Comparison and Selection of Water Restoration Techniques for Artificial Landscape Lakes in Nantong City

As an important part of urban infrastructure,urban water system is of great and far-reaching significance for ensuring urban flood control and waterlogging safety,protecting ecological environment and building livable homes.Taking the urban water system of Nantong as an example,Nantong Water Resources Bureau issued R evision of Nantong Urban Water System Planning in 2017,and put forward the construction of the"two circles,eight lakes and nine veins"water system layout,giving new vitality to the urban water system.In view of problems existing in newly excavated artificial landscape lakes,such as fragile water ecosystem,strong eutrophication trend,poor environmental sensory effect and unsatisfactory water landscape effect,it is urgent to study the in-situ water ecological restoration technique of"algae-controlling zooplankton+submerged plant community"to build a"grass-type clear water"ecosystem for artificial landscape lakes,so as to improve the water sensory index and self-purification ability and finally realize the double improvement of"sensory effect and water quality"of artificial landscape lakes.

Spatiotemporal Differentiation of Urban Spatial Form and Carbon Emissions in Poyang Lake City Group

In response to the inherent requirements of low-carbon land spatial planning in Jiangxi Province and the lack of existing research,this paper explored the mechanism of spatial form elements of Poyang Lake urban agglomeration on urban carbon emissions.Based on generalized linear regression and geographically weighted regression models,this paper analyzed the spatiotemporal distribution characteristics of carbon emissions,the spatiotemporal relationship between urban form index and carbon emissions,and the spatial differentiation of the intensity of dominant factors from 63 county-level administrative units in the Poyang Lake city group from 2005 to 2020.The results showed that:①The carbon emissions of urban agglomerations around Poyang Lake are generally increasing,and the spatial distribution of carbon emissions is characterized by high-value concentration in the middle and low-value agglomeration in pieces;②The main driving factor for the spatial heterogeneity of carbon emissions was the expansion of built-up area;③Improving urban compactness and optimizing urban form could effectively reduce urban carbon emissions.The results showcased the correlation between urban spatial landscape pattern and the spatiotemporal distribution of carbon emissions,which could make the low-carbon land spatial planning in the Poyang Lake city group more reasonable and practical.

Ecological Restoration Technologies of Urban Artificial Landscape Lakes

Aiming at the problems of water pollution and ecological environment degradation in urban artificial landscape lakes,the ecological restoration technologies of artificial landscape lakes at home and abroad were studied to provide some reference for the ecological restoration of urban artificial landscape lakes in China.

Prediction of the concentration of chlorophyll-α for Liuhai urban lakes in Beijing City

The weekly water quality monitor data of Liuhai lakes between April 2003 and November 2004 in Beijing City were used as an example to build an artificial neural networks （ANN） model and a multi-varieties regression model respectively for predicting the fresh water algae bloom. The different predicted abilities of the two methods in Liuhai lakes were compared. A principle analysis method was first used to select the input variables of the models to avoid the phenomenon of collinearity in the data. The results showed that the input variables for the artificial neural networks were T, TP, transparency（SD）, DO, chlorophyll-a （Chl-a）,pH and the output variable was Chl-a. A three layer Levenberg-Marguardt feed forward leaming algorithm in ANN was used to model the eutrophication process of Liuhai lakes. 20 nodes in hidden layer and 1 node of output for the ANN model had been optimized by trial and error method. A sensitivity analysis of the input variables was performed to evaluate their relative significance in determining the predicted values. The correlation coefficient between predicted value and observed value in all data and in test data were 0.717 and 0.816 respectively in the artificial neural networks. The stepwise regression method was used to simulate the linear relation between Chl-a and temperature, of which the correlation coefficient was 0.213. By comparing the results of the two models, it was found that neural network models were able to simulate non-linear behavior in the water eutrophication process of Liuhai lakes reasonably and could successfully estimate some extreme values from calibration and test data sets.

A GIS-based Spatial Analysis of Housing Price and Road Density in Proximity to Urban Lakes in Wuhan City, China

As one of the essential urban open spaces, lakes usually contribute immensely to the quality of residents′ daily lives. Different from hedonic approach employed in existing researches on urban open spaces in China, this paper integrates housing price surface with road density to analyze the spatial characteristics in proximity to urban lakes in Wuhan City, China. With the expansion of Wuhan City, urban lakes became polluted, they shrunk or even disappeared, leading to unfavorable conditions for sustainable development of the city. To better understand the spatial relationship between the city and lakes, we classify the urban lakes in Wuhan central area into ′lakes in the urban center′ and ′lakes in urban fringe′. Based on housing price surface we explore the spatial characteristics in proximity to different lakes and differences between the lakes. We also use Geographic Information System(GIS) tool to calculate road density as a supplementary indicator to reflect the accessibility in proximity to urban lakes. The results indicate that relative independence exists between different towns, and the spatial characteristics are different depending on scales and locations. In most of cases, the road density is lower where closer to the lakeshore while the housing price exhibits an opposite pattern. We conclude that city governments and urban planners should give more considerations to these spatial differences, somewhere should be better planned and protected as an important waterfront and somewhere the control of unreasonable real estate development nearby should be strengthened.

Ecological Landscape Design of Urban Wetland Park: A Case Study of the Aixi Lake Wetland Park in Nanchang City

Wetland as one of the natural landscapes with the richest biodiversity and most closely related to our life is widely distributed all around the world, and capable of storing fl ood, preventing drought, purifying environment, adjusting climate, controlling pollution, maintaining regional ecological balance. Nanchang is famous for "City in the Lake and Lake in the City", and this paper begins with wetland resources in Nanchang City, analyzes problems of local wetlands. Taking the design of the Aixi Lake Wetland Park for example, this paper proposes suggestions for the renovation and improvement by analyzing the problems of its current landscape pattern, and specifi c problems in the landscape design of wetland park, and summarizes the ecological model fi t for the landscape design of urban wetland park in Nanchang City. The research contributes to the ecological restoration and conservation of wetland resources in Nanchang.

A climatic environmental performance assessment method for ecological city construction:Application to Beijing Yanqi Lake

In contrast to the input perspective for evaluating planning metrics, this research takes the climatic environmental output effects as the starting point for assessing ecological city construction. Based on approaches such as observation data analysis, meteorological model simulation, and remote sensing, a set of climatic environmental performance assessment methods is developed and established. These methods mainly focus on surface ventilation assessment and urban thermal environment assessment. With the Yanqi Lake ecological development demonstration area located in Huairou district, Beijing as an example, the assessment of the local climatic environment before and after the construction are conducted, and relevant policy suggestions for urban planning and construction are presented. The results show that after development, the ventilation capacity will decrease overall and the ventilation potential index will decrease from 0.53 to 0.44. While this is not a large reduction, and is still at a favorable level, the ventilation potential in some local areas will markedly decrease. Furthermore, the thermal environment will become poorer to some extent; the urban heat island(UHI) area and intensity will increase compared with the current situation;continuous heat islands may occur in local areas; the UHI potential index of the core area will rise from 0.0878 to 0.1217(still a favorable level).Therefore, urban surfaces should be carefully developed and arranged during planning. It is suggested that the negative impacts of large areas of urban construction on the local climatic environment in the Yanqi Lake could be mitigated by 1) strengthening the airflow by introducing fresh,cold, northwesterly air via constructed ventilation corridors, 2) increasing the number of ecological cold sources, particularly for water bodies and green belts to prevent the UHI in the southern region of Yanqi Lake from becoming linked with each other, and 3) considering a pre-program before sub-domain and building planning to obtain optimum building locations. Different construction standards should be developed for different ventilation potential and UHI intensity levels. For strong heat island areas, land areas should be reserved to serve as cold sources.

Evaluation of and Control Schemes for Current Eutrophication of Land-scape Lakes in Kaifeng City,Henan Province

[Objective] Current eutrophication of landscape lakes in Kaifeng City was evaluated to provide scientific support for the prevention and control of landscape water eutrophication.[Method] The comprehensive trophic level index (TLI) and the modified Carlson's trophic state index (TSIM) were applied. [Result] TLI of water in Longting Lake and Baogong Lake was obtained as 73.84 and 70.23,TSIM was 66.51 and 65.23,respectively.[Conclusion] Water in both lakes was suffering from serious eutrophication,and urgent measures should be taken to control the eutrophication.

Construction and Protection of Qionghai Lake Wetland Ecosystems

Wetland is closely related to survival, reproduction and development of human beings. Due to population growth, industrialization, urbanization and agricultural modernization, wetland ecosystems are suffered from huge pressure of human society and the wetland ecological environment becomes extremely vulnerable. On the basis of analyzing current situations of Qionghai Lake wetland in Xichang City of Sichuan Province, this paper discussed the significance of Qionghai wetland construction and protection, and offered countermeasures and recommendations for solving existing problems in Qionghai wetland.

Comprehensive Management and Protection of Lakes in Kaifeng

Through analysing pollution source and status quo of the main lakes in Kaifeng,such as Dragon Pavilion Lake and Baogong Lake,the conclusion is that Kaifeng＇s lake environment has been in a greater pollution condition. For lake pollution situation,we put forward comprehensive management and protection approaches of lakes,including the relocation of businesses around the lake,plugging the sewage outfall surrounding lakes,dredging and deeply digging to increase the water environment capacity of lake. By dredging the river,the lakes in urban district connect together. Controlling aquaculture scale of lakes,the ecological function of the lake is played. Constructing drainage network around the lake,integration of landscape and lake flood control is formed. Adding new water into lakes,stagnant water becomes flowing water. We sum up the experience of lake management and protection： strengthening protection awareness is the key; lake remediation is the fundamental; attention to ecological protection of the lake is the most important factor in the development of lakes; exploiting a variety of functions of the lakes including landscaping,tourism,recreation,aquaculture,public health is the goal.

阜阳市幸福河湖评价及障碍因子识别

从水资源供给、水资源利用、水环境治理、水生态环境、水经济发展5个方面出发,选取15个指标建立了幸福河湖评价指标体系。基于熵权法和TOPSIS模型对阜阳市2012—2021年的幸福河湖情况进行了综合评价,采用障碍度模型识别了影响阜阳市幸福河湖的障碍因子。结果表明:阜阳市的幸福河湖建设情况在2012—2021年呈逐步增长趋势,影响幸福河湖的主要因素是水资源量、水资源利用及水生态环境情况。据此,结合阜阳市的水资源对经济发展的承载能力等方面,提出了优化阜阳市幸福河湖建设的建议。

区域视角下“城-湖”系统的界域与风景营建认知--以惠州西湖为例

传统“城-湖”系统是中国富有诗情画意的城市山水风景体系中重要的组成部分,对当今城市建设有重要的借鉴意义。结合地方历史文献、地图资料和广东区域史已有的研究成果,在地理信息技术辅助下,以惠州西湖和府城为例,从区域视角对“城-湖”系统的空间范围和风景营建进行了讨论。首先,基于水文分析结果与历史文献图纸比对,明确惠州“城-湖”系统界域范围;其次,从广东地区区域发展史的角度解释了中华人民共和国成立前惠州“城-湖”系统风景营建的统计和空间分析结果所反映的结构性和整体性特征。展示了历史-地理区域与“城-湖”系统之间的复杂关联,以及“城-湖”系统所具有的“城市历史景观”属性,对于理解中国传统空间设计与营建的动因有理论与实践的探索意义。

基于色彩要素量化分析的郑州市龙子湖滨水公园植物群落景观评价

色彩丰富的季相植物景观能提供丰富的视觉感受,营造良好生活环境。以郑州市龙子湖滨水公园为研究对象,基于季节性色彩量化分析,采用AHP法与SBE法对选定的20个植物群落进行植物景观色彩评价,分析影响植物景观色彩质量的主要因子。结果表明,样地植物种类多样,色彩丰富度较高,对比度较低,景观整体色相值偏低,饱和度及明度适中,色彩特征鲜明;AHP法与SBE法虽侧重点不同但二者评价结果具有一致性,可共同应用于景观评价中;根据评价模型可知色彩数量C_(1)、明度指数C_(8)是影响植物景观美景度的主要因子。本次研究结果可为城市园林绿化植物种类的选择及景观塑造提供理论支撑。

西北内陆河流域水资源韧性配置与生态复苏的思考及建议

西北内陆河流域水资源极度短缺,长期的过度开发与不均衡利用,导致水资源供需矛盾突出、生态系统退化、经济社会发展受阻。围绕西北内陆河流域重要战略地位和河湖复苏实践现状,分析了西北内陆河流域高质量发展面临的水资源问题与挑战。研究提出了遵循“四水四定”和“以水定绿”原则,识别经济社会与生态环境用水特性与弹性空间,科学确定用水优先级和调控策略,构建水资源韧性配置模式,实现经济社会发展和河湖生态复苏的统一;基于上中下游空间关联,量化生态服务供需关系,优化人工绿洲和天然绿洲规模,确定适宜的生态格局,实现生态水量优化配置与高效利用;建立“天空地水工”全要素监测体系,构筑水资源管理数字孪生平台,发展水利新质生产力,增强内陆河流域水资源系统的适应性和应对外部压力的能力。

基于生态韧性的山水林田湖草沙一体化保护修复框架

基于生态韧性内涵的山水林田湖草沙一体化保护修复是提升区域生态系统承载力和风险适应性的创新路径。本文阐述了生态韧性内涵与山水林田湖草沙生命共同体的特征,明确了一体化生态修复同生态韧性内涵关联逻辑,构建了山水林田湖草沙一体化保护修复的韧性作用机制和“问题识别-要素分析-策略制定”研究框架。以石家庄市为例,识别了其水土流失、湿地萎缩等生态问题,明确流域单元关键生态要素,并基于石家庄市生态系统地理空间格局以及面临的生态风险,提出调田节水、生境修复、林草保育等保护策略。以期为推进山水林田湖草沙系统修复工作以及增强生态系统应对干扰的抵抗力和适应力提供支撑。

淮安市古运河幸福河湖创建思考

为了探索分析幸福河湖建设经验,本文在分析淮安市古运河基本情况和特点的基础上,总结了古运河幸福河湖打造创建创新举措:管护模式创新、生态运河和文化运河创建、运河水利遗产保护与传承等。同时总结出幸福河湖建设启示:安澜之河是基本保障,以及强化水环境治理、维护河湖健康水生态、推进先进水文化建设、强化幸福河湖建设宣传引导等,以期为建设更多造福人民的幸福河湖提供借鉴。

城市公园常见植物固碳能力评估

为探究杭州市常见植物在四季生长过程中的固碳能力,以杭州西湖风景名胜区典型的50种植物为研究对象,结合便携式光合仪和植物冠层分析仪创新研究方法,分别测算植物四季的光合速率及叶面积,以评估其固碳能力。结果表明:广玉兰固碳能力最强,樟、三球悬铃木等较强,火棘、绣球、金丝桃较弱;乔木固碳能力强于灌木,常绿乔木固碳能力最强;不同季节植物固碳能力为:夏季>秋季>春季>冬季。因此,在植物群落设计时,应加强高固碳能力植物的应用,增加常绿乔木的比例,最大程度提升植物景观美学价值和生态效益。

环鄱阳湖城市群土地利用功能转型及其驱动机制

快速城镇化背景下,推进土地利用高质量转型是实现区域可持续协同发展的重要路径。该研究基于土地利用主导功能,运用综合指数法、耦合协调度模型和时空地理加权回归模型(geographically and temporally weighted regression,GTWR)等方法,分析了环鄱阳湖城市群土地利用功能转型的时空演变特征、耦合协调水平及其驱动机制。结果表明:1)2000—2020年,环鄱阳湖城市群土地利用功能指数从0.20上升到0.55,持续优化提升,但总体上处于中低水平,土地利用功能水平表现为阶段性的变化特征;土地利用功能指数逐渐呈现出中西高、东部低的空间格局。2)生产-生活-生态功能及生产-生活功能的协调度指数持续上升,其余耦合度及协调度指数均呈波动发展的趋势,耦合协调度指数呈现中部和西南部高、东北和西北部低的空间分布格局;以低质量转型为主,平均占比约为50%,功能转型质量有所提升,中西部区县的土地利用功能转型质量要明显优于北部和东部区县。3)不同影响因子的驱动作用存在显著的空间差异。人口密度和城镇化水平的正向驱动作用持续增强,二三产业占比的负向驱动作用增强,人均GDP、人均固定资产投资和人均粮食产量的影响力趋于减弱。应根据各区县土地利用功能的转型阶段,实行差别化的发展政策,补齐区县发展短板,提升功能系统间的耦合协调度。研究结果可为提高区域用地效率,促进土地利用多功能协同发展提供参考和决策依据。

洞庭湖区耕地质量等级评价及障碍因素类型分区——以岳阳市为例

基于特尔斐法和层次分析法,对岳阳市耕地质量等级进行评价;利用障碍度函数模型,划分耕地质量障碍因素类型区,分析平原低阶、丘陵下部、丘陵中部各等级耕地的主要障碍类型区。结果表明:1)岳阳市耕地质量平均等级为4.61,耕地质量良好,以中等、高等地为主,面积共计2.795×10^(5)hm^(2),约占耕地总面积的80%;高等地主要分布在平原低阶和丘陵下部,中、低等地主要分布在平原低阶、丘陵下部和丘陵中部。2)高等地中,平原低阶的水田以排水能力和有效磷障碍类型区为主,占比分别为50.03%、41.72%;丘陵中部的水田以速效钾障碍类型区为主,占比为45.26%,丘陵下部的水田以pH障碍类型区为主,占比为32.37%;中等地中,平原低阶、丘陵下部的水田以排水能力障碍类型区为主,占比分别为52.51%、53.89%,丘陵中部的水田以灌溉能力障碍类型区为主,占比为33.96%;低等地中,平原低阶、丘陵下部水田均为排水能力障碍类型区,丘陵中部的水田以排水能力障碍类型区为主,占比为92.06%;高等、中等、低等地中平原低阶、丘陵下部、丘陵中部的旱地均为灌溉能力障碍类型区。

武汉市南湖2000—2021年水域面积时空变化分析

基于Landsat卫星数据,采用波段比值法获取2000—2021年武汉市南湖水域面积,分析南湖水域面积时空变化。结果表明:南湖2003年水域面积最大,水域面积在2000—2007年呈现缩小,2008—2012年呈现增大,2013—2021年又呈现缩小,南湖治理时间与水域面积增大时间点重合,说明湖泊治理取得了成效。南湖2000—2021年水域面积整体呈现缩小,面积缩小总量为1.02 km~2,且北面、东面的面积缩小变化最为明显,南湖水域面积在2004—2005年呈现突变性快速缩小。南湖水域面积与蒸发量存在正相关,南湖水域面积与气温存在负相关。指数平滑模型和神经网络模型(LSTM)都能预测南湖水域面积,且水域面积在2022—2024年呈现增大,但指数平滑模型预测结果更准确。