDP, service intensity measured by the percentage of service to total GDP and their position in the core/periphery hierarchy of world system(WSP). Based on it, a new ecological footprint model based on partial least squares regression (PLSR) which is specifically designed to deal with multiple regression problems, especially for the number of observations is limited, missing data are numerous and the correlations between the predictor variables are high was conducted to predict the 13 nations' per capita EF used the 110 nations' data. The forecasting accuracy was measured by average absolute error and average relative error. They were 0.012889 and 0.3071% respectively. The results demonstrated that the EF model based on PLSR has good forecasting performance.

The various calculation methods and defects of determining river longitudinal dispersion coefficient were analyzed,a nw method for calculating the river longitudinal dispersion coefficient was put forward. The method was based on SVM theory to establish a SVR regression model. The input variables were mean river depth H,width W,velocity v and friction velocity v*. The output variable was longitudinal dispersion coefficient EX. 22 groups of data were selected to train and test model,among which,20 groups were selected as training data and the rest groups were used as validation data. The mean relative error of the model prediction was 0.29.The result indicated that the SVM algorithm can predict river longitudinal dispersion coefficient efficiently and simply.

In view of the uncertainty of indexes for evaluating water-saving irrigation program,in order to resolve the incompatibility of the evaluation results about water-saving irrigation program,and to raise the resolution of the evaluation model for water-saving irrigation program,we suggested an effective and general model,which is the classification model by K-L absolute information divergence of projection pursuit.It adopts Accelerating Genetic Algorithm based on Real Coding to find the best projective direction,and uses the datum of the best projective direction to research the influence level of each factor on the water-saving irrigation program;the classification results which accord with the fact are obtained,and it provides a decision basis for the water-saving irrigation program.

By use of the Y-type sediment re-suspension generator,laboratory model tests were performed on concentration variations of suspended sediment(SS),ammonia nitrogen(NH3-N) and phosphate(PO3-4) of Zhushan water area in the northwest of Taihu Lake under conditions of algae with different quantities and wastewater with different concentrations of CODCr based the original sediment and water body collected from Taihu Lake.The result shows that during 7 days' simulation under common wind waves,the concentration of SS in Taihu Lake tends to decrease no matter the addition of algae or wastewater,SS tends to reduce,indicating that the particles are possible to settle on the riverbed.However,the concentrations of NH3-N and PO3-4 do not increase with the increase of quantity of algae,indicating that the alive algae can absorb nitrogen and phosphate in the water.The increase of wastewater with different concentrations of CODCr results in the increase of concentrations of NH3-N and PO3-4,and they have a increasing tendency with the time.

SPI series of precipitation in the Dongjiang River Basin from 1951 to 2000 is calculated under different time-scales and precipitation abnormal grade is classified accordingly.Transition probability matrix between the abnormal grades and average durations of different precipitation grades are obtained by Markov Chain analysis.Furthermore,the reliability of precipitation prediction in future 3 months based on statistical precipitation series is evaluated.The results can provide support for water resources management,especially water resources allocation in dry periods.