Compound Planting of Bletilla striata under Forest in the Three Gorges Dam Area

[Objectives] The aim was to study the artificial cultivation of Bletilla striata to realize large scale and standardization planting. [Methods] The comparison tests were conducted on B. striata with different canopy densities of the Magnolia officinalis forests,different compound planting densities and different tending measures and management. [Results] When the stand canopy density was 0. 4-0. 6,the per unit yield of B. striata was 5. 4%,6. 8% higher than that at the canopy density of less than 0. 4 and more than 0. 6,respectively. When the planting density was 30 cm × 30 cm,the per unit yield increased by 16. 1%,12. 0%,13. 1% respectively compared with the planting density of 20 cm × 20 cm,25 cm × 25 cm,35 cm × 35 cm. When B. striata was planted from October to November,the per unit yield was 5. 6% higher than that planted from December to January of the following year,and 21. 3% higher than that from February to March of the second year. When farmyard manure was applied during the cultivation,the per unit yield was 31. 7% and 18. 4% higher than the application of chemical fertilizer and compound fertilizer. When weeding 4 times per year,the per unit yield increased by 240. 1%,137. 0% and 43. 9% respectively from that weeding 1 times,2 times,3 times per year. [Conclusions]When planting B. striata,the stand canopy density of 0. 4-0. 6 could make it receive absolutely shelters and the lighting conditions required for the growth,thereby bringing in high emergence rate,good growth potential and high yield. The best planting effect of B. striata could achieve by planting from October to November with the planting density of 30 cm × 30 cm,which can play the maximum benefit of individual plants. Moreover,weeding 4 times per year combined with the use of farmyard manure can promote the development and growth of tubers,which can greatly improve the yield of B. striata.

Mapping of moraine dammed glacial lakes and assessment of their areal changes in the central and eastern Himalayas using satellite data

The relatively rapid recession of glaciers in the Himalayas and formation of moraine dammed glacial lakes(MDGLs) in the recent past have increased the risk of glacier lake outburst floods(GLOF) in the countries of Nepal and Bhutan and in the mountainous territory of Sikkim in India. As a product of climate change and global warming, such a risk has not only raised the level of threats to the habitation and infrastructure of the region, but has also contributed to the worsening of the balance of the unique ecosystem that exists in this domain that sustains several of the highest mountain peaks of the world. This study attempts to present an up to date mapping of the MDGLs in the central and eastern Himalayan regions using remote sensing data, with an objective to analyse their surface area variations with time from 1990 through 2015, disaggregated over six episodes. The study also includes the evaluation for susceptibility of MDGLs to GLOF with the least criteria decision analysis(LCDA). Forty two major MDGLs, each having a lake surface area greater than 0.2 km2, that were identified in the Himalayan ranges of Nepal, Bhutan, and Sikkim, have been categorized according to their surface area expansion rates in space and time. The lakes have been identified as located within the elevation range of 3800 m and6800 m above mean sea level(a msl). With a total surface area of 37.9 km2, these MDGLs as a whole were observed to have expanded by an astonishing 43.6% in area over the 25 year period of this study. A factor is introduced to numerically sort the lakes in terms of their relative yearly expansion rates, based on their interpretation of their surface area extents from satellite imageries. Verification of predicted GLOF events in the past using this factor with the limited field data as reported in literature indicates that the present analysis may be considered a sufficiently reliable and rapid technique for assessing the potential bursting susceptibility of the MDGLs. The analysis also indicates that, as of now, there are eight MDGLs in the region which appear to be in highly vulnerable states and have high chances in causing potential GLOF events anytime in the recent future.

Monitoring of Land-Cover Dynamic Change in Lancangjiang River Cascaded Hydropower Area

The analysis of the 3 stages＇ （1988,1996,2000） variation of land-cover is performed according to Thematic Mapper （TM） and Enhancement Thematic Mapper（ETM） satellite image by combining ground GIS database with GPS field collected data in the area of Xiaowan-Dachaoshan Reservoirs of Lancangjiang River cascaded Hydropower Area. Consequently, the land-cover is divided into five subclasses, namely water, paddy field and wetland, bare dryland and sparse shrub, secondary forest and density forest. The result showed that the areas of bare land, upland and secondary forest decreased in 1988-1996, whereas from 1996 to 2000, water body and density forest keep invariability while the areas of paddy field and wetland, bare dryland and sparse scrub increasing and the area of secondary forest decrease; Features of reciprocal transformation between density forest and other type of land-cover had two points, i.e. secondary forest, bare dryland and sparse shrub converted to density forest; and density forest converted to secondary forest and paddy field and wetland. It reflects the dynamic variation of density forest; the area which slope less than 8° and greater than 15° shows bigger variation, however, less change in 8°-15°.

楞古水电站V线右岸边坡深部裂隙成因及边坡稳定性分析

针对楞古水电站V线右岸边坡深部裂隙发育特征,以边坡工程地质条件及坡体结构为基础,结合嘎夏帕滑坡破坏模式对其深部裂隙成因进行了分析,认为其深部裂隙是由于边坡滑移-剪切变形所造成,且边坡缓倾角结构面发育程度决定了边坡深部裂隙分布范围及张开度。分析边坡深部裂隙变形程度,结合边坡整体稳定性FLAC3D模拟,得出蓄水后边坡上游侧稳定性较边坡下游侧更低,以后对边坡采取合理的支护措施提供了可靠的依据,并为同类水电站蓄水边坡稳定性研究提供了参考。

Assessment of Diversity, Distribution, Conservation Status and Preparation of Management Plan for Medicinal Plants in the Catchment Area of Parbati Hydroelectric Project Stage-Ⅲ in Northwestern Himalaya

The developmental activities, particularly the construction of hydroelectric projects are causing a great loss of biodiversity in the Indian Himalayan Region. The Himaehal Pradesh, a part of IHR is well known for the development of hydroelectric projects. The Parbati H.E. Project is amongst the major projects of the State. The different stages of the project are all causing loss of biodiversity of the area. Stage Ⅲ of the Parbati H.E. Project is a run of the river scheme on the Sainj River downstream of Power House of Parbati H.E. Project Stage Ⅱ. The project shall utilize regulated discharge of Parbati H.E. Project Stage Ⅱ and inflow of River Sainj for power generation, and has been contemplated as a peaking station operating in tandem with Stage Ⅱ. The present study has been undertaken to see the impact of hydroelectric project on the biodiversity, particularly on medicinal plants. A total of 104 species of medicinal plants, belonging to different life forms, i.e., trees （23 spp.）, shrubs （22 spp.）, herbs （57 spp.） and ferns （2 spp.） were recorded. The species have been analyzed and studied for their distribution, classification, altitudinal zones, part （s） used, indigenous uses, nativity, endemism and rarity.Different parts of these species, such as whole plants, roots （including rhizomes and tubers）, leaves, flowers, fruits, seeds, stems, barks, spikes, nuts and insect galls are used by the inhabitants for curing various diseases and ailments. 3o species are native to the Himalayan region, 9 species native to the Himalayan region and adjacent countries also and 65 species are non-natives. 9 species are near endemics. Considering the whole Himalaya as a biogeographie unit （sensu lato）, the near endemics are endemic to the Himalaya. Among these species, Zanthoxylum armature is categorized as Endangered and Valeriana wallichii as Vulnerable. Hedychium spicatum, Rhus javanica, Berberis lycium, Thalictrum foliolossum, Salvia lanata, Rubia cordifolia and Bergenia ligulata may be considered as threatened species due to their over exploitation for trade. 90 species are propagated by seeds, 8 species by seeds and rhizomes/roots/tubers, 4 species by seeds and cuttings, and 2 species by sori. A management plan for the cultivation and conservation of the medicinal plants in the dam submergence area, and the commercially viable medicinal plants with high value in the catchment area is suggested.

Influences of local habitat, tributary position, and dam characteristics on fish assemblages within impoundments of low-head dams in the tributaries of the Qingyi River, China

Low-head dam impoundments modify local habitat and alter fish assemblages; however, to our knowledge, the pattern of how fish assemblages in the impoundments relate to local habitat, tributary position, and dam characteristics is still unclear. We used data collected in 62 impoundments created by low-head dams Jn headwater streams of the Qingyi River, China, to examine relationships between fish assemblages and local habitat, tributary position, and dam characteristics. We also assessed the relative importance of the three groups of factors in determining fish species richness and composition. Linear regression models showed that fish species richness was related to substrate heterogeneity, confluence link, and dam number upstream. Redundancy analysis showed that fish species compositions were influenced by substrate heterogeneity, confluence link, dam height, dam numbers upstream and downstream. Overall, dam characteristics were more important in affecting fish species richness but less important in determining fish species composition than local habitat （i.e., substrate heterogeneity） and tributary position. Our results suggest that low-head dam may affect fish species richness in impoundments by modifying local habitat and constraining fish movement, and the relative abundances of those fish species may depend more on species habitat presences and stream size than on impoundment size and number.

Ground Penetrating Radar Survey of Dam Structures of Kazakhstan on example of Aktobe and Karatomar Water Storage Basins

Ground penetrating radar surveys of technical condition of Karatomar and Aktobe water storage basins on the river Tobol are shown. In this article we have shown that dams have problems with cavities and identified longitudinal dimensions of anomalous zones of decompression.

Landslide Dam Forming Hazard Analysis Based on Geological and Induced Factors

Landslide dams and lakes can cause great casualties and economic losses.A landslide dammed lake named Tangjiashan by Wenchuan earthquake in China was well known all over the world since May 12,2008. Many other landslide dams or lakes can also formed by rainfall or water fluctuation besides earthquake. Landslides along the river or branch banks in the Three Gorges Reservoir area face dam or lake forming possibility especially within the water

黄土高原径流侵蚀功率输沙模型的改进

水土流失对流域生态危害严重,输沙量模拟和预测可以为流域水土流失防治提供依据,因此精确的输沙模型是流域水土流失治理的重要工具。为了精确模拟变化环境下黄土高原年输沙量,该研究基于黄土高原19个水文站的径流和输沙数据,通过随机森林变量重要性度量方法评估年径流侵蚀功率、淤地坝指数、淤地坝相对指数、归一化植被指数、不透水地面积等因子对流域年输沙量的影响,使用非线性最小二乘法估算年输沙模型参数,对比分析不同因子组合的年输沙模型精度,提出适用性较强的黄土高原年输沙模型,据此开展年输沙量变化贡献率分析。结果表明:1)以幂函数形式构建的仅含径流侵蚀功率单因子输沙模型精度与流域面积有显著的负相关关系,相关系数为-0.505(P<0.05),模型精度随着流域面积增大而下降,在面积大于7000 km^(2)的流域适用性较差;2)年径流侵蚀功率、淤地坝指数及不透水地面积因子组合建立的多因子年输沙模型在黄土高原适用性最佳,模型在率定期纳什效率系数平均值为0.84,均方根误差平均值为0.21亿t,在验证期纳什系数平均值为0.79,均方根误差平均值为0.27亿t。3)影响研究流域年输沙量变化的因素依次是:年径流侵蚀功率、不透水地面积和淤地坝指数。研究可以为黄土高原不同区域水土流失防治和生态治理工作提供理论支撑。

基于HYDRUS-1D模型的水库近坝区土壤水分动态模拟

为探究五强溪水库近坝区土壤水分动态变化规律,以研究区内土壤墒情站为研究对象,利用实测逐日降雨与逐日蒸发数据驱动HYDRUS-1D模型反演土壤水力特性参数,分别在深度为10、20、40 cm观察点处进行土壤水分动态模拟,探讨研究区土壤水分动态变化规律及模型的应用效果。结果表明:不同观察点土壤水分模拟值与实测值的决定系数平均值为0.74,纳什效率系数平均值为0.71,均方根误差在0.011~0.035 cm^(3)/cm^(3)之间;0~10 cm深度的土壤水分对降雨和蒸发的响应最灵敏,波动最大;在水库主汛期(4—6月份)土壤水分变化平稳,且保持在较高的水平;研究期内7—12月份土壤水分在较大降雨情况下出现短暂饱和,土壤干湿变化明显,模拟值与实测值吻合度较高;整体上,HYDRUS-1D模型在研究区土壤水分动态模拟中具有较高的精度,可为研究区土壤水分估计及其动态变化规律研究提供有效方法。

贵州省五千亩以上耕地坝区人口时空演变分析

运用GIS空间统计工具,将贵州省内五千亩以上耕地坝区2000—2020年共计21期WorldPop人口数据进行分析,定量揭示了贵州省五千亩以上耕地坝区21年来的人口分布时空格局及其变化特征。结果表明,贵州省耕地坝区人口呈先增后减的趋势,按人口增长曲线特征可以划分为稳定增长期(2000—2006年)、快速波动增长期(2006—2010年)、快速负增长期(2010—2015年)以及缓慢下降期(2015—2020年)4个阶段,总体下降了0.99万人,其中五千亩耕地坝区上升了0.94万人,万亩耕地坝区下降了1.93万人;五千亩以上耕地坝区人口分布以较低密度聚集区与低密度聚集区为主,人口分布差异较明显;人口密度的空间相关性总体上表现为无明显差异,在局部表现为HH集聚、LL集聚和HL集聚;坝区人口重心迁移幅度较小,经向变化和纬向变化均呈往复移动的趋势。

澜沧江流域某水电站危险区域识别及溃决过程模拟

保证坝体稳定是水利水电工程的关键,在洪水及地质运动的作用下,大坝溃坝风险将会增加,一旦发生溃坝将会造成严重的经济、社会损失。以澜沧江某混凝土重力坝为例,开展坝体危险区域识别及溃决过程分析。利用有限元方法对坝体在洪水作用下的应力、应变进行研究,发现当水位漫顶时坝顶中心点位置位移最大,当伴有近场强震时,该区域极有可能发生破坏导致溃坝;利用HEC-RAS软件对该种工况的洪水演进情况进行了分析。

大型水电站智慧坝区管理平台开发与应用

在信息化时代背景下,传统水电站坝区管理向可视化、智慧化管理转变。结合实际情况,就大型水电站智慧坝区管理平台的开发与应用进行探讨,归纳其建设原则、总体框架及其应用模块与应用成果,提出了一种高效、便捷且可靠的管理方案,为水电站坝区的现代化管理提供新的路径参考。

耕地保护背景下坝区村庄的管控与发展——以石林县路美邑村为例

坝区村庄是具有云南地缘特征的一类农村聚落,广泛分布在各个坝区之中。坝区村庄承载着众多乡村人口的生产、生活功能,具有地势平、人口密、良田多三个特质。在坝区耕地保护政策趋紧的背景下,坝区村庄面临着耕地保护和村庄发展的困境。路美邑村是典型的坝区村庄,文章通过研究坝区相关政策要求和坝区村庄的特征,结合路美邑村的现状及资源优势,分析村庄面临的主要矛盾,以“一优先四融合”的规划措施进行内涵式发展,寻求耕地保护与村庄发展的平衡,力求为坝区空间管控提供有益探索。

三峡船闸上游待闸锚地抵坡丁靠锚位结构设计方案

针对传统抵坡丁靠锚位结构受三峡库区水位周期变化影响,出现周边土体淘刷流失导致结构设计受力条件严重恶化,暴露出的高强度混凝土结构易导致船舶底部损坏等问题,依托实际工程,按三峡坝区50 a一遇水流流速1.0 m∕s、风速22.0 m∕s环境条件,以靠泊5000吨级干散货船为代表船型,进行适用于坝区待闸锚地大型船舶抵坡丁靠锚位结构设计研究,重点对抵坡丁靠锚位尺度、船舶停泊方式、系缆力计算、护坡结构、施工工艺等进行系统论述。采用系缆桩两侧设置防护带,并将系缆设施布置为内嵌结构形式,系船柱顶部不超出坡面的设计方法。结果表明:该抵坡丁靠锚位结构形式既能满足锚泊结构稳定的要求,又能有效防止结构周围水土流失,可在水位落差大、水流流速小的库区船舶锚泊设施建设工程中进行复制推广。

基于HEC-RAS的水库溃坝洪水分析--以仁化县高坪水库为例

水库大坝的溃决通常引起巨大的灾难,特别是在考虑大坝安全应急响应中,溃坝洪水预测研究尤为重要。为研究溃坝洪水带来的影响,以韶关市仁化县高坪水库为例,基于HEC-RAS软件构建了水库溃坝水动力模型,模拟了水库遭遇千年一遇校核洪水且溢洪道闸门无法开启条件下因漫顶发生溃坝的工况计算,分析了溃坝后下游淹没水深及淹没范围。提出了基于HEC-RAS软件进行水库溃坝洪水分析的技术方案,供技术人员参考,可运用到水库防灾减灾工作中,快速分析计算水库的溃坝淹没范围。

基于Mask R-CNN模型的红外灰度图像坝体渗水区域快速检测的技术研究

随着水利工程中坝体安全问题的日益严峻,高效、精准地检测坝体渗水区域成为保障坝体结构安全的关键。红外灰度图像因其对温度变化敏感已逐渐成为渗水区域检测的重要工具。因此,提出了一种基于掩膜区域的卷积神经网络(Mask Region-Based Convolutional Neural Network,Mask R-CNN)的红外灰度图像坝体渗水区域快速检测方法,此方法通过区域提议网络(Region Proposal Network,RPN)和RoIAlign等核心技术,实现对渗水区域的精确定位与像素级分割,并结合噪声抑制和图像增强技术,进一步提升了检测的精度与鲁棒性。通过与传统算法的对比实验,验证了所提方法在复杂背景下的检测优越性。实验结果表明:Mask R-CNN模型不仅在精度和检测效率上显著优于阈值分割和边缘检测等传统方法,同时在渗水区域边界细节的捕捉上具备更强的适应性。

基于MIKE FLOOD耦合模型的城区上游水库溃坝洪水模拟研究

[目的]研究溃坝洪水演进过程模拟方法,为水库溃决风险防控、制定溃坝早期预警及人员疏散方案提供科学依据。[方法]以河南省郑州市上游尖岗和常庄水库为例,基于GIS技术构建高仿真地形数字高程模型,利用MIKE FLOOD耦合模型进行水库溃坝一二维模型耦合,模拟水库溃坝后洪水演进过程,探讨洪水在下游河道和复杂城区的演进特征。[结果]常庄水库和尖岗水库溃坝瞬间最大下泄洪峰流量分别为4542.03和17549.1 m^(3)/s。贾鲁河下游距尖岗水库约15.00~31.39 km范围内河道两岸的漫堤洪水淹没面积为56.37 km^(2)。常庄水库溃决1.00 h后,河道漫堤,开始产生淹没区,溃决4.25 h后,尖岗水库发生溃坝。当尖岗水库溃决洪水演进历时1.25 h后,原淹没区水深显著增加,溃决1.92 h后,淹没范围开始增大。常庄和尖岗水库溃坝后,洪水水位均增大至超过南水北调防护堤堤顶,大量洪水涌进南水北调总干渠,洪水流速普遍增大。[结论]尖岗水库溃坝洪峰流量远大于常庄水库,溃坝危害性更大,溃坝后洪水大量涌进南水北调总干渠,堤防、边坡和进出口闸室冲刷风险增大,下游河道两岸漫堤淹没,严重影响南水北调总干渠输水安全和人民生命财产安全。

民国时期昭鲁坝区的水环境治理与农业发展困境

晚清以后由于天灾人祸频发,整个滇东北地区经济持续衰落、人民生活难以为继,因此民国时期开始对昭鲁坝区水环境进行治理,并取得一定成效。但是,农业经济恢复和发展仍然面对巨大的困境难以突破,究其原因主要在于水利体系没能构建起来、整个坝区仍然十分缺水。这导致昭通地区农业经济难以发展,不但影响政局稳定、导致烟毒泛滥,还影响云南局势和抗战大局。本文认为民国时期虽然有心“除水患、兴水利”,但由于条件限制,只是部分消除了水患,水利并未兴修起来,严重制约当地农业经济发展和人民生活条件的改善。本文以昭鲁坝区水利建设为切入点,分析昭鲁坝区农业经济在民国难以发展的原因和影响。考察民国在昭鲁坝区的水环境治理,可以为今天的生态环境建设、水利环境规划提供重要历史依据和借鉴。