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Title Vandforsyning i Ikamiut, Grønland
Author Gunnarsdottir, Ragnhildur (Institut for Byggeri og Anlæg, Danmarks Tekniske Universitet, DTU, DK-2800 Kgs. Lyngby, Denmark)
Institution Technical University of Denmark, DTU, DK-2800 Kgs. Lyngby, Denmark
Thesis level Master's thesis
Year 2007
Abstract Ikamiut er en bygd i Qasigiannguit kommune som består af byen Qasigiannguit og bygden Ikamiut, hvor der bor 80 mennesker. Ikamiuts drikkevand haves fra en elv som ligger i en afstand på lidt over 3 km uden for byden. Elven er en del af et vandsystem, som består af to søer, et sumpområde og elven. Inde i bygden står der en vandtank på ca. 930 m3 som bliver fyldt op i sommerperioden og vandet herfra bruges i vinterperioden. Bygden har derfor kun vandtankens volumen til rådighed om vinteren. Elven fryser til i september-oktober og tøer op igen i maj-juni, hvilket gør at tapningsperioden kun ligger på omkring 3 måneder. De fleste beboere i Ikamiut er tilsluttet sommervand men de har ønsker om at få helårsvandforsyning. Ligeledes er der en fiskefabrik i bygden som kun er tilstluttet sommervand og den har også ønsket at få helårsvandforsyning da det ønskes at udvide produktionen. Servicehuset er det eneste hus i bygden som har helårsvandforsyning. Nukissiorfiit har derfor ønsket at få det undersøgt om tapningsperioden kan forlænges ved at flytte drikkevandsindtaget fra elven til den større af de to søer; Naajannguit Tasiat; og om den har kapacitet til at forsyne bygden og fiskefabrikken hele året. Som et ekstra tillæg til Nukissiorfiits ønsker om projektets formål, er muligheden for etablering af en brønd i Ikamiuts nærmeste område blevet undersøgt. Under feltarbejde i Ikamiut i juni 2006 blev der udtaget vandprøver fra 13 forskellige lokaliteter i Ikamiut. Analyser på vandet viste at det var meget blødt og pH lå under 7 i alle tilfælde. Hvad angår ionkoncentrationer så lignede alle vandprøver nærmest destilleret vand. Der blev også udtaget jordprøver fra udvalgte lokaliteter til en eventuel brøndinstallation. Sigteanalyser på jordprøverne viste at prøverne enten var ringe sorteret eller usorteret og områderne til alle prøveboringer var præget af klipper samt mosser og lyng. Der strømmede vand frem i alle prøveborginer og vandkvalitet var god i alle tilfælde. Ud fra de meget grove basisanalyser på jordprøverne virker alle lokaliteter lige gode hvad angår jordforhold. Der skal dog udføres en mere nøjagtig analyse på jordforhol m.m. inden det kan besluttes hvilken en a lokaliteterne ville være bedst egnet til brøndinstallation. Ud fra bygdens vandværksjournal blev et gennemsnitligt enhedsforbrug beregnet. For at få en idé om hvor stort vandforbruget kunne blive hvis bygden fik helårsvandforsyning blev der lavet en analyse på vandforbruget i bygden. Den viste at forbruget er væsentlig større om sommeren på grund af fiskefabrikkens produktion og sommervandet, som de fleste beboere er tilsluttet. Det blev antaget at forbrugsvanerne i vinterperioden kommer til at ligne det som de gør i dag i sommerperioden hvis bygden for helårsvandforsyning. På baggrund af den antagelse blev et gennemsnitligt enhedsforburg for sommerperioderne beregnet og det tal blev efterførlgende brugt til at estimere det årlige vandforburg i Ikamiut hvis bygden fik helårsvandforysning. Kapacitetsberegning af Naajannguit Tasiat viste at den har volumen nok til at forsyne bygden i tilfælde af helårsvandforsyning. En beregning på den gennemsnitlige årlige tilstrømning til søen fra hele oplandet viste, at den er en faktor 10 større en det estimerede vandforbrug i Ikamiut, i tilfælde af helårsvandforsyning. Da overfladearealet af de to søer vurderes at være sikre størrelser, blev tilstrømning til Naajannguit Tasiat baseret på de to søers overfladeareal udelukkende ligeledes beregnet. Denne tilstrømning viste sig at være næsten dobbelt så stor som det estimerede årlige vandforbrug i tilfælde af helårsvandforsyning. Det blev derfor konkluderet at Naajannguit Tasiat har stor nok forsyningskapacitet til at forsyne Ikamiut året rundt.
Abstract Ikamiut is a village in the municipality of Qasigiannguit, which consists of the town Qasigiannguit and Ikamiut, where there are 80 inhabitants. Ikamiut´s drinking water resource is a river which is located about 3 km outside the village. The river runs from the lake Naajannguit Tasiat and runs through a swamp. The lake Naajannguit Tasiat is also conncted to a smaller lake, Qulleq. There is a watertankt in the village, with a volume of approx. 930 m3, which is filled in the sommer. The water from the tank is used in the winter. The river freezes in September-October and thaws in May-June, and therefore, the period of tapping is short; only 3 months. Most of the inhabitants are connected to the so called "summer water" (Danish: Sommervand) but they wish to get a year-around-water supply. There is also a fish plant in the village which today has "summer water", but they want to extend their production which requires a bigger water usage. The common house is the only house in the village that has a year-around-water supply. Nukissiorfiit (Greenland´s Energy Supply) has therefore wished for it to be investigated, if the drinking water intake can be moved from the river to the bigger one of the two lakes; Naajannguit Tasiat, and if it has the capacity to supply the village and the fish plant the whole year. The possibility for establishing a well in the surrounding parts of the village were also investigated. During the field work in Ikamtiu, June 24.-30. 2006, watersamples were taken from 13 different loclaities. Analysis shoed that the water was very soft and pH was below 7 in all cases. Ionconcentrations in the watersamples where very low, in fact the water was almost distilled. Soilsamples were also taken from the chosen well-localities. Sieve analysis showed that the soilsamples were either poorly sorted or not sorted. The localities were all characterized by rocks and heather. Water flowed into all of the drillings and the water quality was good in all cases. Based on the basic analysis on soilsamples, the localities ssem to be equally good concering soil conditions. More prcise analysis is though needed in order to decide which one of them would be most suitable for establishing a well. Based on the log from the villages waterworks, an average unit-consumption (L/(inhabitant*day)) was calculated. To get an idea of how big the consumption would be if the village got a year-around-water supply, the consumption in the village was analysed. It showed that the consumption is much bigger in the summer than in the winter because of the production in the fish plant and the "summer water". It was presumed that if the village got a year-around-water supply, the consumption in the winter wold be similar to the summer-consumption. Then, an average unit-consumption for the summers was calculated, and that value was used to estimate the yearly water consumption in Ikatit, in case of a year-around-water suppply. A calculation of the capacity of Naajannguit Tasiat showed that it has a big enough volume to supply the village if it had a year-around-water supply. Still, it is not enought to calculate the volume of the lake; the yearly inflow from the catchment area has to be calculated too, since the inflow has to be bigger than the average consumption in the village. A calculation of the yearly averae inflow from Naajannguit Tasiat´s catchment area showed that it was about 10 times bigger than the estimated yearly consumption in Ikamiut in case a year-around-water supply. Since the surface area of the two lakes are more precise sizes than the catchment area, the inflow to Naajannguit Tasiat based on the two lakes´surface area only, was also calculated. The result was that this inflow was almost twice as big as the estimated yearly consumption in Ikamiut in case of year-around-water supply. The conclusion was therefore, that Naajannguit Tasiat has the capacity to supply Ikamiut the whole year through.
Imprint Technical University of Denmark (DTU) : Kgs. Lyngby, Denmark
Pages 163
Keywords Vandforsyning; Grønland; Søvand; Vandkvalitet; Drikkevand
Admin Creation date: 2008-05-14    Update date: 2009-10-29    Source: dtu    ID: 220289    Original MXD