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GIS och statistik vid dräneringsområdesvis kväveläckagebeskrivning i Halland

Wickberg, Jimmy (2000) In Lunds universitets Naturgeografiska institution - Seminarieuppsatser
Dept of Physical Geography and Ecosystem Science
Abstract
The last decades have shown increased nitrogen leeching from soil to water recipients. This is in
Sweden mainly due to over-manuring of agriculture land, effectivization of drainage systems and the
declining extent of wetlands. The accumulated amount of nitrogen in water doesn’t only make it
unsuitable for use by humans and cattle, but also decreases the biological diversity as well as negatively
affect tourism and fish industry. In the most severe cases shallow maritime grounds can be completely
depleted of oxygen due to decomposition of the increased amount algae and plankton growth.
This study have the aim to describe and quantify the nitrogen leeching from the Genevad drainage
basin, located in southern Halland, Sweden. The... (More)
The last decades have shown increased nitrogen leeching from soil to water recipients. This is in
Sweden mainly due to over-manuring of agriculture land, effectivization of drainage systems and the
declining extent of wetlands. The accumulated amount of nitrogen in water doesn’t only make it
unsuitable for use by humans and cattle, but also decreases the biological diversity as well as negatively
affect tourism and fish industry. In the most severe cases shallow maritime grounds can be completely
depleted of oxygen due to decomposition of the increased amount algae and plankton growth.
This study have the aim to describe and quantify the nitrogen leeching from the Genevad drainage
basin, located in southern Halland, Sweden. The drainage basin (202.5 km2) has been found to be of
particular interesting nature for nitrogen leeching studies. There are several spatially interesting
combinations of soil and land use with different nitrogen leeching characteristics. Also the lack of any
significant point-source of nitrogen within the area is valuable. Use of IR-color air photography scanned
at high resolution (2.5m) enabled accurate area assessments of land use, evaluated with use of
differentiated GPS. Field samples of nitrogen, conductivity, pH and discharge flow have been collected
from two different field visits. One field examination before the start of the agricultural season in
March, and another field examination during the pre-summer season in May. Additional efforts were
also made to investigate the relationship between two measured variables; nitrogen and conductivity in
water-streams.
The results show that soil and land use has significant impact on nitrogen leeching. There were also
notable variations in the nitrogen leaching pattern between the samples from March and May. The
investigation of the relationship between nitrogen and conductivity showed significant and very strong
correlation for both March and May samples as well as all samples pooled together. The daily nitrogen
load from the drainage basin was calculated to 920 kg N/day in March and 320 kg N/day in May. With
use of the significant correlation equation and cluster analysis the generalized average nitrogen load was
calculated to >0-3 kg N/ha year from woodlands on unsorted moraine, 1-8 kg N/ha year from
woodlands on sorted moraine and 20-40 kg N/ha year for open and pasture lands on clay soils.
A general conclusion is that the results from the observed nitrogen load and leeching pattern proved that
the study area follows the established norm from other similar studies regarding soil and land use. It
was also proved by the results from the statistical investigation that during particular biogeochemical
circumstances the conductivity of stream water might be strongly correlated to the concentration of
dissolved nitrogen. Remote sensing, statistics and GIS were used as valuable tools for gathering,
analyzing and handling large amounts of spatial information with high accuracy and integration. (Less)
Please use this url to cite or link to this publication:
author
Wickberg, Jimmy
supervisor
organization
year
type
H1 - Master's Degree (One Year)
subject
keywords
geomorphology, physical geography, geographical information systems, nitrogen leeching, remote sensing, land use, fjärranalys, markanvändning, cartography, pedology, naturgeografi, climatology, geomorfologi, marklära, kartografi, klimatologi
publication/series
Lunds universitets Naturgeografiska institution - Seminarieuppsatser
report number
65
language
Swedish
id
1332894
date added to LUP
2005-10-31 00:00:00
date last changed
2011-07-04 11:26:21
@misc{1332894,
  abstract     = {The last decades have shown increased nitrogen leeching from soil to water recipients. This is in
Sweden mainly due to over-manuring of agriculture land, effectivization of drainage systems and the
declining extent of wetlands. The accumulated amount of nitrogen in water doesn’t only make it
unsuitable for use by humans and cattle, but also decreases the biological diversity as well as negatively
affect tourism and fish industry. In the most severe cases shallow maritime grounds can be completely
depleted of oxygen due to decomposition of the increased amount algae and plankton growth.
This study have the aim to describe and quantify the nitrogen leeching from the Genevad drainage
basin, located in southern Halland, Sweden. The drainage basin (202.5 km2) has been found to be of
particular interesting nature for nitrogen leeching studies. There are several spatially interesting
combinations of soil and land use with different nitrogen leeching characteristics. Also the lack of any
significant point-source of nitrogen within the area is valuable. Use of IR-color air photography scanned
at high resolution (2.5m) enabled accurate area assessments of land use, evaluated with use of
differentiated GPS. Field samples of nitrogen, conductivity, pH and discharge flow have been collected
from two different field visits. One field examination before the start of the agricultural season in
March, and another field examination during the pre-summer season in May. Additional efforts were
also made to investigate the relationship between two measured variables; nitrogen and conductivity in
water-streams.
The results show that soil and land use has significant impact on nitrogen leeching. There were also
notable variations in the nitrogen leaching pattern between the samples from March and May. The
investigation of the relationship between nitrogen and conductivity showed significant and very strong
correlation for both March and May samples as well as all samples pooled together. The daily nitrogen
load from the drainage basin was calculated to 920 kg N/day in March and 320 kg N/day in May. With
use of the significant correlation equation and cluster analysis the generalized average nitrogen load was
calculated to >0-3 kg N/ha year from woodlands on unsorted moraine, 1-8 kg N/ha year from
woodlands on sorted moraine and 20-40 kg N/ha year for open and pasture lands on clay soils.
A general conclusion is that the results from the observed nitrogen load and leeching pattern proved that
the study area follows the established norm from other similar studies regarding soil and land use. It
was also proved by the results from the statistical investigation that during particular biogeochemical
circumstances the conductivity of stream water might be strongly correlated to the concentration of
dissolved nitrogen. Remote sensing, statistics and GIS were used as valuable tools for gathering,
analyzing and handling large amounts of spatial information with high accuracy and integration.},
  author       = {Wickberg, Jimmy},
  keyword      = {geomorphology,physical geography,geographical information systems,nitrogen leeching,remote sensing,land use,fjärranalys,markanvändning,cartography,pedology,naturgeografi,climatology,geomorfologi,marklära,kartografi,klimatologi},
  language     = {swe},
  note         = {Student Paper},
  series       = {Lunds universitets Naturgeografiska institution - Seminarieuppsatser},
  title        = {GIS och statistik vid dräneringsområdesvis kväveläckagebeskrivning i Halland},
  year         = {2000},
}