The book comprises 14 chapters covering all the issues related to water desalination. These chapters emphasize the relationship between problems encountered with the use of feed water, the processes ...developed to address them, the operation of the required plants and solutions actually implemented. This compendium will assist designers, engineers and investigators to select the process and plant configuration that are most appropriate for the particular feed water to be used, for the geographic region considered, as well as for the characteristics required of the treated water produced. This survey offers a comprehensive, hierarchical and logical assessment of the entire desalination industry. It starts with the worldwide scarcity of water and energy, continues with the thermal - and membrane-based processes and, finally, presents the design and operation of large and small desalination plants. As such, it covers all the scientific, technological and economical aspects of this critical industry, not disregarding its environmental and social points of view. One of InTech's books has received widespread praise across a number of key publications. Desalination, Trends and Technologies (Ed. Schorr, M. 2011) has been reviewed in Corrosion Engineering, Science & Technology – the official magazine for the Institute of Materials, Minerals & Mining, and Taylor & Francis's Desalination Publications. Praised for its “multi-faceted content which contributes to enrich it,” and described as “an essential companion...that enables the reader to gain a deeper understanding of the desalination industry,” this book is testament to the quality improvements we have been striving towards over the last twelve months.
Podzemne vode predstavljaju vrlo važan izvor vode, ali i osjetljiv sustav podložan različitim onečišćenjima. Među svim onečišćenjima koja mogu utjecati na kvalitetu podzemnih voda, posebno se ističu ...nitrati zbog svoje učestalosti i rasprostranjenosti. Osim toga, njihova prisutnost u podzemnim vodama izaziva značajan problem zbog negativnog utjecaja na ljudsko zdravlje zato što mogu uzrokovati pojavu različitih bolesti uslijed konzumiranja vode s povećanom koncentracijom nitrata, a u okolišu izazivaju eutrofikaciju. Nitrati nastaju procesima razlaganja dušika i njegovih spojeva, a u podzemnu vodu dospijevaju najčešće poljoprivrednim aktivnostima. Na pronos nitrata utječu brojni čimbenici kao što su vrsta i sastav tla, oborine, poljoprivredne aktivnosti, pokrov tla i sl.
Kako bi se analizirao problem pronosa nitrata, odabran je sliv rijeke Vuke zbog velikog udjela poljoprivredne proizvodnje, ali i zbog toga što je dio sliva proglašen ranjvim područjem na onečišćenje nitratima prema NN 130/2012. Kako na slivnom području dominiraju automorfna i hidromorfna tla, analiza pronosa nitrata ograničena je na uvjete tih vrsta tala. Pronos nitrata je definiran procesima advekcije, disperzije, sorpcije i biodegradacije, a rađen je u sklopu računalnog paketa MT3DMS u GMS programskom okruženju. Kako su za proračun advekcijsko-disperzijske jednadžbe potrebne brzine i definiran tok strujanja podzemnih voda, prvo se pomoću MODFLOW paketa za cijelo područje sliva rijeke Vuke definirao numerički 3D model strujanja podzemnih voda. Model je rađen za stacionarne uvjete unutar vegetacijskog razdoblja 2006. godine. Na takvom modelu je rađena kalibracija, a zatim i parametarska analiza koja je pokazala da najveći utjecaj na strujanje podzemnih voda ima infiltracija, koja iznosi 17% ukupnih oborina palih na slivno područje, a zatim i hidraulička vodljivost slojeva, kao i provodljivost dna vodotoka na području sliva. Najmanji utjecaj od analiziranih parametara imaju evapotranspiracija, provodljivost dna kanala i provodljivost dna akumulacije koji se nalaze na promatranom slivnom području. Takav se model prebacio iz stacionarnog u nestacionarne uvjete tako što su modelu pridodani vodostaji i protoci svih rijeka i kanala koji se nalaze na slivnom području, kao i vrijednosti infiltracije i evapotranspiracije za razdoblje od 2006. do 2015. godine. Rezultati dobiveni takvim modelom za lipanj 2014. godine korišteni su kao ulaz za model pronosa nitrata zato što su tada započeta terenska mjerenja uz kanal Pumpa Orlovnjak koji je smješten na istom slivu. Mjerenja su obuhvatila određivanje razina podzemne vode i koncentracije nitrata pomoću plitkih pedoloških piezometara smještenih uz obale kanala. Dobivene koncentracije nitrata iz piezometara koji su smješteni na lijevoj obali kanala, odmah uz poljoprivredne parcele, su korištene kao neto ulaz nitrata u model. Modelu su još pridodane i početne vrijednosti nitrata izmjerene na nekoliko lokacija na slivu 2014. godine. Nakon kalibracije rađena je parametarska analiza i takvog modela koja je pokazala da najveći utjecaj imaju upravo početne koncentracije nitrata. Manji utjecaj na rezultate imaju ulazne neto koncentracije nitrata, poroznost i vrijednost konstante brzine reakcije prvog reda koja refletkira proces biodegradacije, odnosno u uvjetima saturiranih vodonosnika denitrifikacije.
Posljednji je model rađen kako bi se utvrdila vrijednost konstante brzine reakcije prvog reda koja reflektira utjecaj denitrifikacije za uvjete vegetacije u melioracijskim kanalima u automorfnim i hidromorfnim tlima, a nastao je teleskopskom doradom mreže cijelog sliva rijeke Vuke kako bi obuhvatilo samo područje kanala na kojem su se provodila dvogodišnja terenska mjerenja. Provođenjem kalibracijskog procesa definirana je vrijednost analizirane konstante u iznosu od 0,018.
Kako bi se utvrdila povezanost i utjecaj oborina i podzemne vode na koncentraciju nitrata, detaljno su analizirani rezultati dobiveni terenskim mjerenjima. Vrijednosti koncentracije nitrata zabilježene na lijevoj obali kanala, uz koju su poljoprivrdne parcele, su u 78,1% slučajeva bile veće nego one zabilježene u piezometrima na desnoj obali uz koju je prilazni put. Za tih 78,1% slučajeva, piezometri na desnoj obali kanala su pokazivali smanjenje od čak 62,5% u odnosu na lijevu obalu. Važno je napomenuti da najveća zabilježena koncentracija nitrata iznosi 43,34 mg/l. Kako se pokazala značajna razlika u dobivenim koncentracijama, posebno su analizirani nizovi koncentracija nitrata s lijeve, a posebo oni s desne strane kanala. Rađena je korelacija između oborina, nizova koncentracija nitrata i razina podzemnih voda za obje strane kanala. Osim samih nizova, uspoređivane su i njihove distribucije preko funkcije kopule. Najveća je korelacija dobivena između maksimalnih razina podzemnih voda i odgovarajućih koncentracija nitrata za desnu obalu kanala, s koeficijentom korelacije 0,706. Koristeći Normalnu kopulu, određeno je da vjerojatnost pojavljivanja koncentracije nitrata od 50 mg/l i veće u uvjetima melioracijskih kanala iznosi 10,29%.
Groundwater represent important source of water, but also very sensitive system susceptible to different contaminant. Because of its impact on groundwater quality, frequency and distribution, nitrate contamination is especially standing out. Increased nitrate concentration in consuming water has negative effect on human health causing different deasises. In the environment nitrate can cause occurrence of eutrophication. Nitrates occur by decomposition of nitrogen and its compounds and their presence in groundwater, in the most part, is a result of agricultural activities. Numerous factors such as type and structure of soil, precipitations, agricultural activities and land cover have impact on nitrate fate and transport.
In order of analysing problem of nitrate contamination and transport, River Vuka catchment is chosen because of significant part of agricultural fields in this area. Another reason is the fact that part of this catchment area is highly vulnerable to nitrate contamination according to document NN 130/2012. Entire catchment area is covered with automorph and hydromorphic soils, so nitrate fate and transport is restricted to conditions of these types of soil. Nitrate transport is defined with advection, dispersion, sorption and biodegradation and modeled with MT3DMS package in GMS surrounding. For calculation of advection-dispersion equation, velocities of the groundwater flow are required. For this, three dimensional numerical model of groundwater flow for entire catchment area is constructed within MODFLOW package. Model is constructed under stacionary conditions for vegetation period in year 2006. After model calibration, sensitivity analysis is performed. Results show that infiltration has the highest impact on model results. During calibration process, infiltration is determined in magnitude of 17% of total precipitations. Besides infiltration, hydraulic conductivity of soil layers and conductance of riverbed also have high impact on results. The parameters with lowest impact are rate of evapotranspiration, conductance of canals and acumulation bottoms. After calibration and sensitivity analysis, model was transformed in transient state by assignin values of water levels and observed flows for all rivers, canals and acumulation on catchment area as well as rate of evapotranspiration and infiltration for period between year 2006 and 2015. Result of groundwater flow for June 2006 was input parameter for nitrate transport model. That date was chosen because field observations near canal Pumpa Orlovnjak, wich is situated on catchment area, started at that time. During field observations, groundwater levels and nitrate concentrations were measured with shallow piezometers situated on banks of canal. Obtained nitrate concentrations from piezometers situated on the left bank of canal, were used as recharge concentration from agriculture fields on cathcment area. Besides recharge concentration, initial concentrations for year 2014 for entire observed area were incorporated in model. After simulation, calibration and sensitivity analysis were performed. Parameters with highest imapact are initial concentrations, recharge concentrations, porosity and first order constant reaction rate wich reflects influence of biodegradation, or in this case of confined aquifer, denitrification.
Last model covered much smaller area were field observations were undertaken, and it was constructed from larger model which covers entire cathcment area. The purpose of this model was determination of first order constant reaction rate, or denitrification rate, for vegetation conditions in surface drainage canals in automorph and hydromorphic soils. During calibration proces, first order constant reaction rate is determined as 0.018.
In order of determinating relationship between nitrate concentrations, groundwater levels and precipitations, results obtained by filed observations were analyzed in detail. Obtained nitrate concentrations from left bank of canal were greater in 78.1% cases than concentrations from piezometers situated on right bank which is next to road. In those 78.1% cases, reduction of nitrate concentration on the right side was 62.5%. The highest concentration measured during 2 year field observations is 43.34 mg/l. Because of great difference between obtained concentrations on the right and left bank of canal, two separate series were constructed and analysed. The correlation coefficients were obtained comparing data series of nitrate concentrations from right and lefts bank, groundwater level from the right and lefts bank and precipitations. Distributions of those data series were compared also using copula function. The highest correlation coefficient, 0.706, was obtained comparing highest groundwater levels and related nitrate concentrations on the right bank of canal. Using Normal copula function, probability of oc
U disertaciji se istražuje efikasnost lokalne vodoopskrbe u Bosni i Hercegovini (BiH) i participacija privatnog sektora kao način poboljšanja efikasnosti. Razlog je što se u BiH loše upravlja ...vodoopskrbom. Nisku kvalitetu usluga prate visoki i rastući gubici vode, koji iznose oko 61%. Uz izuzetak Albanije, najveći su u Europi.
Radi smanjenja pristranosti ocjena i donošenja općenitijih zaključaka u ocjeni efikasnosti korištene su kvantitativne metode: analiza omeđivanja podataka i podešena metoda najmanjih kvadrata. Ustanovljeno je da se ista količina vode može isporučiti uz smanjenje ulaganja faktora proizvodnje za minimalno 38.3%, što pokazuje nisku razinu relativne efikasnosti.
BiH je koncem 1990-tih godina otvorila procese participacije privatnog sektora u oblasti lokalne vodoopskrbe. Procesi nisu bili dobro pripremljeni i upravljani pa je došlo do zastoja i sudskih sporova koji traju već desetljeće.
Iskustva gradova europskih tranzicijskih zemalja pokazuju da participacija privatnog sektora može povećati efikasnost vodoopskrbe. To pokazuje i kvaziprivatizacija vodovoda u Modriči.
Studije slučajeva pokazuju da participacija privatnog sektora može biti neuspješna i u najrazvijenijem zemljama i uspješna u najnerazvijenijim zemljama. Proizlazi da nije jednostavno ali ne i nemoguće razviti pravila uključenja privatnog sektora u lokalnu vodoopskrbu radi povećanja efikasnosti i kvalitete usluga.
Preduvjet su uspostavljeni pravni, institucijski i regulacijski okviri. Oni omogućavaju restrukturiranje operatera, liberaliziranje tržišta i povećanje cijena vode do razine pokrivanja objektivno utvrđene razine troškova i pravične dobiti.
Na temelju ocjene efikasnosti operatera identificirano ih je deset za participaciju privatnog sektora u općinama/županijama: Bosansko Grahovo, Kreševo, Ljubuški, Neum, Posušje, Prozor, Sarajevo, Sokolac, Srbac i Stolac.
Participacijom privatnog sektora u BiH može se razviti tercijarno tržište lokalne vodoopskrbe, tj. imati 10-50% stanovništva opsluživanog od privatnih operatera. Sarajevo je jedini relativno veći operater u zemlji, pa se odnosna razina opsluženosti populacije, koju primjerice imaju SAD i Španjolska, može postići dodjelom koncesije za vodoopskrbu Sarajeva. Tako je dodjelom koncesija za vodoopskrbu Sofije odnosno Tallinna razvijeno tercijarno tržište u Bugarskoj odnosno Estoniji.
Sustavno mjerenje efikasnosti vodoopskrbe razvija od 1996, a globalno zamjećuje od 2000. Europske tranzicijske zemlje od skora uvode participaciju privatnog sektora u vodoopskrbu pa još ne postoji velik interes za regulaciju sektora, primjenu metode usporedbe i ocjenu relativne efikasnosti vodnih operatera.
Kao prvo kvantitativno istraživanje efikasnosti lokalne vodoopskrbe u BiH, ovaj rad može poslužiti kao orijentir za buduće ocjene efikasnosti. Izuzev jednog istraživanja, također disertacije, za slučaj Slovenije, ne postoje druga istraživanja za tranzicijske zemlje Jugoistočne Europe.
The dissertation examines efficiency of the local water supply in Bosnia and Herzegovina (BiH) and the private sector participation as a way to improve efficiency. Justification for this work is the reality that the water supply system in BiH is poorly managed. Low quality of service is associated with high and increasing water losses that amount to approximately 61%. They are in Europe second only to Albania.
In order to reduce biasness and draw more general conclusions in efficiency assessment, quantitative methods were applied – the data envelopment analysis and corrected least squares method. It was found that the same amount of water can be provided with at least 38.3% decrease in production factors used; this indicates a low level of relative efficiency.
At the end of the 1990s, BiH opened processes of the private sector participation in the local water supply. These processes were not well prepared and governed managed, this resulting in a standstill and litigations that have been going on for a decade now.
The experience of cities in the European transition countries shows that private sector participation can increase the efficiency of water supply. The quasi-privatisation of water supply system in Modrica (BiH) shows that as well.
As case studies show, private sector participation can fail in the most developed countries and be successful in the least developed countries. Accordingly, it is not easy, but not impossible, to develop rules of private sector involvement in the local water supply with the purpose of increasing efficiency and quality of services.
As a prerequisite, legal, institutional and regulatory frameworks should be established. They would allow restructuring operators, market liberalization and increasing water prices to the level of coverage of realistically determined cost levels and fair profit.
In the area of the efficiency assessment of operators, ten operaters were identified for private sector participation in municipalities/counties: Bosansko Grahovo, Kresevo Ljubuski, Neum, Posusje, Prozor, Sarajevo, Sokolac, Srbac and Stolac.
The introduction of the private sector participation in BiH can develop a tertiary market for local water supply, i.e., to have 10-50% of the population served by private operators. Because Sarajevo is the only relatively large operator in the country, a relative level of population served by the private sector, for instance as currently exists in the United States and Spain, may be achieved by granting a concession for Sarajevo water supply. This way, granting concessions for water supply for Sofia and Tallinn tertiary markets were developed in Bulgaria and Estonia, respectively.
The systematic measurement of water supply efficiency has been developed since 1996, and it is globally noticeable since 2000. Only recently have European transition countries introduced private sector participation in water supply. Consequently, there is until now no great interest in the regulation of the involving conducting benchmarking and assessing the relative efficiency of water operators. As the first quantitative study of local water efficiency in BiH, this work can serve as a guide for future efficiency assessments. With the exception of just one study in Slovenia, also a doctoral thesis, there are no similar studies for transition countries of the Southeast Europe.
AutoCAD je već godinama sinonim za vrhunski alat pri izradi kvalitetnih i preciznih nacrta u različitim ekpertnim područjima, a inženjeri hidrotehnike pri rješavanju sve složenijih i zahtjevnijih ...projektnih zadataka svakodnevno koriste ovaj softver u svojoj praksi. Raster Design je razvijen kao dodatak AutoCAD-u koji omogućava rad s rasterskim podlogama i njihovu prilagodbu potrebama projekta. Civil 3D 2011 je najnovija verzija AutoCAD-a razvijena za potrebe inženjera građevinarstva. Pored sofisticiranih alata za izradu projektnih nacrta, pruža i mogućnost rada s TIN plohama i direktnog integriranja GIS podataka u crtež. Mogućnosti Raster Designa i Civil 3D-a prikazane su na primjeru analize podlokavanja oko stupova mosta Mičevec na rijeci Savi u Zagrebu. Budući da složeni hidrotehnički projekti iziskuju timski rad, iznesena je problematika razmjene grafičkih podloga unutar tima te su objašnjeni mogući postupci referenciranja grafičkih datoteka
U radu su istraženi operativni logistički problemi koji se javljaju prilikom obavljanja tehnoloških procesa u obalnom podsustavu lučkih kontejnerskih terminala. Cilj istraživanja je strukturirati ...optimizacijski model u svrhu potpore taktičkom planiranju na lučkim kontejnerskim terminalima do 1 milijun kontejnera godišnje koji su tipični za šire regionalno okruženje. U užem smislu optimizacijski model rješava problem kod različitih tlocrtnih konfiguracija lučkih pristana gdje su dva pristana postavljena prostorno neovisno.
Kao rezultat istraživanja razvijen je integrirani model optimizacije kod neovisno postavljenih pristana za kompletan obalni podsustav koji objedinjuje tri tipska problema: problem dodjele veza, problem raspodjele dizalica i problem redoslijeda prekrcajnih operacija, a predstavljen je optimizacijskim procesom u tri faze: inicijalizacije, raspoređivanja i usklađivanja. Tipično obilježje procesa je izbor optimalnog scenarija prekrcaja koji se dobije kao rezultat optimizacijske funkcije definirane ukupnim najkraćim vremenom boravka brodova u luci i optimalnog iskorištenja kapaciteta prihvatnih i prekrcajnih resursa. Kao rezultat optimizacije za svaki brod se odabiru tri najbolja scenarija prekrcaja, ovisno o rasporedu tereta na brodu i specifičnim zahtjevima brodara.
Za razvoj modela korištene su metode operacijskih istraživanja: metode linearnog i cjelobrojnog programiranja te metoda asignacije. Model je testiran na temelju simuliranih dolazaka brodova na uzorku od 100 brodova raspoređenim u grupe po 10, 15 i 20 brodova sukladno očekivanom vremenskom horizontu planiranja. Dobiveni rezultati pokazuju primjenljivost modela za rješavanje taktičko-operativnih problema u obalnom podsustavu ciljanih lučkih kontejnerskih terminala.
The present paper addresses the tactical logistical problems in the seaside subsystem of port container terminals. The research goal is to structure optimization model to support tactical planning in maritime container terminals with annual capacity below 1 million TEU per year, which are typical for wider regional environment. In the narrow sense, the optimization model solves the problem with different basin layouts where two quays are placed independently.
As a result of research, an integrated optimization model has been developed for the seaside subsystem that combines three typical logistical problems: Berth Allocation Problem, Quay Crane Assignment Problem and Quay Crane Scheduling Problem. The model is represented by the optimization process to takes up in three stages: initialization, allocation and synchronization. A typical feature of the process is the selection of the optimal handling scenario which is obtained as a result of the optimization function defined by the minimum total service time of ships in port and the optimum utilization of the quay cranes capacity. As a result of the optimization, for each ship the best suite handling scenario is selected among three pre-defined options, depending on the stowage location onboard and depending on specific requirements of shippers.
The methods of operations research has been used in the developing models, that is, methods of linear and integer programming and the assignment method. The model is tested on a sample of 100 virtually generated vessels with simulated stochastic times of arrivals and cargo handling demand. Vessels are arranged in groups of 10, 15 and 20 in accordance with the expected time horizon planning. The results show the applicability of the model for solving tactical operational problems in the seaside subsystem of targeted port container terminals.
U radu je prikazan numerički model simulacije međudjelovanja armirano-betonske konstrukcije i tekućine za 3D (prostorne) probleme pod statičkim i dinamičkim opterećenjem. Konstrukcija je modelirana ...degeneriranim elementima ljuske, a tekućina prostornim „brick“ elementima. Za opis ponašanja tekućine korišteni su linearni i nelinearni model. Nelinearnim modelom tekućine simulirana je pojava kavitacije. Za opis ponašanja betona korišten je specijalni model materijala kojim se može simulirati tečenje betona u tlaku te otvaranje i zatvaranje pukotina u vlaku. Valjanost modela i razvijenog softwarea testirana je na nekoliko numeričkih primjera.
A numerical model of dynamic interaction between fluid and reinforced concrete structure in 3D space is presented in this work. Degenerated shell elements for construction and 3D brick elements for fluid are used. Linear and nonlinear material model are used for a description of the fluid behaviour. Nonlinear model can be used for simulated phenomena of cavitation. Special model, which can describe concrete yielding in compression and crack opening and closing in tension, is used for simulation of the concrete behaviour. The efficiency of model and developed software are tested on several numerical examples.
Lubāna ezers aizņem 8240 ha lielu platību pie normāla ūdens līmeņa un 9553 ha pie maksimāla ūdens līmeņa. Tā krasti ir pārveidoti, tos ieskauj dambju un apvadkanālu sistēma. Lubāns (saukts arī par ...Lubānas un Lubāna ezeru) ir lielākais ezers Latvijā, atrodas uz Rēzeknes un Madonas novadu robežas. Ezeram ir lēzens krasts, bet tas ir stipri aizaudzis. Vienīgā upe, kas iztek no Ezera ir Aiviekste. Tā ir viena no sarežģītākajām un ūdens plūsmas ziņā interesantākajām upēm Latvijā. Augštecē upei ir neliels kritums. Upes gultnē sastopamais dolomīts veido slieksni, kas vienmēr traucējis gultnes padziļināšanos. Nelielais gultnes dziļums, platums un kritums stipri ierobežoja ūdens caurplūdumu. Pavasarī pieplūstošais ūdens daudzums Aiviekstes augštecē 2 - 4 reizes pārsniedz ūdens caurplūduma iespējas. Tā rezultātā pavasaros Aieviekstes augštecē pieplūstošie ūdeņi tecēja nevis uz Daugavu, bet atpakaļ uz Lubānu, kas radīja lielus plūdus. Ūdeņiem bagātajos pavasaros ezers un applūdušie klāni veidoja kopīgu ūdenstilpni 600 km² lielā platībā. Tas ir vismaz 6 reizes lielāku par Lubānu tās dabiskajos krastos. Lai samazinātu applūšanu, pagājušajā gadsimtā Aiviekste tika padziļināta un iztaisnota, bet Lubāns iedambēts. Pēc Lubāna iedambēšanas liela daļa Lubānā ieplūstošo upju pa Meirānu kanālu, apejot Lubānu, tika ievadīti tieši Aiviekstē. Meirānu kanāls ir lielākais Baltijas valstīs. Tā dziļums pārsniedz 10m, bet platums – 80m. Aiviekstes iztekā ūdens pieplūdumu regulē ar slūžām
Lubāna ezers aizņem 8240 ha lielu platību pie normāla ūdens līmeņa un 9553 ha pie maksimāla ūdens līmeņa. Tā krasti ir pārveidoti, tos ieskauj dambju un apvadkanālu sistēma. Lubāns (saukts arī par ...Lubānas un Lubāna ezeru) ir lielākais ezers Latvijā, atrodas uz Rēzeknes un Madonas novadu robežas. Ezeram ir lēzens krasts, bet tas ir stipri aizaudzis. Vienīgā upe, kas iztek no Ezera ir Aiviekste. Tā ir viena no sarežģītākajām un ūdens plūsmas ziņā interesantākajām upēm Latvijā. Augštecē upei ir neliels kritums. Upes gultnē sastopamais dolomīts veido slieksni, kas vienmēr traucējis gultnes padziļināšanos. Nelielais gultnes dziļums, platums un kritums stipri ierobežoja ūdens caurplūdumu. Pavasarī pieplūstošais ūdens daudzums Aiviekstes augštecē 2 - 4 reizes pārsniedz ūdens caurplūduma iespējas. Tā rezultātā pavasaros Aieviekstes augštecē pieplūstošie ūdeņi tecēja nevis uz Daugavu, bet atpakaļ uz Lubānu, kas radīja lielus plūdus. Ūdeņiem bagātajos pavasaros ezers un applūdušie klāni veidoja kopīgu ūdenstilpni 600 km² lielā platībā. Tas ir vismaz 6 reizes lielāku par Lubānu tās dabiskajos krastos. Lai samazinātu applūšanu, pagājušajā gadsimtā Aiviekste tika padziļināta un iztaisnota, bet Lubāns iedambēts. Pēc Lubāna iedambēšanas liela daļa Lubānā ieplūstošo upju pa Meirānu kanālu, apejot Lubānu, tika ievadīti tieši Aiviekstē. Meirānu kanāls ir lielākais Baltijas valstīs. Tā dziļums pārsniedz 10m, bet platums – 80m. Aiviekstes iztekā ūdens pieplūdumu regulē ar slūžām
Lubāna ezers aizņem 8240 ha lielu platību pie normāla ūdens līmeņa un 9553 ha pie maksimāla ūdens līmeņa. Tā krasti ir pārveidoti, tos ieskauj dambju un apvadkanālu sistēma. Lubāns (saukts arī par ...Lubānas un Lubāna ezeru) ir lielākais ezers Latvijā, atrodas uz Rēzeknes un Madonas novadu robežas. Ezeram ir lēzens krasts, bet tas ir stipri aizaudzis. Vienīgā upe, kas iztek no Ezera ir Aiviekste. Tā ir viena no sarežģītākajām un ūdens plūsmas ziņā interesantākajām upēm Latvijā. Augštecē upei ir neliels kritums. Upes gultnē sastopamais dolomīts veido slieksni, kas vienmēr traucējis gultnes padziļināšanos. Nelielais gultnes dziļums, platums un kritums stipri ierobežoja ūdens caurplūdumu. Pavasarī pieplūstošais ūdens daudzums Aiviekstes augštecē 2 - 4 reizes pārsniedz ūdens caurplūduma iespējas. Tā rezultātā pavasaros Aieviekstes augštecē pieplūstošie ūdeņi tecēja nevis uz Daugavu, bet atpakaļ uz Lubānu, kas radīja lielus plūdus. Ūdeņiem bagātajos pavasaros ezers un applūdušie klāni veidoja kopīgu ūdenstilpni 600 km² lielā platībā. Tas ir vismaz 6 reizes lielāku par Lubānu tās dabiskajos krastos. Lai samazinātu applūšanu, pagājušajā gadsimtā Aiviekste tika padziļināta un iztaisnota, bet Lubāns iedambēts. Pēc Lubāna iedambēšanas liela daļa Lubānā ieplūstošo upju pa Meirānu kanālu, apejot Lubānu, tika ievadīti tieši Aiviekstē. Meirānu kanāls ir lielākais Baltijas valstīs. Tā dziļums pārsniedz 10m, bet platums – 80m. Aiviekstes iztekā ūdens pieplūdumu regulē ar slūžām
Lubāna ezers aizņem 8240 ha lielu platību pie normāla ūdens līmeņa un 9553 ha pie maksimāla ūdens līmeņa. Tā krasti ir pārveidoti, tos ieskauj dambju un apvadkanālu sistēma. Lubāns (saukts arī par ...Lubānas un Lubāna ezeru) ir lielākais ezers Latvijā, atrodas uz Rēzeknes un Madonas novadu robežas. Ezeram ir lēzens krasts, bet tas ir stipri aizaudzis. Vienīgā upe, kas iztek no Ezera ir Aiviekste. Tā ir viena no sarežģītākajām un ūdens plūsmas ziņā interesantākajām upēm Latvijā. Augštecē upei ir neliels kritums. Upes gultnē sastopamais dolomīts veido slieksni, kas vienmēr traucējis gultnes padziļināšanos. Nelielais gultnes dziļums, platums un kritums stipri ierobežoja ūdens caurplūdumu. Pavasarī pieplūstošais ūdens daudzums Aiviekstes augštecē 2 - 4 reizes pārsniedz ūdens caurplūduma iespējas. Tā rezultātā pavasaros Aieviekstes augštecē pieplūstošie ūdeņi tecēja nevis uz Daugavu, bet atpakaļ uz Lubānu, kas radīja lielus plūdus. Ūdeņiem bagātajos pavasaros ezers un applūdušie klāni veidoja kopīgu ūdenstilpni 600 km² lielā platībā. Tas ir vismaz 6 reizes lielāku par Lubānu tās dabiskajos krastos. Lai samazinātu applūšanu, pagājušajā gadsimtā Aiviekste tika padziļināta un iztaisnota, bet Lubāns iedambēts. Pēc Lubāna iedambēšanas liela daļa Lubānā ieplūstošo upju pa Meirānu kanālu, apejot Lubānu, tika ievadīti tieši Aiviekstē. Meirānu kanāls ir lielākais Baltijas valstīs. Tā dziļums pārsniedz 10m, bet platums – 80m. Aiviekstes iztekā ūdens pieplūdumu regulē ar slūžām
