Relict non-glacial surfaces occur in many formerly glaciated landscapes, where they represent areas that have escaped significant glacial modification. Frequently distinguished by blockfield mantles, relict non-glacial surfaces are important archives of long-term weathering and landscape evolution processes. The aim of this thesis is to examine the distribution, weathering, ages, and formation of relict non-glacial surfaces in the northern Swedish mountains. Mapping of surfaces from aerial photographs and analysis in a GIS revealed five types of relict non-glacial surfaces that reflect differences in surface process types or rates according to elevation, gradient, and bedrock lithology. Clast characteristics and fine matrix granulometry, chemistry, and mineralogy reveal minimal chemical weathering of the blockfields. Terrestrial cosmogenic nuclides were measured in quartz samples from two blockfield-mantled summits and a numerical ice sheet model was applied to account for periods of surface burial beneath ice sheets and nuclide production rate changes attributable to glacial isostasy. Total surface histories for each summit are almost certainly, but not unequivocally, confined to the Quaternary. Maximum modelled erosion rates are as low as 4.0 mm/kyr, which is likely to be near the low extreme for relict non-glacial surfaces in this landscape. The blockfields of the northern Swedish mountains are Quaternary features formed through subsurface physical weathering processes. While there is no need to appeal to Neogene chemical weathering to explain blockfield origins, these surfaces have remained continuously regolith-mantled and non-glacial since their inception. Polygenetic surface histories are therefore indicated, where the large-scale surface morphologies are potentially older than their regolith mantles.

Water and vapour flows from land to sea and the atmosphere are important for water resources, coastal ecosystems and climate. This thesis investigates possible methods for modelling these flows under often encountered unmonitored hydrological conditions and data limitations. Two contrasting types of drainage basin and associated data limitation/availability cases are considered: the Swedish unmonitored near-coastal catchment areas Forsmark and Simpevarp, for which detailed spatial but not much temporal variability data is available; and the much larger Aral Sea Drainage Basin (ASDB), for which spatial hydrological information is limited, while there is relatively well-known temporal change occurring in the Aral Sea itself and in the land and water use of the region over the last 50 years. The hydrologic modelling for the Forsmark and Simpevarp catchment areas showed that the relatively large focused stream flows, and the mean values and total sums of the diffuse small stream-groundwater flow fields in between the large stream flows from land to sea are largely constrained by the catchment hydrological balances and relatively robust and certain to estimate. The ASDB hydrologic modelling indicated an evapotranspiration return flow to the atmosphere from the irrigation water input on irrigated land that is much higher than previous estimates in atmospheric modelling, implying possible considerably larger than previously estimated non-local water and climate effects of the world’s irrigated areas. The more detailed groundwater-seawater dynamics modelling carried out for the coastal parts of the ASDB showed that regional topography and bathymetry largely influence coastal water fluxes during sea level lowering, with the Aral Sea shrinkage decreasing the seawater intrusion risk into the coastal groundwater considerably more for steeper than for flatter coastal topography parts of the region.

This thesis presents a palaeoglaciological study aimed to determine the location, geometry and temporal evolution of palaeo-ice streams of the north-easternmost Laurentide Ice Sheet. The work was accomplished through the geomorphological interpretation of satellite imagery over 3.19 x 106 km2 of the Canadian Arctic, using a glaciological inversion scheme. Ice streams were active in this region during most of the time between the Last Glacial Maximum and the last deglaciation. A web of ice streams and inter-ice stream areas existed. Three major ice stream networks are identified: the M'Clintock Channel, Gulf of Boothia – Lancaster Sound and Hudson Strait. The M'Clintock Channel bears the most complex landform record, comprising three generations of palaeo-ice streams. Their location was weakly controlled by the subglacial topography and their geometry was determined by frozen-bed portions of the ice sheet, thus providing evidence for pure ice streams in the Laurentide Ice Sheet. In contrast, the more pronounced relief of the Gulf of Boothia – Lancaster Sound corridor supported topographically controlled ice streams. The landform record on emerged land along Hudson Strait is insufficient to support the existence of ice streams. It is therefore proposed that ice streams were constrained within the deep parts of the strait while flanked by cold-based zones on the margins. Small transient ice streams on Baffin and Prince of Wales islands drained local remnant ice caps during the collapse of the ice sheet. Analysis of the controls on the location and flow of palaeo-ice streams suggests that the interaction between the subglacial topography and thermal state of the substrate plays a more fundamental role than the geology. It is concluded that the behaviour of ice streams cannot be explained in terms of environmental controls alone, but the complex dynamics of ice stream shear margins and onset zones must be considered.

This thesis investigates how variations in the oxygen isotopic composition of lake waters in northern Fennoscandia are recorded in lake sediment archives, especially diatoms, and how these variations can be used to infer past changes in climate and atmospheric circulation. Results from analyses of the oxygen isotopic composition of lake water samples (δ18Olakew) collected between 2001 and 2006 show that δ18O of northern Fennoscandian lakes is mainly controlled by the isotopic composition of the precipitation (δ18Op). Changes in local δ18Op depend on variations in ambient air temperature and changes in atmospheric circulation that lead to changes in moisture source, vapour transport efficiency, or winter to summer precipitation distribution. This study demonstrates that the amount of isotopic variation in lake water δ18O is determined by a combination of the original δ18Olakew, the amount and timing of the snowmelt, the amount of seasonally specific precipitation and groundwater, any evaporation effects, and lake water residence time. The fact that the same isotope shifts have been detected in various δ18Olakew proxies, derived from hydrologically different lakes, suggests that these records reflect regional atmospheric circulation changes. The results indicate that diatom biogenic silica isotope (δ18Odiatom) records can provide important information about changes in atmospheric circulation that can help explain temperature and precipitation changes during the Holocene. The reconstructed long-term Holocene decreasing δ18Op trend was likely forced by a shift from strong zonal westerly airflow (relatively high δ18Op) in the early Holocene to a more meridional flow pattern (relatively low δ18Op). The large δ18Olakew depletion recorded in the δ18O records around ca. 500 cal yr BP (AD 1450) may be due to a shift to more intense meridional airflow over northern Fennoscandia resulting in an increasing proportion of winter precipitation from the north or southeast. This climate shift probably marks the onset of the so-called Little Ice Age in this region. / At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 1: In press. Paper 2: Submitted. Paper 5: In progress.

The objectives of this thesis are to assess: to what degree have natural resources deteriorated in a grazing area in northern Namibia, how do perceptions of environmental change held by local stakeholders there, correspond to scientific assessments, and how do these relate to national estimates? Analysis of the process of developing national indicators for monitoring of land degradation concluded that specific indicators should be developed on national level, and in some instances even on local level as there are no universal causes of land degradation. According to farmers overgrazing and low rainfall since the early 1990s cause negative environmental changes in the study area, partly confirming findings from national monitoring. Results also suggest that: less grazing outside the study area, improved access, permanent water supply, and fencing of large areas, also contributed. Results show that improved water supply was the most important factor. Investigation of the influence of permanent water points on grazing resources showed that perennial grasses are replaced by less palatable annual grasses as far as 6 km from water points along a water pipeline. No significant grazing induced changes in grass composition were observed around privately owned wells. Private ownership seems to be a key factor preventing over-utilization of grazing resources around the latter. A remote sensing study using Landsat TM imagery identified bare ground, saltpans and grassland with a fair accuracy. Separation of woodland from shrubland and shrubland from grassland was less accurate using supervised classification. The results show that the soil adjusted vegetation index provides valuable information about variations of green biomass over time in semi-arid environments. However, it is suggested that satellite based investigations should be supported by thorough ground based assessment due to the influence of underlying soil in this environment.

För att ta fram vårflodsprognoser används idag en hydrologisk modell, HBVmodellen, som används operationellt både i Sverige och i andra länder för att ta fram tillrinningsprognoser. Ett av problemen med dessa prognoser är dock att de ofta har felaktigheter i beräkning av tillrinningsvolymer. I den här studien undersöks Vängelsjöns delavrinningsområde. Ett prognosområde där HBV-modellens tillrinningsprognos tidigare gett stora volymfel. Rapporten undersöker därför om det går att korrigera den operationella modellens snömängd genom snödjupsobservationer, för att ta fram mer tillförlitliga vårflodsprognoser. I rapporten har snödjupsobservationer och densitetsmätningar från Vattenregleringsföretagen (VRF), tillsammans med snödjupsobservationer från Sveriges meteorologiska och hydrologiska institut (SMHI), analyserats för att se om de kan användas för att förbättra tillrinningsprognosen för Vängelsjöns delavrinningsområde. Studien visar att det finns potential till att använda snödjupsobservationer för att minska osäkerheter i tillrinningsprognosen för Vängelsjöns delavrinningsområde. Det bästa resultatet gavs genom att använda tre stationer från SMHI tillsammans med två stationer från VRF. Resultatet för dessa fem stationer gav ett volymfel i uppmätt vattenekvivalent på 6 %, 7 %, 22 % och 17 % för mars månad perioden 2014-2017, vilket gav en markant förbättring mot det modellerade prognosvärdet med volymfel på 40 %, 77 %, 24 %, och 49 % för samma period. / Today, spring flood forecasts are calculated through a hydrological model, the HBVmodel. It is a model that is used operationally both in Sweden and in other countries to obtain catchment forecasts. One problem with these forecasts is that they often give errors in calculations to the inflow volume. In this study the Vängelsjö sub catchment will be examined. A forecast area where the HBV-model flow forecasting has given large volume errors. In the report it is therefore examined if the operational model can be corrected with snow measurement data. In this report snow depth observations and density measurements from Vattenregleringsföretagen (VRF) have been analyzed, together with snow depth observations from the Swedish Institute for Meteorology and Hydrology (SMHI) to see if the data can be used to improve the forecasting for Vängelsjö sub catchment. The study shows that there is a potential in using snow measurement observations to reduce insecurities in the flow forecast for Vängelsjö sub catchment. The best result was received by using three snow stations from SMHI and two from VRF. The result from those five stations gave a volume error in measured snow water equivalent (SWE) at 6 %, 7 %, 22% and 17 % for Mars during the period 2014-2017, which gave a significant improvement against the modelled forecast value with volume errors of 40 %, 77 %, 24 % and 49 % for the same period.

In this project, we analyse the ability of two regional climate models to simulate meteorological conditions on Nordenskiöldbreen, a glacier in Svalbard. To do so, regional climate model output is compared with in situ measurements from an automatic weather station. Detailed information about the weather conditions on Nordenskiöldbreen is important for simulating the glacial mass balance in a changing climate. The parameters analysed were the following: temperature, air pressure, relative humidity, precipitation, cloud cover, wind speed and wind direction. The weather station did not measure all parameters, cloud cover was instead estimated through the incoming longwave radiation and temperature, while precipitation was calculated from snow depth. The results show that the models represent certain parameters better than others. Temperature, air pressure and wind speed and direction are found to be simulated with high precision. Poorest agreement is found for precipitation, which appears to be both difficult to simulate and observe. Relative humidity and cloud cover show average agreement with the station. The conclusion of the project is that the estimation of some of the parameters is satisfactory, while others are lacking. None of the models can be determined to have performed significantly better than the other. / I det här projektet analyserades två regionala klimatmodellers förmåga att simulera meteorologiska förhållanden på Nordenskiöldbreen, en glaciär på Svalbard. Detta gjordes genom jämförelser av data från regionala klimatmodeller mot lokala mätningar från en automatisk väderstation. Detaljerad information om väderförhållandena på Nordenskiöldbreen är viktigt för att kunna simulera glaciärens massbalans i ett föränderligt klimat. Parametrarna som jämfördes var temperatur, lufttryck, relativ luftfuktighet, nederbörd, molntäcke samt vindhastighet och vindriktning. Stationen mätte inte alla parametrar, molntäcket uppskattades istället genom inkommande långvågig strålning och temperatur, medan nederbörd beräknades via snödjup. Resultatet visar att modellerna representerar vissa parametrar bättre än andra. Temperatur, lufttryck, vindhastighet och vindriktning simuleras med hög precision. Parametern med lägst samband är nederbörd, somverkar vara svår både att simulera och observera. Relativ luftfuktighet och molntäcke har ett medelmåttigt samband till stationen. Slutsatsen av projektet är att modellernas uppskattning av några parametrar är tillräckligt bra, medan andra är bristfälliga. Ingen av modellerna kan bedömas ha presterat signifikant bättre än den andra.

I dagsläget finns ett stort behov av exploatering för nya bostäder och förtätning i många svenska städer. Bra boende - och livsmiljöer innefattar ofta en närhet till grönområden. Utanverken i Kristianstad, Skåne län, är ett grönområde med höga natur - och kulturvärden. Omkring området planeras en stor exploatering av bostäder vilket betyder att grönområdet är viktigt för staden. Genom grönområden kan olika upplevelsekaraktärer upplevas och olika kulturella ekosystemtjänster tas ut. Dessa karaktärer och tjänster är en viktig hälsoaspekt för människan. För att ta reda på vilka upplevelsekaraktärer och kulturella ekosystemtjänster som upplevs och utnyttjas av de boende omkring undersökningsområdet idag genomfördes en enkätundersökning. Resultatet visar att det finns karaktärer och tjänster som upplevs och utnyttjas mer än andra. Däremot finns det meningsskiljaktigheter kring utveckling av undersökningsområdet mellan olika grupper av de boende. För att tillgodose dagens och framtidens invånares önskningar bör det alltid föras en dialog mellan beslutsfattare och invånare. Vid planering av grönområden bör det även tas i beaktande över vilka funktioner dessa bör innehålla för att främja speciella upplevelsekaraktärer och kulturella ekosystemtjänster för skapandet av bra boendemiljöer i urbana områden.

Despite being one of the most productive ecosystems on earth, wetland areas have been heavily affected by human activities. The Cienaga Grande de Santa Marta (CGSM) in Colombia is one of these wetlands, where the inadequate construction of roads modified the hydrology and connectivity of this water body, generating massive mangrove mortality episodes. The lack of knowledge on the hydrological processes and connectivity of the CGSM has impaired mangrove restoration plans. Here we use wetland interferometry technique to remotely monitor the wetland and understand the flow of water in/out and across the CGSM wetland complex. A close collaboration with Miami University allowed us to access CGSM’s interferograms created with ALOS Palsar satellite data (from 2007 until 2011). The interferograms resulting from the analysis were correlated with daily hydrological data (precipitation, runoff in the main inflow of freshwater to the wetland, tide charts) to finally identify two main paths of inflow of water that are still active and are continuously feeding freshwater into the Cienaga. The most persistent was identified in the south-west part of the CGSM; a water flow coming directly from the Magdalena River and entering the main lagoon in its south-west corner. The second was located in the north-west area, where most of the mangroves have died. In this case, different interferograms showed different potential water flow paths depending on the season (dry / wet season), the Magdalena River’s discharge and the rainfall. These results reflect the complex hydrology of the CGSM . Furthermore, a coherence analysis was conducted to assess the quality of the remote sensing data and to better understand the different responses of the features within the Cienaga. The results showed that the coherence analysis could also be potentially used to identify areas of dead mangrove. This study confirms that despite the blockage of the connectivity of the wetlands, there are still important freshwater flow paths feeding the CGSM. Additional hydrological studies are needed to ensure the further understanding of the hydrology of the CGSM and confirm the results of this study.

Increasing attention is being given to acid sulphate soils wherever they occur. The problems that leaching sulphate soils gives with significant lowerings of pH and mobilization of heavy metals influence large spectra of our society from fisheries to agriculture to construction. Mapping these soils is consequently of great importance and the methods of doing this is very much lacking in function and precision. This study was therefore carried out to investigate whether conductivity in running water can be used as a simple instrument to identify acid sulphate soils in the catchment. 31 coastal streams in the county of Västerbotten were analyzed for different catchment properties such as occurence of marine sediments and basic water chemistry including conductivity and sulphate. Sulphate proved to be the dominant factor controling conductivity in most streams, constituting up to 90 % of the anions. The results also showed that the concentrations of sulphate correlated to 67 % with marine sediments in the catchment. Where conductivity values exceeded 90 µS/cm the influence of acid sulphate soils could be determined for certain. The major conclusion drawn from this study is that high conductivity values serves as a reliable indicator of leaching acid sulphate soils whereas lower values can not exclude them. / flisik