Hydraulic & Design Parameters in Full-Scale Constructed Wetland & Treatment Units: Six Case Studies

The efficiency of pond and constructed wetland (CW) treatment systems, is influenced by the internal hydrodynamics and mixing interactions between water and aquatic vegetation. In order to contribute to current knowledge of how emergent real vegetation affects solute mixing, and on what the shape and size effects are on the mixing characteristics, an understanding and quantification of those physical processes and interactions was evaluated. This paper presents results from tracer tests conducted during 2015-2016 in six full-scale systems in the UK under different flow regimes, operational depths, shapes and sizes, and in-/outlet configurations. The aim is to quantify the hydraulic performance and mixing characteristics of the treatment units, and to investigate the effect of size and shape on the mixing processes. Relative comparison of outlet configuration, inflow conditions, and internal features between the six different treatment units showed variations in residence times of up to a factor of 3. A key outcome of this study, demonstrated that the width is a more important dimension for the efficiency of the unit compared to the depth. Results underlined the importance of investigating hydrodynamics and physics of flow in full-size units to enhance treatment efficiency and predictions of water quality models

A Genome-Wide Association Study of Diabetic Kidney Disease in Subjects With Type 2 Diabetes

dentification of sequence variants robustly associated with predisposition to diabetic kidney disease (DKD) has the potential to provide insights into the pathophysiological mechanisms responsible. We conducted a genome-wide association study (GWAS) of DKD in type 2 diabetes (T2D) using eight complementary dichotomous and quantitative DKD phenotypes: the principal dichotomous analysis involved 5,717 T2D subjects, 3,345 with DKD. Promising association signals were evaluated in up to 26,827 subjects with T2D (12,710 with DKD). A combined T1D+T2D GWAS was performed using complementary data available for subjects with T1D, which, with replication samples, involved up to 40,340 subjects with diabetes (18,582 with DKD). Analysis of specific DKD phenotypes identified a novel signal near GABRR1 (rs9942471, P = 4.5 x 10(-8)) associated with microalbuminuria in European T2D case subjects. However, no replication of this signal was observed in Asian subjects with T2D or in the equivalent T1D analysis. There was only limited support, in this substantially enlarged analysis, for association at previously reported DKD signals, except for those at UMOD and PRKAG2, both associated with estimated glomerular filtration rate. We conclude that, despite challenges in addressing phenotypic heterogeneity, access to increased sample sizes will continue to provide more robust inference regarding risk variant discovery for DKD.Peer reviewe

Implementation of automatic sensors for continuous monitoring of runoff quantity and quality in small catchments

Development of new automatic sensor-based techniques has expanded the possibilities for intensive monitoring of water quality in small catchments. In this study turbidity and concentration of nitrate-N were monitored with probes in the Savijoki catchment, which has been observed with traditional methods for decades. Particular attention was paid to implementation of the equipment, calibration of the probes and calculation methods. All equipment functioned technically well during the one year monitoring period. Calibration of turbidity and nitrate-N proved that the sampled values agree well with the probe results. However, it seems that loading estimates made with the traditional method are not very reliable for individual years. The research period in this study was exceptional with its many runoff peaks in winter. It is not possible to catch the peaks with traditional monitoring, why the results and comparisons between automatic probes and traditional monitoring cannot be generalized. However, the results proved that novel monitoring techniques have to be continued and extended. In further studies the calculation methods need developed and improved to be to get reliable loading estimations from the sensor data as simply as possible. In a changing climate, the monitoring, loading estimations, and consequently the assessment of the effect of agricultural water protection measures will probably turn even more difficult and challenging.;Lewis, J. 1996. Turbidity-controlled suspended sedimentsampling for runoff-even load estimation. Water Resources research 32: 22992310. Mustonen, S. 1965. Hydrologic investigations by the Board of Agriculture during the years 1957 to 1964. Helsinki. 144 p. Puustinen M, Koskiaho J. & Peltonen K. 2005. Influence of cultivation methods on suspended solids and phosphorus concentrations in surface runoff on clayey sloped fields in boreal climate. Agriculture, Ecosystems and Environment 105: 565579. Puustinen, M., Tattari, S., Koskiaho, J. & Linjama, J. 2007. Influence of seasonal and annual hydrological variations on erosion and phosphorus transport from arable areas in Finland. Soil & Tillage Research 93: 4455. Rekolainen, S. 1993. Assessment and mitigation of agricultural water pollution. Publications of the Water and Environment Research Institute 12. National Board of Waters and Environment, Helsinki, Finland. 34 p. Seuna, P. 1983. Small basins a tool in scientific and operational hydrology. Publications of the Water Research Institute 51. National Board of Waters, Finland. 61 p. Turtola, E. 1999. Phosphorus losses in surface runoff and drainage water affected by cultivation practices. Academic Dissertation. University of Helsinki. 47 p. Valkama, P., Lahti, K. & Särkelä, A., 2007. Automated water quality monitoring in the river Lepsämänjoki. Terra 119: 195206. Vehviläinen, B. & Huttunen, M. 2002. The Finnish watershed simulation and forecasting system (WSFS). Proceedings of the XXIst Conference of the Danubian countries on the hydrological forecasting and hydrological bases of water management. Bucharest-Romania. 26 September 2002. Vuorenmaa, J., Rekolainen, S., Lepistö, A., Kenttämies, K. & Kauppila, P., 2002. Losses of nitrogen and phosphorus from agricultural and forest areas in Finland during the 1980s and 1990s. Environmental Monitoring and Assessment. 76: 213248. SELOSTUS Jatkuvatoimisten antureiden soveltuvuus veden määrän ja laadun seurantaan pienillä valuma-alueilla Jarmo Linjama, Markku Puustinen, Jari Koskiaho, Sirkka Tattari, Helmi Kotilainen ja Kirsti Granlund Suomen ympäristökeskus Automaattisten antureiden viimeaikainen kehittyminen on avannut uusia mahdollisuuksia pienten valuma-alueiden monitorointiin. Tässä tutkimuksessa kymmenien vuosien ajan seuratulle valuma-alueelle, Savijoelle, asennettiin sameus- ja nitraattianturi ja tehtiin kuormituslaskenta sekä antureiden tulosten perusteella että perinteiseen harvaan näytteenottoon perustuvin menetelmin. Huomiota kiinnitettiin erityisesti laitteiden asentamiseen ja antureiden kalibrointiin. Huolellisen asentamisen jälkeen laitteet toimivat vuoden mittaisen havaintojakson ajan teknisesti moitteettomasti. Sameuden ja nitraattikäyrien kalibrointi vesinäytteiden perusteella osoitti, että vesinäytteiden ja anturidatan vastaavuus on erittäin hyvä. Alustavien tulosten mukaan perinteiseen seurantaan perustuva kuormitusarvio ei ole yksittäisten vuosien osalta kovin luotettava. Tämän tutkimuksen seurantavuosi oli kuitenkin poikkeuksellinen useiden talviaikaisten valuntapiikkien vuoksi, joita harvan, perinteisen seurannan vesinäytteet eivät olisi tavoittaneet. Tässä esitettyä automaattiantureiden ja vesinäytteiden tuloksiin perustuvaa kuormituslukujen vertailua ei voida yleistää. Tulos kuitenkin osoittaa, että tämänkaltaista monitorointia on tärkeä jatkaa ja laajentaa. Jatkotutkimuksissa huomiota tulee kiinnittää laskentamenetelmien kehittämiseen, erityisesti siihen, kuinka anturiaineistosta päästään mahdollisimman yksinkertaisesti luotettaviin kuormitusarvioihin. Ilmaston muuttuessa valuma-alueiden seuranta ja kuormitusarviointi ovat todennäköisesti entistä vaativampia ja maatalouden vesiensuojelutoimenpiteiden vaikutusten havaitseminen myös entistä haasteellisempaa

Reduced tillage: Influence on erosion and nutrient losses in a clayey field in southern

Reduced tillage was compared with traditional ploughing in terms of erosion and phosphorus (P) and nitrogen (N) losses in an experimental field in southern Finland. One part of the field has been ploughed (treatment PF) and the other part harrowed (treatment NPF) every autumn since 1986. Flow volume and water quality data was collected separately from surface runoff and subsurface drainage waters during 1991-1995 (surface runoff volume since 1993). Erosion was higher in PF (on average 234 kg ha-1yr-1 in drainage flow and 479 kg ha-1 yr-1 in surface runoff) than in NPF (158 kg ha-1yr-1 in drainage flow and 160 kg ha-1yr-1 in surface runoff). Total N loss in drainage flow was also higher in PF (7.2 kg ha-1yr-1) than in NPF (4.6 kg ha-1yr-1). Total P losses did not differ muchAurattoman viljelyn ja perinteisen syyskynnön vaikutuksia eroosioon sekä typen ja fosforin huuhtoutumiseen verrattiin eteläsuomalaisella, savimaalla sijaitsevalla koekentällä. Vaikka koe aloitettiin jo syksyllä 1986, tässä artikkelissa esitetään lähinnä vuosien 1991-1995 tuloksia. Koekenttä oli jaettu kahteen lähes samansuuruiseen lohkoon, joista toinen kynnettiin 25 cm syvyyteen ja toinen äestettiin lapiorullaäkeellä 5 cm syvyyteen joka syksy.Eroosio oli suurempi kynnetyltä lohkolta (keskimäärin 234 kg ha-1 v-1 salaojavalunnassa ja 479 kg ha-1 v-1 pintavalunnassa) kuin kyntämättömältä (keskimäärin 158 kg ha-1 v-1 salaojavalunnassa ja 160 kg ha-1 v-1 pintavalunnassa). Niinikään typpihuuhtoumat olivat suurempia kynnetyltä lohkolta, josta kokonaistyppeä huuhtoutui salaojavalunnassa keskimäärin 7,2 kg ha-1 v-1, kun vastaava määrä kyntämättömältä lohkolta oli 4,6 kg ha-1 v-1. Kokonaisfosforihuuhtoumissa ei havaittu eroa lohkojen välillä: huuhtoutunut määrä oli molemmilta lohkoilta osapuilleen 0,7 kg ha-1 v-1. Ero havaittiin sen sijaan liuenneen reaktiivisen fosforin huuhtoumissa, jotka olivat kyntämättömältä lohkolta selvästi suuremmat, esim. pintavalunnassa keskimäärin 0,21 kg ha-1 v-1, kun kynnetyltä lohkolta huuhtoutui vastaavasti 0,05 kg ha-1 v-1. Tulokset vahvistavat aiempia käsityksiä aurattoman viljelyn eduista eroosion ja nitraattihuuhtoumien vähentämisessä. Ympäristölle koituvaa hyötyä kuitenkin vähentää liuenneen ja samalla leville suoraan käyttökelpoisen fosforin kuormituksen kasvu, jolla on vesistöjä rehevöittävä vaikutus

Retention performance and hydraulic design of constructed wetlands treating runoff waters from arable land

Abstract Agriculture is the main source of nitrogen (N) and phosphorus (P), which are the nutrients accelerating the eutrophication of waters in Finland. Hence, mitigation measures are needed to reduce the nutrient loading from the arable land. Since Finland's accession to the EU in 1995 and the subsequent adaptation to its agri-environmental policy, constructed wetlands (CWs) have been one of the mitigation measures for which farmers may receive agri-environmental subsidies. The aim of this study was to find out how efficiently such CWs are able to retain the loading and how they should be designed and dimensioned in order to optimize their performance. Particular attention was paid to CW hydrology and hydraulics, since the dynamics of the water flowing through a CW is the major factor governing retention. Water quality and flow measurements were made in three CWs located in agricultural watersheds in southern Finland during 1999-2002. Hydraulic properties were examined in 2 of the CWs by simulations with 2-dimensional hydrodynamic and water quality models. According to the calculations of material fluxes, the maximum annual retention was 72% for solid material (TSS), 67% for total P and 40% for total N. The lowest retentions were slightly negative, because the CW with the smallest CW-to-watershed area ratio (0.5% in the Alastaro CW) sometimes acted rather as a source than a sink of nutrients. The highest percent retentions were found in the Hovi CW with the largest CW-to-watershed area ratio (5%). In terms of mass per CW area, the Hovi CW retained 25 kg of total P and 300 kg of total N per one hectare per one year. In the Hovi CW also dissolved reactive P retention was high (49% in situ and 34% in laboratory microcosm experiments), obviously due to high contents and low P saturation of Al and Fe oxides of the CW soil. The basic underlying reason behind the high retentions of both dissolved nutrients and particulate matter in the Hovi CW was the long water residence time coupled with high hydraulic efficiency. In the deep part of the Hovi CW, near-bottom increase of dissolved O2 was found in phase with diurnal temperature changes. The oxygen transport by this kind of convective circulation of CW water inhibited near-bottom anoxia and thus decreased the risk of P desorption. According to the hydrodynamic simulations coupled with simulated tracer tests made for the Hovi CW, a 40% improvement in hydraulic efficiency was achieved by baffles directing the main flow to optimally exploit the CW area. The rectangular, elongated shape of the Alastaro CW also showed fairly high hydraulic efficiency. Hydrodynamic simulations were also coupled with a sediment transport model, which proved to be a useful method in predicting the change of TSS concentrations in CWs. Hourly datasets of inflow and outflow revealed high attenuation of runoff peaks in the well-designed and -dimensioned Hovi CW. The hourly outflow modeled with the reservoir routing method corresponded to the observed with a reasonable accuracy. When carefully designed, painstakingly implemented and wisely located, CWs may – even in cold climate – efficiently contribute to agricultural water pollution control

Małe sztuczne zbiorniki wodne w krajobrazie rolniczym Finlandii: ochrona jakości wody na tle wielozadaniowych funkcji tych zbiorników i aspektów socjalno-ekonomicznych

This case study summarizes the current knowledge in Finland on the efficiency of constructed wetlands to improve water quality at the same time providing multiple benefits. The efficiency is highly dependent on the wetland's relative size compared to the upstream catchment area, and on the amount of agricultural land in the upstream catchment. The case study analyses the incentives designed to motivate landowners to construct wetlands in Finland such as the non-productive investment support and the agri-environment payment support for wetland management. Farmers think that the support system is heavy and bureaucratic, and thus the target number of new constructed wetlands is far from being met. Individual projects have been more successful in wetland construction than the official support system. General wetland plans drafted for hotspot areas is an example of enabling factors and strict eligibility rules form one of the barriers of wetland construction identified in this case study. In spite of the criticism of the current wetland incentives, a support system for wetland construction is needed. One option would be to give regional authorities more freedom to select priority areas according to e.g. River Basin Management Plans.Artykuł stanowi podsumowanie stanu wiedzy w Finlandii na temat wielofunkcyjności niewielkich sztucznych zbiorników wodnych, w tym szczególnie poprawy jakości wody. Efektywność takich zbiorników w ochronie wód w dużym stopniu zależy od stosunku wielkości tych akwenów do obszaru zlewni bezpośredniej i wielkości powierzchni użytkowanej przez rolnictwo w tej zlewni. Badania obejmowały analizę takich czynników, jak pomoc w planowaniu i organizacji lub udzielanie wsparcia finansowego w ramach programów rolnośrodowiskowych w motywowaniu rolników do budowy niewielkich zbiorników wodnych (ang. "constructed wetlands") na cele ochrony jakości wody na terenach rolniczych. Farmerzy uważają, że system wsparcia jest zbyt zbiurokratyzowany i dlatego liczba nowych zbiorników jest dużo mniejsza od spodziewanych. Indywidualne projekty podejmowane z inicjatywy rolników są dużo efektywniejsze w stosunku do oficjalnego wsparcia. Ogólnokrajowe plany skierowane głównie na obszary "hot spots" są przykładem jednej z barier ograniczających szerokie zastosowanie małych zbiorników do ochrony jakości wody. Mimo dość krytycznej oceny, oficjalny system wsparcia jest jednak niezbędny. Szersze zastosowanie niewielkich zbiorników wodnych do ograniczenia zagrożeń wody w wyniku dopływu zanieczyszczeń z obszarów użytkowanych rolniczo wymaga zwiększenia uprawnień władz lokalnych do typowania obszarów, na których celowa jest budowa tego typu urządzeń. Zadania związane z budową zbiorników do oczyszczania wody powinny być uwzględniane w zlewniowych planach gospodarowania wodą

Testing a river basin model with sensitivity analysis and autocalibration for an agricultural catchment in SW Finland

Modeling tools are needed to assess (i) the amounts of loading from agricultural sources to water bodies as well as (ii) the alternative management options in varying climatic conditions. These days, the implementation of Water Framework Directive (WFD) has put totally new requirements also for modeling approaches. The physically based models are commonly not operational and thus the usability of these models is restricted for a few selected catchments. But the rewarding feature of these process-based models is an option to study the effect of protection measures on a catchment scale and, up to a certain point, a possibility to upscale the results. In this study, the parameterization of the SWAT model was developed in terms of discharge dynamics and nutrient loads, and a sensitivity analysis regarding discharge and sediment concentration was made. The SWAT modeling exercise was carried out for a 2nd order catchment (Yläneenjoki, 233 km2) of the Eurajoki river basin in southwestern Finland. The Yläneenjoki catchment has been intensively monitored during the last 14 years. Hence, there was enough background information available for both parameter setup and calibration. In addition to load estimates, SWAT also offers possibility to assess the effects of various agricultural management actions like fertilization, tillage practices, choice of cultivated plants, buffer strips, sedimentation ponds and constructed wetlands (CWs) on loading. Moreover, information on local agricultural practices and the implemented and planned protective measures were readily available thanks to aware farmers and active authorities. Here, we studied how CWs can reduce the nutrient load at the outlet of the Yläneenjoki river basin. The results suggested that sensitivity analysis and autocalibration tools incorporated in the model are useful by pointing out the most influential parameters, and that flow dynamics and annual loading values can be modeled with reasonable accuracy with SWAT. Sensitivity analysis thus showed the parameters which should be known better in order to result in more realistic parameter values. Moreover, the scenario runs for CWs made with SWAT revealed the high demand of land area for this protective measure to be substantially effective.;Mallityökalut ovat osoittaneet tarpeellisuutensa arvioitaessamuun muassa maatalouden aiheuttamaa ravinnekuormaa ja vesiensuojelumenetelmien tehokkuutta. Erityisesti Vesipuitedirektiivin (VPD) täytäntöönpanon myötä mallinnustyölle on asetettu konkreettisia haasteita mallitulosten luotettavuuden suhteen. VPD:n puitteissa tarve soveltaa malleja laajoille alueille on myös kasvanut, vaikka perinteisesti prosessipohjaisia malleja on enimmäkseen sovellettu yksittäisillä valuma-alueilla. Vesiensuojelumenetelmien tehokkuuden arvioinnissa prosessipohjaiset mallit ovat avainasemassa, mutta tulosten yleistäminen yhdeltä valuma-alueelta toiselle on edelleen vaikeaa. Tässä tutkimuksessa parametrisoitiin prosessipohjainen SWAT -malli Yläneenjoen valuma-alueelle, joka edustaa tyypillistä lounaissuomalaista maatalousvaltaista aluetta. Yläneenjoen vedenlaatua on seurattu jo pitkään ja havaintojen määrä on riittävä sekä mallisovelluksen luomiseen että kalibrointiin. Lisäksi alueen viljelykäytännöt ja toteutettujen vesiensuojelutoimenpiteiden määrä ovat hyvin tiedossa. Aiempien tutkimusten perusteella mallista valittiin kolmekymmentä parametria, joille herkkyysanalyysi tehtiin. Näin tunnistettiin tärkeimpiin tulosmuuttujiin, virtaamaan ja sedimenttikuormaan, vaikuttavat parametrit. Virtaaman osalta herkimmät parametrit liittyivät pohja- ja pintavesivaluntaa, haihduntaa ja lumen sulamista kuvaaviin prosesseihin, kun taas vastaavasti sedimenttikuormaa selittivät uomaprosesseja ja eroosion kulkeutumista valuma-alueelta kuvaavat parametrit. Tätä tietoa hyödynnettiin mallin kalibroinnissa Rakennetulla SWAT -sovelluksella arvioitiin joen ainevirtaamaan muutoksia sekä tarkasteltiin kosteikkojen vaikutusta jokiveden laatuun. Tulokset osoittivat, että herkkyysanalyysin perusteella mallin kalibrointia voitiin selvästi tehostaa. Parametrivirityksellä saatiin simuloitu virtausdynamiikka ja ainevirtaamat vastaamaan paremmin mitattuja, tosin ainevirtaamien osalta havaintojen vähäinen määrä rajoitti vertailua. Ainehuuhtoumien kalibroinnissa kannattaakin useimmiten pitää lähtökohtana vuotuisia arvoja, koska pitoisuushavaintoihin sisältyy lukuisia epävarmuustekijöitä, joita mallissa on usein mahdotonta ottaa huomioon. Kosteikkosimulointien perusteella voidaan todeta, että merkittävien (n. 20 %) kuormitusvähenemien aikaansaamiseksi kosteikkopinta-alaa tarvittaisiin huomattavan paljon, satoja hehtaareja. Tämä johtuu siitä, että ollakseen tehokas yksittäisen kosteikon tulee olla yläpuoliseen valuma-alueeseensa nähden suuri (n. 2 % tai enemmän). Simulaatioajojen perusteella tuntuvakaan kosteikkojen lukumäärän lisäys ei auta, jos niiden mitoitus on riittämätön. Suuresta pinta-alavaatimuksesta johtuen ei ole realistista laskea vesiensuojelua rakennettavien kosteikkojen varaan, vaan pikemminkin nähdä ne osana laajaa toimenpidevalikoimaa kokonaisvaltaisessa vesiensuojelun suunnittelussa. Rakennettavien kosteikkojen etuna ovat useat kuormitusvähenemien ohessa saatavat lisähyödyt, kuten maiseman elävöityminen ja luonnon monimuotoisuuden, erityisesti linnuston, lisääntyminen, jotka lisäävät kiinnostusta paikallisen väestön keskuudessa

Reduced tillage: Influence on erosion and nutrient losses in a clayey field in southern

Reduced tillage was compared with traditional ploughing in terms of erosion and phosphorus (P) and nitrogen (N) losses in an experimental field in southern Finland. One part of the field has been ploughed (treatment PF) and the other part harrowed (treatment NPF) every autumn since 1986. Flow volume and water quality data was collected separately from surface runoff and subsurface drainage waters during 1991-1995 (surface runoff volume since 1993). Erosion was higher in PF (on average 234 kg ha-1yr-1 in drainage flow and 479 kg ha-1 yr-1 in surface runoff) than in NPF (158 kg ha-1yr-1 in drainage flow and 160 kg ha-1yr-1 in surface runoff). Total N loss in drainage flow was also higher in PF (7.2 kg ha-1yr-1) than in NPF (4.6 kg ha-1yr-1). Total P losses did not differ muc