Optimization of water-urban-agricultural-ecological land use pattern:A case study of Guanzhong Basin in the southern Loess Plateau of Shaanxi Province,China

Extensive land use will cause many environmental problems.It is an urgent task to improve land use efficiency and optimize land use patterns.In recent years,due to the flow decrease,the Guanzhong Basin in Shaanxi Province is confronted with the problem of insufficient water resources reserve.Based on the Coupled Ground-Water and Surface-Water Flow Model(GSFLOW),this paper evaluates the response of water resources in the basin to changes in land use patterns,optimizes the land use pattern,improves the ecological and economic benefits,and the efficiency of various spatial development,providing a reference for ecological protection and high-quality development of the Yellow River Basin.The research shows that the land use pattern in the Guanzhong Basin should be further optimized.Under the condition of considering ecological and economic development,the percentage change of the optimum area of farmland,forest,grassland,water area,and urban area compared with the current land use area ratio is+2.3,+2.4,-6.1,+0.2,and+1.6,respectively.The economic and ecological value of land increases by14.1%and 3.1%,respectively,and the number of water resources can increase by 2.5%.

Using the concept of ecological groundwater level to evaluate shallow groundwater resources in hyperarid desert regions

This paper, based on the analysis and calculation of the groundwater resources in an arid region from 1980 to 2001, put forward the concept of ecological groundwater level threshold for either salinity control or the determination of ecological warning. The surveys suggest that soil moisture and soil salinity are the most important environmental factors in determining the distribution and changes in vegetation. The groundwater level threshold of ecological warning can be determined by using a network of groundwater depth observation sites that monitor the environmental moisture gradient as reflected by plant physiological characteristics. According to long-term field observations within the Ejin oases, the groundwater level threshold for salinity control varied between 0.5 m and 1.5 m, and the ecological warning threshold varied between 3.5 m and 4.0 m. The quantity of groundwater re- sources （renewable water resources, ecological water resources, and exploitable water resources） in arid areas can be calculated from regional groundwater level information, without localized hydrogeological data. The concept of groundwater level threshold of ecological warning was established according to water development and water re- sources supply, and available groundwater resources were calculated. The concept not only enriches and broadens the content of groundwater studies, but also helps in predicting the prospects for water resources development.

A general multi-objective programming model for minimum ecological flow or water level of inland water bodies

Assessment of ecological flow or water level for water bodies is important for the protection of de- graded or degrading ecosystems caused by water shortage in arid regions, and it has become a key issue in water resources planning. In the past several decades, many methods have been proposed to assess ecological flow for rivers and ecological water level for lakes or wetlands. To balance water uses by human and ecosystems, we proposed a general multi-objective programming model to determine minimum ecological flow or water level for inland water bodies, where two objectives are water index for human and habitat index for ecosystems, respectively Using the weighted sum method for multi-objective optimization, minimum ecological flow or water level can be determined from the breakpoint in the water index-habitat index curve, which is similar to the slope method to de- termine minimum ecological flow from wetted perimeter-discharge curve. However, the general multi-objective programming model is superior to the slope method in its physical meaning and calculation method. This model provides a general analysis method for ecological water uses of different inland water bodies, and can be used to define minimum ecological flow or water level by choosing appropriate water and habitat indices. Several com- monly used flow or water level assessment methods were found to be special cases of the general model, including the wetted perimeter method and the multi-objective physical habitat simulation method for ecological river flow, the inundated forest width method for regeneration flow of floodplain forest and the lake surface area method for eco- logical lake level. These methods were applied to determine minimum ecological flow or water level for two repre- sentative rivers and a lake in northern Xinjiang of China, including minimum ecological flow for the Ertix River, minimum regeneration flow for floodplain forest along the midstream of Kaxgar River, and minimum ecological lake level for the Ebinur Lake. The results illustrated the versatility of the general model, and can provide references for water resources planning and ecosystem protection for these rivers and lake.

Protection and Ecological Restoration of Water Level Fluctuation Zone in the Three Gorges Reservoir

Water level fluctuation zone(hereinafter referred to as "WLFZ") is a transitional ecosystem between terrestrial ecosystem and aquatic ecosystem,and also a key area to control its neighboring terrestrial and aquatic ecosystem. After the Three Gorges Reservoir was put into use,ecological environment of its WLFZ has aroused wide concern from domestic and foreign experts. On the basis of introducing characteristics of WLFZ of the Three Gorges Reservoir,current ecological environment and main problems of this area were analyzed,plant selection and configuration was elaborated as well as the implementation effect of many WLFZ protection and ecological restoration modes. In view of the actual conditions,pertinent suggestions were proposed for WLFZ of the Three Gorges Reservoir,namely classified protection and ecological restoration,enhancing monitoring and assessment of current situation and change tendency,carrying out technical researches and demonstration of WLFZ wetland ecological restoration.

Estimation of Ecological Water Requirements Based on Habitat Response to Water Level in Huanghe River Delta,China

In recent years,wetland ecological water requirements (EWRs) have been estimated by using hydrological and functional approaches,but those approaches have not yet been integrated for a whole ecosystem.This paper presents a new method for calculating wetland EWRs,which is based on the response of habitats to water level,and determines water level threshold through the functional integrity of habitats.Results show that in the Huanghe (Yellow) River Delta water levels between 5.0 m and 5.5 m are required to maintain the functional integrity of the wetland at a value higher than 0.7.One of the dominant plants in the delta,Phragmites australis,tolerates water level fluctuation of about ± 0.25 m without the change in wetland functional integrity.The minimum,optimum and maximum EWRs for the Huanghe River Delta are 9.42×106 m3,15.56×106 m3 and 24.12×106 m3 with water levels of 5.0 m,5.2 m and 5.5 m,corresponding to functional integrity indices of 0.70,0.84 and 0.72,respectively.A wetland restoration program has been performed,which aims to meet these EWRs in attempt to recover from losses of up to 98% in the delta's former wetland area.

Thoughts on Integrated Monitoring of Ecological Environment at Provincial Level

The Law of Soil and Water Conservation entitles the administrations of water resources at various level to monitor ecological environment and to proclaim status of soil erosion periodically.Monitoring units of soil and water conservation approved by local governments are obliged to undertake this work.How to develop a monitoring program needs an overall and long-term concept.Particularity and objectives of ecological environment monitoring was discussed. Monitoring at provincial level may be divided into two levels:province-wide and at project level. Those indicators meaningful,sensitive to any disturbances,and simple to measure may be selected to test status of ecosystem stability and health.It makes sense to have an integrated sampling design,to set up permanent observation plots and to collect data, so that to have a relative timely,accurate understanding of ecosystems in the province.A program regarding sampling design,field methods, data analysis,documentation and implementation was detailed.

Dynamic Change of Arable Land Ecological Security: A Case Study of Panyu District, Guangzhou City

Ecological security of arable land is closely related to grain security and social stability. This paper took 12 typical indexes from the aspects of ecological pressure, state and response of arable land considering natural, social and economic conditions to construct the ecological index system of arable land in Panyu District, Guangzhou City, and adopted objective weighting method and comprehensive analysis method to analyze the dynamic change of ecological security and security level of arable land in the study area. The results showed that ecological security pressure value and response value of arable land in Panyu District from 2008 to 2013 increased and the overall ecological security level was low, manifesting the level of "sensitive–risky–sensitive". Specifi cally, ecological security of arable land in 2008 was sensitive, risky from 2009 to 2011, and the security level rose to the sensitive level again in 2012 and 2013. Ecological restoration and rebuilding of arable land should be enhanced, and ecological security early warning system should be established by protecting quantity and quality of arable land, so as to protect arable land resources effectively, and promote sustainable development of arable land.

Spatial distribution,sources and ecological risk assessment of heavy metals in Shenjia River watershed of the Three Gorges Reservoir Area

Surface soil/sediment samples were collected from the Water-Level Fluctuation Zone(WLFZ), cultivated land and forest land at 50 different grid points from Shenjia watershed, the Three Gorges Reservoir area in August 2013. The spatial distribution, sources and ecological risk assessment for Arsenic(As), Cadmium(Cd),Chromium(Cr), Copper(Cu), Nickel(Ni), Lead(Pb)and Zinc(Zn) were analyzed in this study. The results showed all tested metals had similar distribution patterns except Ni and Cr, with areas of high concentrations distributed in the southwest(WLFZ and watershed outlet) of the study area. Ni and Cr,which were highly positively correlated and present in high concentrations, were primarily distributed in the south and middle zones of the study area. Lower concentration areas of all metals were uniformly distributed west of the high-elevation zones and forest land. Factor analysis(FA) and factor analysismultiple linear regression(FA-MLR) showed that the major sources of Cd were fertilizer and traffic sources,which together accounted for 87% of Cd. As, Zn and Cu levels were primarily supplied by industrial and domestic sources, accounting for 76% of As, 75% of Cu and 67% of Zn. Surface soils/sediments of the study watershed contaminated by Cd represent a high ecological risk, whereas other metals represent low ecological risks. The potential ecological risk index(PERI) analysis indicated that it had a low(widerange) ecological risk and a moderate(small-range)ecological risk primarily distributed in the outlet of the study watershed. Fertilizers and traffic are the primary sources of Cd pollution, which should be more closely controlled for the purposes of water quality and ecological conservation.

长江下游干流沉积物重金属特征及生态风险评价

【研究目的】长江下游干流沿岸分布众多取水口,为保障用水安全和生态环境健康,亟需了解近岸沉积物中重金属相关现状。【研究方法】调查过程中自上而下分左右岸共采集沉积物样品85组,利用描述统计分析重金属含量特征,综合相关性分析和主成分分析探讨重金属来源,采用地累积指数法、污染负荷法分析重金属污染程度,并评估其潜在生态风险。【研究结果】平均含量由高至低为Zn>Cr>Cu>Ni>Pb>As>Cd;上游至下游,Cu、Zn、Cr、Ni呈小幅波动增加趋势,As、Pb呈小幅波动下降趋势,Cd呈较大波动下降趋势;Cd的污染程度最重,主要来源于农业生产等人类活动,1~4级污染分别占比1.18%、1.18%、18.82%和34.12%,Cr和Ni为无污染,主要是工业生产源和地球化学自然源;中等污染程度(1≤PLI_(point)<2)的样点占比34.18%,潜在生态风险指数(RI)为19.48~388.62,轻微潜在生态风险、中等潜在生态风险、强潜在生态风险和极强潜在生态风险占比分别为38.82%、42.35%、17.65%和1.18%。【结论】长江下游干流沉积物中重金属含量较低,流域整体处于轻微—中等风险的无污染状态(PLI_(area)<1),右岸重金属平均含量、污染程度和潜在生态风险均普遍高于左岸。

长江经济带生态文明建设水平变化特征与影响因素分析

长江经济带生态文明建设水平的高低关系到长江流域绿色协调发展能力,深刻影响我国生态安全格局。从生态经济、生态环境、生态社会3个层面构建评价指标体系,使用改进TOPSIS方法模型测算长江经济带生态文明建设水平,利用地理加权回归模型(GWR)分析其影响因子。研究结果表明:(1)在2011—2020年,长江经济带生态文明建设水平整体上呈上升趋势,由东向西沿轴线逐步扩散。(2)各子系统建设水平异质性特征显著,生态经济建设水平东部高于西部,以长江下游地区和省会城市为核心向周围辐射发展;生态环境水平在各省会及其周边城市增长较快,而工业发展型城市有不同程度的降低。生态社会水平高值区集中分布在江浙沪地区,低值区分散分布于中上游各省会城市。(3)地形、常住人口城镇化水平、第三产业占比、恩格尔系数、科技财政支出占比均正向影响了研究区生态文明建设水平,每万人在校大学生数对生态文明建设水平呈弱负相关。

海南岛地下水资源状况及其环境地质问题

【研究目的】海南既是中国最大的经济特区,又是“一带一路”倡议中的重要支点,揭示海南岛地下水资源禀赋,探究地下水资源分布特征及存在的环境地质问题,可以为海南生态保护和高质量发展提供重要支撑。【研究方法】本文以海南岛为研究区,划分评价单元,分析地下水流场特征,评价地下水资源量及水质情况,探究地下水开发利用状况,查明主要环境地质问题。【研究结果】海南岛多年平均地下水资源量约为132.05×10^(8)m^(3)/a,在行政区中,海口市的地下水资源量最大,多年均值为11.33×10^(8)m^(3)/a,昌江县的最小,多年均值为0.07×10^(8)m^(3)/a。海南岛地下水水质整体较差,水质较差区分布在滨海平原区和山前地带,超标因子主要为pH、Al、Mn。岛内存在一系列的环境地质问题,包括琼北盆地的区域性水位下降问题、三亚市海棠湾和榆林湾、东方市板桥镇等地区的海水入侵和土壤盐渍化问题、东方市、昌江县和乐东县等地区的土地沙漠化问题、矿山开采产生的地质环境问题。【结论】海南岛地下水资源量较为丰富,分布差异大,地下水水质较差,环境地质问题突出,应进一步加强水文地质与水资源调查监测工作,加快构建水资源节约集约利用新格局,推进地下水生态环境保护。

省域国土空间生态修复规划体系构建的逻辑与实践——基于“规划—设计—治理”的视角

国土空间生态修复是推进国土空间治理的重要手段,厘清其规划体系的构建逻辑对于国土空间生态修复规划的编制实施和作用发挥至关重要。从需求层次出发,阐明国土空间生态修复规划体系构建的基本逻辑,以浙江省为例,探索建立省域国土空间生态修复规划体系构建的理论。研究表明:(1)国土空间生态修复规划在需求层面上可体现为“功能修复—韧性提升—价值实现”3个层次。(2)围绕着“整体规划—深化设计—系统治理”的逻辑,提出国土空间生态修复规划作为专项规划的体系构建逻辑。(3)基于构建逻辑,将省域国土空间生态修复规划梳理形成“编制—实施—支撑”3个体系。国土空间生态修复规划要从需求层次变化的认识入手,以维护生态安全、提升空间价值为目标,在省域范围内通过纵向传导、横向深化及全流程支撑3个维度构建规划体系,为系统化开展国土空间生态修复工作探索实施路径。

西辽河平原地下水失衡及其与土地利用的互馈关系

西辽河平原是我国北方重要的生态屏障,但是生态环境脆弱。2004年以来农田灌溉用水增加,地下水水位持续下降。为查明区域地下水失衡、生态效应及其影响因素,开展了西辽河平原地下水水位统测和长期监测,采用空间相关性分析、水均衡分析、土地利用转移矩阵、对地下水水位变化贡献度分析等方法,分析了区域地下水均衡状况及其与土地利用的互馈关系。结果表明:西辽河平原2020年地下水水位比2004年平均下降2.23 m,地下水储存量年均减少10.90×10^(8) m^(3);平原中部农业集中灌溉区地下水水位下降幅度较大,尤其通辽科尔沁区地下水水位下降最为明显;西辽河平原地下水开采量对地下水水位下降的贡献度为33%,科尔沁区超过50%;地下水水位下降区水位埋深从4.71 m下降至8.34 m,导致草地退化,面积减少,覆盖度下降;西辽河平原地下水可持续开采量为24.28×10^(8) m^(3)/a。用于农业灌溉的地下水开采量增大是造成地下水水位下降的主要原因,为防止地下水水位持续下降,提出了提高节水灌溉能力,调整种植结构、引入外源水及压缩地下水开采量等综合治理建议。该研究成果可为区域农业种植规划、地下水管理与保护提供技术支撑。

宿迁市河流生态水位管控目标与预警机制分析

针对宿迁市近年水环境保护与水生态修复实践,阐述了宿迁市开展的第一批及相关重要河道生态水位制定情况与实施政策,分析了河道生态水位管理的工程调度原则与预警机制方案设计等技术内容,提出了河道生态水位管控目标保障措施。相关技术方法对构建完善的生态水位目标管控长效机制,提升宿迁市河湖水生态环境质量具有重要决策参考价值。

中国生态经济发展水平的统计测度

加强生态环境保护、推进生态文明建设可促进经济社会全面绿色转型,赋能生态经济高质量发展。文章选取2005—2021年我国30个省份的面板数据作为研究样本,构建了生态经济发展水平测度指标体系,并使用纵向拉开档次法、等距离划分法及TOPSIS模型对生态经济发展水平进行综合测度,为生态经济高质量发展提供数据支撑。研究结果显示:2005—2021年我国生态经济发展水平增速显著,生态经济取得较大发展成效;分维度来看,生态发展效益指数最高,生态投资次之,生态产出再次,生态环境水平增速相对缓慢。据此提出加大生态经济投资力度、提高生态经济产出效率、优化生态环境保护方式、强化生态效益发展根基的建议。

数字生态、金融发展与区域创新水平

数字化发展对经济社会产生了巨大影响,催生了新型商业模式。良好的数字生态激发了创新活力,给区域创新带来了根本性变化。基于2013—2020年31个省(区、市)的面板数据,探究数字生态与区域创新水平之间的关系。研究发现:数字生态对区域创新水平存在显著的正向影响,且这一结论在进行了一系列稳健性检验后仍然成立;在考虑区域异质性的情况下,东部地区数字生态对区域创新水平存在显著的正向影响,中部和西部地区数字生态对区域创新水平的影响并不显著;数字生态能通过促进金融市场的高水平发展,进而推动区域创新水平提高。基于研究结论,提出了相应的数字生态发展建议,以期带动区域创新发展。

江苏省平原水网区河湖生态水位确定探索与实践

保障河湖生态流量,事关江河湖泊健康。本文在分析江苏平原水网区域特点的基础上,选择生态水位作为河湖生态流量的表征指标,根据水利部确定的江苏省26条全国生态流量保障重点河湖名录,科学选定控制断面,采用1990—2020年水文序列资料,选用Qp法分析计算90%、95%、99%保证率下的水位,同步对比分析近10年最枯月水位、最低通航保证水位,最终确定了26条河湖的生态水位。通过制定保障措施方案、开展监测预警评估、强化统一调度管理等措施,全面保障区域河湖生态水位,为平原水网地区河湖生态水位的确定与保障提供了经验。

考虑生态限制的内河港口岸线等级评价研究

为明晰港口岸线的优劣情况,给港口开发及整合提供参考,提出了一种考虑生态限制条件的港口岸线等级评价方法。首先,选取自然条件、社会经济、交通发展等3个方面的12个指标,借助物元可拓模型进行港口岸线资源等级初评。然后,以生态限制条件为减分因素对初评结果进行修正,得出岸线等级可划分为4类:一级规划岸线、二级规划岸线、三级规划岸线、四级规划岸线。其中,一级规划岸线最适宜建设深水港,二级规划岸线适宜建港,三级规划岸线和四级规划岸线不宜建港。最后,基于长江重庆段五段不同岸线的数据进行案例分析,分析结果表明:评价结果与实际情况基本一致;改进的等级评价指标、定性定量相结合的方法能够提高评价结果的准确性;将生态因素作为限制条件从综合评价中独立出来进行等级结果修正能够有效避免岸线开发利用时侵占生态资源。

南昌市象湖湿地公园消落带植物景观生态修复策略

为减轻城市湿地公园的消落带生态退化问题(环境污染、水土流失、土壤侵蚀、功能退化等),探求高效的生态修复策略。以南昌市象湖湿地公园为研究对象,在系统分析消落带的共性生态环境问题及现状基础上,提出了相应的景观生态修复策略:1)在广泛调查地域性消落带植物种类及其群落组成的基础上,筛选出适合公园环境的湿生植物种类;2)适度调整消落带的护坡和护岸结构,以自然式护岸为主;3)以乡土的湿生植物为主,建议配植适生植物群落,修复受损的消落带生境,形成特色护岸景观。研究城市湿地公园消落带的植物景观生态修复,有利于实现消落带生境修复、景观游憩、水体净化、减污增汇等生态效益,以构建生态环境友好型的消落带景观。