The purpose of this dissertation is to examine the experiences of St. Bernard Parish, La., residents as they coped with the impact of the catastrophe of Hurricane Katrina on August 29, 2005. An estimated 50,000 St. Bernard Parish residents relocated to a new home one year after Katina in 2006, and many of those residents moved again. This study examines the effects of the decisions of St. Bernard residents to relocate or to return on their social connections. The utility, adaptability and durability of social networks of these residents will be explored to enrich our knowledge about the social effects of recovery and the role that distance plays in the way residents connect to each other six years after Hurricane Katrina. It also examines the applicability of disaster theory as it relates to this case and develops a methodology for examining the impact of geographic dispersal on social networks.

Before the creation of Mammoth Cave National Park, this area was home to numerous communities, each with a sense of identity. To prepare for the creation of the National Park, all residents living within these communities were relocated, and many of these communities were lost to the passage of time. Today, public memory of these lost communities is being fostered by the descendents of the pre-park area. Through the use of a Historical Geographic Information System, 1920 Edmonson County manuscript census data, and statistical analysis, the demographic composition of these lost communities was explored. This project not only brought to light a past that is not well known, but also built interest in sustaining public memory of the Mammoth Cave pre-park area through the use of historical GIS and public participation.

This thesis enters the context of smallholder agriculture communities in the developing world. It explores the potentials of biochar and what biochar systems could bring to the smallholder communities while simultaneously bringing environmental benefits. It then acknowledges the challenges of diffusion –the spreading of an unfamiliar innovation. It seeks to answer the question of what will make diffusion of biochar systems more successful in the smallholder context, fixating on the characteristic of compatibility as well as the role local community members can play in making a new biochar system more visible to the rest of the communities.

While much attention has been given to the ways local communities may be impacted by climate change, this dissertation focuses ethnographically on the local agencies decision-making processes, a less-studied aspect of this topic. The primary purpose of this dissertation research is to understand how government agencies in southern Florida integrate climate change into their decision-making processes while dealing with political resistance. This research expands our understanding on the cultural politics of a new kind of environmental change, where national and international climate-change politics is brought into local water politics to illuminate how new and not so new visions about life in the contemporary metropolis collide and collude. Using multiple research methods including ethnographic fieldwork, participant observation, semi-structured interviews, and document research, I analyze the activities of the Miami-Dade County Climate Change Advisory Task Force Committee (MDC-CCATF) as well as the water management practices of the regional water management agency, the South Florida Water Management District (SFWMD). My findings include the following: (1) the Task Force activities have spearheaded Miami’s institutional adaptation to climate change; (2) historic legacies have expanded and complicated decision-making processes at the District; (3) a focus on the certainties of climate-change science allows climate change to persist in politically contentious planning contexts. My dissertation concluded that while planning for potential climate-change impacts can be difficult due to multiple institutional constraints that resource agencies like the District have, scientists and policy-makers have crafted an innovative culture that is particularly visible at sites where science and decision making intersect.

Tidal marshes serve as important “blue carbon” ecosystems that accrete large amounts of carbon with limited area. While much attention has been paid to the spatial variability of sedimentation within salt marshes, less work has been done to characterize spatial variability in marsh carbon density. Driven by tidal inundation, surface topography, and sediment supply, soil properties in marshes vary spatially with several parameters, including marsh platform elevation and proximity to the marsh edge and tidal creek network. We used lidar to extract these morphometric parameters from tidal marshes to map soil organic carbon (SOC) at the meter scale. Fixed volume soil samples were collected at four northeast U.S. tidal marshes with distinctive morphologies to aid in building our predictive models. Tidal creek networks were delineated from 1-m resolution topo-bathy lidar data using a semi-automated workflow in GIS. Sample distance to tidal creeks and flow distance to the marsh edge were then determined. Log-linear multivariate regression models were developed to predict soil organic content, bulk density, and carbon density as a function of these predictive metrics at each site and across sites. Results show that modeling salt marsh soil characteristics with morphometric inputs works best in marshes with simple, single creek morphologies. Distance from tidal creeks was the most significant model predictor. Addition of distance to the inlet and tidal range as regional metrics significantly improves cross-site modeling. Our process-based approach results in predicted total marsh carbon stocks comparable to previous studies but provides trade-offs to existing simplistic carbon mapping methods. Further, we provide motivation to continue rigorous mapping of soil carbon at fine spatial resolutions and to use these results to guide salt marsh restoration projects and aid in the development of carbon markets.

Water constraints for humans and nature are gaining more and more public attention as a critical environmental dilemma that needs to be addressed. When aquifers and rivers are running dry, the debate refers to an ongoing “world water crisis”. This thesis focuses on the water and agricultural production complexity in a global, regional and local perspective during different phases of development. It addresses the river basin closing process in light of consumptive water use changes, land use alterations, past and future food production in waterscarce developing countries in general, and a south Indian case study basin in particular, the Bhavani basin in Tamil Nadu. The study focuses on early phases of global agricultural development and addresses consumptive use and river depletion in response to land use change and irrigation expansion. It shows that focus must be shifted from a water use to a consumptive water use notion that considers both green and blue water resources. The Bhavani basin development trajectory reveals a dynamic interplay between land and water resources and different socio-political groups during the “green revolution” period. The present system has emerged as a step-by-step adaptation in response to hydro-climatic variability, human demands and infrastructure constraints. The study reveals three kinds of basin closure: allocation closure; hydrological closure; and perception wise closure. Many concerted actions on multiple scales have contributed to an increasing water use complexity even after closure. The study shows the extent to which natural variability hides creeping changes, and that the “average year” is a deceptive basis for water allocation planning. Future consumptive water requirements to feed growing populations in the developing world is analysed with a back-casting country-based approach. The study shows a doubling of water requirements by 2050 and how the challenge can be halved by increased water productivity. Since blue water accessibility for irrigation clearly will be insufficient, additional green water has to be acquired by horizontal agricultural expansion into other terrestrial ecosystems. The task will be substantial and increase the importance of global food trade. / Vattenbrist för människor och ekosystem är en mer och mer uppmärksammad miljöfråga. Sjunkande grundvattennivåer och uttorkade floder gör att många talar om en ”global vattenkris”. Denna avhandling fokuserar på de komplexa sambanden mellan vatten och jordbruksproduktion utifrån ett globalt, regionalt och lokalt perspektiv under olika utvecklingsfaser under fyra sekler. Den redogör för hur avrinningsområden överintecknas och slutligen ”stängs” för ytterligare vattenutvinning. Effekterna av ökad vattenutvinning i relation till historisk och framtida matproduktion analyseras generellt i utvecklingsländer med vattenbrist, och i detalj i en fallstudie i Bhavani avrinningsområde i Tamil Nadu i södra Indien. Studien visar för den tidiga jordbruksutvecklingen på global nivå hur förändrad markanvändning och bevattningsexpansion leder till förändrad balans mellan evapotranspiration och avrinning, med uttorkning av vattendrag som följd. Den visar vidare vikten av ett paradigmskifte där fokus flyttas från vattenanvändning till ”konsumerande” vattenanvändning, och som inkluderar både grönvatten- och blåvattenresurser. Analysen av Bhavaniområdets utvecklingskurva under det senaste seklets jordbruksutveckling visar på ett dynamiskt växelspel mellan land- och vattenresurser och mellan olika samhällsgrupper. Den nuvarande vattenanvändningssituationen har stegvis växt fram som en respons på hydroklimatisk variabilitet, människors behov och infrastrukturbegränsningar. Studien påvisar att ett avrinningsområde kan ses som ”stängt” på tre skilda sätt: när flödet är överintecknat, när utflödet sinar, och när vattenanvändare upplever att behoven överstiger tillgången. Även efter ”stängning” har etablering och intensifiering av vattenutvinning fortsatt och resulterat i ett alltmer komplext och sammanflätat vattenanvändningsmönster. Studien visar vidare hur hög hydroklimatisk variabilitet, dels gör att ”genomsnittlig vattentillgång” är förledande vid planering av vattenfördelning i ett avrinningsområde, och dels döljer smygande kumulativa effekter av ökad vattenutvinning. Slutligen anlyseras ländervis framtida vattenbehov för att möta matbehovet i världens utvecklingsländer, vilket visar på en fördubbling fram till 2050. Tack vare ökad vattenproduktivitet kan behovet emellertid halveras. Endast en bråkdel av det resterande behovet kan mötas genom ökad bevattning, dvs. med mera blåvatten. En stor del av vattenbehovet måste istället täckas med mera grönvatten via uppodling av andra terrestra ekosystem. Uppgiften innebär en betydande utmaning och global handel med jordbruksprodukter kommer att öka avsevärt i betydelse.