Comprehensive security risk factor identification for small reservoirs with heterogeneous data based on grey relational analysis model

Identification of security risk factors for small reservoirs is the basis for implementation of early warning systems.The manner of identification of the factors for small reservoirs is of practical significance when data are incomplete.The existing grey relational models have some disadvantages in measuring the correlation between categorical data sequences.To this end,this paper introduces a new grey relational model to analyze heterogeneous data.In this study,a set of security risk factors for small reservoirs was first constructed based on theoretical analysis,and heterogeneous data of these factors were recorded as sequences.The sequences were regarded as random variables,and the information entropy and conditional entropy between sequences were measured to analyze the relational degree between risk factors.Then,a new grey relational analysis model for heterogeneous data was constructed,and a comprehensive security risk factor identification method was developed.A case study of small reservoirs in Guangxi Zhuang Autonomous Region in China shows that the model constructed in this study is applicable to security risk factor identification for small reservoirs with heterogeneous and sparse data.

Estimation of Small Reservoir Sedimentation in Semi-Arid Southern Zimbabwe

Small surface reservoirs play an important role of providing ready and convenient source of water for various uses in semi-arid areas which are characterized by erratic and low rainfall. Lack of current data on reservoir capacity loss due to sedimentation is one of the challenges to the sustainable management of surface reservoirs. The study investigated the capacity loss due to sedimentation from 2000-2012, and estimated the trap efficiency of the Mutangi reservoir which is located in semi-arid Chivi, Southern of Zimbabwe. Hydrographic surveys, grab sampling and water depth-capacity methods were used to determine the capacity of the dam as of 2012. To compute capacity loss from 2000 to 2012, the 2000 and 2012 dam capacities were compared whilst the trap efficiency of the reservoir was determined using a set of empirical models that relates trap efficiency to the capacity-watershed area ratio and capacity-inflow ratio. The results show that Mutangi reservoir has a trap efficiency of 95% - 98% (av = 96.4%) and has lost 37% of its capacity due to sedimentation in 12 years (2000 and 2012). Rates of sedimentation were 8539 t·yr-1, 9110?t·yr-1 and 8265 t·yr-1 for the hydrographic survey, grab sampling and water depth-capacity method respectively, and the little difference in these figures demonstrates that any method can be used to determine sedimentation rates. The area specific sediment yield (ASY) ranged from 14 - 15.5 t·ha-1·yr-1 (av = 14.956 t·ha-1·yr-1). At the current rate of sedimentation the projected dead level of the reservoir will be lost to sedimentation in 8 years while the useful life of the reservoir is estimated to be 30 years. Capacity loss due to sedimentation is further complicating the already strained water scarcity situation in semi-arid areas and management decisions should be made based on the current sedimentation rates estimated by different methods. These results imply that management practices that reduce erosion, hence sedimentation in these small reservoirs should be practiced in order to prolong their lifespan.

Assessment of Sedimentation Impacts on Small Dams—A Case of Small Reservoirs in the Lotsane Catchment

Sedimentation is a major problem for agricultural dams in Botswana, as it reduces the storage capacity and life span of the reservoirs. The process of sedimentation starts from day one of the impounding of water in any given reservoir. Even though a provision is made for every reservoir during planning for a certain storage capacity, specifically for sediment deposition, called dead storage, a major portion of the sediment gets deposited for many years of the reservoir’s life in areas other than the dead storage, and this trend cannot be reversed at easy cost. This study is aimed at the analysis of prevailing sedimentation processes in the nearby dozens of dams found in the Lotsane catchment located within the Limpopo Basin of Botswana, and focuses on assessment of annual sedimentation rate. A spatial analysis and modelling study was conducted based on the Revised Universal Soil Loss Equation and GIS to determine sediment yield and degree of impact of each reservoir for a given landscape, rainfall and catchment heterogeneity. Field observations and soil sampling were carried out in order to determine the factors that lead to reservoir sedimentation. Spatial data on the dams in Lotsane catchment were also collected from Ministry of Agriculture, which were used for ground-truthing, GIS-based calculations and model validation. The average sediment rate and sediment delivery ratio were found to be 1.74 t/ha/year and 81%, respectively. These are useful parameters to estimate service life of the dams and plan remedial measures related to sedimentation problems.

Research and application of flood detention modeling for ponds and small reservoirs based on remote sensing data

This paper proposes a method of small reservoir flood detention modeling that utilizes data from the American land resources satellite Landsat TM/ETM+. Precipitation and potential evapotranspiration are taken as the control conditions in this method on the basis of basin terrain classification. The objective of this method is to solve the question of a small-scale water conservancy project’s influence on flood forecasting precision, which can be used in the basin with multitudinous small reservoirs in the upstream region and can help estimate non-runoff data for small reservoir runoff. Taking the 20060826 flood as an example, the flood detention quantity of 19 small reservoirs is modeled. The results show that the absolute error of the total flood detention quantity is 0.2×10 4 m 3 , and the relative error is 0.12%. The flood detention quantity of small reservoirs in the entire basin is then modeled using this method, and the primary flood forecasting model is adjusted. After adjustment, the precision is significantly improved, with the relative error decreasing from 31.8% to 10.1%.

Impact of the Small Town Construction on Original Inhabitants in the Three Gorges Reservoir Area——A Case Study in Lishu Village, Changling Town, Chongqing Municipality, China

Based on the five-year long dynamic tracking and investigation of the peasant households of the Lishu village, the influences by small town construction on the economy and employment of the original peasant households are discussed. On the one hand, small town construction plays a positive role in adjustment of the industrial structure of the original peasant households and in the transfer of their employment towards non-agricultural industries. On the other hand the economic growth of the original peasant households is not so well sustainable, and is so fluctuating. Moreover, the unbalance of income distribution of the said households has been furthered, and small town construction has made the existing labor surplus of the original peasant households more serious, particularly the women labor surplus.

The Influence of Land Use and Fish Farming on the Contents of Ca²⁺, Mg²⁺, K⁺and Na⁺in Pond and Reservoir Ecosystems in an Agricultural Small Watershed, China

It is not understood well that how the effects of land use and fish farming on the contents of alkali metals (Ca2+, Mg2+, K+ and Na+) in small water bodies of pond and reservoir ecosystems at the watershed scale. In this study, the concentrations of Ca2+, Mg2+, K+ and Na+ in water bodies were measured for 103 ponds and reservoirs used as fish farming or surrounded by different agricultural land use types in the subtropical hilly watershed of Jinjing (105 km2), China. The two important environmental factors of fishing farming and agricultural land use influenced the spatial variation the contents of alkali metals. The ponds and reservoirs in residential area had significantly higher concentrations of Ca2+ and Na+ than those with other land use types, reflecting the influence of domestic wastewater. Compared with those of natural ponds with non-fish farming, no significant increase of alkali metal contents occurred in fish farming ponds, due to the regular cleaning of ponds by farmers. However, the effect of fish culture on alkali metal contents was still supported indirectly by the fact that the alkali metal contents significantly correlated with nitrate contents in fish farming ponds and but high related with that of DIP in natural ponds. The suitability assessment for irrigation on the pond water indicated that almost all of ponds were suitable for irrigation except some ponds surrounded by residential area and tea plantation. Generally, our results demonstrated that fish farming and agricultural land use affected the contents of alkali metals in ponds and reservoirs. The agricultural water irrigation would be with caution from the ponds with tea plantation and residential area in the subtropical hilly watershed.

基于Django的小水库雨水工情一体化监测平台研究与开发

文章基于Django的开发框架,研究开发了小型水库雨水工情一体化监测信息管理平台,解决了平台开发过程中Web应用扩展开发困难、表单处理能力不足、数据库开发要求较高等问题,可实现小型水库雨量、水位、大坝渗压自动监测和信息综合展示功能。工程数据试验表明,该平台可靠、可高速运行。

山东省小型水库专业化管护模式实践研究

小型水库专业化管护是破解小型水库安全难题的重要举措,随着小型水库管理体制改革不断深化,各地探索实行的管护模式具有相似性,也表现出区域差异性。以山东省小型水库管护模式建设为例,在梳理山东省基层管护现状、管护模式分类和管护模式组织机构基础上,选取16个典型县区进行管护模式实践成效分析,总结得到不同管护模式的适应条件与建设要点。从管护模式推行、工程基础、管护企业培育、巡库员队伍建设、智慧化管护等方面提出了小型水库专业化管护模式长效运行相关建议。

小型水库洪水预报模型研究及应用

针对缺资料地区小型水库入库洪水预报难的问题,构建了一种小型水库入库洪水预报模型,其产流模块采用SCS模型,汇流模块采用地貌瞬时单位线,模型参数基于高精度地形地貌数据确定,不依赖于实测流量资料进行模型参数率定,并在安徽省永堌水库进行了应用。采用1818号台风“温比亚”期间永堌水库强降雨洪水进行了验证分析,应用结果表明,构建的模型对该场次洪水过程两次洪峰模拟值与专家反推的入库洪峰较为一致,相对误差分别为3.2%和-11.8%,均在±20%以内,峰现时差均为0,径流深模拟相对误差为-19.2%,确定性系数为0.949,说明建立的小型水库入库洪水预报模型对本次降雨洪水模拟效果较好,对其他小型水库入库洪水预报具有较好的参考和借鉴意义。

小型水库大坝无人机巡检和行人定位方法

针对小型水库大坝缺少准确的坐标转换参数,无人机识别的行人目标难以精确三维定位的问题,提出无人机坐标系与坝体局部坐标系的转换方法。实际工程应用结果表明,坐标转换后生成的点云与激光扫描点云基本一致,对坝顶目标的非接触测量精度优于10cm。提出方法可以从任意角度和位置准确测量小目标行人在坝体结构上的位置,为小型水库大坝无人机常规巡检和建立电子围栏等提供高效且经济的方法。

广东省某县小型水库除险加固设计中遇到的隐患及对策分析

广东省内某县的小型水库大多建设在20世纪的50、60年代,以均质土坝为主。这些水库建设时期较早,大多存在土坝漏水、牛皮胀、输水涵管老化破漏和土溢洪道经常受冲破坏等一系列问题。基于此,通过分析小型水库中存在的常见问题,结合现今的加固技术,从挡水建筑、泄水建筑及输水建筑3个方面分别叙述、讨论针对常见问题适用的加固措施,为今后类似的小型水库加固设计项目提供一定的参考。

小型水库调洪演算及日常管养工作研究

以晋江市东山水库为例,根据小型水库调查测绘情况,梳理水库设施存在的问题并分析原因,提出相应的措施建议.对试运行的小型水库山围塘日常管理和养护制度进行评估分析,提出更科学合理、契合当地实际的日常管养方案,研究维修养护部分(除草、灭蚁、灌浆)市场化运作方案及成本核算等.其成果可为其他地区小型水库山塘调洪演算及日常管养工作提供借鉴参考.

加强小型水库运行管理的思考与建议

以小型水库运行管理为例,提出了当前小型水库存在的问题,分析了小型水库运行管理面临的形势,结合实际提出了加强小型水库运行管理工作的相关建议,可为小型水库运行管理工作提档升级提供参考与借鉴。

小型水库除险加固防渗提升技术应用研究

水利工程除险加固对于水库的长期安全运行至关重要,水磨坑水库建成年代早,影响水库安全稳定的工程地质条件复杂,同时坝体存在渗流安全稳定隐患,亟需提升大坝防渗能力。以水磨坑水库为研究背景,从混凝土防渗墙、坝基帷幕灌浆和重设排水棱体等多方面,针对大坝渗流和安全稳定进行加固优化提升,并进行复核分析,提出合理的变形渗流监测补充措施。

小型水库除险加固工程主要水工建筑的安全与设计研究

某小型水库存在渗流稳定,溢洪道不满足泄洪要求的问题,这些安全隐患严重影响水库的安全稳定运行。以某小型水库为研究对象,在其除险加固工程的过程当中,对大坝坝体和溢洪道进行安全复核和加固设计,通过比对相应的除险加固方案,最终发现采用充填灌浆,重建溢洪道消力池等方案处理小型水库的病险问题具有良好效果。

临泽县小型水库管理体制改革实践与启示

深化小型水库管理体制改革是推动水利高质量发展的重要举措,也是保障水安全的现实需要。甘肃省临泽县按照“政府主导、明权赋能、专业管理、财政兜底”的原则,以创建深化小型水库管理体制改革样板县为目标,通过政府主导、规划引领、财政带动、项目支撑、考核激励,探索出了工程产权明晰化、运行管理制度化、管护队伍专业化、管护经费稳定化、库区环境景区化的“五化”小型水库管护模式,可供其他地区深化小型水库管理体制改革参考。

鄱阳县小型水库管理体制改革探索及实践

鄱阳县小型水库众多,是防洪、灌溉的重要水利基础设施。对管理体制进行改革,建立一套适宜的管理体系,以保障工程安全可靠运行及效益得到充分发挥,是鄱阳县小型水库运行管理亟待解决的问题。本文分析了鄱阳县小型水库管理运行中存在的典型问题,提出了鄱阳县小型水库体制改革管理模式及保障措施,论述了鄱阳县小型水库体制改革取得的实践成效,以期能为相关管理人员开展小型水库运行管理工作提供一定的参考。

基于层次分析法的小水库退役影响评价模型及应用研究

小水库退役影响评价具有重要的意义和价值,可以为小水库退役拆除工作提供必要的支持和帮助。此次研究利用层次分析法构建起小水库退役影响评价模型,并以辽宁省小东沟水库为例,验证评价模型的准确性和可靠性。结果显示,评估模型获得的小东沟水库退役影响评价具有良好的准确性,可以为相关研究提供一定的支持和借鉴。

江苏油田复杂小断块高含水油藏注采井网优化技术

江苏油田复杂小断块油藏经过长期的注水开发后,目前处于中高含水开发期。现阶段储层非均质性对注采井网的影响更加突出,局部存在低效无效注水循环问题,亟需优化调整注采井网。根据非均质油藏剩余油富集类型和影响因素,在原井网基础上,利用油藏数值模拟方法,开展相控条件下的注采井网优化技术政策研究。根据模拟结果,确立了抽稀井网和转注高含水油井两种注采井网优化技术的政策界限,指导陈2断块、韦2断块注采井网优化调整,取得了良好的应用效果,为改善高含水油藏水驱开发效果提供了技术支撑。

高性能改性聚合物修补砂浆和单组分聚脲防水涂料在小型水库防渗加固处理中的应用

某小型水库坝体为浆砌石拱坝,经多年运行,坝体背水面出现了较大面积潮湿现象,存在一定的安全隐患。为及时消除安全隐患,确保坝体的整体稳定性,设计采用高性能改性聚合物修补砂浆和单组分聚脲防水涂料对坝体迎水面进行整体修复加固与防渗处理。笔者详细介绍了高性能改性聚合物修补砂浆和单组分聚脲防水涂料的性能特点,以及采用这两种材料进行防渗加固处理的施工工艺和质量控制要点。结果表明,两种材料组合使用在水库防渗加固处理中取得了良好的效果,既满足了工程应用要求,又简化了施工过程并降低了工程投资。