The intensification of land-water management due to agriculture, forestry, and urbanization is a global phenomenon increasing the pressure on worlds water resources and threatening water security in North America. The Prairie Pothole Region of North America covers approximately 775,000 km2 and contains millions of wetlands that serve important hydrological and ecological functions. The unique hummocky topography and the variable effect of different processes contribute to high spatio-temporal variability in soil water, posing major challenges in hydrological studies. The objectives of this study were to a) examine the spatial pattern of soil water storage and its scale and location characteristics; and b) to identify its controls at multiple scales. Soil water content at 20 cm intervals down to 140 cm was measured along a transect extending over several knolldepression cycles in a hummocky landscape. High water storage in depressions and low water storage on the knolls created a spatial pattern that was inversely related to elevation. Spatial patterns were strongly similar within any given season (intra-season rank correlation coefficient as high as 0.99), moreso than between the same season over different years (inter-annual rank correlation coefficient as high as 0.97). Less similar spatial patterns were observed between different seasons (inter-season rank correlation coefficients as high as 0.90). While the intra-season and inter-annual spatial patterns were similar at scales >18 m, the inter-season spatial patterns were similar at much large scales (>72 m). This may be due to the variations in landform elements and micro-topography. The similarity at scales >72 m were present at any time and depth. However, small- and medium-scale spatial patterns changed with depth and with season due to a change in the hydrological processes. The relative dominance of a given set of processes operating both within a season and for the same season over different years yielded strong intra-season and inter-annual similarity at scales >18 m. Moreover, similarity was stronger with increasing depth, and was thought to be due to the dampening effect of overlying soil layers that are more dynamic. Similarity of spatial patterns over time helps to identify the location that best represents the field averaged soil water and improves sampling efficiency. Change in the similarity of scales of spatial pattern helps identify the change in sampling domain as controlled by hydrological processes. The scale information can be used to improve prediction for use in environmental management and modeling of different surface and subsurface hydrological processes. The similarity of spatial pattern between the surface and subsurface layers help make inferences on deep layer hydrological processes as well as groundwater dynamics from surface water measurements.

The intensification of land-water management due to agriculture, forestry, and urbanization is a global phenomenon increasing the pressure on worlds water resources and threatening water security in North America. The Prairie Pothole Region of North America covers approximately 775,000 km2 and contains millions of wetlands that serve important hydrological and ecological functions. The unique hummocky topography and the variable effect of different processes contribute to high spatio-temporal variability in soil water, posing major challenges in hydrological studies. The objectives of this study were to a) examine the spatial pattern of soil water storage and its scale and location characteristics; and b) to identify its controls at multiple scales. Soil water content at 20 cm intervals down to 140 cm was measured along a transect extending over several knolldepression cycles in a hummocky landscape. High water storage in depressions and low water storage on the knolls created a spatial pattern that was inversely related to elevation. Spatial patterns were strongly similar within any given season (intra-season rank correlation coefficient as high as 0.99), moreso than between the same season over different years (inter-annual rank correlation coefficient as high as 0.97). Less similar spatial patterns were observed between different seasons (inter-season rank correlation coefficients as high as 0.90). While the intra-season and inter-annual spatial patterns were similar at scales >18 m, the inter-season spatial patterns were similar at much large scales (>72 m). This may be due to the variations in landform elements and micro-topography. The similarity at scales >72 m were present at any time and depth. However, small- and medium-scale spatial patterns changed with depth and with season due to a change in the hydrological processes. The relative dominance of a given set of processes operating both within a season and for the same season over different years yielded strong intra-season and inter-annual similarity at scales >18 m. Moreover, similarity was stronger with increasing depth, and was thought to be due to the dampening effect of overlying soil layers that are more dynamic. Similarity of spatial patterns over time helps to identify the location that best represents the field averaged soil water and improves sampling efficiency. Change in the similarity of scales of spatial pattern helps identify the change in sampling domain as controlled by hydrological processes. The scale information can be used to improve prediction for use in environmental management and modeling of different surface and subsurface hydrological processes. The similarity of spatial pattern between the surface and subsurface layers help make inferences on deep layer hydrological processes as well as groundwater dynamics from surface water measurements.

Tillage erosion is the dominant soil erosion process in hummocky landscapes. The topsoil lost from the convex upper slope positions (i.e., hilltops knolls, ridges) gradually makes its way to the concave lower slope positions (i.e., foot slopes, toe slopes/depressions), while reducing yield capability in the knolls. The accumulation of topsoil in the concave lower slope positions does not increase yield potential. Landscape restoration is a process by which organic-rich topsoil is removed from lower slope positions and is moved to the knoll positions where it is applied and incorporated as additional topsoil. Field studies on this matter have shown increases in crop yield productivity due to land restoration on the convex upper slope positions. Using a model developed in STELLA ®, this research examines the net monetary benefit of landscape restoration in specific landscape scenarios modeled after areas in Manitoba which are prone to tillage erosion. This study demonstrates that farming operations in hummocky landscapes, experiencing topsoil loss at knolls benefit from landscape restoration as it can lead to positive net returns. In this study, the research shows that landscape restoration, in the Rural Municipality of Lorne (South Western Manitoba), led to revenues greater than restoration costs for arable land used for agricultural purposes. Depending on soil conditions and tillage choices the payback period for landscape restoration ranged from 8 to 18 years.

Tillage erosion is the dominant soil erosion process in hummocky landscapes. The topsoil lost from the convex upper slope positions (i.e., hilltops knolls, ridges) gradually makes its way to the concave lower slope positions (i.e., foot slopes, toe slopes/depressions), while reducing yield capability in the knolls. The accumulation of topsoil in the concave lower slope positions does not increase yield potential. Landscape restoration is a process by which organic-rich topsoil is removed from lower slope positions and is moved to the knoll positions where it is applied and incorporated as additional topsoil. Field studies on this matter have shown increases in crop yield productivity due to land restoration on the convex upper slope positions. Using a model developed in STELLA ®, this research examines the net monetary benefit of landscape restoration in specific landscape scenarios modeled after areas in Manitoba which are prone to tillage erosion. This study demonstrates that farming operations in hummocky landscapes, experiencing topsoil loss at knolls benefit from landscape restoration as it can lead to positive net returns. In this study, the research shows that landscape restoration, in the Rural Municipality of Lorne (South Western Manitoba), led to revenues greater than restoration costs for arable land used for agricultural purposes. Depending on soil conditions and tillage choices the payback period for landscape restoration ranged from 8 to 18 years.