Magistrantūros studijų baigiamajame darbe analizuojamas drenažo sistemų eksploatacijos efektyvumas. Darbą sudaro – įvadas, 5 skyriai, išvados ir rekomendacijos, naudotos literatūros sąrašas. Darbo apimtis – 56 puslapiai kompiuteriu spausdinto teksto, įskaitant 6 lenteles ir 37 paveikslus. Naudotos literatūros sąrašą sudaro – 34 šaltiniai. Nepriklausomybės metais, skiriant melioracijos darbams mažiau lėšų, melioracijos statinių būklė palaipsniui blogėjo. Pagal 2009 metų duomenis, Šilutės rajone nusausintų žemių iš viso yra 85113,90 ha, o nusausintas drenažu plotas sudaro 68352,30 ha, valstybei nuosavybės teise priklausančių melioruotų žemių ir melioracijos statinių balansinė vertė – 283902,773 tūkst. Lt. Žemės ūkio gamyba ir jos našumas tiesiogiai priklauso nuo melioracijos sistemų būklės, nes ji vyksta nusausintose žemėse, todėl būtina atsižvelgti į šio sektoriaus konkurencingumą rinkos sąlygomis bei Šilutės rajono ir bendrą Lietuvos žemės ūkio plėtrą, todėl tikslinga išanalizuoti melioruotų žemių inventorizacijos darbus ir nustatyti svarbiausius rodiklius, aktualius dabar ir ateityje naudojant melioruotą žemę ir melioracijos statinius. Šiai dienai esamų melioracijos statinių vidutinis amžiaus vidurkis siekia 35 metus. Žemės savininkai neturi lėšų tinkamai naudoti ir prižiūrėti melioracijos statinius, todėl jų techninė būklė sparčiai blogėja. Melioracijos statiniai teikia naudą žemdirbiams, kaimo gyventojams ir visai mūsų visuomenei. Nenorintis ar nepajėgiantis savo žemėje... [toliau žr. visą tekstą] / In the final work of master studies, we analyze efficiency of operating of drainage systems. The work consists of introduction, 5 chapters, conclusions and recommendations, a list of references. This makes 56 pages of printed text, including 6 tables and 37 pictures. Thirty -four references have been used. During the years of independence, with less means being assigned for land reclamation works, the technical state of land reclamation structures gradually became worse. According to the data of 2009, the drained area of land in Šilutė district consists of 85113,90 hectares (ha), of which 68352,30 ha are drained by drainage systems. The balance value of reclaimed lands and reclamation constructions owned by the state is 283902,773 Lt. Production of agriculture and its fertility is directly influenced by the condition of reclamation systems because drained lands are where cultivation occurs. Therefore it‘s necessary to consider land reclamation for its effect on competitiveness in the market and development of agriculture in Šilutė region and Lithuania. Thus, it is useful to analyze inventory works of reclaimed lands and determine the most important indicators, which are actual now and for the future, while using reclaimed land and reclamation constructions. The average age of presently used reclamation constructions is up to 35 years. The owners of lands do not have enough money to use and maintain reclamation constructions properly, so their condition becomes worse very fast... [to full text]

Orientador: Bruno Coraucci Filho / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-09T00:15:10Z (GMT). No. of bitstreams: 1 Tonon_Daniele_M.pdf: 3768702 bytes, checksum: 5674b41afca2a80b6486eb02fa20eef2 (MD5) Previous issue date: 2007 / Resumo: A desinfecção de águas residuárias, tanto para atender a padrões de lançamento em corpos receptores quanto para o reúso agrícola, é um processo de tratamento indispensável à proteção da saúde publica. Neste trabalho o hipoclorito de cálcio apresenta-se como desinfetante, pois, uma das grandes vantagens desta técnica é que ela deixa um residual de cloro em contato com os efluentes capaz de eliminar os organismos causadores das principais doenças de veiculação hídrica, o inconveniente desta técnica é a provável formação de subprodutos da desinfecção, os chamados trialometanos. O objetivo geral proposto por este trabalho é a avaliação da desinfecção de efluentes de uma lagoa anaeróbia, situada em Franca, São Paulo e administrada pela Sabesp; e, dos efluentes das valas de filtração construídas com 0,25, 0,50 e 0,75m de camada de areia, as quais foram alimentadas com efluente proveniente de uma fossa filtro e coletada na ETE Icaraí, administrada pela Sanasa, Campinas, São Paulo. Na desinfecção foi utilizado hipoclorito de cálcio promovendo variações dos tempos de contato em 30, 45 e 60 minutos. Dosagens de hipoclorito de cálcio entre 25 e 32 mg L-1 e dosagens 1,6 e 3,25 mg L-1 foram necessárias para adequar os efluentes da lagoa anaeróbia e das valas de filtração, respectivamente, aos padrões estabelecidos pela OMS (1989) para reúso agrícola; e, pela CONAMA 357/05, para padrões de lançamento em corpos receptores de classe 2. Os resultados sobre inativação de protozoários e helmintos foram considerados não satisfatórios para o efluente da lagoa anaeróbia e para as valas de filtração verificou-se que há uma retenção desses microrganismos nas camadas de areia / Abstract: The wastewater disinfection is an indispensable pratice to the protection of public health, it needs to follow the standards estabilished of launching water in the rivers and lakes and for the reuse on agriculture. In this process the hypochlorite of calcium is presented as disinfecting agent, therefore, one of the great advantages of this technique is that it leaves a residual of chlorine in contact with effluents capable to eliminate organisms causing of the main illnesses of hydric propagation, the inconvenience of this technique is the probable by-product formation of the disinfection, called the trihalomethanes. The general objective considered by this work is the evaluation of the disinfection of effluent of an anaerobic pond, situated in Franca, São Paulo and managed by the Sabesp and of the effluent ones of the ditches of filtration of 0,25, 0,50 and 0,75m of effluent sand layer fed with proceeding from one fosse filter and collected in the ETE Icaraí managed for the Sanasa, Campinas, São Paulo, with hypochlorite of calcium varying the times of contact in 30, 45 and 60 minutes. Dosages of hypochlorite of calcium between 25 and 32 mg L-1 and dosages 1,6 and 3,25 mg L-1 had been necessary to adjust the effluent of the anaerobic pond and the ditches of filtration, respectively, to the standards established for the OMS (1989) for agriculture reuse and CONAMA 357/05 for standards of launching in the receptors of class 2. The results on inactivation of protozoa and helminths have been considered not satisfactory for the effluent ones of the anaerobic ponds and for the filtration ditches it was verified that it has a retention of these microorganisms in the sand layers / Mestrado / Saneamento e Ambiente / Mestre em Engenharia Civil

Reframing the Ditch explores the application of native canopy using green street tools as a method to move beyond minimums and improve biological diversity of stormwater conveyances in a way that is consistent with visual landscape preference theory. Small stream water quality impairment is an issue found in 83% of stream headwaters in the Eastern United States. The Clean Water Act (1972), which regulates pollutant discharge into U.S. surface waters, mandates that municipalities create an implementation plan to improve water quality of their impaired streams. Water quality impairment is often exacerbated when headwater streams flow through urban areas. Urban areas are concentrations of human activity and as such bring concentrations of impermeable surfaces and stormwater runoff. As development increases, dedicated space for stormwater changes. Natural flow patterns that interacted with stratified layers of native vegetation often become constrained to ditches and pipes with little or no vegetation within the conveyance corridor. Reframing the Ditch creates an approach to help municipalities improve water quality of headwater streams by addressing water quality in ditches before water reaches the stream. The objective of urban conveyance systems is to move stormwater runoff into waterways as quickly as possible. When we design these conveyances to simply minimize stormwater interference, we ignore the potential contribution this land has for our public urban systems. This project looks for an intermediary between minimums and maximums. Maximums, also known as restoration, allows for messy, dynamic systems that are not hydrologically or visually appropriate in most urban environments. This thesis reveals ditches as complex landscapes that require high preforming vegetation, which ultimately limits the number of native species suitable for such harsh environments. Additionally, the more impermeable an environment is and the farther a ditch is from the top of the watershed, the more stormwater runoff there is, and the more space is required to process water and improve water quality. Cost, lack of available vegetation and lack of space may limit the application of this design in most circumstances. However, there are appropriate landscapes where this design methodology can provide valuable insight for landscape implementation plans aimed at improving water quality, while also providing public space, enriching neighborhood aesthetics and highlighting the function of our urban drainage systems. / Master of Landscape Architecture / The Environmental Protection Agency, through the Clean Water Act, dictates what is an appropriate level of contamination in streams and rivers within the United States. Waterway impairment is a widespread issue affecting 83% of headwater streams in the Eastern United States. Improving the quality of headwater streams, the smallest parts of stream and river networks, is generally thought of as the first opportunity to improve water quality downstream. Reframing the Ditch suggests an alternate first opportunity by looking at how we can improve water quality by addressing design of the urban ditch. Urban ditches, mostly in the form or open channels or curb-and-gutters, collect and move stormwater runoff. Ditches, typically have little vegetation and work to more water as quickly and efficiently as possible. When we eliminate vegetation from urban ditches, we also eliminate valuable function. In natural stream processes, vegetation slows, filters, and infiltrates water, improving water quality, while also improving biodiversity and providing habitat. However, theses natural stream processes are dynamic and messy systems that are often not appropriate for urban settings. In order to define a design method that is appropriate for urban settings, Reframing the Ditch utilizes a green street toolkit to create a strong sense of place, while processing stormwater, within our public rights-of way. By focusing on the application of native urban canopy within a drainage network, we can adhere to landscape preference and increase biodiversity. The design reveals that ditches are complex, context specific landscapes. While there is opportunity to increase utility of these spaces, there is complexity and cost to doing so. Layering utility into our stormwater conveyances is a valuable design strategy that serves individuals, neighborhoods, municipalities and watersheds. This project is an effort to help municipalities reframe their ditches, by providing ecological and social benefit, and ultimately improving water quality downstream.

La mise en place de réseaux écologiques est considérée comme l'un des moyens de pallier aux effets néfastes de la fragmentation sur la biodiversité. Dans les paysages agricoles, les éléments linéaires non cultivés peuvent constituer de larges réseaux, et jouer un rôle d'habitat-refuge et/ou de corridor de dispersion pour les espèces végétales. L'objectif de cette thèse est de comprendre quel rôle un réseau dense de fossés de drainage peut jouer dans le maintien et la dispersion d'espèces végétales dans un paysage agricole intensif du nord de la France. Nous avons également cherché à savoir dans quelle mesure les caractéristiques du paysage, la connectivité du réseau et les traits d'histoire de vie des espèces végétales impactent la dispersion des propagules au sein du réseau de fossés. Nos résultats montrent que les fossés jouent bien un rôle de corridor écologique pour les espèces végétales. En ciblant plus précisément les espèces hydrochores, nous avons démontré qu'elles dépendaient essentiellement de la composition et de la connectivité du réseau de fossés et des éléments immédiatement adjacents aux berges. Le réseau détermine également la structuration des flux de gènes chez deux espèces végétales de berges de fossés. Enfin, nos résultats montrent que la réponse des espèces à un gradient de connectivité du réseau dépend d'une combinaison de traits de dispersion, et qu'une diminution de cette connectivité entraîne une convergence fonctionnelle de ces traits à l'échelle de la métacommunauté. L'ensemble de ces résultats permet de mieux comprendre le rôle de corridor des fossés pour les espèces végétales, afin de permettre leur intégration au sein des projets de continuités écologiques dans les paysages agricoles. / The establishment of ecological networks is considered as one of the solutions to mitigate the negative effects of fragmentation on biodiversity. In agricultural landscapes, non-crop linear elements may form large networks, and constitute refuge habitats and/or dispersal corridors for plant species. The objective of this study is to understand which role may a dense drainage ditch network play for the maintenance and dispersal of plant species in an intensive agricultural landscape located in northern France. In addition, we also investigated the impact of landscape characteristics, network connectivity and plant species life-history traits on propagule dispersal within the ditch network. Our results indicate that ditches are indeed ecological corridors for plant species. By focusing more specifically on hydrochorous species, we demonstrated that they essentially depend on ditch network composition and connectivity and on elements immediately adjacent to the banks. The network also drives patterns of gene flow for two ditch bank plant species. Finally, our results also indicate that species’ response to ditch network connectivity depends on a combination of dispersal traits, and that connectivity reduction leads to functional convergence of those traits at the metacommunity scale. Together, these results provide a better understanding of the corridor role of ditches for plant species, in order to include these features into ecological network planning in agricultural landscapes.

L’étude présentée a pour objectif de mieux comprendre l’influence de l’hydrodynamique sur le transfert de produits phytosanitaires lors d’écoulement dans les fossés agricoles. Quatre paramètres ont plus particulièrement été étudiés : i) la vitesse de l’écoulement de surface ; ii) la submergence, définie comme le rapport moyen entre la hauteur des formes du lit et la hauteur d’eau ; iii) la forme du lit et iv) le degré de saturation en eau du lit avant la contamination par les produits phytosanitaires. L’influence de ces paramètres a été étudiée en conditions semicontrôlées à travers la mise en oeuvre d’expérimentations en canal expérimental, au fond duquel a été fixé pour chaque expérimentation un substrat type constitué d’un assemblage de fibres de chanvre utilisé pour approcher de manière simplifiée un système naturel relativement complexe et hétérogène (en considération des nombreux substrats rencontrés dans le lit des fossés naturels : herbes, feuilles mortes, végétation en décomposition, paille, sédiments, …). Les fibres de chanvre ont été choisies après une étude préliminaire en laboratoire visant à comparer les possibilités d’adsorption et de désorption des produits phytosanitaires sélectionnés sur diverses fibres couramment utilisées dans l’industrie géotextile (jute, lin, chanvre, polyamide, polypropylène et polyester). Les expérimentations en canal expérimental ont été menées de manière à tester l’influence spécifique des paramètres étudiés. La comparaison des différentes expérimentations indique qu’une augmentation de la vitesse de l’écoulement de surface augmente la quantité de produits phytosanitaires transférés de l’écoulement de surface vers le lit, ainsi que la cinétique de ce transfert. Le constat est le même lorsqu’on augmente la submergence, ou bien lorsqu’on passe d’une géométrie de petites formes en « dunes » à une géométrie de grandes formes en « créneau ». Enfin, le fait que le lit soit saturé en eau en début d’expérimentation réduit fortement le transfert de la lame d’eau vers le lit. On observe également que l’influence de chaque paramètre semble être interdépendante. Devant le coût en temps et en argent de ces expérimentations, un modèle a été sélectionné dans la littérature, codé et utilisé pour conforter et compléter l’interprétation des données expérimentales. / The aim of this work was to better understand the influence of hydrodynamics on the transfer of pesticides in water flows in agricultural ditches. Special attention was given to four parameters: i) the speed of the surface water flow, ii) the submergence, defined as the mean ratio between the height of the bedforms and the water depth, iii) the shape of the bedforms and iv) the water content of the bed substrate before contamination by pesticides. The influence of these various parameters was investigated with an experimental flume, using a standard of substrate made of hemp fibres. Hemp fibres were chosen as a simplified model of natural substrates such as grass, dead leaves, decaying vegetation, straw and sediments, which are rather complex and heterogeneous. Hemp fibres were selected from preliminary laboratory studies which allowed to compare the adsorption and desorption characteristics of various pesticides for different fibres often used in the geotextile industry (jute, linen, hemp, polyamide, polypropylene and polyester). The flume experiments were designed in order to assess the influence of the four parameters mentioned above. The comparison between the different experiments shows that an increase in surface water speed results in an increase in the amount of pesticides transferred from the water to the bed substrate and the transfer kinetics. A similar result is observed when increasing the submergence, or when going from small sinusoidal bedforms to larger rectangular bedforms. In addition, the data show that the transfer of pesticides from surface water to the bed substrate is strongly decreased when the substrate was saturated with water at the beginning of the experiments. Also, it appears that there is a link between the influence of the differents parameters. When considering the long time duration and the cost of the experiments, it was decided to use a model from the literature which was adapted and used to confirm and extend the interpretation of the experimental data.

Magistratūros studijų baigiamajame darbe analizuojama melioruotų žemių ir melioracijos statinių būklė. Tyrimai buvo atlikti Utenos rajone. Rajone nusausinta 30625 ha arba 59,9 % nuo šlapių žemių fondo – 51130,95 ha. Nuo 1966 iki 1990 metų drenažu nusausinta 28564 ha, o nuo 1991 iki 1995 metų – 1570 ha ploto. Daugiausiai žemių drenuota 1970, 1971 ir 1975 metais – daugiau kaip po 1400 ha į metus. Mažiausiai naudoti atiduota 1994 metais – 298 ha, o daugiausiai 1975 metais – 1800 ha. Iki 1975 metų žemių sausinimo darbų tempai Utenos rajone didėjo, o vėliau sulėtėjo. Melioruotų žemių ir melioracijos statinių būklės tyrimais Utenos rajone nustatyta, kad geros būklės melioruotos žemės ir melioracijos statinių techninė būklė kasmet blogėja. Žemės ūkio ministerijos lėšų skirtų melioracijos darbams nepakanka, kad užtikrintų jų gerą būklę. Norint Utenos rajone palaikyti gerą melioruotos žemės ir melioracijos statinių būklę, valstybė turėtų skirti metams 2 mln. Lt. t.y. du kartus daugiau lėšų nei dabar. Šiandien, esamų melioracijos statinių vidutinis amžiaus vidurkis siekia 35 metus. Žmonės neturi lėšų tinkamai naudoti ir prižiūrėti melioracijos statinių, todėl jų techninė būklė sparčiai prastėja. Melioracijos statiniai teikia naudą žemdirbiams, kaimo gyventojams ir visai visuomenei. Nenorintis ar nepajėgiantis savo žemėje tvarkyti ir prižiūrėti drenažo, ūkininkas kenkia ir kaimyno nusausintoms žemėms. Sunykti melioracijos statiniams jokiu būdu negalima leisti, nes jiems atstatyti... [toliau žr. visą tekstą] / The condition state of reclaimed lands and land reclamation hydraulic structures was analysed in the final work of master studies. Researches were carried out in Utena district. 30625 ha or 59.9% of the wetlands fund (51130.95 ha) have been reclaimed in the district. In the period of 1966-1990 28564 ha of the total area have been reclaimed and in the period of 1991-1995 – 1570 ha, respectively. The largest areas of lands were reclaimed in 1970, 1971 and 1975, i.e. more than 1400 ha per year. The smallest areas returned for the use were in 1994 – 298 ha and the largest areas returned for the use were in 1975 – 1800 ha. By 1975 the speed of draining works in Utena district increased and later slowed down. With the help of the researches of reclaimed lands and the condition state of land reclamation hydraulic structures in Utena district it was determined that the technical condition of land reclamation structures and reclaimed lands that used to be in good condition is worsening every year. The means committed to the land reclamation works by the Ministry of Agriculture are not sufficient for the ensuring of the good condition state of these structures. In order to maintain the good condition of reclaimed lands and land reclamation hydraulic structures situated in Utena district the State should commit 2 million Lt per year, i.e. twice as much. At present the average age of land reclamation hydraulic structures reaches 35 years. People have not enough means for the proper use... [to full text]

Magistrantūros studijų baigiamajame darbe analizuojama melioruotų žemių ir melioracijos statinių būklė. Tyrimai buvo atlikti Vilniaus rajone, pagal Lietuvos Respublikos žemės ūkio ministerijos duomenis. Rajone nusausinta 43224,8 ha arba 67,8 % šlapių žemių fondo - 56269 ha. Nuo 1960 iki 2008 metų drenažu nusausinta 39061,4 ha. Daugiausia žemių drenuota 1976-1980 metais - daugiau kaip po 1800 ha per metus. Mažiausiai naudoti atiduota 1996-2000 metais – iš viso 155,7 ha. Iki 1980 metų Vilniaus rajone žemių sausinimo darbų tempai didėjo, o nuo 1985 m. sumažėjo iki 1400 per metus, vėliau darbų kiekiai tapo dar mažesni. Nuo 2000 m. nebuvo vykdomos naujos statybos. 2006 m. atlikus Vilniaus rajone melioruotų žemių ir melioracijos statinių būklės tyrimus nustatyta, kad geros būklės melioruotos žemės ir melioracijos statinių techninė būklė kasmet blogėja. Skirtų biudžeto lėšų melioracijos darbams nepakanka, kad užtikrintų jų gerą būklę. Norint Vilniaus rajone palaikyti gerą melioruotos žemės ir melioracijos statinių būklę, valstybė turėtų skirti metams 4 mln. Lt, t.y. 4 kartus daugiau lėšų, nei skiriama dabar. Šiandien esamų melioracijos statinių vidutinis amžiaus vidurkis siekia 35 metus. Žemės savininkai neturi lėšų tinkamai naudoti ir prižiūrėti melioracijos statinių, todėl jų techninė būklė sparčiai prastėja. Melioracijos statiniai teikia naudą žemdirbiams, kaimo gyventojams ir visai visuomenei. Nenorintis ar nepajėgiantis savo žemėje tvarkyti ir prižiūrėti drenažo, ūkininkas... [toliau žr. visą tekstą] / The condition of reclaimed lands and of land reclamation hydraulic structures was analyzed in the final work of master studies. Research was carried out in the district of Vilnius. 43224,8 ha or 67,8% of the wetlands fund (56269 ha) have been reclaimed in the district. In the period of 1960-2008, 39061,4 ha were reclaimed and in the period of 1976-1980, 1800 ha per year were reclaimed. The smallest areas returned for the use were in 1996-2000, 155,7 ha per year and the largest areas returned for the use were in 1985, 1400 ha were reclaimed. From 2000, no new construction was carried out. With the help of the research of reclaimed lands and the condition of land reclamation hydraulic structures in Vilnius district, it was determined that the technical condition of land reclamation structures and reclaimed lands which was in good condition is now deteriorating every year. The grant committed to the land reclamation works, issued by the Ministry of Agriculture, is not sufficient for ensuring that these structures remain in good condition. In order to maintain the good condition of reclaimed lands and land reclamation hydraulic structures situated in Vilnius district, the State should commit 4 million Lt during the year, i.e. a fourfold increase. At present, the average age of land reclamation hydraulic structures is 35 years old. Farmers do not have enough funds for the proper use and exploitation of land reclamation hydraulic structures, therefore, their condition is rapidly... [to full text]

Joniškio rajono šlapių žemių fondas yra 98341 ha. Rajone nusausinta 80524,65 ha arba 81,9 % nuo šlapių žemių fondo. Darbo tikslas: Išanalizuoti ir įvertinti melioruotų žemių, bei statinių būklę Joniškio rajono savivaldybės teritorijoje. Pagal atliktos 2006 metų inventorizacijos duomenų analizę melioruotas žemės plotas įskaitant plotą sausinamą drenažu nuo1987 metų padidėjo 1232,64 ha kas sudaro 1,55 %. Blogos būklės plotas sudaro 4490,99 ha iš kurių numatoma rekonstruoti 3190,76 ha., remontuoti 1083,04 ha. ir nurašyti 217,19 ha. Didžiausi pažeidimai melioruotame plote: užmirkęs drenuotas plotas, žemės ūkio naudmenos neveikiančio drenažo plote ir drenuotas plotas užstatytas statiniais, kur nutiesti keliai ar kitos komunikacijos. Blogai veikiančio drenažo plotas sudaro 6 % viso drenuoto žemės ploto. 2006 metų inventorizacijos duomenimis magistralinių griovių Joniškio rajone yra 1230,0 km. Bloga būklė sudaro 357,64 km., tai sudaro 29 %. Didžiausi pažeidimai: vaga užaugusi medžiais ir krūmais, vaga užnešta nešmenimis ir patvenkta vaga. Išanalizavus 2006 metų inventorizavimo duomenis paaiškėjo, kad pralaidų būklė Joniškio rajone yra bloga: 56 % jų blogos būklės. Pagrindinės pažeidimų priežastys: pažeistos vietinių įgriuvų, įgriuvę antgaliai, apirę betoniniai elementai. Šiandien, esamų melioracijos statinių vidutinis amžiaus vidurkis siekia 35 metus. Neturint lėšų, tinkamai naudoti ir prižiūrėti melioracijos statinių neimanoma, todėl jų techninė būklė sparčiai prastėja. ... [toliau žr. visą tekstą] / Wet territory corpus is 98341ha in Joniskis district. 80524,65 ha or 81,9 % of the wetlands fund have been reclaimed in the district. Main job goal is to inspect existing melioration building’s condition in the local government’s territory of the Joniskis district. According inventorisation data analysis accomplished in 2006 improved land’s area, including drained area become bigger from 1987, 1232,64 ha has structure 1,55 %. Quantity of building’s in bad shape has structured 4490,99 ha from which 3190,76 ha have been reconstructed, also 1083,04 ha have been reconditioned and 217,19 ha have been discarded as unusable. Most common drainage system break is influated by new buildings, roads and communication systems. The malfunction of the drainage area has structure 6 % of all land area. According inventorisation of 2006 have emerged that main roads in the Joniskis district are 1230,0 km. Bad condition has structured 357,64 km, it is 29%. Most common drainage system breaks are: the main canal, which is overgrown by trees and scrubs, also main canal is choked up by outwashes and affluented. According inventorisation were done become clear that overflows are in bad shape in the district of Joniskis city; that is 56 % of all them bad condition. The major reasons of breaks are: local failures are damaged, also the snouts are tumbled and finally the details of concrete are broke up. At present the average age of land reclamation hydraulic structures reaches 35 years. People... [to full text]

I detta examensarbete har det undersökts om digitala höjdmodeller, framställda från LIDAR-data som insamlats av Lantmäteriet, kan användas för komplettera och lokalisera nya bäckar och diken som inte finns med i Lantmäteriets databaser idag. I Lantmäteriets verksamhet karteras bäckar och diken först och främst idag med hjälp flygfotografier i stereo. Då metoden fungerar bra på öppen mark kan det vara svårt att urskilja bäckar under tät vegetation som till exempel barrskog. Metoden som använts för att lokalisera bäckar och diken går ut på att beräkna flödesriktningar och flödesackumuleringar i höjdmodellerna. I projektet testas hur metoden påverkas av höjdmodeller av olika upplösningar och ursprung. Förutom Lantmäteriets egna höjdmodeller testas en modell som tagit fram genom en så kallad B-spline interpolation av laserdata. Detta för att undersöka om Lantmäteriets modeller duger för att göra de hydrologiska beräkningar som krävs för att identifiera bäckar och diken. För att evaluera noggrannheten på bäckarna mäts ett antal bäckar och diken in under olika terräng- och vegetationstyper mot vilka en areaavvikelse per meter referensbäck och andelen som ligger under godkänt noggrannhetskrav i plan beräknas. Studien har visat att Lantmäteriets bäcklinjer under tät vegetation, främst barrskog, har en lägre noggrannhet än på öppen mark. Lantmäteriets egna höjdmodeller med 1 meters upplösning har visat sig prestera bäst eller likvärdigt med övriga modeller under dessa förhållanden och genererar bäckar med större noggrannhet än reda karterade bäcklinjer. Dock är metoden beroende av kompletterande information om bäckarnas utformning från till exempel flygfotografier eller fältstudier, eftersom genererade bäckar måste väljas ut manuellt. Detta gör att inga nya bäckar med absolut säkerhet kan lokaliseras med denna metod. Det rekommenderas därför att metoden endast används för att komplettera redan karterade bäckar och diken. / This Master thesis investigated whether digital elevation models, derived from LiDAR data collected by the Swedish mapping and surveying agency, Lantmäteriet, which is a public authority that manages geographic information in Sweden, can be used to map streams and dikes not included in their databases today. Today Lantmäteriet identifies streams and dikes mainly with the photogrammetric methods. The methods works well on open land, but it can be difficult to distinguish smaller streams and ditches covered by dense vegetation. The method used to locate streams and dikes is to calculate flow directions and flow accumulations in the height models. The project tests how the methods are influenced by elevation models with different resolutions and origins. In addition to the national elevation model, a new model interpolated from LiDAR-data was tested, using a so-called B-spline method. This was to find out if the model produced by Lantmäteriet is useful to make the hydrological calculations required to identify streams and dikes. In order to evaluate the accuracy of the streams, a number of reference stretches of streams and dikes were surveyed in areas with different terrain and vegetation types. The area deviation per meter reference stretch and the proportion below approved accuracy was calculated. The results shows that Lantmäteriet’s mapped watercourses under dense vegetation, mainly coniferous forest, have a lower accuracy than on open fields. Lantmäteriet’s height models with 1 meter resolution have been shown to perform best or equivalent to other models under these conditions, and generate broads with greater accuracy than finding marked pelvic lines. However, the method is dependent on supplementary information about the streams distribution from, for example, aerial photographs or field studies, as generated streams must be manually selected. This means that watercourses cannot be mapped accurately with this method. It is therefore recommended that the method should only be used for supplement already mapped streams and dikes.

Les fossés agricoles sont des lieux préférentiels d’écoulement des pesticides à l’échelle du bassin versant depuis les parcelles agricoles vers les masses d’eau avales de surface et souterraines. Du fait de leur capacité de rétention ils sont réputés pouvoir exercer un pouvoir tampon pour limiter la dispersion des pesticides dans l’environnement. Les opérations d’entretien des fossés sont identifiées comme un moyen d’améliorer ce pouvoir tampon. Cependant, la connaissance du pouvoir tampon des fossés en fonction de leurs caractéristiques et de leur entretien est très limitée. L’objectif de ce travail est ainsi de quantifier l’impact des principales pratiques d’entretien sur l’évolution du pouvoir tampon d’une gamme de fossés infiltrants.La démarche suivie repose sur i) une caractérisation expérimentale de l’effet des principales pratiques d’entretien sur l’évolution des propriétés des fossés, ii) une analyse de l’influence de ces propriétés sur deux processus clé modulant la rétention des herbicides : la sorption et l’infiltration, iii) une exploration numérique, conçue sur la base des expérimentations, de l’effet de chaque pratique sur l’évolution annuelle du pouvoir tampon des fossés. Le dispositif expérimental a combiné des observations in situ à l’échelle du fossé élémentaire sur 3 bassins versants et des expérimentations au laboratoire et a concerné l’étude du comportement de 3 herbicides, glyphosate, diuron et isoproturon.Les résultats de ce travail ont mis en évidence que les opérations de brûlis, fauche et désherbage chimique améliorent le pouvoir tampon des fossés par rapport à un fossé non-entretenu alors que le curage le détériore. Ils ont aussi permis d’améliorer notre connaissance des propriétés et de la variabilité des matériaux formant les fossés, de proposer un nouvel indicateur de la capacité de rétention des fossés et d’évaluer des approches de modélisation de la rétention des pesticides par un bief de fossé infiltrant. / By linking cropped fields to downstream groundwater and surface water bodies, farm ditches constitute preferential pathways for pesticide dispersal at the catchment scale. But thanks to their pesticide retention capacity ditches are known for buffering pesticide non-point source pollutions. Ditch management operations were identified as mean to improve ditch buffering capacities. However, little is known about how pesticide retention capacities of ditches vary as a function of ditch properties and management. Accordingly, the objective of this work is to quantify how pesticide retention capacity in a range of infiltrating ditches evolves subsequently to the main management operations.The methodology relies on i) an experimental characterization of the main management operation effects on the evolution of ditch properties, ii) an analysis of how these properties influence two key processes regulating herbicides retention: sorption and infiltration, iii) a numerical exploration, based on the previously mentioned experimentations, of each operation effects on the yearly evolution of pesticide retention capacity of ditches. The experimental design combined in situ observations at the reach scale on 3 catchments as well as laboratory experimentations and concerned the behavior of 3 herbicides, glyphosate, diuron and isoproturon.The results of this works highlighted the fact that burning, mowing and chemical weeding operations increase pesticide retention capacities of the ditches as compared to an unmanaged ditch while dredging deteriorates it. They also allowed us to improve our knowledge on ditch materials properties and variability, to propose a new indicator of ditch retention capacity and to evaluate different modelling approaches of pesticide retention by infiltrating ditches.