Characteristics and influencing mechanisms of production-living-ecological space dynamics in the Three Gorges Reservoir Area(TGRA),Chongqing,China

The Three Gorges Reservoir Area(TGRA)is an important ecological barrier in the Yangtze River Basin,China.Therefore,it is of great importance to understand the spatio-temporal variation and the driving factors of production-living-ecological spaces for sustainable and high-quality development in the TGRA.This study investigated the dynamic variation of production-living-ecological spaces in the TGRA by employing land use data in 2000,2005,2010,2015,and 2018,and detected the influencing factors by using the Geographic detector(GeoDetector).Results implied that the structure and dynamic trajectories of production-living-ecological spaces in the TGRA varied in both horizontal and vertical directions,and the study area was dominated by ecological space.A spatial orientation towards the northeast was detected in the evolution of production-living-ecological spaces during 2000-2018.In terms of quantity,the transition from ecological space(grassland and woodland)to agriculture land accounted for the largest proportion from 2000 to 2018.However,the reverse transition from agriculture land to ecological space has increased since 2000 with the efforts of“Grain for Green”.In terms of temporal scale,there was a fluctuating trend in production space with the continuous expansion of living space,while ecological space showed an inverted U-shaped trend during 2000-2018.The dynamic pattern of production-living-ecological spaces in the TGRA was influenced by both physical and socio-economic variables as basic determinants and dominant driving factors,respectively.Finally,the harmonization and protection of production-living-ecological spaces still require policy-makers’efforts.This work may have potential in advancing our understanding about land use conflicts,and provide a reference for rational layout of spatial functions and the realization of sustainable development in the TGRA.

Malaria Transmission Potential in the Three Gorges Reservoir of the Yangtze River, China

Objective To define and evaluate the malaria transmission potential in the Yangtze River, following construction of the Three Gorges Reservoir. Methods Six villages, namely, Kaixian, Fengjie, Wanzhou, Fuling, Yubei, and Zigui were selected for investigating the malaria transmission potential in the reservoir. Transmission potential was estimated by mathematical modeling and evaluation of the local malaria situation. Factors that influenced the transmission potential were analyzed using Poisson regression analysis in combination with Grey Systematic Theory （based on evaluation by the Delphi method）. Results Indirect fluorescent antibody data and the incidence of malaria in the local population were consistent with the malaria transmission potential calculated for the area. Multivariate Poisson regression analysis showed a statistically significant association between the riparian zone and the man‐biting rate. Conclusion The risk of a malaria epidemic can be forecasted using the malaria transmission potential parameters investigated here which was closely correlated with the riparian zone.

Climate observation of the Three Gorges Region of the Yangtze River in 2019

2019年,长江三峡地区年平均气温17.5℃,较常年偏高0.3℃;冬季偏冷,春,夏,秋三季气温均偏高;年高温日数偏多.2019年三峡地区年降水量1035.1毫米,较常年偏少13%;四季降水均偏少;年暴雨日数偏少.2019年,长江三峡地区年平均风速较常年偏大;年平均相对湿度接近常年;酸雨强度弱,为1999年以来的最弱年,近十余年酸雨强度呈现明显的减弱趋势.2019年,长江三峡地区高温过程多,持续时间长;三峡中东部地区出现伏秋连旱;华西秋雨开始早,三峡中西部雨量多.

State of the climate over the Three Gorges Region of the Yangtze River in 2018

2018年长江三峡地区气温较常年偏高,降水量接近常年,暴雨日数少,风速偏大,相对湿度接近常年,酸雨弱。年内高温出现早,持续时间长,强度大;夏季出现阶段性伏旱;暴雨和强降水引发城市内涝。

State of the climate in the Three Gorges Region of the Yangtze River basin in 2020

2020年,长江三峡地区年平均气温17.2℃,接近常年;年平均降水量1530.8毫米,偏多29%,为1961年以来第二多,仅次于1998年.6月,7月降水量及年平均暴雨日数均为1961年以来第二多.平均风速较常年偏大;相对湿度略偏高;各月均无酸雨出现,近十余年酸雨强度呈现明显减弱趋势.2020年,三峡地区夏季暴雨洪涝灾害重.分析表明,冷空气频繁南下与西南暖湿水汽丰沛是造成三峡地区6–7月降水异常偏多的直接原因.2020年春季以来,印度洋海温持续偏暖导致西北太平洋副热带高压持续偏强偏南可能是造成6–7月长江流域气候异常的重要原因.

Intensive Observation of Reservoirinduced Seismicity and Preliminary Analysis on the Causes of Earthquakes in the Three Gorges Reservoir Area,Yangtze River

根据第 11 五年的计划的国家关键技术 RD 节目的要求，由 26 个地震车站组成的一个使增加密度的地震网络在 2009 年 3 月 21 短时期的地震计在湖北省的节在三个峡水库区域被建立， 5 宽带数字地震计。从三月到 2009 年 12 月， 2,995 ML -0 的一个总数。8 - 2。9 地震在从 145 m 三朵峡水库水水平玫瑰扣押到 172.8m 的试用期间被检测。用双差别地震地点算法， 2,837 地震精确被重定位。小本地地震的模式聚集在三个峡水库区域的结果表演呈现了线性分布或像团的簇分发，事件的像团的簇通常在从水滨的 5 km 的距离以内，并且地震的线性分发能被扩大到 16 km 的距离离开水滨。在三座峡水库的湖北节，地震主要在 Xiangxihe 河附近在 Xiannvshan 和 Jiuwanxi 差错的北结束被集中，并且沿着在在 Badong 区域的北河岸上的 Xietan 镇区和 Shenlongxi 区域的西方的长江的河岸，与焦点的深度不到 10km ，和 4km 在平均。在水库区域的地震频率与水库水水平变化有积极关联，显示 seismicity 属于水库导致的地震。沿着在水库区域的 Shenlong 河，地震在北 Badong 县显示出三线性分布，并且根据石灰岩地区常见的地形散布了分发。在碳酸盐阶层有地下的河。当水库被扣押时，水渗入了进地下的河，因此导致地震。在 Xiannvshan 的 crossriver 片断上的区域的地震指责， Jiuwanxi 差错并且在 Xietan ， Shazhen 和 Xizhen 的区域西方，可能与弄软断绝有关 Xiannvshan 差错，或床上用品例如 Nukou 差错，连接，它将导致岩石群众的失败因此，导致地震。然而，关于被触发的机制的有说服力的结论仍然需要进一步的学习。另外， Zigui 县并且在 Badong 县的 Rangkou 镇东方的 Wenhua 和 Yanglin 向南接近区域， mininginduced 地震在水库的岸是的附近，并且上的矿发生了一些倒塌地震。

Three-Gorges Reservoir Area on the Yangtze River Faced with Risk of Induced Destructive Earthquakes

The Three-Gorge Water Conservancy Project on the Yangtze River started to impound water by locking gates on June 1, 2003. A swarm of more than 2000 small earthquakes suddenly occurred densely along the river section in Xinling Town north of Badong, Hubei Province, on June 7. This caused grave concern in the following years, but, with the completion of the second- and third-phase engineering construction, the water level in the reservoir will rise up to 156 m and 175 m respectively, no matter whether it can induce larger and stronger earthquakes. After an analysis of the distribution of active faults in the eastern part of the reservoir area, their intersections and capability to generate earthquakes from a seismo-tectonic viewpoint, we consider that after the reservoir impounding, two potential focal zones existing in Badong and Zigui counties may generate M 5.5 earthquake, the seismic intensity of which may reach Ⅷ. It will induce landslide bodies in the reservoir area to be reactivated and slide. The evidence is the large-scale landslide occurring on the Shazhenxi Creek river in Zigui County on June 12, 2003.

Filling of the Three Gorges Reservoir to the 135-m Level: Instant Effects on the Yangtze Discharge and Suspended Sediment Concentration Entering the Estuary

Via the valuable opportunity of the Three Gorges Reservoir (TGR) 135-m filling in June 2003, the Yangtze discharge and suspended sediment concentration (SSC) entering the estuary during the period from 15 May to 15 July 2003 were analyzed to examine the instant effects of the filling on them. The Yangtze discharge and SSC entering the estuary in the periods before, during and after the filling clearly indicated three phases: 1) the pre-storage phase characterized by natural conditions, in which the SSC increased with increasing water discharge; 2) the storage phase, during which the SSC decreased dramatically with decreasing water discharge; and 3) the post-storage phase, during which both the SSC and water discharge remained at relatively low levels first until the end of June, then the SSC increased gradually with increasing water discharge. It seems that the times for the instant effects of the decreasing discharge downstream from the upper Yangtze on the Yangtze discharge and SSC entering the estuary due to the TGR 135-m filling to take place were about 5 d and 1 d respectively, while both were about 18 d for those of the increasing discharge. This probably reflects the buffering and resultantly hysteresis of the 1800-km stretch from the upper Yangtze to the estuary. The results are helpful for scientific and hydrological investigation of the Yangtze mainstream downstream from the TGR Dam and of the estuarine and adjacent coastal waters.

REMOTE SESING INVESTIGATION AND APPRAISAL OF LAND USE AND CAPACITY IN THE REGION OF THE YANGTZE RIVER GORGES’PROJECT

The region around the Three Gorges project on the Yangtze River has an area of 62552 square kilometres and population of 20.14 million. It limits a range hetween the sorth-north watersheds and from Yichang of Hubei Province to Jiangjin of Sichuan, including 24 cities and counties-Chongjing, Yichang and Wanxian etc. In this region, relief are mainly hills and middle-low mountains. Remote censing investigation and appraisal of land use and capacity which are two of the major restrict factors for the Three Gorges project have provided related scientific bases for macro-dicision-making of the project.

AN ANALYSIS ON THE STRUCTURE TYPES AND BENEFITS OFSLOPELAND AGROFORESTRY SYSTEMS-Taking the Three Gorge Reservoir Area As An Example

The modem term 'agroforestry system' is derived from agricultural practices. It is an organic combination of agriculture and forestry, ecology and economy, product variation and scientific management. On the basis of analyzing the types and structure of agroforestry system in the Three Gorges Reservoir area,the paper poins out that agroforestry system can be divided into diffend structutal levds. Taking some typical cases as examples, it compares the benefits of four kinds of structures. The result illustrates that the hedge row agroforestry system on slopeland is an effective way to realize coordinate development of ecology and economy.

Seasonal variation and longitudinal distribution of copepods in the main river area of the Three Gorges Reservoir

The ecosystem of the Three Gorges in the Yangtze River was changed into an artificial lake(reservoir)ecosystem after impoundment in June 2003.We surveyed the seasonal variation and spatial distribution of copepods from April 2004 to January 2005 in order to provide data for clarifying the successional pattern of the ecosystem.From Jiangjin to Maoping,eight copepod species were collected and classified into Calanoida(2),Harpacticoida(1),and Cyclopoida(5).Among them,Mesocyclops pehpeiensis,M.leuckarti and Sinocalanus dorrii had a relatively wide distribution.No distinct difference in species number was found among the sampling sites,but the species composition was different.Species composition,distribution and density of copepods showed significant seasonal variations.In addition,copepod density showed an obvious gradient with the distance from the reservoir dam:the nearer to the dam,the denser the copepods.

Come and Join the Fengdu Temple Fair Celebrations

Located in the beautiful Three Gorges Reservoir Area on the Yangtze River,Fengdu County of Chongqing is traditionally known as Ghost City.

加快三峡水库管理保护立法 为长江经济带高质量发展提供良好法治保障

三峡工程是“国之重器”,是保护和治理长江的关键性骨干工程。三峡水库功能效益显著,地理位置重要,管理保护涉及事项复杂。在长江流域生态环境保护和高质量发展由量变到质变的关键时期,加快推进立法工作,依法依规加强三峡水库管理保护,对工程安全运行和综合效益发挥,以及库区和流域高质量发展十分必要和迫切。建议从国家层面制定出台专门行政法规,协调和规范三峡水库的开发、利用、管理、保护行为,统筹库区和上下游生态环境保护和经济社会发展事项,为长江经济带高质量发展提供良好法治保障。

1998—2019年三峡水库总磷浓度与形态变化及通量汇算

研究1998—2019年三峡水库磷浓度及形态变化,并进行通量汇算。研究时段分为3个阶段:1998—2002年(阶段Ⅰ,三峡水库运行之前)、2003—2012年(阶段Ⅱ,过渡时期)和2013—2019年(阶段Ⅲ,三峡水库实现175m正常蓄水位,且金沙江下游段向家坝水库运行后),以阶段Ⅰ和Ⅲ为重点时段进行对比分析。结果表明,随着三峡成库、水位抬高及金沙江向家坝水库和溪洛渡水库的运行,三峡水库悬浮泥沙浓度值已降至很低(常年回水区2013—2019年均值为42mg/L,丰水期均值为96mg/L)。22年间,泥沙入库量和出库量皆呈下降趋势。三峡成库后的2003—2012年,泥沙淤积量巨大(平均1.546亿t/a);向家坝成库后的2013—2019年,泥沙淤积大为减少,淤积量仅为2003—2012年的37%。2013年是三峡库区磷污染程度由加重趋势至减轻趋势的拐点,之后三峡水库总磷和溶解态磷浓度皆呈显著下降趋势。三峡水库磷的主导形态由颗粒态变为溶解态,溶解态磷占比由成库前的39%上升为2017—2019年的69%。2004—2012年是总磷滞留的高峰期,期间总磷入库量大且年际波动大,约60%的磷随泥沙发生沉降,年均滞留量为8.222万t/a;2013—2019年,总磷入库量大幅度减小且年际波动变小,入库和出库磷通量趋于平衡。总磷、溶解态磷和颗粒态磷通量均表现为丰水期>平水期>枯水期。河流泥沙总磷浓度与泥沙含量正相关的实质是颗粒态磷浓度与泥沙含量的正相关。总磷浓度、通量和形态发生变化的主要驱动力是泥沙含量下降和磷污染控制。

三峡水库秋汛期水沙特点及秋汛洪水对库区冲淤的影响

长江上游秋汛洪水是三峡水库重要水沙事件,对三峡库区冲淤特性有直接影响。基于1954-2022年实测资料分析表明,近70年来长江上游秋汛期来水量变化不大,来沙量均值在2013年前后减幅达到87%。2013年以后,三峡库区秋汛洪水的来沙高度集中于嘉陵江流域,占寸滩沙量的70%以上,秋汛洪水通过影响嘉陵江的水沙条件,进而间接影响三峡水库秋汛期的入库水沙条件。与汛期洪水相比,秋汛洪水的泥沙90%以上在库区淤积,且库尾淤积更加突出。实测资料分析结果表明,秋汛洪水期间适时加大水库下泄流量,可显著增大排沙量,减轻库区淤积。研究成果对加深三峡水库淤积特性认识、优化三峡水库秋汛洪水调度具有重要意义。

发挥长江经济带关键骨干作用 促进三峡工程安全运行和库区高质量发展

三峡工程是“国之重器”,具有防洪、发电、航运、水资源利用等巨大的综合效益,是长江的骨干性、控制性水利枢纽工程,在长江大保护与长江经济带高质量发展中发挥了巨大的作用。按照习近平总书记关于三峡工程“一个标志、三个典范”的高度评价,文章准确把握了三峡工程和三峡库区在长江经济带发展中的关键骨干作用,深入理解了三峡工程安全运行和库区高质量发展面临的新形势新要求,合理确定了世界水工程安全运行管理典范、国家重要淡水资源战略储备库、生态优先绿色发展和谐稳定共同富裕示范区、人与自然和谐共生三峡新文化引领者等四大战略定位,系统谋划了促进三峡工程高水平安全运行和库区高质量发展的具体实施路径。

为长江经济带绿色发展贡献水库移民和乡村振兴水利保障力量

长江经济带水网密布、河流众多,大中型水库移民数量超过1000万人,涵盖346个脱贫县,是水库移民工作的“主战场”也是乡村振兴水利保障工作的“主战场”。文章总结了长江经济带绿色发展的重大意义,全面梳理了水库移民和乡村振兴水利保障工作高质量发展的主要实施路径和对策考虑。

三峡水库蓄水后长江中游嘉鱼河段河床演变特性分析

嘉鱼河段是长江中游典型的碍航河段之一,需重点关注河床演变特性。根据1970~2021年实测水下地形资料,全面分析了该河段的冲淤、岸线、河床形态、洲滩深槽等变化,研究该河段自2003年三峡水库蓄水运用及2006年实施航道整治工程以来河床演变特性。结果表明:自三峡水库蓄水运用以来,该河段岸线基本稳定,河床冲刷部位主要在枯水河槽;近些年断面形态逐渐趋于稳定,岸线变化不大;河段内洲滩平面位置保持相对稳定的状态,仅在复兴洲尾部左缘、燕窝镇对面江中形成了一个新的江心洲;深槽平面位置较为稳定。研究成果可为该河段防洪调度、河道治理等提供参考。

Spatiotemporal patterns of the fish assemblages downstream of the Gezhouba Dam on the Yangtze River

An explicit demonstration of the changes in fish assemblages is required to reveal the influence of damming on fish species.However,information from which to draw general conclusions regarding changes in fish assemblages is insufficient because of the limitations of available approaches.We used a combination of acoustic surveys,gillnet sampling,and geostatistical simulations to document the spatiotemporal variations in the fish assemblages downstream of the Gezhouba Dam,before and after the third impoundment of Three Gorges Reservoir(TGR).To conduct a hydroacoustic identification of individual species,we matched the size distributions of the fishes captured by gillnet with those of the acoustic surveys.An optimum threshold of target strength of 50 dB re 1 m 2 was defined,and acoustic surveys were purposefully extended to the selected fish assemblages(i.e.,endemic Coreius species) that was acquired by the size and species selectivity of the gillnet sampling.The relative proportion of fish species in acoustic surveys was allocated based on the composition(%) of the harvest in the gillnet surveys.Geostatistical simulations were likewise used to generate spatial patterns of fish distribution,and to determine the absolute abundance of the selected fish assemblages.We observed both the species composition and the spatial distribution of the selected fish assemblages changed significantly after implementation of new flow regulation in the TGR,wherein an immediate sharp population decline in the Coreius occurred.Our results strongly suggested that the new flow regulation in the TGR impoundment adversely affected downstream fish species,particularly the endemic Coreius species.To determine the factors responsible for the decline,we associated the variation in the fish assemblage patterns with changes in the environment and determined that substrate erosion resulting from trapping practices in the TGR likely played a key role.

Analysis and prediction of sediment trapping efficiencies of the reservoirs in the mainstream of the Lancang River

存储的水和水库套住的沉积在下游的水路环境上导致物理、化学、生态的效果。关于水库沉积的量的研究是钥匙估计它的环境影响。在位于 Manwan 水库的 upstream 和 downstream 的计量车站在 39 年获得的沉积负担数据被用来估计 Manwan 水坝的套住的效率(TE ) 。TE 价值当时与用修改 Brune 和 Siyam 模型的估计相比。结果显示那：(1 ) 计量数据估计的 Manwan 水坝的 TE 是 60.48% ，并且两个都， TE 值由修改 Brune 计算了， Siyam 模型是 60.03% 。近似 TE 价值显示修改 Brune 和 Siyam 模型能被用来在 Lancang 河的主流作为 Manwan 水库与类似的存储能力预报另外的水库的 TE；(2 ) Gongguoqiao， Dachaoshan 和 Jinghong 水坝的 TE 价值是大约 30.23% ， 66.05% 和 63.50% 由修改 Brune 模型估计了，并且 38.81% ， 63.97% 和 62.30% 由修改 Siyam 当模特儿。在论文采用的结果和方法论能也被用来在西南的中国在另外的河盆估计 TE。