Browsing by Subject "Land Use Change"

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    Assessing the Hydrologic Implications of Land Use Change for the Upper Neuse River Basin
    (2010-04-30T16:59:49Z) Conaghan, Kelly
    Land cover plays a vital role in the chemistry and the quantity of runoff, and therefore can indirectly have an immense impact on the water quality of stream and river systems. Simulation models have become extremely useful tools available to watershed managers as geospatial environmental datasets become increasingly more available. The Soil and Water Assessment Tool (SWAT) is a deterministic hydrologic model that can predict hydrologic conditions over various temporal and spatial scales. This project evaluates the accuracy of the SWAT model for the Upper Neuse River Basin, while comparing two land use scenarios in an effort to identify sensitive regions in the watershed. A regression analysis between observed and predicted stream velocity demonstrated that the initial model required calibration of stream parameters in order to more accurately model the natural system. After calibration, stream sedimentation values were compared by subbasin between a current (2001) and future (2010) land use scenario, in order to identify areas in the watershed that were the most susceptible to degradation via urbanization. Out of the 138 catchments delineated in the watershed, 29 experienced no relative change while the remaining 109 all displayed an increase in the relative difference of the sedimentation rate between scenarios. Subbasins with the greatest potential for degradation were identified and prioritized for conservation efforts or further analysis. The subbasins experiencing the highest increase in both the relative change as well as the percent change in sediment yield are all in either Wake or Durham County, suggesting a need for conservation planning in these regions. Moreover, through examining the spatial variability of these results, the influence of regional characteristics like slope, land use and soil type can be exemplified. The tremendous variation in sediment yield that occurs with urbanization suggests that local spatial conditions can exert a noticable influential on water quality and should be taken into account to maximize future management efforts. Overall, environmental tools such as the SWAT model demonstrate their usefulness in helping inform land use decisions, and can assist environmental managers in protecting water quality.
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    Roads, Rights, and Rewards: Three Program Evaluations in Environmental and Resource Economics
    (2017) Kaczan, David

    This dissertation presents three program evaluations in environmental and resource economics. In the first chapter, I ask whether rural roads can contribute to a reversal of tree cover loss. Prior literature shows roads to be strong drivers of deforestation; however, I hypothesize that in some settings the opposite relationship may hold. Roads may (1) increase the relative productivity of labor in non-agricultural sectors, reducing agricultural activity and allowing reforestation; (2) raise profits from forest management or plantations by linking markets, encouraging forest planting; and (3) provide access to imported fuel sources, reducing pressure on forests from firewood collection. I use a large-scale rural road construction program in India to explore these possibilities. I construct a nationwide, village-level panel, and estimate the impacts of roads on tree cover using a differences-in-differences approach. In aggregate I find that road construction contributed to tree cover expansion, in great contrast to the existing empirical road-forest literature. I also find considerable variation in road impacts across settings within India: frontier settings saw reductions in tree cover due to new roads, while less isolated settings with more established agriculture saw increases in tree cover.

    In the second chapter, I apply similar quasi-experimental methods to a very different question: does rights-based fisheries management increase fish prices? Rights-based management, specifically “catch shares,” is known to extend fishing seasons by slowing the destructive “race to fish.” This reduces fishing costs. It may also increase fishing revenues, because longer fishing seasons reduce product gluts that depress prices. I test this hypothesis for the majority of U.S. catch share fisheries (all those with data available) using an individually matched control fishery for each treated, catch share fishery and a difference-in-differences approach. I find evidence for increased ex-vessel prices among fisheries that undergo season decompression; however, highly variable results suggest that there is a need for a richer theoretical understanding of transitions to rights-based management. I discuss effort substitution in multispecies fisheries systems as a possible explanation for this heterogeneity.

    In the third chapter, I consider how environmentally beneficial actions can be incentivized by conditional payments (i.e. payments made in return for specific actions or outcomes) in collective land management settings. I use a framed field-lab experiment with participants from collective lands enrolled in a new payments for ecosystem services (PES) program in Mexico. I test the impact of increasing collective conditionality. Because social interactions are integral in collective decision-making, I also test the impact of PES design features that aim to improve group cooperation. Greater collective conditionality raised contributions, with higher impact on lower baseline contributors. Giving groups a way of participating in program rule-setting further improved their cooperation with those rules.