Social and Behavioral Sciences Commons^™

Reconstructing Late Holocene Fire, Agriculture, And Climate From Sediment Records In Costa Rica And The Dominican Republic, Erik Nicholas Johanson

Doctoral Dissertations

We use multiple proxies from sediment cores to identify periods of climate stress during the late Holocene across the circum-Caribbean region and to determine how fire activity and signals of Pre-Columbian agriculture coincide with these arid periods. We examine evidence of aridity from stable carbon isotope ratios and shifts in elemental composition, along with pollen and microscopic charcoal, at Bao Bog in the highlands of Hispaniola. We infer two major periods of aridity (3600–2300 and 1040–850 cal yr BP), with the later period associated with the late phase of the Terminal Classic Drought. A third, less marked interval of aridity …

Using Gis To Detect Land Use Changes In The Salinas River Valley From 2001 And 2011, Brian Strukan

Capstone Projects and Master's Theses

The use of a Geographic Information System (GIS) to explore, analyze, and interpret our environment is a relatively new technology with exciting new advances emerging each day. GIS can be used along with satellite imagery to detect changes on Earth’s surface (Delavar, 2015). With the human population growing rapidly, it has become very important to monitor when, where, and how we are changing the planet. Using the theory of land economics, coupled with land classification maps from 2001 and 2011, I will explain how cities are changing in the Salinas River Valley, a prime agricultural zone in central California. Are …

Uncertainty Analysis Of The Performance Of A System Of Best Management Practices For Achieving Phosphorus Load Reduction To Surface Waters, Jason D.M. Igras

Electronic Thesis and Dissertation Repository

The repeated occurrence of Lake Erie’s harmful algal blooms suggests an inadequate phosphorus management system that results in excessive loads to the lake. In response, Canadian and United States’ governments have issued a new management objective, a 40% reduction in total and dissolved reactive phosphorus loads relative to 2008. To provide scientific evidence to guide managers toward achieving their management objective, we used the International Organization of Standardization (ISO) 31010 Bowtie Risk Analysis Tool to analyze the performance of the phosphorus management system. The effectiveness of agricultural best management practices (BMPs) and their adoption were combined into a Bayesian belief …

Reconciling Agriculture, Carbon And Biodiversity In A Savannah Transformation Frontier, Lyndon Estes, T. Searchinger, M. Spiegel, D. Tian, S. Sichinga, M. Mwale, L. Kehoe, T. Kuemmerle, A. Berven, N. Chaney, J. Sheffield, E. F. Wood, K. K. Caylor

Geography

Rapidly rising populations and likely increases in incomes in sub-Saharan Africa make tens of millions of hectares of cropland expansion nearly inevitable, even with large increases in crop yields. Much of that expansion is likely to occur in higher rainfall savannas, with substantial costs to biodiversity and carbon storage. Zambia presents an acute example of this challenge, with an expected tripling of population by 2050, good potential to expand maize and soya bean production, and large areas of relatively undisturbed miombo woodland and associated habitat types of high biodiversity value. Here, we present a new model designed to explore the …

Evaluation Of The Uav-Based Multispectral Imagery And Its Application For Crop Intra-Field Nitrogen Monitoring And Yield Prediction In Ontario, Yang Song

Electronic Thesis and Dissertation Repository

Unmanned Aerial Vehicle (UAV) has the capability of acquiring high spatial and temporal resolution images. This new technology fills the data gap between satellite and ground survey in agriculture. In addition, UAV-based crop monitoring and methods are new challenge of remote sensing application in agriculture.

First, in my thesis the potential of UAV-based imagery was investigated to monitor spatial and temporal variation of crop status in comparison with RapidEye. The correlation between red-edge indices and LAI and biomass are higher for UAV-based imagery than that of RapidEye. Secondly, the nitrogen weight and yield in wheat was predicted using the UAV-based …

Farmer Perceptions Of Climate Change: Associations With Observed Temperature And Precipitation Trends, Irrigation, And Climate Beliefs, Meredith T. Niles, Nathaniel D. Mueller

College of Agriculture and Life Sciences Faculty Publications

How individuals perceive climate change is linked to whether individuals support climate policies and whether they alter their own climate-related behaviors, yet climate perceptions may be influenced by many factors beyond local shifts in weather. Infrastructure designed to control or regulate natural resources may serve as an important lens through which people experience climate, and thus may influence perceptions. Likewise, perceptions may be influenced by personal beliefs about climate change and whether it is human-induced. Here we examine farmer perceptions of historical climate change, how perceptions are related to observed trends in regional climate, how perceptions are related to the …

A Generalized Computer Vision Approach To Mapping Crop Fields In Heterogeneous Agricultural Landscapes, Stephanie R. Debats, Dee Luo, Lyndon Estes, Thomas J. Fuchs, Kelly K. Caylor

Geography

Smallholder farms dominate in many parts of the world, particularly Sub-Saharan Africa. These systems are characterized by small, heterogeneous, and often indistinct field patterns, requiring a specialized methodology to map agricultural land cover. Using a variety of sites in South Africa, we present a new approach to mapping agricultural fields, based on efficient extraction of a vast set of simple, highly correlated, and interdependent features, followed by a random forest classifier. We achieved similar high performance across agricultural types, including the spectrally indistinct smallholder fields as well as the more easily distinguishable commercial fields, and demonstrated the ability to generalize …

Agriculture On The Brink:Climate Change, Labor And Smallholder Farming In Botswana, William G. Moseley

Faculty Publications

No abstract provided.

Crops Or Crafts? Changes In Land Use In The Imbabura Valley Of Ecuador, Christopher Richard Hair

Master's Theses

In rural societies where urbanization and modernization are contributing to rapid growth, changes in land use can both reflect and bring about broader changes within a community. This study seeks to investigate changes in land use in the Imbabura valley of Ecuador from the perspective of the local inhabitants. To accomplish this, three data collection techniques were employed: repeat photography, ethnographic interviews, and archival research. Repeat photography involves re-photographing historic photographs from the original site. A combination of 35 historic photographs taken in the 1950s were re-photographed during the summer of 2015. The resulting repeat photo pairs were used in …

Conterminous United States Crop Field Size Quantification From Multi-Temporal Landsat Data, Lin Yan Dr., David P. Roy

GSCE Faculty Publications

Agricultural field size is indicative of the degree of agricultural capital investment, mechanization and labor intensity, and it is ecologically important. A recently published automated computational methodology to extract agricultural crop fields from weekly 30 m Web Enabled Landsat data (WELD) time series was refined and applied to a year of Landsat 5 Thematic Mapper (TM) and Landsat 7 Enhance Thematic Mapper Plus (ETM +) acquisitions for all of the conterminous United States (CONUS). For the first time, spatially explicit CONUS field size maps and derived information are presented. A total of 4,182,777 fields were extracted with mean and median …

Using Food Flow Data To Assess Sustainability: Land Use Displacement And Regional Decoupling In Quintana Roo, Mexico, Marco Millones, Benoit Parmentier, John Rogan, Birgit Schmook

Geography

Food flow data provide unique insights into the debates surrounding the sustainability of land based production and consumption at multiple scales. Trade flows disguise the spatial correspondence of production and consumption and make their connection to land difficult. Two key components of this spatial disjuncture are land use displacement and economic regional decoupling. By displacing the environmental impact associated with food production from one region to another, environmental trajectories can falsely appear to be sustainable at a particular site or scale. When regional coupling is strong, peripheral areas where land based production occurs are strongly linked and proximate to consumption …

The Feasibility, Practicality And Uses Of Detecting Crop Water Stress In Southern Ontario Apple Orchards With A Uas, Thomas S. Tiidus Mr.

Theses and Dissertations (Comprehensive)

UAS (Unmanned Aerial Systems) are becoming more common place in agricultural sites around the world. While the accuracy of achieving NDVI (Normalized Difference Vegetation Index) from a UAS is well understood, few studies have attempted to acquire other plant health attributes such as CWSI (Crop Water Stress Index), particularly in horticulture such as apple orchards. In addition, no academic studies up to the time of this writing have explored the perceived usefulness of data obtained from a UAS for the average farmer. This study explored the practicality and feasibility of using UAS for apple orchards in Southern Ontario. This study …