hydraulic and bioengineering solutions for rivers! 1

8/10/2019 Hydraulic and bioengineering solutions for rivers! 1

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Rzvan Voicu

METODE ECOTEHNICEDE RESTAURARE ALE

CURSURILOR DE AP

ECOTECHNIC METHODSOF RESTORATIONINGTHE WATERCOURSES

Bucureti2008


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Rzvan Voicu

METODE ECOTEHNICE DERESTAURARE ALE

CURSURILOR DE AP

ECOTECHNIC METHODS OFRESTORATIONING THE

WATERCOURSES

Dr.ing.Rzvan Voicu

Prin izvoarele lor munii i oglidesc istoria. Through their sources the mountains reflect their history


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[email protected]: 978-973-0-05814-7

Introducere

Cartea de fa este realizat din respectulnemrginit pentru Natur, care are amabilitatea de a nelsa o planet locuibil prin care noi, oamenii, s putemexplora Universul.

Distanarea omului tot mai pronunat fa deNatur, din cauza egoismului i fugii lui dup bani, anceput s aduc o degradare continu a ecosistemelor.Biosfera, a nceput s-i piard din valenele ei ecologicetocmai datorit faptului c nu se ine cont de sistemele eifuncionale, reflectate n sistemele funcionale aleecobiomurilor. Natura a realizat n timp diverse i

performante reele ecologice, geologice, energetice,biologice , chimice, geografice etc, extrem de sensibileprin nsi structura lor, sedimentate cu grij de pilonulcentral al Universului: TIMPUL.

Omul, ncearc prin diferite procedee, s extragcte o component, deseori minuscul, din acestestructuri, nenelegnd c prin fiecare component pierdutstructurile biosferei dispar, conducnd Terra ctre formainiial unde viaa, aa cum este astzi, nu putea exista.Cartea de fa, pledeaz prin metodele ei ecotehnice

pentru o conlucrare rapid pe plan global a diferitelortiine aparent intangibile. De fapt, aproape toate tiinelencearc s descopere i s neleag principiileUniversului. Dup cum vei vedea n aceast carte,conlucrarea benefic dintre ingineria costruciilorhidrotehnice i ecologie, a dus la finalizarea teoretic amai multor metode de restaurare ecologic aplicabile pediverse sectoare ale cursurilor de pe ntreaga suprafa aTerrei.


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This book accentuates the importance ofecotechniques as a all- important domain without which

the world would have no success.

1. The ecotechnical method for directioning thewatercourse on the center of layer and of creating arectangular wetlandin the middle of the minor layer.

The presented ecotechnical method can be applied

on an anthropogenic or natural channel, without concrete,situated on a hill or plane surface of different areas on thePlanet.

It can be symmetrically positioned regarding thecenter of rectangular layer of the selected river sector, twoidentical structures made of oxidation-resisting metal (Fig.1.2) that, in their run, are symmetrically positionedtowards the center of selected river sector. These

structures are dimensioned regarding the water flow Q,layers depth H, rectangular layers width L and theselected sectors length l.

Inside metallic systems or structures of 1-3 cmthickness, excavation on mobile bridges positioned on theselected layer sector is performed in order to planthydrophilic plants (reed, bulrush, sallow, cat tail, alder,aquatic plants etc.) in order to create performing wetlands.Plants are selected according to the local clime and, also,according to the necessities of new created ecosystem.The metallic structures are facilitating the physical

building of an ecosystem, directly, and after the species ofhydrophilic plants are planted, the metallic structures helpthem to grow fast.

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After planting and growth, inside a new createdwetland, of 50% of herby aquatic flora biomass and 20%

of ligneous biomass which just set the radicular massgiving signs of development, the water shall be set free

percentually through the dams created by the junction areaof the metal structures frameworks with the selectedwatercourse for environmental restoration (Fig. 1.2). Afterremoval of metallic structures with specialized equipment,the new created wetlands on the watercourse becomehigher with 5 to 15 cm (x) compared to the multiannual

average level of water (d) before the environmentalrestoration (fig.1.1).The metallic systems dimensioning is performed in

proportion to the slope 1 , structure of layer along thebanks, granulometric structure of a layer, thereforebiotope, the amount of biomass necessary to the properfunctioning of the ecosystem, etc.

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Why do we want to create the wetlands on theselected river sectors that are extremely polluted primarilywith organic matter and secondly metals? We know thatwetlands: are an important habitat for fish and mollusks,water birds and a large number of animals, and for many

plants, insects and other inhabitants contribute tomaintaining the quality of water, filter the pollutants,retain the sedimentary material, oxygenate the water by arich vegetation, absorb the nutrients (nitrogen,

phosphorus, etc.), recycle them or, regulate themicroclimate, contribute to preventing floods, erosion,aquifer reloading, water supplies, the production of timber,reeds and other exploitable plants, energy production(peat), offering areas for grazing, fishing, hunting,recreation, educational activities, scientific research andlast but not least the wetlands have an aesthetic value to beappreciated. We know that a wetland slows the passage of

water and increases the nutrients and sediments carried byflowing water, lodging sediments downstream may be

blocking the water, reduce the force of rain and impedethe floods down the river, by storing water in the soil orretain it at the surface, such as wetlands replacedadvantageous hydrotechnical structures and not only, builtat large expenses. After the development of wetlandswithin the new ecosystem, we can also create riparian

areas by leveling the banks and planting some species ofplants which are can adapt to those areas.

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The riparian areas are important ecologically for avariety of reasons: provide an erosion control through the

regularization of transport and distribution of sediments,improve water quality, produce organic matter for aquatichabitats and ensure the wild habitat regarding the flora andfauna, remove the excess of nutritive substances and othercontaminated substances, shape the fluctuations of watertemperature , maintain the reloading flux and the baselineflux of groundwater towards running water, stabilize the

banks and have effective control upon floods.

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Due to newly created wetlands in the river sectorwhere ecotechnical methods have been applied, the initialflow Q will be approximately the same as Q ', the flow ofthe particular sector (fig.1.4). If the water level passes overnewly created wetlands, the rate of flow in the selectedlayer sector is less than the rate of flow before the layer

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If the water level passes over newly createdwetlands, the rate of flow in the selected layer sector is

less than the rate of flow before the layer sector chosen forreconditioning because layers surfacing in order to buildriparian areas. If the water level does not pass over newlycreated wetlands, the rate of flow in the selected layer ishigher than the previous rate of flow when the layer sectorwas chosen for reconditioning. The newly createdwetlands both functional and riparian can resist thedrought on a relatively large period of time.

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2. Method of layer drilling and terraces performance

for riparian areas.

In case of mountain rivers, which generally have agood ecological condition because of the lack of theanthropogenic item, the banks erosion and powerful floodsdestroy the habitat of many aquatic inhabitants and creategreat damages to the people. That is why I proposed toapply this method (fig.2.1) on water courses in Romania

and beyond.

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The method consists in carrying out circulardrilling in the river layer in order to reduce the rate of flowinto the layer of the river, to take the surplus of water fromthe wave of flood and create refuge platforms for manyaquatic inhabitants. The circular drilling performed intothe layer is done according to river flow: for a rate of flowof 4 m/s the radius of drilling is about 1m, the thickness

between 0.10 m and 0.20 m, for a rate of flow of 3 m/sthe resulting radius of drilling is about 0.80 m, thethickness between 0.10 meters and 0.20 meters, for a rateof flow of 2 m/s the radius of drilling is approximately0.50 m, the thickness is between 0.10 meters and 0.05 m. Igave some examples to better understand how theseoperations of drilling into the layer should bedimensioned. Given that the layers of watercourses in themountain regions are so different morphologically, thesize of these drillings will be finally set only depending onthe local conditions.

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On the bank where the drillings into the layer havenot been made, terraces will be built in order to create

riparian areas. (Fig. 2.2). These terraces are effective inmany cases: control the erosion by the means of sedimentstransport and distribution regularization, increase waterquality, produce organic matter for aquatic habitats andensure the wild habitat for flora and fauna, eliminate theexcess of nutritional substances and other contaminatedsubstances, shape the fluctuations of water temperature,maintain the flux of recharging and the base flux of

groundwater towards water flowing, stabilize the banksand have control over the floods.So those three important issues the mountain rivers

are facing with caused by strong floods and accidentalpollution (damaged properties, devastation of habitats,water contamination) can largely be solved if we put intoeffect the following method: Method of layer drillingand terraces performance for riparian areas.

The riparian people must understand that themethod no 2 implies lower costs than the classic methodsof diking that it has a greater efficacy against floods thanthe classic methods, it provides to the layer a naturaltouristic aspect, create and maintain a functionalecosystem, a real antipollution firewall for everyone.

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3. Derivation method of the water flow throughparallel channels and building the bridge over the

selected sector, as support for increasing thehydrophilic vegetation

The presented ecotechnical method can be applied onan anthropogenic or natural channel, without concrete,situated on a hill or plane surface of different areas on thePlanet.

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In addition to protecting wildlife, soilsedimentation, protection against erosion, conservation of

biological diversity, the mangrove forest, also, constitutesa natural filter, through its aerial roots, against pollutioncaused by organic substances, heavy metals, chemicalfertilizers and particulate matter. In the newly formedecosystem, the roots of hydrophilic trees, which are to be

planted over 20% of their natural size, with time (severalyears), will enter through the grids of the metallic bridgeinto the selected sector of the river layer and into the

banks of the layer sector. Inside this small forest, variousspecies of obsolescent birds and animals may live and rest.Under the bridge, inside the water, a similar naturalhabitat like the one into the watercourses, benefic forthe ihtiofauna shall be created, where species protectedby law and properly developed hydrophilic vegetationcan be found.

Besides the fact that this method leads to thecreation of an ecosystem as a natural filter against

pollution of any kind, dissipater against floods, banksstabilizer, it also represents a way of biomass creation and

protection which will belong to the river sector selectedfor the research but to all limitrophe areas of this riversector. The robustness of this work as well as the low costsin comparison with classical methods of environmental

protection, in my opinion, makes this ecotechnical methodbecame an effective support for the aquatic and riparian

ecosystems.

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4. The method of creating parallel channels withwetlands areas.

The presented ecotechnical method can be applied

on an anthropogenic or natural channel, without concrete,situated on a hill or plane surface of different areas on thePlanet.

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The river flow must be directed through tworectangular channels, each of them having a capacity of

10% of the layer sector flow, which is going to be restored(fig.4.1). The two channels with flows q1 and q2 are builtfor several reasons:

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water filtration within the three areas- creating a performing riparian areaWithin the channels, two pools which are shared

by three or more biomass ecological lanes (wetlands)composed of hydrophilic plants (name of the plants) used

as filter for water, are built.The method of creating parallel channels withwetlands lanes is a modern ecological method that, besidesacting like an efficient filter regarding the contaminatedwater, it is also acting like a floods dissipater. Thecompact lanes consisted of vegetation facilitate the growthof aquatic flora and fauna because of the water quality: forexample: the last basin is habitat for ihtiofauna whichdisappeared from the watercourse or is about disappearing.The method is effective, generally, for the 3rd quality ofwater. Many aquatic birds may live into these basins.

A new functional ecosystem consisting of water,wetlands and riparian areas, extremely useful for the areaswith less biomass, is to be created.

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5. Creating wetlands into the minor layer by successivemeandering.

The presented ecotechnical method can be appliedon an anthropogenic or natural channel, without concrete,situated on a hill or plane surface of different areas on thePlanet.

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In the selected sector, two parallel side channelsthat will take over almost all rate of flow from the studied

sector shall be created in order to perform the ecologicalrestoration. After the lateral channels will have beendeveloped and will have been in service, the old layer ofthe river sector where the water flows not longer, will befilled with earth having the same physical-chemicalqualities in order to create a rectangular compact beltwhere mixed areas of riparian forests and wetlands shall

be created (fig 5.1).

Wetlands are an important habitat for fish andmollusks, water birds and a large number of animals, andfor many plants, insects and other inhabitants contribute tomaintaining the quality of water, filter the pollutants,retain the sedimentary material, oxygenate the water by arich vegetation, absorb the nutrients (nitrogen,

phosphorus, etc.), recycle them or, regulate themicroclimate, contribute to preventing floods, erosion,aquifer reloading, water supplies. The riparian areas shapethe fluctuations of water temperature, maintain the flux ofrecharging and the base flux of groundwater towards waterflows, stabilize the banks and have control over the floods.Taking into account the functions of wetlands and riparianareas listed above I proposed this method which facilitatesa direct collaboration between riparian areas and wetlands

by creating a performing and auto-functional ecosystem.The main and secondary water supply channels which

capture 20% of the maximum flow Q of a river sector,maintain the functionality of riparian-wetlands areas. (fig5.1).

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The components of this method of ecological

restoration are dimensioned regarding the water flow Q,layers depth H, rectangular layers width L and theselected sectors length l. The hydrophilic vegetation(alders, sallow, bushes and semi-aquatic grass, etc.), thatare to be used for creating riparian areas and wetlands,must be perfectly adaptable to the area. This newly createdecosystem will be a rest area for birds of passage; some ofthem are protected by law. Thus the wetlands and the

riparian areas successfully replace the artificial structuresbuilt with high and non-functional expenses.After the recent big floods in Romania and not

only, the big floods cannot be totally counter-balanced bythe lake accumulation, dams, watercourses recalibration,check dams, watercourses concreting etc. The onlysolution can be an engineering project aboutenvironmental principles in order to strive towards anecological arrangement of watercourses. Without havingthe necessary information about ecological principles,nobody will be able to perform a sustainable and efficientconstruction. The Natures reaction regarding thedestructive offensive of people will find the necessarymeans to protect its ecosystems or to create new ones,affecting the ample hydrotechnical construction, so theirexistence and humans also. Those consequences are validfor all anthropogenic construction.

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6. The method of layers ecologizing by the means of a

metallic structure similar to the biotope bridgesstructure from extent no 3.

The presented ecotechnical method may be appliedon an anthropogenic or natural channel, concreted andunconcreted, with a varied form of layer, not necessarilyrectangular or trapezoidal, which is located on a hill or

plain from various parts of the Earth.This method is effective, also, for the concreted or

paved water courses in North-West Europe which transitdifferent cities.

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A metallic inoxidable structure of grating weldedlongitudinally and transversally forming rectangles of

about 0.05 x0, 08m between them, is created. In case ofunconcreted river sectors having a layer with anunadequate geometrical shape, then the shape of layer will

be changed by the means of excavators of othermechanisms for drilling in order to create metallicstructures easier (fig6.1). On this steel structure, a layer ofaquatic soil shall be fixed by the means of an inoxidablewire system; the layer thickness will be set according to

the layers opening and rate of flow, and various aquaticplants resistant to depollution but also to redress thezoobentos in the, shall be fixed, also will lead to creationof some fish species. These aquatic plants will act as afilter. The metallic structure having 1 to 3 cm thickness,will be introduced and fixed into the layer after thehydrophilic vegetation will have reached 50% of maturity.The 50% growth of the vegetation is valid only fornonligneous plants (aquatic grass, reeds, etc.). Forhydrophilic ligneous plants (alders, sallow etc.) 20% ofmaturity is available, where the most important aspect isrelated to fixing and development of the radicular mass.Besides the inoxidable wire net, the radicular systems,also, includes the soil mass. The hydrophilic ligneousvegetation (alder, sallow etc.) will be planted by the end ofthe lower base of the cross-sectional wet perimeter andinto the minor layer, too (fig 6.3). The ecological

preparation of the layer sector which is to be renaturated(that means hydrophilic ligneous vegetation shall be plantinto the soil surface), will be performed in a place fairlyclose to that sector.

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Soil will be fixed on the inoxidable metal structureby an inoxidable net wire (fig 6.2). That upstream side of

the net that encompasses soil will be protected against thewater flow by an inoxidable metallic support weldedtogether with the metal structure.

After work completion, the water layer must be0.01 to 0.02 m over ground level inside the metallicframework. The land dimensioning will be madedepending on the average level of the water, slope, flowand rate of flow in the sector. This method is applied forthe layer sectors with housing construction and patrimony,which are very close to the river banks and that can not bemoved in case the water courses can not be changed.

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The water flow average should be of 1 . Qb nq, where n is the number of connecting pipes between the

sector selected for restoration and the stagnant waterchannel.The ecotechnical systems are dimensioned

regarding the water flow Q, rate of flow V, layers depthH, rectangular layers width L and the selected sectorslength l, the size of stagnant water channel and theenvironmental conditions.

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8. The method for changing the shape of a river sectorbanks in order to create new ecosystems.

There are many situations where the banks ofrivers doe not favor the growth of vegetation, do notprotect people against floods and where the ihtiofauna cannot move, laterally or longitudinally, in case of pollution.Therefore, by the means of ecotechniques, the banks ofrivers will be shaped and transformed into environmental

banks in order to be able to bear ecosystems created bywetlands and riparian areas. In this case, a study upon thelayer sector where the banks are totally inefficient bothecologically and engineerically regarding the protectionagainst floods is elaborated.

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On the right bank of the river is a small quantity ofhydrophilic and completely inefficient vegetation for the

bank establishment in order to act as a filter for thepolluted water and as habitat for various hydrophilicinhabitants. The left bank of the river has no vegetation, isgnawed and does not resist in case of major floods.

In this situation, the right bank must be built interraces of height h 'and length l' as shown in (fig.8.2) inorder to form a wetland and a riparian area controlling soilerosion through the regularization of sediments transport

and distribution, enhancing the quality of water, producingorganic matter for aquatic habitats and providing wildhabitat for flora and fauna, eliminating the excess ofnutritional substances and other contaminated substances,modeling the fluctuations of water temperature,maintaining the recharging and basic flux of groundwatertowards running water, stabilizing the banks andcontrolling the floods. After building the terraces on the

bank, a plastic support for a strong sustaining of the banksand the planted hydrophilic vegetation, is fixed. The left

bank has not so much place for remodeling, therefore,where is possible, we can extend it regarding the averagelevel of water and the layers width, so we will do itvertically. Inside the layer, where the extension has been

performed, some dissipaters shall be mounted for eachmeter and the newly created bank will be protected bywooden fascines.

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After remodeling, the initial width L of the layersector becomes width L '. Flow will be the same as Q but

V will become smaller - V'- according to the flowfunctional parameters.

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The above-mentioned methods are available because:

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New functional and useful ecosystems are builtfor areas without many biocenotic values.

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Confers an excellent habitat for various speciesof flora and fauna that have migrated or lived innewly created ecological areas.

- After environmental restoration the groundwaterquality will be improved and useful for riverain

people and more.-

The natural aesthetic aspect that encourages the

organized tourism will have other values.

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-Beside the classical improvement of river water(cleaning, treatment), the methods listed above

imply much lower costs.

Very important to know:

-The restored ecological zones must beimmediately designated as areas SPA(avifaunistic protection areas) and SCI (areas ofcommunitarian interest).

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The development local fauna and flora must becarefully surveilled.-Drastic measures must be taken for those who

fail to comply with environmental law.- In case of proper conditions, the ecological

restoration of water course must be performedin order to recover and make operational thelocal ecobiomes.

-The ecosystemic energy system should bemaintained by creating new ecosystems.

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Concluzii

Coninutul acestei cri arat prin exempleconcrete, c rurile care reprezint de fapt suportul vieiipot fi restaurate dnd o und de speran florei i fauneiacvatice i semiacvatice. Dispariia nielor ecologice dincauza impactului antropic asupra ecosistemelor de oricefel, a dus la dispariia funcionalitii trofice deci ladispariia biocenozelor din cadrul ecosistemelor lsnd

biotopurile nefuncionale. Cu ajutorul metodelor

prezentate se creaz miniecosisteme funcionale,adevrate generatoare ecologice, care vor duce la creareafuncionalitii locale i apoi globale a reeleiecobiomurilor din cadrul bazinelor hidrografice.Ceea ceam prezentat sunt doar cateva dintre metodele ce pot fiaplicate, dar n funcie de condiiile locale pot realiza ialte metode de restaurare ecologic a sectoarelorcursurilor de ap. in s precizez, c n crile mele, amncercat s scot in eviden importana gndirii ecologice

prin crearea metodelor de restaurare ecologic acursurilor de ap. Este necesar, acolo unde sunt condiii,ca sectorul de albie reconstruit, adic ecosistemul s nufie izolat ci s stabileasc legturi i cu alte ecosisteme pecursul rului, astfel nct acestea s formeze un ecobiomlocal progresiv funcional.

Ecotehnia, bazndu-se pe principii solideecologice direcioneaz alte tiinte ctre perceperea ifolosirea principilor naturale cu schimburi energeticefuncionale benefice pentru mediul nconjurtor, cuconsumarea minim a combustibililor fosili sau a altorresurse naturale.

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nchei, cu ncrederea c, cititorii mei, unii multmai profesioniti dect mine n domeniul ecotehniei, dar

i alii din multe alte domenii tiinifice i nu numai, vorfi responsabili,vor nelege i vor veni cu soluii viabile nvederea pstrrii mcar n condiiile actuale ale mediuluinconjurtor pentru generaiile viitoare.

Conclusion

The content of this book shows, by concreteexamples, that the rivers which, actually represent the lifesupport, can be restored by giving a hope for aquatic andsemi-aquatic flora and fauna. Disappearance of ecologicalniches because of the anthropogenic impact uponecosystems of any kind, led to the disappearance oftrophic functionality , therefore, disappearance of

biocenosis of the ecosystems leaving non-functional

biotops. By the means of presented methods, it waspossible to create functional miniecosystems, genuineecological generators, which will lead to the creation oflocal and after global functionality of the ecobiomesnetwork within the hydrographical basins. I have just

presented some of the methods that can be applied, but,depending on local conditions, other methods ofecological restoration of watercourse sectors can be

provided.

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I would have to mention that, in my books, I tried

to emphasis the importance of ecological thinking bycreating ecological methods of watercourses restoration. Itis necessary, where conditions are available, to rebuild thelayers sector in order not to isolate the ecosystem but tomaintain connections with other ecosystems along theriver so that they form a local progressive functionalecobiome.

Based on solid ecological principles, theecotechniques is directing other sciences towardsperception and use of natural principles along functionalenergetic exchanges beneficial to the environment, by aminimal consumption of fossil fuels and other naturalresources.

I conclude, having the confidence that my readers,some more professional in ecotechniques than me, but alsoothers from many other scientific fields and not only, will

be responsible, will understand and will come up withviable solutions in order to preserve at least the actualconditions of the environment for the future generations.

Tiprit la:

S.C. Nedea Print S.R.L., Bucureti,Tel: 021-685.0514; Fax: 021-771.27.30Mobil: 0744.384.598E-mail: [email protected]

All rights reserved

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ISBN: 978-973-0-05814-7

hydraulic and bioengineering solutions for rivers! 1

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