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Identifying Cloud Forest Landslides in Satellite Imagery: A Machine Learning Approach
Get PDFLandslide formation is a significant contributor to montane rainforest biodiversity, opening gaps in the tree canopy and leading to the germination of pioneer plants. In order to study the spatio-temporal patterns of landslide formation, we developed a technique using a machine learning algorithm (random forest) to automatically identify landslides in high resolution satellite imagery. Using 4-band Planetscope and 5-band RapidEye satellite imagery, we identified landslides associated with major rain events over the Monteverde Cloud Forest Reserve in Costa Rica. The classifier uses reflectance values along with texture measures and topographic slope to sort pixels into different landscape classes. Slope was calculated using digital elevation models. The overall accuracy of the resulting classifier was 99% when tested against a validation set consisting of landforms that were visually classified using the imagery. Ground-truthing was also performed in July 2019, and several features that were classified in the imagery were visited in the field. This work confirmed the accuracy of the classifier for large features, though some small features observed in the field were not identified by the algorithm. By applying the classifier to imagery collected before and after major rain events, we have been able to see the development and subsequent recovery of landslides associated with the events
Using Remote Sensing to Monitor Ecohydrological Changes in Great Lakes Interdunal Wetlands/Slacks
Get PDFInterdunal wetlands/slacks develop in the Great Lakes coastal dunes when the wind scours the sand to the water table within a dune. Our previous review of historic aerial photograph/satellite imagery of Saugatuck Harbor Natural Area on Lake Michigan’s eastern shore shows slacks expand in times of higher water levels and contract, sometimes disappearing, with lower water levels, suggesting a link between the slacks’ water tables and those of Lake Michigan-Huron (MH). We extended these studies to Warren Dunes and Ludington State Parks, Leelanau Peninsula, Crystal Lake and Point Betsie using images from 1952–2018. Using QGIS, we drew polygons around three types of slack features, wet sand, standing water and slack vegetation on georeferenced photos, calculating perimeters and areas for each feature on each photo. Wetland perimeters and areas were summed annually for each feature. These values were then totaled on an annual basis (wetland extent) and compared to the Lake Michigan water level curve. Overall the wetland extent in Warren Dunes, Leelanau and Crystal Lake reflects the lake level curve, increasing as water levels rise and decreasing as they fall. Wetland extents at Point Betsie and Ludington follow the lake level curve with the exception of 1965 and 1993 at Point Betsie, and 1993–2012 at Ludington. Possible explanations for these variances include photo quality and/or a rain event(s). Overall this method provides a reliable way to evaluate historic ecohydrological changes in response to fluctuating lake levels. 3-band (red, green, near-infrared) drone imagery has also been used as lake levels rise (2017, 2018, and 2019) to examine the ecohydrological changes occurring in the large slack (\u3e1 ha in size) at SHNA where ridges and pools create a diverse vegetation mosaic. Vegetation quadrat sampling (32 quadrats) was used to ground-truth the image interpretations
Where the Ground Was the Enemy: Setting as a Character in The Things They Carried
Get PDFThis article examines the role of the setting in Tim O’Brien’s classic postmodern novel The Things They Carried. Based on close reading and researched analysis of the text itself, we demonstrate that O’Brien so thoroughly personifies the landscape and terrain of Vietnam that it becomes more than just the setting--it becomes a character. Moreover, the terrain becomes the principal antagonist faced by the narrator and his comrades.
Such a literary move allows the author to avoid demonizing the people, whether friend or foe, of Vietnam. After establishing our basic claim about the role of the landscape, we take our analysis further by using historical, biographical, and a bit of geographical research to demonstrate that such a reading of The Things They Carried is entirely consistent with the ideology expressed by both the invented narrator of the book (whom the author also names Tim O’Brien) as well as the author himself
Setback of Foreign Aid in Sub-Saharan Africa
Get PDFEvery year, tens of billions of dollars are transferred as foreign aid to so-called developing countries, including sub-Saharan African states. My research regards the overall effectiveness in the development of these recipients. Some evidence supports the success of foreign aid in fostering development. My focus is to understand the effectiveness of foreign aid beyond the individual outcomes of various aid programs. Particularly, I will explore how aid affects investment, self-determination, democracy, and transparency in recipient nations. In this study, I examine the realities of the countries at individual country-levels rather than the macro measures focused on by such scholars as Paul Collier. This paper will answer whether or not the real meaningfulness of the impact of foreign aid is treated as an ‘externality’. Furthermore, it checks to see if foreign aid really created more negative impacts than positive
The Resource Curse in Africa
Get PDFCountries with an abundance of highly valued natural resources face the possibility of thriving or struggling due to the presence of such resources. This project examines the potential resource curse in sub-Saharan Africa. The research here will draw on previous insights on how resources affect economic and political development in Africa. I will consider how the availability of valuable resources affects political elites’ relationship with their citizens and why the impact of resources matters in a comparative perspective. Using data collection and research on the existence of the resource curse, I expect to find that the curse is real and effectively marginalizes many people groups from democratic participation and competition in countries across the continent. The resource curse carries significance because it helps to explain the political and economic realities found in sub-Saharan Africa
Spera: 2020
Get PDFYearly publication that serves as a spotlight on faculty research and scholarly work .https://digitalcommons.hope.edu/spera/1002/thumbnail.jp
Creating Nitrogen Beams in an Alphatross™ Ion Source for Injection into a Tandem Accelerator
Get PDFOver the past 15 years, Hope College has been creating hydrogen and helium ion beams with an Alphatross™ ion source and Pelletron™ tandem Van de Graaff accelerator. The manufacturer stated the possibility of creating nitrogen ions in this source, but Hope College has not, up until now, attempted to do so. By mixing approximately 1% nitrogen into hydrogen source gas, nitrogen (N-) and imidogen (NH-) ions were created and accelerated through the tandem accelerator. These ion beams were directed and isolated by a dipole bending magnet for identification. Alternate beams such as these open up new possibilities for future experiments such as nitrogen implantation
The Digital Divide in Sub-Saharan Africa
Get PDFThe existence of a digital divide affects all information technology (IT) users. The digital divide is known as the gap between those who are able to make effective use of technology and the Internet, and those who are not. My project will explore the existence of a digital divide between countries in the global north and countries in the global south. Additionally, I will investigate the possible causes of the digital divide, and the positive or negative effects the divide may have on societies, all with an emphasis on sub-Saharan Africa. Causes of the digital divide can be traced to economic instability, an urban and rural divide, and lack of infrastructure. Effects of the digital divide include increasing the urban and rural divide, lack of opportunity and education, and inability of economic growth. I specifically look at the digital divide in the Democratic Republic of Congo. Using data from the Democratic Republic of Congo regarding aspects such as electricity, mobile phones, and internet access, and internet cafes, I will analyze the existence of a digital divide in the country
Primary and Secondary Education for Refugee Children in Malaysia: Facing Barriers with Resilience
Get PDFThis project investigated challenges refugee and asylum-seeking children in Malaysia encounter in obtaining primary and secondary education. The obstacles covered in this study fall into three categories: legal and governmental failure to protect refugees and asylum-seekers, Malaysians’ ignorance and prejudice, and weaknesses in existing educational systems. Because Malaysia does not recognize refugee rights as defined by international law, its domestic legislation treats asylum-seekers like illegal immigrants, without regard for often markedly different circumstances of arrival. Legal indifference is reflected in general ignorance among Malaysians about what refugees are, breeding fears about “threats” they pose to the economy and public safety. Because Malaysian law prohibits refugees from attending public schools, primary and secondary education for these children are provided solely by non-governmental organizations. However, the lack of adequate funds and manpower limits the effectiveness of these informal schools. Drawing from library research, interviews, and personal experience volunteering in refugee schools, this research focused on how such barriers affect these displaced communities, but also how children and their families respond with resilience. For example, NGOs work with refugee communities to establish learning centers and offer vocational training for teenagers. Some students go on to take international high school exams, such as the British-based IGCSE, and receive scholarships to enroll in private colleges and universities around Malaysia. Arts also become a catalyst for empowerment: through plays, poetry competitions, and music recitals, young refugees assert their capability and initiative. Clearly, this issue is not uniquely Malaysian: displacement is a global phenomenon, education is a universal children’s right, and the current United States administration has taken a harder stance on DACA. In the face of substantial ignorance and growing hostility towards refugees, it is crucial for host populations to understand the complexities surrounding displacement and learn to respond with sensitivity and compassion