An impact analysis of future human settlements on biological resources and greenhouse gas emissions in California, and on wildlife corridors in a Maasai group ranch in Kenya.

摘要

Patterns of human settlement can have profound effects on the natural environment and biological resources, including direct habitat destruction, contribution to greenhouse gases, and obstruction of animal movement. Over half the world's population live in urban areas, which are experiencing tremendous growth rates. Planners and scientists are struggling to accommodate urban growth while conserving natural resources. UPlan, a spatially-explicit urban growth model, was developed to help decision-makers quantify and visualize the potential implications of land use decisions by modeling patterns of future human settlement and measuring their relative impacts.;Kenyan Maasai pastoralists are transitioning from communal land tenure to individual parcel ownership, leading to a sedentary, agriculture-based livelihood with more fenced land. Effects of land subdivision include landscape-scale habitat fragmentation and decreased wildlife populations. To date, there has been no systematic way of estimating longer-term impacts of differing growth scenarios on wildlife and other environmental resources in Africa. Chapter three explores whether UPlan can be adapted to the Kenyan policy framework. I test the feasibility of using UPlan in rural Kenya by applying it to the Mbirikani Group Ranch. The modeled pattern of human settlement from each policy scenario is combined with wildlife routes across Mbirikani. Findings indicate that the scenario with the highest level of fencing has the most detrimental effects on migratory corridors.;In chapter one, I apply UPlan to the San Joaquin Valley, California, to model urban growth impacts from land use policy scenarios on conservation priority lands. Results indicate that the least detrimental impacts are from the growth scenario that emphasizes higher housing densities and a smaller human settlement footprint. To better understand the relative contribution of urban growth to California's greenhouse gas emissions, in chapter two I use UPlan's greenhouse gas (GHG) calculator to estimate emissions from buildings accommodating new growth through the year 2050 in California. The GHG calculator can test alternative emission-reducing measures to help determine what actions will be needed to achieve the 2050 reduction targets. Reducing very low residential housing lowers emissions by 1%, suggesting targets cannot be met without a higher percentage of renewable energy sources and/or implementing conservation measures.