CHEMICAL WEATHERING PROCESSES AND ATMOSPHERIC CO_2 CONSUMPTION OF HUANGHE RIVER AND CHANGJIANG RIVER BASINS

Rock weathering plays an important role in studying the long-term carbon cycles and global climatic change. According to the statistics analysis, the Huanghe (Yellow) River water chemistry was mainly controlled by evaporite and carbonate weathering, which were responsible for over 90% of total dissolved ions. As compared with the Huanghe River basin, dissolved load of the Changjiang (Yangtze) River was mainly originated from the carbonate dissolution. The chemical weathering rates were estimated to be 39.29t/(km2·a) and 61.58t/(km2·a) by deducting the HCO3- derived from atmosphere in the Huanghe River and Changjiang River watersheds, respectively. The CO2 consumption rates by rock weathering were calculated to be 120.84×103mol/km2 and 452.46×103mol/km2 annually in the two basins, respectively. The total CO2 consumption of the two basins amounted to 918.51×109mol/a, accounting for 3.83% of the world gross. In contrast to other world watersheds, the stronger evaporite reaction and infirm silicate weathering can explain such feature that CO2 consumption rates were lower than a global average, suggesting that the sequential weathering may be go on in the two Chinese drainage basins.

AN ANALYSIS OF THREE ELEMENTS OF WATER BALANCE IN THE CHANGJIANG RIVER BASIN

The general trend of three elements (precipitation, runoff and evaporation) of the water balance of the Changjiang River Basin is discussed from the regional distribution of the mean annual values of view, i.e. isogram. The distribution of precipitation is non-uniform. The distribution of runoff mainly supplied from precipitation is more uniform than that of precipitation. The distribution of the evaporation from land is much more uniform than that of precipitation and runoff. Time distribution of these three elements shows the characteristics of comparatively distinct yearly variation and few variation between years. The relationship between precipitation and runoff, and between precipitation and evaporation in the humid region in the Changjiang River is analyzed. The slopes of their straight line correlation are nearly equal. The internal relationship between variables should be paid attention to, otherwise, a pseudo correlation may be resulted in. The paper provides the method of quantitative

Economic Structure Transformation and Land Use Change of the Changjiang River Basin

Land, as a key factor of production, is an appropriate indicator of national and regional economic structure transformation. Land use in the Changjiang (Yangtze) River Basin (CRB) since the 1950s has experienced these changes. Industrialization has been the most powerful force of the change in the regional development of the CRB. Virtually all regional resources were put into this effort to modernize the industrial production and urban construction systems of the CRB whose industrialization and urbanization has been a success story, with impressive structural change in both pro- duction and land use. These changes are evident in modern urban areas, but even more in traditionally rural areas. The regression analysis of regional development in the CRB over an extended period shows that the dominant factor in re- gional land use change is widespread industrialization in rural areas rather than the expansion of urban area. Thus, ur- banization has had a limited influence on land use change in the CRB. A major task in realizing more sustainable land use in the future development of CRB is to relocate industrial activities from rural to urban areas.

Spatiotemporal variations and driving factors of habitat quality in the loess hilly area of the Yellow River Basin:A case study of Lanzhou City,China

Rapid industrialization and urbanization have led to the most serious habitat degradation in China,especially in the loess hilly area of the Yellow River Basin,where the ecological environment is relatively fragile.The contradiction between economic development and ecological environment protection has aroused widespread concern.In this study,we used the habitat quality of Integrated Valuation of Ecosystem Services and Tradeoffs(InVEST-HQ)model at different scales to evaluate the dynamic evolution characteristics of habitat quality in Lanzhou City,Gansu Province of China.The spatiotemporal variations of habitat quality were analyzed by spatial autocorrelation.A Geographical Detector(Geodetector)model was used to explore the driving factors that influencing the spatial differentiation of habitat quality,including natural factors,socio-economic factors,and ecological protection factors.The results showed that the habitat quality index of Lanzhou City decreased from 0.4638 to 0.4548 during 2000-2018.The areas with reduced the habitat quality index were mainly located in the Yellow River Basin and Qinwangchuan Basin,where are the main urban areas and the new economic development areas,respectively.The spatial distribution of habitat quality presented a trend of high in the surrounding areas and low in the middle,and showed a significant positive spatial autocorrelation.With the increase of study scale,the spatial distribution of habitat quality changed from concentrated to dispersed.The spatial differentiation of habitat quality in the study area was the result of multiple factors.Among them,topographic relief and slope were the key factors.The synergistic enhancement among these driving factors intensified the spatial differentiation of habitat quality.The findings of this study can provide a scientific basis for land resources utilization and ecosystem restoration in the arid and semi-arid land.

A decade of variation of COD in the Changjiang River (Yangtze River) and its variation trend analysis

The average annual value of COD (chemical oxygen demand) fluxes of the Changjiang River (Yangtze River) and its main tributaries in the past decade (i.e., 1991–2000), has been evaluated. Based on the data from the Datong Hydrological Station (DHS), it was found that the Dongting Lake drainage basin contributed the greatest water discharge (35.8%) and COD flux (48.3%) among the main tributary drainage basins, followed by the Poyang Lake drainage basin with the contributions of 15.4% and 19.3%,respectively. By the end of the year of 2000, COD flux in the Changjiang River rose by almost 45% relative to that in the year of 1991, reaching about 1941000 ton/a at DHS. Statistical analysis revealed that industrial wastewater discharge, as well as COD in it, was found decreasing in the same period, due to the gradual reinforcement of environmental management. Moreover, correlation analysis indicated that non-point pollution from agriculture and increasing discharge of domestic sewages caused by rapid growth of population along the Changjiang River drainage valley should be responsible for the high COD. Furthermore, with the current trend of population growth and agricultural development in this basin, water quality of the Changjiang River, in terms of COD level, is going to deteriorate in the near future. Thus, the rational applications of fertilizers and pesticides in agriculture and the proper treatment of domestic sewages before they are discharged would be the most concerned controlling parameters.

Analysis of Micro Organic Compound Pollution in Major City River Reaches of the Main Stem of the Changjiang River

It has become general for surface waters being polluted by micro organic compounds. In order to know the current pollution situation and the properties of micro organic compounds in the Changjiang River, a test was performed on micro organic compounds in the water, bottom material and fish bodies which were sampled from major city river reaches of the Changjiang River. Based on the test result, researchers described and analyzed the sorts, concentration level and distribution features of micro organic compounds. A comprehensive evaluation was conducted by adopting the method of MEG (Multimedia Environmental Goals). The study indicated that ① the water body of major city river reaches of the Changjiang River has been generally polluted. In the test, totally 12 types with 308 kinds of organic compounds were detected. The main pollutants were paraffins, PAHs and lipids; and ② micro organic pollutant content in fish bodies was generally higher than that in bottom material which is in turn higher than that in water; and ③ pollution is relatively severe in the river reaches of mid-to-large comprehensive industrial cities with fairly great TAS (Total Ambient Severity) of public health and ecological system.

海温异常对长江流域夏季典型旱涝的影响研究

为研究长江流域夏季旱涝特征及其与海温异常之间的关联性,基于中国326个气象站降水量、NCEP/NCAR再分析资料等,采用合成分析、EOF分解等方法,分析了长江流域夏季典型旱涝年的降水分布、同期大气环流及前期海温特征,并以2018年为例,初步揭示了2018年前期海温异常对大气环流的可能影响。结果表明:①长江流域夏季典型旱年,仅嘉陵江和岷沱江会表现出局部偏涝,全国为典型的Ⅰ类雨型,多雨区位于黄河流域及以北地区。前期冬季赤道太平洋表现出类拉尼娜的东冷西暖分布,同时黑潮区海温偏低,西风漂流区海温偏暖。受多海域协同作用,同期欧亚环流场上自西北向东南呈现出“+-+”三极型分布,东亚地区为自北向南“-+-”的EAP负位相。长江流域典型涝年,全国多为典型的Ⅱ类和Ⅲ类雨型,环流及海温呈现出相反特征。②2018年为典型的长江中下游偏旱年,仅在岷沱江降水偏多近3成,为历史第4多,与长江流域夏季降水的主模态正位相类似,解释方差达24%。③2018年前冬出现弱拉尼娜、春末夏初西风漂流区异常偏暖、NAT异常正位相,三者共同作用,使得东亚副热带西风急流偏北,东亚沿岸出现EAP负位相,大陆热低压明显偏强,东亚夏季风为1961年以来最强,同时副高脊线最北,造成夏季降水主雨带北推至华北、西北地区,岷沱江、嘉陵江异常多,而长江中下游异常少,为典型的Ⅰ类雨型。研究成果可为长江流域旱涝预测、水资源调度提供参考。

长江流域青海区域水生生物完整性评价

依据《长江流域水生生物完整性指数评价办法(试行)》的要求和指标,通过梳理历史记录和文献,厘清了长江流域青海区域水生生物完整性评价的基准值;于2022年开展全面系统地野外调查,并对研究区域的水生生物完整性进行了评价。结果显示:长江流域青海区域鱼类种类基准值为20种,鱼类种类现状值为19种;长江在青海省境内的长江源河段、大渡河源河段,以及长江流域青海区域整体的水生生物完整性得分分别为88.22,82.67分和81.56分,完整性等级均为“良”。其中,长江源河段历史有记录以来的15种鱼类在此次调查中均被发现,反映长江源流域水生生物群落受人类干扰较少,重点保护物种完整。研究区域鱼类栖息地生境良好,但主要制约完整性的因素是水电站对河流的阻隔、外来物种入侵和关键物种川陕哲罗鲑的缺失。研究结果可为全面评估长江水生态完整性提供青海区域的基础数据,还可为科学评估长江十年禁捕成效、针对性开展水域生态修复提供科学依据。

数字孪生驱动的长江流域干旱防御平台设计与开发

在全球气候变化的背景下,长江流域发生了多次严重的高温干旱灾害,流域抗旱管理面临着旱情监测告警效率较低、旱灾预报预警精度不高、抗旱预案推演能力不足等瓶颈,迫切需要开展数字化转型。从长江流域抗旱减灾业务管理和“四预”应用需求出发,基于智慧水利和数字孪生建设的总体要求,综合运用WebGL、GIS等技术,建立了干旱防御数字孪生平台,研发了遥感干旱监测评估、干旱专业模型动态加载、旱警水位超限预警、抗旱预案可视化等关键技术,初步实现了“预报-预警-预演-预案”全链条贯通业务应用,切实提升了长江流域抗旱管理智能化、精细化水平,为流域干旱防灾减灾提供了技术支撑。

新时期长江流域生态补偿机制与关键科学问题研究

流域生态补偿是协调长江经济带经济社会发展与生态环境保护矛盾的重要手段。当前,长江流域生态补偿实践中仍面临着整体性和系统性不足、补偿标准依据缺乏、市场体系不健全、责权利不清晰等问题。根据新时代长江保护与发展的战略需求,新时期长江流域生态补偿需要具备更为丰富的内涵,亟需针对长江流域经济社会发展与生态资产保护的多维互馈关系及良性协同机制、流域生态资产的定量核算方法与生态服务空间流转特征、多元化流域生态补偿格局与长效运行机制、区域试点示范引领与全流域统筹协调推进之间的关系等关键科学问题开展系统研究,并从创新体制机制、完善技术体系、强化立法保障、培育市场主体等方面为探索制定长江流域生态补偿总体框架提供科技支撑和政策建议。

嘉陵江沿线古城“山-水-城”景观特征研究

嘉陵江是长江水系中第二大支流,空间上连接南北丝绸之路,是巴蜀地区重要的文化廊道。在典型山地曲流环境中,其沿线古城蕴含了丰富的山水营建智慧。从自然环境、文化环境、行政建制三方面梳理了嘉陵江沿线古城的形成基础,并以上、中、下游8个古城为例,通过历史文献系统梳理及结合GIS平台的历史地图空间转译,提炼其“山-水-城”景观特征。具体为“宏观格局把控”方面“巴蜀要冲,控扼形胜”的城市选址、“襟江带河,群山四望”的山水格局、“江山聚结,生气聚集”的风水脉络;“中微观空间结构塑造”方面“迎山接水,不拘一格”的城市空间结构、“依形江山,因地制宜”的城市功能营建;以及“沿江山集群,南北人文关联”的“跨尺度风景审美经营”等在地特征,以期为巴蜀文化遗产保护与传承、西南山地宜居城乡建设提供参考。

黄河流域乡村集群的空间协同发展路径——以黄河滨州段为例

立足于黄河流域生态保护和高质量发展、乡村振兴国家战略在山东的地域性实践背景,基于对黄河流域乡村集群的空间协同发展路径研究,阐释乡村集群的概念并归纳沿黄乡村集群特征,从黄河流域乡村的发展壁垒入手,将乡村集群类型划分为城乡融合型、带状集聚型、组团提升型等3种集群空间模式,提出统筹体系架构与空间优化两层面的协同路径。随后,以《滨州市黄河沿岸国土空间规划》为例,以229个村庄为样本,构建由城乡融合示范区、特色集聚段、门户提升段构成的“一区三段”乡村集群空间格局,提出“尺度嵌合、显隐结合、城乡融合”的空间协同路径,以及空间多尺度的分类传导和规划多嵌套的分级传导体系,以期为黄河流域乡村高质量发展提供可参考的路径模式。

黄河流域收缩城市“三生”功能耦合协调分析

利用第五、第六和第七次全国人口普查资料对黄河流域的收缩城市进行识别并测算其收缩强度,借助多指标综合评价法、耦合协调度模型分析2010年、2015年和2020年收缩城市的“三生”功能大小及耦合协调度,进一步运用随机森林模型探究其关键影响因素。结果表明:在黄河流域内90个地级市(州、盟)中,持续收缩型城市有27个,阶段收缩型城市有9个,潜在收缩型城市有29个,城市收缩现象显著;不同区域收缩城市的“三生”功能水平差异显著,其中生产和生活功能整体呈上升态势;“三生”功能的耦合协调度呈现由勉强协调向初级协调发展的特征,中、下游区域协调度优于上游,经济社会的快速发展和人民生活水平的提高有助于“三生”功能的耦合协调发展。

沿黄城市生态保护与高质量发展耦合协调时空演变分析

为丰富黄河流域生态保护和高质量发展研究,并为沿黄城市经济发展提供对策建议,分别构建生态保护和高质量发展评价指标体系,以60个沿黄地级市为样本单元,采用熵值法对指标赋权并计算2010—2020年沿黄各市生态保护指数、高质量发展指数,采用耦合协调度模型计算生态保护与高质量发展耦合度、协调度并划分协调等级,计算相对发展度以判断生态保护与高质量发展耦合协调类型,分析沿黄城市生态保护与高质量发展耦合协调动态演变情况,结果表明:2010—2020年沿黄城市生态保护与高质量发展协调度大都稳中有升、少数城市呈下降趋势,2020年协调等级整体上还较低,尚有37个城市处于失调状态,生态保护与高质量发展的耦合协调任重道远;从空间上看,沿黄城市生态保护和高质量发展协调度总体上呈现下游>中游>上游的格局,研究时段生态保护与高质量发展协调度平均值大小排序前十位的城市多为沿海城市或省会城市、后十位的城市多为各省(区)的边缘城市,地理位置、资源禀赋、政策扶持程度和经济发展模式等对耦合协调度有重要影响;2020年沿黄城市生态保护与高质量发展耦合协调类型为生态保护滞后型的城市有31个、为均衡型的城市有5个、为生态保护领先型的城市有24个,表明沿黄城市生态保护整体上滞后于高质量发展。

黄河流域城市能源综合效率时空分异与影响因素研究

经济发展和环境保护的双重压力下,能源效率成为反映一国经济发展质量的关键指标,不断提升能源效率是必然的趋势。本文使用非参数的super-SBM模型、地理信息系统空间分析法、面板Tobit回归和地理加权回归(GWR)模型对黄河流域2007—2018年城市能源综合效率的时空格局和影响因素进行分析。结果表明:①研究期内,城市能源综合效率基本保持平稳,但有下降趋势。效率分布的区域差异有所缩小,且呈现出明显的连片分布特征,具体来说上游城市多处于低效、中低效率区间,中下游城市多位于中低和中高效率区间;②影响因素的Tobit回归结果表明,经济发展水平和绿色创新对城市能源综合效率具有显著正向影响,碳排放水平、产业结构和环境规制对城市能源综合效率具有显著的负向影响,区域异质性回归结果也基本保持不变;③地理加权回归结果表明,各影响因素作用的空间异质性存在并且具有一定分布规律。研究结论为促进黄河流域城市能源综合效率提供思路。

黄河流域城市群水资源利用与城市发展协调水平评价

黄河流域城市群水资源利用与城市发展交互状态是影响流域城市群高质量发展的关键,亟须在可持续发展目标下探讨二者之间的耦合协调关系,为探索黄河流域城市群生态保护与高质量发展协同机制提供新思路。以黄河流域5个城市群为例,依据联合国提出的可持续发展目标,建立2010—2019年水足迹与城市发展指数的耦合协调度及水资源利用差异分析框架,采用Theil变异指数方法,对耦合协调结果的空间差异进行评价。结果表明:2010—2019年黄河流域城市群水足迹年均减少0.43%,城市发展指数年均增长0.73%,二者耦合协调等级呈升—降—升的不稳定状态;城市群水资源利用水平差异是造成城市发展水平差异的主要原因,且在不同城市群发展阶段中水资源利用与城市发展协调关系差异显著。建议构建跨域水资源共治体系、发挥城市群水资源公共政策的调节作用、系统规划城市群水环境保护与水资源开发利用安全格局。

吉林省松原市:经济增长、生态环境、人口聚集耦合协调研究

松辽流域是国家“十四五”发展规划中的重要生态研究基地。松花江流域的协调发展对促进东北区域经济振兴战略、落实国家旅游建设、实现乡村振兴有着重要意义。文章基于2012—2021年松花江流域吉林段市区数据,从对外贸易、经济、生态环境三个维度,构建综合评价指标体系。同时,运用熵值法和耦合协调模型进行计算,评估松花江流域各市区对外贸易、经济发展与生态环境之间的耦合协调发展水平。基于分析结果,提出发展对外贸易、实施东北振兴、坚持生态保护举措、加快推动松花江流域经济一体化发展等建议。

典型河湖治理经验及对长江流域生态保护的启示

为做好长江生态环境修复保护工作,选取欧洲莱茵河、英国泰晤士河、韩国清溪川和美国奥基乔比湖4个具有典型特征的河湖作为案例,整理和归纳了这4个河湖的污染治理过程与对应的政治、经济、金融、法律相关的治理措施。针对长江流域生态治理中存在的同类问题,总结了这4个河湖在跨区域协同治理、跨部门统筹管理、健全法律体系、加强公众参与和商业运营等方面的经验,提出建立跨区域共同协商的流域水污染管理体制、强化不同部门之间的统筹管理机制、完善流域统一的环境保护法律体系、公共参与等措施和建议。研究成果可为协同长江的保护与发展、进一步提升长江流域的水生态环境质量提供参考。

黄河流域城市群碳足迹及隐含碳转移研究

选择黄河流域5个国家级城市群合计71个城市构建了2017年环境扩展的MRIO模型,评估了包括化石能源燃烧､煤炭开采逃逸､农业非能源排放等3个来源的碳足迹,分析了城市群之间以及城市群内部城市､部门之间的隐含碳转移.结果表明:5个城市群碳足迹总计约2478.34Mt,其中化石能源燃烧贡献了86.42%,是碳足迹的主要来源,煤炭开采逃逸和农业非能源排放亦不容忽视,分别贡献了10.09%和3.49%.煤炭开采和洗选业､金属冶炼和压延加工业､电力热力的生产和供应业是碳足迹的重点部门,生产和消费两个视角下合计分别占总碳足迹的62.67%和36.77%.金属冶炼和压延加工业､电力热力的生产和供应业是隐含碳输出的关键部门,输出量合计占城市群内隐含碳转移量的51.43%,批发零售和住宿餐饮业是输入的关键部门,占比为26.79%,金属冶炼和压延加工业→批发零售和住宿餐饮业是隐含碳主要转移路径.碳足迹和隐含碳转出的重点城市多为资源消耗型､重化工产业占比较高的城市,如鄂尔多斯､滨州等.隐含碳转入的重点城市为维持自身发展需要消耗大量其他城市的产品,如青岛､呼和浩特等.碳足迹主要集中在“几”字弯都市圈､山东半岛和中原城市群,三者碳足迹合计占比在生产和消费视角下分别达到了85.89%和85.02%,“几”字弯都市圈是隐含碳输出最大的城市群,输出量约占城市群间转移量的40.68%,中原城市群是隐含碳输入最多的城市群,输入量约占42.24%.研究结果可为制定和完善黄河流域城市群控碳政策和降碳措施提供更充分合理的依据.

基于RSEI的黄河中游地区生态环境质量时空演化特征及驱动因素——以延安市为例

[目的]生态环境质量评价是开展黄河中游地区生态环境保护和生态文明建设的重要基础,探究其生态环境质量动态及不同主导因子对其影响,可为生态环境保护战略与经济发展战略的协调发展提供理论依据。[方法]基于遥感生态指数(remote sensing ecological index,RSEI)并辅以Sen趋势分析、Manna-Kendall突变点检验、变异系数、Hurst法对黄河中游地区延安市1990—2020年的生态环境过去和未来演化特征进行了分析,并利用随机森林和结构方程模型探究了不同阶段RSEI对不同驱动因素的敏感性。[结果](1)延安市近31年生态环境质量整体呈变好趋势。其中,绿度和湿度指标均呈增加趋势,热度指标和干度指标均呈减小趋势,各指标共同促进了延安市的生态环境质量变化。(2)1995年前RSEI为上升趋势,1995—2001年RSEI为下降趋势,2001年后RSEI呈增加趋势。(3)1990—1995年RSEI变化属于较高波动变化,1996—2001年以高波动变化为主,2002—2020年属于较低波动变化。RSEI在未来一段时间内会出现大面积的下降趋势。(4)1990—1995年RSEI受到日最低气温极低值的正影响最大,受到日最高气温的极高值、日最高气温的极低值和干旱的负影响较大;1996—2001年土地利用对RSEI的正影响最大,日最高气温的极低值、干旱和日最低气温的极低值对RSEI为负影响最大;2002—2020年连续5日最大降雨量对RSEI的负影响最大,日最高气温的极低值、日最高气温的极高值和日最低气温的极低值对RSEI为负影响较小,但其均对连续5日最大降雨量产生影响从而间接对RSEI产生较大影响。[结论]近31年来延安市生态环境质量整体呈增加趋势,但气候变化对导致的生态退化现象需要引起政府重视,尽快提出一系列生态修复措施,防止其生态环境进一步恶化。