The understanding of how different parts of a landscape contribute to streamflow by storing and releasing water has long been a central issue in hydrology. Knowledge about what controls streamflow dynamics across landscapes can further our understanding of how catchments store and release water, facilitate predictions for ungauged catchments, and improve the management of water quality and resources. This thesis makes use of data from the Krycklan catchment in northern Sweden. Streamflow data from 14 catchments (0.12 - 68 km2) with variable landscape characteristics such as topography, vegetation, wetland cover, glacial till soils and deeper sediment soils were used to investigate spatial patterns and controls on runoff. The differences in specific discharge (discharge per unit catchment area) between nearby catchments were large at the annual scale, and have the same magnitude as predicted effects of a century of climate change or the observed effects of major forestry operations. This variability is important to consider when studying the effects of climate change and land use changes on streamflow, as well as for our understanding of geochemical mass balances. Streamflow from different catchments was strongly related to landscape characteristics. The distribution of wetland areas had a particularly strong influence, with an annual specific discharge 40-80% higher than catchments with high tree volume on till soils. During drier periods, catchments with deeper sediment soils at the lower elevations of Krycklan had a higher base flow compared to both forested till and wetland catchments. This pattern was reversed at high flows. The storages releasing water to streams in downstream sediment areas were able to maintain base flow for longer periods and were less influenced by evapotranspiration compared to the more superficial till and wetland systems. The results of this thesis have led to a better understanding of the landscape wide patterns of streamflow during different seasons and time scales. The strong associations to landscape characteristics and variable spatial patterns with season and antecedent conditions form the basis for a conceptual understanding of the processes and spatial patterns that shape the heterogeneity of streamflow responses in boreal catchments. / Hur olika delar av landskapet påverkar vattenbalansen och bidrar till avrinning har länge varit en central fråga inom hydrologin. Kunskap om vad som styr avrinningsdynamiken i ett landskap kan öka vår förståelse av hur olika delar av landskapet bidrar till avrinning, hur avrinningsområden lagrar vatten och bildar avrinning, underlätta prognoser för avrinningsområden utan vattenföringsmätningar och förbättra hanteringen av vattenkvaliteten och vattenresurser. Denna avhandling använder data från Krycklans avrinningsområde i norra Sverige. Vattenföringsdata från 14 delavrinningsområden (0.12 - 68 km2) med olika landskapskarakteristik såsom topografi, vegetation och jordarter, användes för att undersöka rumsliga mönster hos avrinningen över olika tidsperioder samt hur landskapet påverkar variabiliteten. Skillnaderna i specifik avrinning (avrinning per areaenhet) mellan närliggande avrinningsområden var stor för årliga värden, och är i samma storleksordning som effekterna av stora skogsavverkningar samt av förutspådda effekter av det kommande seklets förväntade klimatförändringar. Denna variation är viktig att ta hänsyn till när man studerar hur klimatförändringar och ändrad markanvändning påverkar avrinningen, liksom för vår förståelse av geokemiska massbalanser. Avrinning från olika områden var starkt relaterad till deras landskapsegenskaper. Förekomsten av våtmarker hade ett särskilt starkt inflytande. Områden med en stor andel våtmarker hade 40-80% högre årlig specifik avrinning än områden med hög trädvolym på moränjordar. Under torrare perioder hade områden med djupare sedimentjordar hög avrinning jämfört med både områden med skog på morän och med våtmarker. Under höga flöden var detta mönster omvänt. De vattenlager som bidrar till avrinning i sedimentområden kan upprätthålla basflöde under längre tidsperioder och påverkas mindre av evapotranspirationen än de ytligare flödessystemen i morän och våtmarker. Avhandlingen har givit en bättre förståelse av avrinningens rumsliga variation under olika årstider och i olika tidsskalor. Det starka sambandet mellan landskapskarakteristik och avrinningens varierande mönster under olika årstider och lagringsförhållanden utgör en grund för en begreppsmässig förståelse av de processer och rumsliga mönster som skapar heterogeniteten i flödesrespons i boreala områden.

The objectives of this research are to measure the aquifer properties (S, T, and K) of selected watersheds delineated to the U.S. Geological Survey gauging stations using streamflow recession and baseflow data and to describe the relations among the properties of shallow aquifers and the physical properties of the basins, such as slope, regolith type and thickness, and land use type. Geographic Information System (GIS) techniques are utilized to investigate critical physiographic controls on transmissivity and storage coefficients on a regional basis. Moreover, the effect of evapotranspiration on recession index is illustrated. Finally, a detailed quantitative comparison of results for the Piedmont and the Blue Ridge Physiographic Provinces in southeast of the U.S. is provided. Recession index, annual groundwater recharge, and annual baseflow data were obtained from 44 USGS-gauging stations with drainage areas larger than 2 (mi2) and less than 400 (mi2). These gauging stations are located in Georgia and North Carolina. Analyses of data focused on GIS techniques to estimate watershed parameters such as total stream length, drainage density, groundwater slope, and aquifer half-width. The hydraulic diffusivity, transmissivity, and storage coefficient of watersheds were computed using hydrograph techniques and the Olmsted and Hely, and Rorabaugh mathematical models. Median recession index values for the Blue Ridge and Piedmont Provinces are 87.8 and 74.5 (d/log cycle), respectively. Median areal diffusivity values for the Blue Ridge and Piedmont are 35,000 and 44,200 (ft2/d), respectively. Median basin-specific estimates of transmissivity for basins in the Blue Ridge and Piedmont are 150 and 410 (ft2/d), respectively. The large values of transmissivity obtained for the Piedmont regolith may be attributed to the thick regolith, low values of basin relief, and voids that develop as a result of fracturing, foliation, weathering, and fractured quartz veins in the saprolite. Median basin-specific estimates of storage coefficient for basins in the Blue Ridge and Piedmont are 0.005 and 0.009, respectively. In general, the results from this study reveal great differences in basin-specific hydraulic parameters of the regolith material within the Piedmont compared to that of the Blue Ridge Physiographic Province.