A case history of use and management of the Baton Rouge fresh water aquifer system

The Southern Hills Aquifer located in southeastern Louisiana has provided residents of Baton Rouge and surrounding communities with high-quality, fresh drinking water for many decades. However in recent years increasing pumping rates, evidence of saltwater intrusion, and concerns about the equitable and sustainable use of the aquifer have led residents and researchers to begin to examine more critically how groundwater is managed in this area. Louisiana is one of only six states without a groundwater management plan, and to date, the officials in charge of monitoring the Southern Hills Aquifer have not developed any guidelines for limiting withdrawal. This thesis presents a detailed case study of the use and management of the Southern Hills Aquifer in Baton Rouge. Specifically, these research questions will be addressed: 1) What is the state of the Southern Hills Aquifer system concerning salt-water intrusion?; 2) What is the current State management structure for the aquifer? 3) How may a new organization based on the principles of collaborative environmental planning improve the structure of groundwater management in Baton Rouge? A review of technical reports by the US Geological Survey and others indicates that saltwater intrusion into the aquifer has occurred and is spreading at an increasing rate. The state groundwater management structure includes two organizations. Legal responsibility for management of the aquifer lies with the Louisiana State Department of Natural Resources (DNR) through the Office of the Commissioner of Conservation, while the Capital Area Groundwater Conservation Commission appears to function as a permanent task force, holding quarterly public meetings concerning groundwater issues. In 2011, a small group of residents formed the Baton Rouge Citizens to Save Our Water, Inc. The group seeks to promote collaborative environmental planning principles and, as a first step, is working to disseminate technical information about the Aquifer and to encourage residents to lobby for a groundwater management plan that limits industries’ use of the water. The case study includes a detailed timeline of the interactions between the citizens group and state groundwater officials. A review of subsequent public statements by the officials indicates that the citizen group has been successful in moving the policy debate toward a more comprehensive groundwater management plan

A Comparison of Photointerpretive and Digital Production Methods for Four Key Remote Sensing-Based Information Products

No abstract availabl

Modeling History Dependence in Network-Behavior Coevolution

Spatial interdependence--the dependence of outcomes in some units on those in others--is substantively and theoretically ubiquitous and central across the social sciences. Spatial association is also omnipresent empirically. However, spatial association may arise from three importantly distinct processes: common exposure of actors to exogenous external and internal stimuli, interdependence of outcomes/behaviors across actors (contagion), and/or the putative outcomes may affect the variable along which the clustering occurs (selection). Accurate inference about any of these processes generally requires an empirical strategy that addresses all three well. From a spatial-econometric perspective, this suggests spatiotemporal empirical models with exogenous covariates (common exposure) and spatial lags (contagion), with the spatial weights being endogenous (selection). From a longitudinal network-analytic perspective, we can identify the same three processes as potential sources of network effects and network formation. From that perspective, actors\u27 self-selection into networks (by, e.g., behavioral homophily) and actors\u27 behavior that is contagious through those network connections likewise demands theoretical and empirical models in which networks and behavior coevolve over time. This paper begins building such modeling by, on the theoretical side, extending a Markov type-interaction model to allow endogenous tie-formation, and, on the empirical side, merging a simple spatial-lag logit model of contagious behavior with a simple p-star logit model of network formation, building this synthetic discrete-time empirical model from the theoretical base of the modified Markov type-interaction model. One interesting consequence of network-behavior coevolution--identically: endogenous patterns of spatial interdependence--emphasized here is how it can produce history-dependent political dynamics, including equilibrium phat and path dependence (Page 2006). The paper explores these implications, and then concludes with a preliminary demonstration of the strategy applied to alliance formation and conflict behavior among the great powers in the first half of the twentieth century

Network Selection and Path-Dependent Coevolution

Scholars have increasingly become aware that actors’ self-selection into networks (e.g., homophily) is an important determinant of network-tie formation. Such self-selection adds methodological complexity to the empirical evaluation of the effects of network ties on individual behavior. Moreover, the endogenous network formation implies that network-tie structures and actors’ behavior “coevolve” over time. Therefore, in longitudinal network studies, it is very crucial for scholars to understand the nature of coevolutionary dynamics in the data, in order to explain the network-formation and the behavioral-decision-making mechanisms accurately. In this project, we claim that one of the most important aspects of the coevolutionary dynamic is its connection with history dependence. By history dependence, we primarily focus on what Page (2006) defines as “phat” and path dependence. We first establish theoretically that systems with coevolution can easily generate multiple equilibria (i.e., the steady states of the system), using a simple Markov type-interaction model that allows for endogenous tie formation. The potential of multiple equilibria posits an important and very difficult empirical question--how sensitive are equilibrium distributions (over types) to the past states? More simply put, to what extent does history matter? What is at stake in this question is not trivial. If history matters for an equilibrium attained in the society, then we can also analyze the potential policy interventions that could change the path of the social process such that it would lead to a socially optimal equilibrium. As for the empirical strategy, we start with developing a discrete-time Markov model, combining a spatial-logit and p-star model to evaluate the empirical significance of coevolutionary dynamics in the data. The strength of this empirical approach is in its direct connection with the theoretical Markov interaction model, and can provide a foundation for developing statistical tests for history dependence generated by coevolution

Petrography of Lower Cretaceous sandstones on Spitsbergen

The sandstone petrography of sample suites from four sites spanning the Rurikfjellet (Hauterivian) to Carolinefjellet (Aptian–Albian) formations in central Spitsbergen was investigated. The sandstones show a distinct stepwise shift in composition from quartz arenites to sublitharenites and lithic arenites, typically within the upper part of the Helvetiafjellet Formation. This shift is related to the introduction of 10 - 25 % (grain %) plagioclase grains and volcanic lithics, and a notable increase in basement and sedimentary lithics. Quartz grain character also changes, and grain shapes become more varied. The shift is also associated with the transgressive arrival of marine sediments in the area, and the introduction of sands from the east-northeast by shore-parallel transport. Regional regression and subsequent transgression, and the change in sandstone composition is attributed to the development of the High Arctic Large Igneous Province in the region. The relative constancy of sand composition and volume of volcanic detritus within the Carolinefjellet Formation suggests long term (≈ 20 M) stability of the sediment system and a large volcanic source area, consistent with LIP (Large Igneous Province) derivation, along with significant exposure of basement rocks. Sample spacing and sediment recycling and mixing do not allow detection of events that would have changed sandstone composition that were less than ≈ 1 M duration. Preservation of significant amounts of plagioclase in a sediment-starved shelf can be explained by relatively cold climatic conditions

The common case study: Lockheed design of a supersonic cruise vehicle

The objective was to compare the characteristics of SSTs designed for the same mission by Lockheed, McDonnell Douglas, British Aerospace (U.K.), Aerospatiale (France), and the USSR. This comparison was to be used to calibrate parametric design studies of the tradeoff between SST direct operating cost (DOC) and noise levels at the FAR 36 certification points. The guidelines for this common case study were to design an aircraft with the following mission: payload 23 247 kg (51 250 lbm), range - 7000 km (3780 n. mi.), and cruise Mach number - 2.2. Field length was constrained to 3505 m (11 500 ft). Other airfield constraints and fuel reserves were also specified, but no noise constraints were applied

The Meridional Thermospheric Neutral Wind Measured by Radar and Optical Techniques in the Auroral Region

Radar observations of ion velocities in the magnetic zenith over Chatanika, Alaska, were used to determine the geomagnetic meridional component of the thermospheric neutral wind. Corrections for molecular diffusion and molecular ion contamination of the pure O+ composition assumed for the ionosphere were included in the analysis. Comparison of the averaged diurnal variation of the meridional wind showed good agreement between the two measurement techniques. Good agreement was also found for several cases of simultaneous observations. The evidence suggested that differences were caused by gravity waves. The 7 years of radar meridional wind results were examined with respect to magnetic activity, solar cycle phase, and season. During the day, the meridional component is poleward with a maximum of about 65 m/s between 1400 and 1600 local time. During the night, the wind is equatorward with a maximum of about 175 m/s between 0200 and 0500 local time. This maximum occurs after local magnetic midnight, which is about 0130 local time. When the neutral wind is averaged for 24 hours, there is a large net equatorward flow. During periods of increased magnetic activity, the nighttime wind between 2300 and 0600 local time becomes stronger toward the equator. The average increase between 0200 and 0600 local time is about 100 m/s; however, on individual days it can be as large as 400 m/s. These data pertain mostly to equinox, but the few summer and winter observations in the data set differ in the manner predicted by theory. Comparison of these results with theoretical models shows good agreement at most times, but suggests possible heating poleward of Chatanika during the morning hours. Observed exospheric temperature increases support this hypothesis