Riparian systems are comprised of interacting aquatic and terrestrial elements that contribute distinctively to the natural capital of arid landscapes. Riparian vegetation is a major component of riparian systems, providing the ecosystem services required to support watershed health. The spatial and temporal distributions of riparian vegetation are influenced by hydrologic and disturbance processes operating at scales from local to regional. I believe both these processes are well suited to monitoring using synoptic and multitemporal approaches.The research in this dissertation is presented as 3 related studies. The first study focused on historical riparian dynamics related to natural disturbance and land use. Using current and historical riparian vegetation maps, we examined vegetation change within catchments of varying land use intensity. Results suggest that land use activities and wastewater subsidy affect the rate of development and diversity of riparian community typesThe second study used moderate resolution satellite imagery to monitor changes in riparian structure and pattern within a land cover change framework. We classified Landsat Thematic Mapper satellite imagery of the Upper Santa Cruz River watershed using Classification and Regression Tree (CART) models. We tested the ability of our models to capture change at landscape, floodplain, and catchment scales, centering our change detection efforts on a riparian tree die-off episode and found they can be used to describe both general landscape dynamics and disturbance-related riparian change.The third study examined historical and environmental factors contributing to spatial patterns of vegetation following two riparian tree die-offs. We used high resolution aerial imagery to map locations of individual live and dead trees and collected a suite of environmental variables and historical variables related directly and indirectly to land use and disturbance history. We tested for differences between groups of live and dead trees using Multi-response Permutation Procedures and found strong relationships between historical factors and mortality incidence.The results from these studies demonstrate the importance of examining historical information and spatial linkages across scales when monitoring riparian vegetation. From a land management perspective, the results identify the need for landscape-level, ecosystem-based management programs to maintain functioning and spatially connected riparian systems.

This project analyzes satellite images from 1976, 1985 and 2000 of Dutse, Jigawa state, in north-western Nigeria. The analyzed satellite images were used to determine land-use and vegetation changes that have occurred in the land-use from 1976 to 2000 will help recommend possible planning measures in order to protect the vegetation from further deterioration. Studying land-use change in north-western Nigeria is essential for analyzing various ecological and developmental consequences over time. The north-western region of Nigeria is of great environmental and economic importance having land cover rich in agricultural production and livestock grazing. The increase of population over time has affected the land-use and hence agricultural and livestock production. On completion of this project, the possible land use changes that have taken place in Dutse will be analyzed for future recommendation. The use of supervised classification and change detection of satellite images have produced an economic way to quantify different types of landuse and changes that has occurred over time. The percentage difference in land-use between 1976 and 2000 was 37%, which is considered to be high land-use change within the period of study. The result in this project is being used to propose planning strategies that could help in planning sustainable land-use and diversity in Dutse.

Land use/land cover (LULC) change and variations in precipitation can alter the quantity and quality of freshwater flows. The Mission-Aransas (M-A) estuary depends on inputs of freshwater and material from streams in order to maintain its ecological integrity. Freshwater inflow estimates for the M-A estuary have been established, but no analyses using scenarios of LULC change and precipitation variability have been conducted that inform how freshwater inflows could be impacted. A land change analysis for the M-A region was conducted by classifying two Landsat images for the years 1990 and 2010. A large degree of LULC change occurred within the M-A region during this time; with 27.1% of the land area experiencing LULC change. Furthermore, developed land increased by 44.9%. A SWAT hydrological model was developed to model the quantity and quality of freshwater inflows. SWAT was calibrated at a monthly scale using data from a stream gage. Model evaluations indicated that the model had a good performance rating with a Nash-Sutcliffe model efficiency coefficient (NS) of 0.66 and coefficient of determination (R2) of 0.66 for the calibration period; and an NS of 0.76 and R2 of 0.78 for the validation period. Three LULC change scenarios and three precipitation scenarios were developed to be used in a scenario analysis with the calibrated SWAT model. Each LULC change scenario represents a different amount of developed land (3.4, 3.7, and 4.7% of watershed area). Precipitation data was analyzed to select weather data for each precipitation scenario that each had different amounts of annual precipitation (763, 907, and 996 mm). A scenario analysis was conducted that analyzed how stream/channel flows and loads of sediment, total nitrogen, and total phosphorus were impacted under scenario conditions. A general increase in all output variables was exhibited as the amount of precipitation and developed land increased; with impacts from precipitation variability outweighing impacts from varying amounts of developed land. Furthermore, sediment loads were the variable most impacted by differing amounts of developed land. This study provides information on how LULC and precipitation can influence watershed hydrology that can be used in watershed management for the M-A region.

Water is the most important resource on Earth. Climate and land cover changes are two important factors that directly influenced water resources. This research provides important information for water resources management and contributes on understanding of the responses of water resources to climate and land cover changes in two different climates. The Neches River watershed located in a humid subtropical climate had a 0.7 °C increase in temperature and a 16.3 % increase in precipitation. Developed and crop land covers increased whereas vegetation cover decreased, as a result of human activities. Hydrologic responses to climate and land cover changes resulted in the increases of surface runoff (15.0 %), soil water content (2.7 %), evapotranspiration (20.1 %), and a decrease of groundwater discharge (9.2 %). Surface runoff had an increasing trend with precipitation whereas soil water content was sensitive to changes in land cover, especially human intervention. The Canadian River watershed, a semi-arid watershed, experienced a 0.9 °C increase in temperature and a 10.9 % decrease in precipitation. Land cover was converted from developed and crop lands into barren land and grass covers, as a result of the decrease in human activity. The change of grass and forest covers into bush/shrub cover is thought to be linked to climate change. Surface runoff, groundwater discharge, soil water content, and evapotranspiration were all decreased by 10.2 %, 10.0 %, 7.7 %, and 9.4%, respectively. Hydrologic parameters generally follow similar patterns to that of precipitation. The trend in water resources followed a similar trend of precipitation for the two watersheds with different climates; a humid watershed and a semi-arid watershed. The humid climate watershed, the Neches River watershed, experienced increasing trends in temperature and precipitation. Groundwater discharge was sensitive to changes in land cover caused by human activities. The semi-arid watershed, the Canadian River watershed, had an increase in precipitation and a decrease in precipitation. Conversion of developed and crop land covers into barren and grass land covers was thought to be the result of the decrease in human activity. The volume of soil water was relatively offset by a combination of precipitation changes and land-cover changes.

Many protected areas around the world face degradation in the face of poverty, maladapted agricultural practices and population growth in their surroundings. This research uses a multidisciplinary approach to study this complex problem in the context of a montane ecosystem. The study area comprises Ngel Nyaki and Kurmin Danko Forest Reserves on the Mambilla Plateau in Eastern Nigeria and the surrounding landscape, comprising pastoral lands, farmland, villages and homesteads. Ongoing degradation of the Forest Reserves through their illegal use as grazing areas by the local Fulani pastoralists indicates that the exclusionary protection of the forest is not working. It may be that a participatory forestry approach to conservation would be more successful. The research presented in this thesis uses a variety of methods (interviews, remote sensing, geographic information systems (GIS) and ecological monitoring) to evaluate the current situation in the study area with the aim of determining the likelihood of such a participatory approach to conservation being successful. Satellite images from the years 1988, 2000 and 2009 were used to quantify changes in forest cover to measure deforestation and regeneration rates. Interviews were used to understand the Fulani's pastoral management systems, land ownership status, cattle movements and living situation. Data from interviews and observations as well as from satellite imagery were combined in a GIS to approximate stocking rates and property boundaries and to identify the level of livelihood diversification the different Fulani families have undergone. As grass and water availability have been identified as the main environmental factors determining grazing and cattle movements, environmental data was collected to determine changes in the rates of grass productivity and streamflow over the course of one dry season. The study found that the extent of natural forest is decreasing all over the study area, on privately owned properties, commonly owned properties and in the Forest Reserves. Evidence of human impacts such as charred grassland by late burning and cattle tracks were clearly visible throughout the reserves, with the exception of the core forest area, indicating ongoing intensive use and management of the reserve for cattle grazing. The stocking rates in dry and wet seasons have been found likely to exceed carrying capacities, which results in overgrazing and a reduction in vegetation cover. The Fulani in the study area have already undergone a transition from relying purely on livestock and livestock products to relying on a mix of livestock, agriculture and silviculture. This transition shows potential for forest transition according to the 'forest transition theory', which, supported by the right policy incentives could be transformed into landscape scale conservation of endemic flora and fauna. xii Biomass productivity and water availability in wet and dry seasons were found to be highly asymmetric, which seriously restricts the number of suitable cattle management systems. Data indicate that tall riverine vegetation may have effects on stream water availability during the dry season. The findings of this section point to the need of carefully reassessing the current management of tall riverine vegetation on the Mambilla plateau, also in view of the sustainability of the water supply for pastoral livelihoods.

The purpose of this research is to investigate mesoscale-equivalent temperatures (TE) in Kentucky and potential land cover influences. Kentucky presents a unique opportunity to perform a study of this kind because of the observational infrastructure provided by the Kentucky Mesonet (www.kymesonet.org). This network maintains 65 research-grade, in-situ weather and climate observing stations across the Commonwealth. Equivalent temperatures were calculated utilizing high-quality observations from 33 of these stations. In addition, the Kentucky Mesonet offers higher spatial and temporal resolution than previous research on this topic. As expected, the differences (TE-T) were greatest in summer (smallest in winter), with an average of 35 ºC (5 ºC). In general, the differences were found to be largest in the western climate division. This is attributed to poorly drained land and the mesonet stations’ adjacency to agricultural land. These differences are smaller during periods of drought, signifying less influence of moisture. Additionally, an inverse relationship between TE and pressure deviation on a daily timescale was found, suggesting a synoptic influence on near-surface heat content.

The major objective of this thesis was to produce descriptions of the land vegetation-cover in Europe for selected time windows of the Holocene (6000, 3000, 500, 200, and 50 calendar years before present (BP=1950)) that can be used in climate modelling. Land vegetation is part of the climate system; its changes influence climate through biogeophysical and biogeochemical processes. Land use such as deforestation is one of the external forcings of climate change.  Reliable descriptions of vegetation cover in the past are needed to study land cover-climate interactions and understand the possible effects of present and future land-use changes on future climate. We tested and applied the REVEALS (Regional Estimates of VEgetation Abundance from Large Sites) model to estimate past vegetation in percentage cover over Europe using pollen records from lake sediments and peat bogs. The model corrects for the biases of pollen data due to intraspecific differences in pollen productivity and pollen dispersion and deposition in lakes and bogs. For the land-cover reconstructions in Europe and the Baltic Sea catchment we used 636 (grouped by 1˚x1˚ grid cells) and 339 (grouped by biogeographical regions) pollen records, respectively. The REVEALS reconstructions were performed for 25 tree, shrub and herb taxa. The grid-based REVEALS reconstructions were then interpolated using a set of statistical spatial models. We show that the choice of input parameters for the REVEALS application does not affect the ranking of the REVEALS estimates significantly, except when entomophilous taxa are included. We demonstrate that pollen data from multiple small sites provide REVEALS estimates that are comparable to those obtained with pollen data from large lakes, however with larger error estimates. The distance between the small sites does not influence the results significantly as long as the sites are at a sufficient distance from vegetation zone boundaries. The REVEALS estimates of open land for Europe and the Baltic Sea catchment indicate that the degree of landscape openness during the Holocene was significantly higher than previously interpreted from pollen percentages. The relationship between Pinus and Picea and between evergreen and summer-green taxa may also differ strongly whether it is based on REVEALS percentage cover or pollen percentages. These results provide entirely new insights on Holocene vegetation history and help understanding questions related to resource management by humans and biodiversity in the past. The statistical spatial models provide for the first time pollen-based descriptions of past land cover that can be used in climate modelling and studies of land cover-climate interactions in the past.

Rapid urban growth and unprecedented rural to urban transition, along with a huge population growth are new phenomena for both high and low income countries, which started in the mid-20th century. However, urban growth rates and patterns are different in developed countries and developing ones. In less developed countries, urbanization and rural to urban transition usually takes place in an unmanaged way and they are associated with a series of socioeconomical and environmental issues and problems. Identification of the city growth trends in past decades can help urban planners and managers to minimize these negative impacts. In this research, urban growth in the city of Isfahan, Iran, is the subject of study. Isfahan the third largest city in Iran has experienced a huge urban growth and population boom during the last three decades. This transition led to the destruction of natural and agricultural lands and environmental pollutions. Historical and recent remotely sensed data, along with different remote sensing techniques and methods have been used by researchers for urban land use and land cover change detection. In this study three Landsat TM and ETM+ images of the study site, acquired in 1985, 2000 and 2009 are used. Before starting processing, radiometric normalization is done to minimize the atmospheric effects. Then, processing methods including principal component analysis (PCA), vegetation indices and supervised classification are implemented on the images. Accuracy assessment of the PCA method showed that the first PC was responsible for more than 81% of the total variance, and therefore used for analysis of PCA differencing. ΔPC1t1-t2 shows the amount of changes in land use and land cover during the period of study. In this study ten vegetation indices were selected to be applied to the 1985 image. Accuracy assessments showed that Transformed Differencing Vegetation Index (TDVI) is the most sensitive and accurate index for mapping vegetation in arid and semi-arid urban areas. Hence, TDVI was applied to the 2000 and 2009 images. ΔTDVIt1-t2 showed the changes in land use and land cover especially the land use transformation from vegetation cover into the urban class. Supervised classification is the last method applied to the images. Training sites were assigned for the selected classes and accuracy was monitored during the process of training site selection. The results of classification show the expansion of urban class and diminishment in natural and agricultural lands.

This dissertation investigates selected empirical and theoretical aspects of land-use and land-cover change (LUCC) in exurban areas. Two challenges – observation and monitoring of LUCC, and spatially explicit modeling, are addressed using three main approaches – measuring, reviewing and agent-based modeling (ABM). All of these approaches focus on LUCC at the individual household level, investigating how micro-scale elements interact to influence macro-scale functional patterns—bottom-up analysis. First, the temporal change of the quantity and pattern of land-cover types within exurban residential parcels in three townships in the southeastern Michigan is examined using landscape metrics and local indicators of spatial association at the parcel and parcel-neighborhood level respectively. The results demonstrate that the number and area of exurban residential parcels increased steadily from 1960 to 2000, and different land-cover types have distinctive temporal changes over time. The results also indicate that there is a convergence process at the neighborhood level through which the quantity and pattern of land cover in parcels conform with the neighborhood appearance. Second, 51 urban residential choice models based on ABM are reviewed. The results divide these models into three categories (i.e. models based on classical theories, models focusing on different stages of urbanization process; and integrated ABM and microsimulation models). This review also compares the differences among these models in their representations of three essential features brought by the technique of ABM: agent heterogeneity, the land market and output measurement. Challenges in incorporating these features, such as the trade-off between the simplicity and abstraction of model and the complexity of urban residential system, interactions of multiple features and demands for data at individual level, are also discussed. Third, the effects of agent heterogeneity on spatial and socioeconomic outcomes under different levels of land-market representations are explored through three experiments using a stylized agent-based land-market model. The results reveal that budget heterogeneity has prominent effects on socioeconomic outcomes, while preference heterogeneity is highly pertinent to spatial outcomes. The relationship between agent heterogeneity and macro-measures becomes more complex as more land-market mechanisms are represented. The results also imply that land-market representation (e.g., competitive bidding) is indispensable to reproduce the results of classical urban land market models (e.g., monocentric city model) in a spatial ABM when agents are heterogeneous.

Movement of growth faults, a type of normal fault which is formed during sedimentation and is characterized by having greater vertical thickness on the downthrown fault side, on barrier islands contributes to wetland losses. The opening objective of this study was to quantify land cover change within a Matagorda, Texas wetland that results from sea level rise and elevation change over time due to coastal faulting. The closing objective of this study was to simulate land cover conversion as a function of relative sea level rise (RSLR) within the wetland and to compare and contrast the impact of specific rates of both fault-induced elevation change and predicted International Panel on Climate Change (IPCC) sea level rise projections. To accomplish these objectives a time series of aerial images was classified using automated unsupervised classification and hand digitization. After classification, total wetland losses on both the upthrown and downthrown sides of the fault were evaluated as a function of spatial distance from the fault plane. This classified product was draped over a digital elevation model (DEM) layer to evaluate elevations of land cover classes and model potential future outcomes based on RSLR. Classification results show that while wetland loss occurred on both sides of the fault, losses were far more extensive on the downthrown side. It was concluded that this vertical fault movement impacts wetland losses, especially on the downthrown side. Modeling results show that rapid water level rise can force wetland land cover class conversion regardless of whether this relative rise is caused by vertical fault displacement or eustatic sea level rise, resulting in the destruction of vital wetland areas. Current recorded conditions of sea level rise along the Texas Gulf Coast leave a grim outlook for regions similar to this study area.