Assessment of multi-objective reservoir operation in the middle and lower Yangtze River based on a flow regime influenced by the Three Gorges Project

The construction of multi-function reservoirs is important to guaranteeing the development and utilization of water and hydropower resources, but the construction of any hydrologic projects will inevitably affect the downstream flow regime that provides the driving force for riverine ecosystems. This paper therefore aims to propose a framework for assessing multi-objective reservoir operation models based on flow regime using the middle and lower Yangtze River as a case study. Using indicators of hydrologic alteration (IHA) and the histogram matching approach (HMA), critical influential factors for flow were investigated at the Yichang and Datong gauges, which are typical of the middle and lower Yangtze River. This found the magnitude of annual extreme minimum water flow rates to be the most dramatically changed indicator, with an overall degree of hydrologic alteration at the Yichang and Datong gauges of 41.98% and 34.58%, respectively. The monthly mean discharges of February and October at Yichang have been significantly changed as a result of the Three Gorges Reservoir (TGR) operation. Meanwhile, an improved range of variability approach (IRVA) was developed to obtain ideal target ranges for monthly average flow. A multi-objective ecological reservoir operations model was created for the TGR; the Non-dominated Sorting Genetic Algorithm II (NSGA-II) was applied to the model. Three typical years of wet, normal and dry years were selected, and the operation results with corresponding ideal target ranges were analyzed for the downstream Yichang and Datong cross sections. The results showed that there should be a reduction by 23.57%, 28.10% and 39.92% in the monthly mean flow of February and an increase by 34.48%, 112.36% and 52.12% in the monthly mean flow of October at Yichang cross section in wet, normal and dry years, respectively.Close attention therefore needs to be given to integrating ecological objectives with appropriate flow regimes into multi-objective operation models.     

水利工程对坝下径流的影响——以葛洲坝、三峡水利枢纽为例

水利工程建设在给人类带来抗旱防洪效益、发电效益、航运效益、养殖等效益的同时,也对河流水文动态产生了一系列的影响,主要表现为对径流的调节。基于宜昌站1890—2014年径流数据,综合采用径流集中度、集中期和相位差分析等多种方法,分析了水利工程建设对径流年内分配以及枯水期的影响。结果表明:宜昌站径流集中度呈现缓慢下降趋势并在2004年发生突变,2003年以后径流集中度相对于2003年以前下降0.06(下降幅度为12.98%),说明葛洲坝水利枢纽、三峡工程建成以后宜昌站径流在年内分配变得平缓,洪峰被有效削弱,且三峡工程对宜昌站径流集中度减少的贡献率大于葛洲坝水利枢纽(贡献率分别为92.03%和7.97%);葛洲坝和三峡水利枢纽建成后,宜昌站径流重心提前8d(集中期从8月9日提前至7月31日);宜昌站进入枯水期的时间提前约20d(三峡大坝建设以前,宜昌站在12月7—11日进入枯水期,建设以后在11月底进入枯水期),水利工程对水文过程的影响可能导致下游枯水期污染加剧和湿地生境提前缩小,进而影响下游水环境和湿地生物多样性。上述结果定量揭示了水利工程对水文过程的影响及其潜在生态效应,可为认识水利工程的生态影响以及流域生态环境变化的驱动因素提供科学依据。     

Spawning activity of the four major Chinese carps in the middle mainstream of the Yangtze River,during the Three Gorges Reservoir operation period,China

River flow alterations caused by dams have introduced many ecological problems, in particular a decline in aquatic species such as fishes. One compensatory measure is to create a hydrological process similar to the natural state with regard to the survival requirements of the fish. In recent years, the Three Gorges Reservoir (TGR) has introduced man‐made flood by ecological operation experiments to facilitate spawning of the four major Chinese carps in the Yangtze River, China. To investigate the fish spawning activities and their responses to the TGR operation, eggs from the four major Chinese carps were sampled using conical drift nets in the middle mainstream of the Yangtze River, May to July in 2012 and 2013. Spawning timing, location, and scale of the four carps were studied and compared between the 2 years; key hydrological and environmental factors associated with spawning were determined by principal component analysis and stepwise regression analysis. Two factors were significantly positive when correlated with egg abundance: one was increasing rate of the river flow (flood amplitude), and the other was river transparency; only one factor, starting of the river flow (flooding occasions), was significantly and negatively correlated with the time of spawning. Comparison of egg abundance in one flood pulse response to different operation rules showed that flooding made by an ecological operation induced a larger scale of spawning than a conventional operation. The study implied that suitable flood conditions could produce a successful spawning event, and that the occasion and pattern of the flood process might result in different responses in fish spawning. Further research is required to develop more scientific monitoring designs in order to obtain accurate field data for both biotic and abiotic factors, and explore new research methods for egg abundance estimations combined with particle experiment and hydrodynamic modeling. This work is fundamental to improve the strategic decisions on reservoir operation and river management.     

Assessing the effect of the Three Gorges reservoir impoundment on spawning habitat suitability of Chinese sturgeon (Acipenser sinensis) in Yangtze River,China

The Chinese sturgeon (Acipenser sinensis), a kind of maricolous anadromous migratory fish species, is endangered and protected in China. Historical spawning habitats were distributed in the lower reaches of Jinsha River and the upper reaches of Yangtze River. Since the establishment of the Gezhouba water conservancy pivot in 1981, the migratory route of Chinese sturgeon spawning was blocked. Therefore, the fish was forced to propagate in a new spawning ground which was mainly distributed in the 4-km-long mainstream from Gezhouba Dam to Miaozui in the middle Yangtze River. After water storage and power generation of the Three Gorges reservoir (TGR) in 2003, the propagation of Chinese sturgeon has been impacted gradually. According to field surveys, the fish used to spawn twice a year before TGR impoundment, but only once happened after that. Besides, the spawning scale is also declining with each passing year.In order to simulate and evaluate the effect of TGR impoundment on spawning habitats of Chinese sturgeon, with consideration of their reproductive characteristics, an eco-hydrodynamic model was established by coupling a two-dimensional hydrodynamic model and a fuzzy fish habitat module based on fuzzy logic inference. Flow fields at the studied site in an impoundment scenario and an assumed no impoundment scenario were simulated with the 2D hydrodynamic model. Afterwards, by linking hydrodynamic conditions to the expert knowledge base, the fuzzy habitat model used fuzzy logic inference to compute habitat suitability of the Chinese sturgeon. In addition, the approach was used to propose a suitable instream flow range during the propagation period for Chinese sturgeon. The results indicated that the suitable instream flow needed for Chinese sturgeon spawning in middle Yangtze River should be between 10,000 m³/s and 17,000 m³/s and it also showed that after TGR was put into pilot impoundment operation at the designed water level of 175 m, the habitat suitability has decreased significantly in October. Besides, the water temperature of spawning habitat increased to a higher level in propagation period due to the impoundment of the TGR. All these alterations have had imposed tremendous impacts on the propagation of Chinese sturgeon. Therefore, adjusting impoundment schedule of the TGR to recover the water flow over spawning habitat in October is a crucial way to improve the habitat suitability. Furthermore, the presented method also provides a theoretical basis for further research on the assessment of habitat suitability of aquatic species at a micro-habitat scale.     

Multi-objective optimization of cascade reservoirs using NSGA-II: A case study of the Three Gorges-Gezhouba cascade reservoirs in the middle Yangtze River,China

A multi-objective optimization model of cascade reservoirs was developed to maximize the power generation and minimizie the appropriate ecological flow shortage index (AEFSI) downstream from the reservoir. Additionally, the non-dominated sorting genetic algorithm (NSGA-II) was used to search for multi-objective Pareto optimal solutions. The paper took the Three Gorges-Gezhouba cascade reservoirs as a case study. After validating the model, data from three typical years were used in the optimization. The results indicated that maximizing power generation by adjusting the optimal rules increased power generation by 1.07%, 0.91%, and 1.03% in normal, wet, and dry hydrological years, respectively, while increasing the AEFSI by 22.12%, 11.78%, and 14.67% (compared to real operations). The AEFSI was improved (decreased) by 21.90%, 10.27%, and 18.52% when the optimal rules favored the downstream ecology, but power generation decreased by 1.61%, 1.06%, and 2.29%, respectively, in the different hydrological years. Moreover, the results provide a set of well-distributed optimal solutions along the Pareto front that allow decision-makers to easily determine the best compromised solutions based on the trade-offs between the economic and ecological benefits. The results of this study provide guidance for decision-makers to improve the comprehensive benefits of the Three Gorges-Gezhouba cascade reservoirs.     

A Holocene environmental record from the southern Yangtze River delta, eastern China

The Holocene sedimentary record of core ZX-1, recovered west of mid-Holocene Chenier ridges on the monsoon-controlled Southern Yangtze delta, eastern China, consists of lagoon, salt marsh, upper tidal flat, and limnic facies, reflecting low-energy depositional environments. Holocene deposits mainly originated from the surrounding Tai Lake drainage basin. The temporal variation of most geochemical element percentages corresponds with the climatic phases inferred from the pollen record, i.e., the relatively low values of SiO₂, Na₂O, CaO and high values of Al₂O₃, K₂O, MgO, Fe₂O₃, FeO, FeO + Fe₂O₃ and TiO₂ generally concur with the warm and humid climate, and vice versa. Three geochemical indices − Al₂O₃/Na₂O, K₂O/Na₂O, and CaO/K₂O − are found to be sensitive to past precipitation in the monsoon-controlled southern Yangtze River delta. Based on fine sediment analysis of core ZX-1, the samples deposited under a dry climate with a mean annual precipitation (MAP) < 500–900 mm tend to have Al₂O₃/Na₂O values less than 12.2, and the samples deposited under a moist climate with an MAP 1000–1800 mm mostly have Al₂O₃/Na₂O values higher than 12.2. Similarly, the K₂O/Na₂O boundary value is 2.0. However, for CaO/K₂O, the dry climate sediments likely show values higher than 0.9, and those wet climate ones generally have values less than 0.9. This geochemical response suggests the potential application of these indices in the interpretation of palaeoclimate variation of monsoon-controlled eastern China.

Holocene climatic variation history is reconstructed for the southern Yangtze delta. From 8000 to 7000 yr BP, regional climate demonstrated frequent fluctuations, with warm and wet periods (8000–7700; 7500–7200 yr BP) alternating with cool and less humid periods (7700–7500; 7200–7000 yr BP). From 7000 to 6000 yr BP, the climate was relatively warm and humid. Since then, it had turned cool and dry, climaxing in an intense cold event around 4000 yr BP. After the cold event, it became warm and humid until around 2500 yr BP.     

Freshwater icefishes (Salangidae) in the Yangtze River basin of China: Spatial distribution patterns and environmental determinants

Synopsis We surveyed 86 lakes affiliated to the Yangtze River to assess the status of natural freshwater icefishes, and to study their spatial distribution patterns and environmental relationships. Results showed that the spatial patterns of icefish diversity and the occupancy of each species related closely to the historical process of habitat fragmentation. Statistical analyses indicated that the spatial structure of the icefish assemblage significantly related to the area- and isolation-related environmental variables. These results illustrated the significant impacts of hydrological engineering (dykes and floodgates) on the historical dynamics of the icefish populations, and shed light on the essentiality and feasibility of conserving and wise using freshwater icefishes by managing suitable habitats and re-connecting the river-lake network in the Yangtze River basin.     

长江三峡库区土地利用/覆盖的长期变化

了解土地利用/覆盖的时空变化有助于揭示气候变化和人类活动对生态系统的影响,是开展生态系统管理的重要前提.长江三峡库区是我国重要的生态脆弱区,环境变化影响的复杂性显著,但目前对此仍缺乏系统了解.本文通过解译Landsat时序遥感影像,获取三峡库区土地利用/覆盖数据,研究土地利用/覆盖构成结构及其分布的长期时空变化特征,以揭示三峡库区土地利用/覆盖的演变规律,为深入了解生态脆弱区生态系统变化复杂性和区域生态系统管理提供科学依据.结果表明: 1990—2015年间,三峡库区土地利用/覆盖结构的空间异质性和变化显著,农田面积比例由66.2%降至40.4%,林地面积比例由31.3%增至53.5%,库区由农业景观转变为以森林、灌木林等为主的林地景观,建设用地和水体逐渐增加;林地逐渐向库区中部扩张,建设用地点状扩张;海拔500～1000 m和坡度15°～25°区域林地面积比例增长最明显,针叶林、针阔混交林和灌木林等植被类型增长最快.研究期间,三峡水库建设和各类生态恢复工程的实施促使区域土地利用/覆盖结构呈阶段性变化,总体表现为生态恢复趋势.积极的生态恢复措施有助于消减工程建设对区域生态环境的负面影响.     

Length–weight relationships of 55 fish species from the Three Gorges Reservoir in the Yangtze River,China

The paper reports the length–weight relationships of 55 species from the Three Gorges Reservoir (TGR) of the Yangtze River, China, and the largest reservoir in the world. A total of 24,176 specimens were collected from July 2012 to January 2015. Length–weight relationships for 33 fish species not recorded previously in FishBase, and the maximum total lengths computed for eight species are presented. The a values varied between 0.00054 and 0.01923, and the b values ranged from 2.729 to 3.583. The results will be useful for the application of sustainable management and conservation of these fishes in the TGR of the Yangtze River.     

Ecological reservoir operation based on DFM and improved PA-DDS algorithm: A case study in Jinsha river,China

Abstract

This study aims to explore the optimization of reservoir operation in the Jinsha River, accounting for both economic and ecological needs. Power generation was set as an objective to express economic needs, while water supply, shipping, and flood control were considered as restrictions. The distribution flow method (DFM) based on Pearson-III curve was proposed to calculate the most optimal ecological flow (MOEF). Additionally, minimal difference between the outflow and MOEF was set as an objective to reflect ecological needs. Results indicated that the DFM was more objective, effective, and convenient than the improved Tennant method and monthly frequency computation method in calculating the MOEF. An improved Pareto archived dynamically dimensioned search (PA-DDS) algorithm was introduced to address completed reservoir optimization. Results highlighted that the application of the improved PA-DDS produced more convergence, uniformity, and stability in nondominated solutions (NDS), compared with the non-dominated sorting genetic algorithm-II (NSGA-II). Separate optimization and joint optimization of cascade reservoir operation were studied using the improved PA-DDS. The results indicated that joint optimization produced higher power generation in the dry year and normal year, and significant reduction in the difference between the outflow and MOEF in the wet year.     

Freshwater fish biodiversity in the Yangtze River basin of China: patterns, threats and conservation

We synthesized information on freshwater fish biodiversity in the Yangtze River basin. We documented 361 species and subspecies that had been recorded and described from the basin. Of these, 177 species are endemic. The basin is usually divided into three parts, i.e. the upper reaches, the middle reaches and the lower reaches. This study indicated that the three reaches approach was not supported by fish distribution patterns. Hydrological alterations are perhaps the largest threat to fish biodiversity in the basin. Fishes in the upper reaches will be seriously affected by the construction of the Three Gorges Dam and other dams, and action should be taken for priority conservation. The most immediate restoration need is reconnection of the Yangtze River with its lakes. The cluster of lakes in the Central Yangtze should be protected to maintain habitats for spawning, feeding and migration of migratory fishes. Our study indicates a need to identify areas of high fish biodiversity and to select nature reserves to mitigate the loss of fish biodiversity in the Yangtze River basin.     

桥边河大型底栖动物生境适宜性

构建精度高,适用性强的水生生物生境适宜性评价模型,为河流生境质量评价和生境修复提供理论依据。以长江一级支流桥边河为例,采用典范对应分析和独立性分析,筛选出影响桥边河大型底栖无脊椎动物优势种河蚬生境质量的关键化学因子和物理因子,利用广义加性模型与多项式拟合模型构建生境因子与生物选择的关系。结果表明:(1)影响桥边河河蚬生境质量的主要因子为COD_Mn、TN、DO、Tur (浊度)和Dep (水深);其中COD_Mn、TN、Tur、Dep与大型底栖无脊椎动物分布成负相关,DO与大型底栖无脊椎动物分布成正相关;(2)桥边河流域河蚬的最适宜COD_Mn含量为1.228 mg/L,最适宜TN含量为0.269 mg/L,最适宜DO含量为11.170 mg/L,最适宜Dep为0.3 m,最适宜Tur为1.130 NTU。(3)线性拟合情况下两种方法均适用;非线性拟合情况下广义加性模型较优于传统多项式拟合模型,且GAM模型在处理离散程度大的数据集时,可以很好的规避多项式拟合过程中出现的过拟合现象。研究显示,运用GAM模型可以更加精确、合理的模...     

Spatio-temporal patterns of zooplankton in a main-stem dam affected tributary: a case study in the Xiangxi River of the Three Gorges Reservoir,China

As the ecologically important recipient channels for riverine ecosystems, tributaries provide unique microhabitats for microorganisms, among which zooplankton constitutes the most important heterotrophic organisms. In particular, the reduced water velocity caused by dams is more favorable for zooplankton development; therefore, dammed rivers are expected to support extremely diverse and abundant zooplankton communities and notably different spatiotemporal distribution patterns. So far,however, only very few molecular studies support these assumptions. Using high-throughput sequencing, a high number of 350 operational taxonomic units(OTUs; 97% cutoff) were retrieved from 30 samples collected in the Xiangxi River, the nearest large tributary upstream of the Three Gorges Dam. Zooplankton did not show significant spatial distribution in the channel. Instead,the community structures varied significantly over sampling dates, corroborating the seasonal patterns found in lakes and ponds in the subtropical zone. As expected, the community compositions were deterministically governed by environmental filtering processes(phylogenetic clustering), in which water velocity appeared to be much less important than other investigated environmental factors. Moreover, most of the detected phylotypes(OTUs) had a relatively high(90%) sequence similarity to previously deposited sequences, suggesting a mediocre degree of genetic novelty within the zooplankton communities in the Xiangxi River.     

基于土地利用变化的典型喀斯特流域生态风险评估——以漓江流域为例

以漓江流域为研究对象,利用1973、1986、2000和2013年4期遥感影像,提取土地利用数据,构建生态风险指数,借助“3S”技术,分析漓江流域生态风险时空演化特征.结果表明: 1973—2013年,漓江流域土地利用结构处于相对合理状态,并不断优化;研究区生态风险一直处于较低水平,以低和较低生态风险为主,但高生态风险区域扩张迅速;生态风险空间分布整体格局基本稳定,呈现明显的圈层结构,以兴安县城—灵川县城—桂林市区—阳朔县城为轴向外风险程度逐渐降低,低生态风险区主要集中分布在流域北部以及中东部的自然山林地带,高生态风险区主要分布在桂林市区;生态风险分布具有明显的坡度、高程差异,表现出随坡度和高程增加生态风险逐渐下降的分布特点;研究期内,低级别向高级别生态风险转化的面积不断下降,反向转化的面积持续增加,流域生态风险整体上呈加速下降趋势.     

Morphological and photosynthetic responses of riparian plant Distylium chinense seedlings to simulated Autumn and Winter flooding in Three Gorges Reservoir Region of the Yangtze River, China

To evaluate the tolerance of riparian plant Distylium chinense in Three Gorges Reservoir Region to anti-season flooding, a simulation flooding experiment was conducted during Autumn and Winter, and morphology and photosynthesis of D. chinense seedlings and their recovery growth after soil drainage were analyzed in different duration of flooding and flooding depth. The seedlings were submitted to four treatments: (1) 40 seedlings unflooded and watered daily as control (Unflooded, CK); (2) 120 seedlings flooded at 1 cm above the ground level (F-1 cm); (3) 120 seedlings flooded at 12 cm above the ground level (F-12 cm) and (4) 120 seedlings completely submerged with 2 m water depth (F-2 m, top of plants at 2 m below water surface). The flooding survival, plant height, stem diameter, adventitious roots, stem lenticels, epicormic shoots, chlorophyll content and photosynthesis parameters were determined at 0, 15, 30, 90 days in flooding stress and 15, 60 days after soil drainage. The results showed that the survival of the seedlings subjected to flooding was 100% for all repeated measurements in all treatments. Adventitious roots, hypertrophied lenticels and stem hypertrophy were observed in the seedlings flooded for more than 15 d, and increased with the prolonged flooding duration, while disappeared after the soil was drained. Flooding duration and flooding depth showed significant individual and interactive effects on leaf chlorophyll a (Chl a), chlorophyll b (Chl b), and their ratio, chlorophyll (a + b), the net photosynthesis rate (P_n), transpiration rate (T_r), stomatal conductance (C_s), and inter-cellular CO₂ concentration (C_i) of D. chinense seedlings (P < 0.01). After 15 days of flooding, there was no significant decrease in P_n of the flooded seedlings as compared with that of the control seedlings. P_n of the flooded seedlings was significantly lower than that of the control seedlings after 30 days of flooding (P < 0.05), whereas P_n showed no significant difference among seedlings from three flooding depths. After 90 days of flooding, P_n of the F-2 m flooded seedlings was significantly lower than that of the controls, F-1 cm and F-12 cm flooded seedlings (P < 0.05), but still maintained high photosynthetic capacity. P_n of the F-1 cm and F-12 cm flooded seedlings rose gradually after soil drainage, while, it was significantly lower than that of the control seedlings after 15 days of recovery (P < 0.05). After 60 days of recovery, P_n of all seedlings flooded with different depths showed no significant difference as compared with that of the control seedlings and new leaves grew out in the F-2 m flooded seedlings. The effect of all flooding treatments on Gs, T_r, Chl a, Chl b, Chl a/Chl b and chl (a + b) was basically the same as their effect on P_n, while the effect of all flooding treatments on C_i was quite the contrary. Correlation analysis showed that P_n was positively relative with Gs, T_r, Chl a, Chl b and chl (a + b) (P < 0.05) and significantly negative with C_i (P < 0.05). Therefore, the present study demonstrates that D. chinense has high survival and good recovery growth after long-term flooding in anti-season flooding and could be taken as an excellent candidate species in the re-vegetation of water-level-fluctuation areas in Three Gorges Reservoir Region.     

Palynological evidence for Holocene environmental change in the Changjiang (Yangtze River) Delta, China

Holocene vegetation changes in response to climate fluctuations and human impacts are reviewed on the basis of pollen analyses from borehole cores taken from the Changjiang (Yangtze River) delta, China, and other previously reported data. During the earliest Holocene (10,930−9000 cal yr BP), the climate was warm and wet, allowing thermophilous hardwoods to occupy mid- and low-elevations surrounding a palaeo-Changjiang estuary. The climate became gradually cooler, and cool-tolerant conifers, grasses and ferns became dominant until 7600 cal yr BP, when the estuary became a delta. A mid-Holocene climatic optimum occurred between 7600 and 4800 cal yr BP, when evergreen and broadleaved deciduous trees flourished at mid- and low-elevations surrounding the delta front-prodelta. After this time, climate became cooler again until 1340 cal yr BP. During this period, evergreen and broadleaved deciduous trees were replaced by conifers and grasses inhabiting the inter/subtidal flat-delta front. This development of conifer-grassland vegetation was shortly interrupted between 3860 and 3200 cal yr BP when thermophilous tree cover increased and open vegetation with scattered conifers was reduced. Since 1340 cal yr BP, the vegetation has been similar to that at present under warm, wet conditions. Human impacts are recognized by the first appearance of Fagopyrum and a sudden increase in herb pollen at 4500 and 1340 cal yr BP, respectively.     

Length–weight relationships for five endemic fish species in the upper Yangtze River basin,China

Length – weight relationships were estimated for five endemic fish species in the upper Yangtze River: Platysmacheilus nudiventris Luo, Le & Chen, 1977, Xenophysogobio nudicorpa (Huang & Zhang, 1986), Homatula potanini (Günther, 1896), Leptobotia rubrilabris (Dabry de Thiersant, 1872), and Euchiloglanis kishinouyei Kimura, 1934. The a values ranged from 0.0079 to 0.0134, and b values from 2.833 to 3.081. These five endemic species are rare, small and difficult to find and capture. Thus the sampling period was lengthy, from May 2010 to May 2014. A total of 718 specimens were available for analysis, and the length – weight relationships are the first reports for these five endemic fish species.     

Plant biodiversity and its conservation strategy in the in-undation and resettlement districts of the Yangtze Three Gorges, China

The investigation on and conservation project of plant biodiversity in the inundation and resettlement districts of the Three Gorges region were carried out with the ongoing construction of the Three Gorges Dam. Based on the first-hand specimens collected for many years and the historical records, we found that there were about 1784 higher plant species, belonging to 762 genera of 170 families, which accounted for 59.19%, 75.30% and 85.85% of the total amount of species, genera and families in the Three Gorges region, including 27 species specific in these two districts. The shrub and grass communities were mostly distributed along the low-altitude river bank zone of the Yangtze River and were largely influenced by the dynamic water level of the Three Gorges reservoir area. The measurement of Shannon-Wiener and Pielou evenness indexes on 21 Pinus massoniana (Masson pine) communities distributed in the Three Gorges reservoir area was carried out, and results showed that the biodiversity of shrub layers was the highest, followed by grass layers, the middle, and tree layers, the lowest. Among the 11 typical shrub communities in this region, the abundance of shrub layers of Form. Rhus chinensis, Form. Cotinus coggygria var. cinerea, Form. Vitex negundo var. cannabifoliaand and Form. Coriaria sinica was relatively higher, which were 16, 26, 29 and 15, respectively. These four shrubs also showed high biodiversity index (H′), which were 1.791, 3.427, 2.949 and 1.718, respectively. Among the 9 grasslands mainly distributed along the river bank zone, 4 grassland communities with higher altitude (Form. Dicranopteris dichotoma, Form. Miscanthus floridutus, Form. Imperata cylindrica var. major and Form. Arthraxon hispidus) showed higher abundance and biodiversity, which were 1.697, 1.354, 1.144 and 1.018, respectively. Considering the inundation and resettlement districts, there were 22 vegetation types threatened by submersion, including 4 woody plant communities, 9 shrub communities and 9 grassland communities. The 6 shrub communities of Form. Securinega wuxiensis, Form. Bauhinia brachycarpa, Form. Geum aleppicum, Form. Distylium chinense, Form. Buxus henryi and Form. Myrsine africana would be fully submerged and part of Adianthum reniforme var. sinensis and Buxus ichangensis would be also submerged. At present, plant species conservation and monitoring stations in the Three Gorges region have been constructed, and more than 200 plant species have already been transplanted and conserved, including 37 threatened species listed in the China Plant Red Data Book and 11 local constructive species.