River Improvement Works Research Articles

THE ACTIONS OF OTTOMAN STATE TO OPEN THE PORT OF TEKİRDAG TO INTERNATIONAL TRADE (1840-1920)

Since the 1840s, the Ottoman Empire has carried out a series of activities to rehabilitate the Edirne Meriç River and Enez Port and bring them into international trade. The inspiration for these studies is the Paris Embassy Report (Sefaretname), written by Mehmet Çelebi during his Paris embassy. While the Ottoman Empire prioritized the use of rivers and lakes only for military purposes, after this date, it was faced with the fact that rivers and lakes could also be connected to international trade routes. However, the Ottoman Empire could not take the necessary steps in this regard for a long time. Among the reasons for this was that Ottoman engineers did not have the river technologies and engineering knowledge developed in European countries such as France. For this reason, Sultan Abdulmecid wanted to benefit from foreign experts. Monsieur Borel, one of the experts he invited from France, stated that although he worked on Meriç and its tributaries for a while, it would be more profitable and practical to connect the Rumelian trade routes to the newly established docks, piers and ports by opening new channels instead of improving this river. In this statement, he also gave great importance to Tekirdağı (Tekfurdağı) Port. He emphasized that if the Tekirdağ port, which was a very small port at that time, was enlarged and expanded, it would be the shortest way to transport all the goods and commodities to be produced in Rumelia to the Mediterranean and Istanbul. As a matter of fact, when Monsieur Borel's statement is examined, it is understood that Tekirdağı port can be a very busy and comprehensive port if the suggested roads and channels to be opened are built. Although river improvement works were not mentioned among the renovation works initiated by the Ottoman Empire after the Tanzimat, recent research has revealed that the Ottoman Empire had a great desire and desire to establish national and international trade routes. In this article, the works and results of the Ottoman Empire's efforts to establish and expand the Tekirdağ port and make it the busiest port in Rumelia and the Balkans between 1840 and 1920 will be emphasized using original documents.

Assessment on the Efficiency of Flood Mitigation Measures

Storms and floods are frequent occurrences that can disrupt communities and harm ecosystems. An effective flood management plan requires a decision-making process that balances financial, social, and environmental benefits. This paper provides an overview of a study that applied a decision-making process using engineering analysis to determine the most effective approach in selecting the most effective flood mitigation measures. This study used hydrodynamic modelling to determine the effectiveness of proposed measures, such as the construction of a flood wall and river improvement works. The results showed that the combination of both measures could provide 100 ARI level protection, reducing the flood area from 6.11 km2 to 0.00 km2 areas without flooding. The study highlights the importance of considering financial, social, and environmental benefits in selecting effective flood mitigation measures.

Using Simple LSTM Models to Evaluate Effects of a River Restoration on Groundwater in Kushiro Wetland, Hokkaido, Japan

Wetland ecosystems with proper functioning provide various ecosystem services. Therefore, their conservation and restoration are of fundamental importance for sustainable development. This study used a deep learning model for groundwater level prediction to evaluate a wetland restoration project implemented in the Kushiro Wetland in Japan. The Kushiro Wetland had been degraded due to river improvement work. However, in 2010, a wetland restoration project was carried out to restore the meandering river channel, and a decade has passed since its completion. In this study, the wetland restoration project was evaluated by comparing the response of the groundwater level using a model that reproduced physical conditions with different characteristics before and after the restoration. At first, a deep learning model was created to predict groundwater levels pre- and post-restoration of a meandering river channel using observation data. Long short-term memory (LSTM) was used as the deep learning model. The most important aspect of this study was that LSTM was trained for each of the pre- and post-restoration periods when the hydrological and geological characteristics changed due to the river channel’s restoration. The trained LSTM model achieved high performance with a prediction error of the groundwater levels within 0.162 m at all observation points. Next, the LSTM models trained with the observation data of the post-restoration period were applied to evaluate the effectiveness of the meandering channel restoration. The results indicated that the meandering channel restoration improved hydrological processes in groundwater levels, i.e., their rainfall response and average groundwater water levels. Furthermore, the variable importance analysis of the explanatory variables in the LSTM model showed that river discharge and precipitation significantly contributed to groundwater level recovery in the Kushiro Wetland. These results indicated that the LSTM model could learn the differences in hydrological and geological characteristics’ changes due to channel restoration to groundwater levels. Furthermore, LSTM is a data-driven deep learning model, and by learning hydrological and geological conditions to identify factors that may affect groundwater levels, LSTM has the potential to become a powerful analysis method that can be used for environmental management and conservation issues.

秋田県雄物川流域におけるアカツツガムシ生息調査（2011年～2014年）

In Akita Prefecture, patients with Kato type of tsutsugamushi disease (Sucrub typhus) transmitted by Leptotrombidium akamushi were identified in August 2008 for the first time in 15 years, and in 2010 as well. We conducted surveys of the habitat of L. akamushi using Suzuki’s Method (MITORI-HO) between 2011 and 2014 in 74 areas of riverbed in which the disease was prevalent, including the upstream, midstream, and tributary areas of the Omono River. Habitats of L. akamushi were identified in 40 areas in three cities and one town, and the total distance along Omono River was approximately 10 km shorter than that reported by a survey conducted in 1964. Some of those areas were inhabited by L. akamushi gradually after river improvement work and the disease temporarily became prevalent there, although no patient had been identified in these areas prior to the construction. L. akamushi was only collected from sand, sandbanks, and other areas in the vicinity of the river, which can easily be flooded when the water level rises. No extensive research has been conducted on the re-emergence of tsutsugamushi disease transmitted by L. akamushi. It is necessary to continue to provide people with information and increase their awareness.

한천의 대표입경을 이용한 조도계수 산정

Roughness coefficient was computed for review of applicability based on measurement of the representative grain diameter reflecting channel characteristics of Han Stream. After field survey, collection of bed material, and grain analysis on the collected bed material, roughness coefficient was computed using representative grain and existing empirical equation for roughness coefficient. Value of roughness coefficient calculated using equation by Meyer-Peter and Muller (1948) was 0.0417 for upstream, 0.0432 for midstream, and 0.0493 for downstream. As a result of comparing the computed roughness coefficient to other empirical equations for review of applicability, the coefficient was larger in Strickler (1923) equation by 0.006. Smaller coefficient was shown by Planning Report for River Improvement Works. Equation by Garde and Raju (1978) was larger by 0.004, and equations by Lane and Carlson (1953) and by Meyer-Peter and Muller (1948) were larger by 0.001. Such precise roughness coefficient is extremely important when computing the amount of flood in rivers to prevent destruction of downstream embankments and property damages from flooding. Since roughness coefficient is a factor determined by complicated elements and differs according to time and space, continued management of roughness coefficient in rivers and streams is deemed necessary.

利根川下流部における河道改修の経緯とその効果

In the Lower Tone River, channel dredging and widening have been conducted for the river improvement works to respond to the flood discharge increase. However, the discharge capacity of the current river channel is still not sufficient even for the present design flood. So, it is required to discuss about the method for the appropriate river improvement works in the Lower Tone River. But, the effects of the past river improvement works on changes in river bed elevation are not sufficiently investigated. We investigated the process of the river improvement works in the Lower Tone River and clarified how the river improvement works have effects on changes in the river bed elevation by investigating the changes of channel shape and longitudinal distributions of hydraulic quantities. The results demonstrated the sediment deposition disappeared and the large bed scouring occurred and disappeared by the effect of the channel dredging and widening in each area.

댐하류하천정비사업의 댐 운영개선 효과 경제성 분석 (I) -용수공급 및 발전생산 회복편익

댐의 계획과 설계단계에서 설정된 유효저수용량은 여러 가지 이유로 운영단계에서 잘 지켜지지 못하는 경우가 있다. 어떤 댐은 운영과정에서 내 외적인 주변여건의 변화로 본연의 운영목적을 달성하는데 어려움이 있을 수 있다. 따라서 이를 개선하기 위해서는 시설물의 목표 달성을 위한 기능회복이 적절히 이루어져야 하며, 관련 대안들이 마련되어야 한다. 특히댐 하류하천의 부적절한 관리는 댐의 홍수조절기능과 하천환경에 부정적인 영향을 미친다. 결국 댐의 다목적 기능을 정상화 시키고, 댐의 경제적 가치를 높이기 위한 댐하류하천정비가 댐사업자에 의해 진행되고 있다. 본 연구는 댐하류하천정비의 미흡으로 홍수조절을 위해 제약되었던 댐의 유효저수용량의 회복에 의한 이수편익을 분석하였다. 분석결과 임하, 대청 및 용담댐 등 3개댐에서 용수공급량은 19.9백만<TEX>$m^3$</TEX>/년 그리고 발전량은 20.8GWh/년이 증대되는 것으로 나타났다. 아울러 본 연구를 통해 얻어진 이수효과 정보는 댐직하류하천정비사업의 전체 경제성 평가 및 비용배분의 기초자료로 활용되었다. Allocated water storage of dam at the planning and design stage does not seem to be maintained well at the operation stage because of unexpected critical reasons. A dam is likely to be subject to negative effects caused by changes of dam operation conditions and it is hardly avoidable. Therefore, it must be timely improved to recover its original functions and looked for better alternatives to keep its original roles. Specifically the improper management of river condition degrades flood control capability in a dam and river eco-system. The dam downstream river improvement work is needed for normalizing dam functions and its valuations. This study focuses on estimating water use benefits from recovering its own effective storage buffer restricted for flood control. As the results, the water supply and the hydropower benefits in Imha, Daechung and Youngdam Dam are recovered totally by 19.9 million <TEX>$m^3$</TEX>/year and 20.8 GWh/year respectively. Also those results are used for the basic information of the economic analysis in the dam downstream river improvement work.

댐하류하천정비사업의 댐 운영개선 효과 경제성 분석 (II) -경제적 편익 및 비용분담률 분석

댐이 건설된 이후 댐직하류 하천구간은 하천구역내 사유지 경작과 하상주차장 등의 입지, 사주가 발달하여 하폭감소에 의한 문제가 발생하였다. 특히 하천정비의 미흡으로 홍수시 하천통수능력이 감소하여 유역전반에 영향을 미치고 있다. 댐 운영조건도 일부 제약을 받고 있는데 이의 해소를 통한 댐 기능의 회복과 운영의 효율성 제고가 하천의 치수 안정성 확보와 함께 개선대책이 필요하였다. 따라서 댐 운영관리개선과 연계된 댐직하류 하천정비사업이 시행되고 있는데 사업의 타당성, 경제적 편익, 비용배분 및 투자비 회수방안 등과 같은 문제점이 제기되었다. 아울러 댐사업자가 하천사업을 주관한 사례가 없어 이들 사업에 대한 경제성 평가의 객관적 해석과 편익에 대한 정량화 방법의 개발이 요구되었다. 본 연구는 댐직하류 하천정비사업의 사업주체(국가와 용수 및 발전사업자 등)간의 합리적인 건설비용 배분방법을 제시하고 그 적정성을 평가하고자 하였다. 평가결과, 시범 적용 3개 댐의 경제적 편익은 14,405.8백만원/년으로 추정되었고, 편익 중 사업시행자인 K-water의 재무적 가치는 40%, 정부의 공공성 편익은 60%로 분석되었다. Flood discharge capacity in a dam downstream reach has been decreased after dam construction because of the river cross section reduction impacted by farm lands, sand-bars and parking lots, etc. in river flood plains. Those obstacles being in the river inside areas have caused negative influences to the dam operation policy. Therefore, the dam downstream river improvement work associated with the dam operation improvement plan is under construction for removing reduction factors on the dam effective storage, assuring flood safety in the dam downstream river and incrementing dam operation benefits. But the project has issued some problems such as project feasibility, economic evaluation, cost allocation and benefit share, etc. Since a dam enterpriser has not committed such kind of project before, it is necessary to set up an objective analysis process and a quantitative financial valuation. This study examines the measurable economic benefits and the cost allocation of the project for the fairness between benefit owners (central government and water electricity enterprisers). As a result, the total economic benefit from 3 dams (Imha, Daechung and Youngdam Dam) accounts for 14.41 Billion Won/year. The financial valuation of K-water as a project enterpriser is approximately estimated at 40% of the total value and the government is 60%.

DERIVATION AND APPLICABILITY OF THE SEDIMENT TRANSPORT FORMULA CONSIDERING THE EFFECT OF RIVER WIDTH AND CROSS-SECTIONAL FORM

Estimation of sediment transport rate is important for flood control and river environment. In the previous studies, sediment transport formulae have been derived as functions of tractive stress at the river bed. However, the authors believed that sediment transport rate was regulated by the same mechanism as the determination of a stable cross-sectional form of rivers. In this study, we proposed a sediment transport formula considering the effect of river width and cross-sectional form. At first, we investigated relationships among dimensionless quantities of bed load movement by the dimensional analysis. Then, we derived the sediment transport formula using field observed data of bed load in the United States and Japanese rivers. Finally, we showed that the proposed formula was useful for river course design and river improvement work by the cooperation with the existing bed load formulae.

Evaluation of recovery process of aquatic insects after river improvement works

Evaluation of recovery process of aquatic insects after river improvement works

Regime relationships of alluvial canal with seepage

The estimation of the stable or regime condition of alluvial canals has a significant implication on the design practice of irrigation canals, river improvement works and general fluvial hydraulics applications. The existing regime relationship for this stability does not consider the effect of downward seepage from the canal, causing an increase in the mobility of canal bed material and thus changes the canal stability. Regime conditions for the prediction of canal geometry in alluvial canals affected by seepage are presented in the form of regression equations. This approach has been developed based on the application of functional analysis of the salient variables controlling the canal behaviour. It has been found that for no seepage, Lane's profile matches the experimental observations, which is not the case in seepage experiments. Regression relationships for the canal dimensions have been formulated using the experimental observation under seepage.

Potential impacts of flooding events and stream modification on an endangered endemic plant, Schoenoplectus gemmifer (Cyperaceae)

AbstractRiver management often conflicts with the conservation of species in river ecosystems. In Japan, almost all river systems have been covered by concrete walls. Such river improvement works caused critical damage to river ecosystems. Here we report the ongoing extinction process of a rare aquatic plant by several consecutive heavy rains. The aquatic plant, Schoenoplectus gemmifer C. Sato, T. Maeda &amp; Uchino, is an extremely rare endemic species that is strictly associated with springwater. The species is only found in 23 locations in Japan, including only two major habitats: Hamamatsu and Oita. We monitored the population fluctuations of S. gemmifer at three river systems in Hamamatsu. In the largest habitat, Higashikanda River, the population size of the species decreased to nearly 1/10th in 2004, due to several severe floods. Spatial and temporal records exhibit four stages of damaging process. The stepwise damages were found to be caused by a rapid flow of water accelerated by the river improvement work (made in 1985). The reproduction and growth by seeds and gemmae did not evidently cover the losses by flood washed out. In the other two rivers, one was extinct and the other is now at the risk of extinction. The modified river structures may be responsible for the near‐extinction of S. gemmifer in Hamamatsu area. We propose two policies for the conservation of this species: (1) the artificial cultivation of gemmae and seedlings and (2) the modification of river structure to decrease the number of washed‐out plants. In particular, it is important to decrease the water velocity at floods by some methods.

THE ROLE OF STONES ON THE RIVER BED STABILITY IN STONY BED RIVERS

River cross sectional form had settled in the dynamic equilibrium form at the relationship between discharge, the river bed slope and bed material when river improvement is not progressing so much. But, river channels do not seem to satisfy the equilibrium condition of sediment transport due to river improvement work in progress. As the result, many problems have arisen on river management. Sediment transport became discontinuous by the dam and removing large size of bed materials as stones and gravel from rivers is mentioned. In this study, we describe the bed stabilization mechanism of the stony bed rivers found by the field experiment of the Joganji River and the difference in sediment transport mechanism of the stony bed river and the gravel bed river. Moreover, we insist on the problem on washing out of dam reservoir sediment and the necessity for the new bed variation analysis method in the stony bed rivers.

RELATIONSHIP BETWEEN HABITAT OF AQUATIC ORGANISMS AND PHYSICAL, RESOURCES FACTORS FOR IMPROVEMENT OF RIVER ENVIRONMENT

River improvement and maintenance works can play an important role in conserving rivers and restoring them to a more natural state. This paper focuses on aquatic organisms (specifically, benthic animals) as indicators of river conditions, toward clarifying the relationship between inhabitation by these animals and the physical conditions of a river channel (flow velocity, water depth, bottom materials) and the food environment (i. e., periphyton and particulate organic matter). The relationship was examined by comparing pools and riffles in various types of river channels, such as those with and without river improvement works.The examination found that improved sections have less storage of organic matter than unimproved sections have. We also confirmed our findings on restoring a river to its natural state by varying the physical conditions and food environment in the improved section.

Public–private partnership as an example of flood control measures in Japan

Prior to the old River Act of 1896, flood control measures in Japan were executed on the principle of a co-existence of the river and human activity. Until the 19th century, through the feudalistic period, the public sector did not have plans for completely controlling a large-scale flood, as it is almost impossible by only technological methods, in particular, to control a major flood in monsoon Asia. In practice, people in monsoon Asia live away from river courses and lowlands in order to alleviate flood damage. Farmers in those areas planted crops that could withstand inundation. The flood control strategy of the public sector laid emphasis on protecting the castle or city centre area, but not defending the whole area where people were living. In areas not protected by the public sector, people formed their own groups to fight against flood damage. They were skilful at flood fighting, and were familiar with the characteristics of floods and the behaviour of inundation in their river basins. Thus a kind of public–private partnership existed at that time. Based on the River Act of 1896, the Japanese government began historical flood control measures, with the aim of completely controlling even a huge flood. They constructed a high, continuous levee system, with broadening river width, and dredging of the river beds in key rivers in Japan. Almost all river improvement works had been finished by about 1930. The flood damage in alluvial plains decreased remarkably as a result of these major works. However, after the Second World War Japan suffered from severe flood damage almost every year. During the period of so-called high economic growth, from 1950 to 1970, Japanese engineers overcame water shortage and flood damage by constructing many dams with various river improvement works. Because of the high level of engineering required, it became unnecessary to co-operate with the private sector. Due to the continuously active river works, the riparian environment and its ecosystems were destroyed everywhere. The private sector also played an important part in environmental protection. Environmental topics are different for each region and river, and therefore the public sector could not standardize plans for the whole of Japan. Here, the necessity of new partnerships between public and private sectors in the present flood control and environmental policy in Japan should be recognized. In reviewing these facts, the River Act was revised in 1997, by adding the terms “conservation of river environment” and “referring to the inhabitants' intentions”.

ECONOMIC DESIGN OF FLOOD‐ATTENUATION RESERVOIRS FOR URBAN AREAS EXPLOITING CATCHMENT HYDRODYNAMICS IN SOUTH‐WEST UK

ABSTRACTRunoff from new development in urban areas tends to increase the downstream flood peak which has to be attenuated or accommodated in the river channel to avoid increases in flood risk. The built environment close to the river often makes river‐improvement works difficult, if not impossible. This paper introduces the concept of rising‐limb attenuation, to mitigate downstream flood risk — especially in urban areas. Relying on the implicit difference in runoff times of concentration between rural and urban areas, it is possible to design efficient, self‐regulating storage structures, to counteract increases in peak flow in the main urban watercourse, by attenuating the later contribution from less urbanised or rural tributaries. Because rising‐limb attenuation is partial and temporary, volumes of storage are much less than for conventional attenuation reservoirs, with consequent savings in land take and costs. Because the controlled flow is also less, the associated structure is also generally smaller and simpler. Implementations of this type of structure have been carried out in two locations in the UK, and the outline design of these structures is described by reference to a case study.

Desnagging to resnagging: new directions in river rehabilitation in southeastern Australia

AbstractExtensive desnagging (removal of large woody debris and living riparian vegetation) and associated river improvement works were conducted in rivers of southeastern Australia (Victoria and New South Wales) between at least 1886 and 1995. Swamp drainage, large woody debris removal and vegetation clearing were strongly supported by legislation, government funding and institutional arrangements in both states. As a result, large amounts of large woody debris were removed from rivers, regenerating indigenous vegetation was cleared from within designed alignment widths and, ironically, huge numbers of exotic trees, especially willows, were planted. The environmental impacts of desnagging have only been documented on a few impacted rivers but have included increased flow velocity, spatially extensive bed degradation, massive channel enlargement and loss of fish habitat. Recognition of the need for more integrated land and water management, and new research on the hydraulic, geomorphic, biogeographic and ecological significance of large woody debris and the values of indigenous riparian vegetation during the 1980s led to a major shift in river rehabilitation. We have drawn on our own and other published research to further develop a set of guidelines for the incorporation of large woody debris into river rehabilitation plans. Our guidelines extend those recently prepared for southeastern Australia and address site selection, where to place timber, the amount to be introduced, how to distribute it, techniques of introduction and woody debris sources. However, in the long term, riparian vegetation rehabilitation within the potential recruitment zone is essential to supply large woody debris. Given that our results demonstrate that very large woody debris makes a significant contribution to the total loading, it will be a very long time (&gt;100 years) before natural recruitment can be recreated. Copyright © 2003 John Wiley &amp; Sons, Ltd.

A Study on the Phased Construction Executed on the Flood Control Improvement for the Kiso, Nagara and Ibi River during the Houreki Period in the Edo Era

The Kiso, Nagara and Ibi River, which were flowing on the Central Japan, are known generally as “Kiso Sansen” . To control floods occurring on these rivers, the large-scale river improvement was executed from the year 1754 to 1755 for the Houreki period during the Edo era . The officials of the Tokugawa Shogunate made the plan for this improvement . And the feudal domain of Satsuma paid the expenditure and oversaw the construction work at sites.In those days, the river improvement works were organized by using the natural materials such as woods and stones. And the planner could not measure using such as modern mathematical theory . Therefore, some plans or constructions were phased checking the change of river flow and bed .Nowadays, such phased construction is named “Mitameshi” in Japan. And the Japanese traditional river improvement techniques have been used some rivers. The purpose to apply these old techniques is to make the natural circumstances on the river channel. For the circumstances, it is important that engineers check the changing of river flow and bed. However, the phased construction is not used now .To execute these traditional river improvements and make natural circumstance on Japanese rivers, this study traces the large-scale river improvement of the “Kiso Sansen” during the Houreki period and makes clear the process of the phased construction.

Questionnaire of Environmental Ethics of River Engineers

We investigate environmental ethics of river engineers who have many problems about conflicts river improvement works and nature-conservation movements with questionnaire. In this paper, we report a variety of troubles related to the conflicts which most of the engineers who answered the questionnaire. We classify the described concrete troubles into some categories (Negotiation and decision making, Construction cost, Evaluation method of nature and etc.) and show you some typical examples of the troubles. Finally we discuss what we have to do to find out a solution of the conflicts.

Transition of the Design for Amenity in the River-front

“Noryo-yuka”, which is temporary water terrace looking on the river, has been succeeded in the Kamo River, Kyoto. The traditional water terrace has aroused public behavior to the river, and created the proper landscape. This paper aims to make clear the knowledge maintaining amenity in the river-front based on the relations between transformations of water terrace and river improvement works. As a result, people have especially designed the boundary space between the city and the river, and enjoyed staying there by making buffer equipments and using temporary devices.