Water Management Decision Making in the Face of Multiple Forms of Uncertainty and Risk

In the Wasatch Range Metropolitan Area of Northern Utah, water management decision makers confront multiple forms of uncertainty and risk. Adapting to these uncertainties and risks is critical for maintaining the long‐term sustainability of the region's water supply. This study draws on interview data to assess the major challenges climatic and social changes pose to Utah's water future, as well as potential solutions. The study identifies the water management adaptation decision‐making space shaped by the interacting institutional, social, economic, political, and biophysical processes that enable and constrain sustainable water management. The study finds water managers and other water actors see challenges related to reallocating water, including equitable water transfers and stakeholder cooperation, addressing population growth, and locating additional water supplies, as more problematic than the challenges posed by climate change. Furthermore, there is significant disagreement between water actors over how to best adapt to both climatic and social changes. This study concludes with a discussion of the path dependencies that present challenges to adaptive water management decision making, as well as opportunities for the pursuit of a new water management paradigm based on soft‐path solutions. Such knowledge is useful for understanding the institutional and social adaptations needed for water management to successfully address future uncertainties and risks.     

Separability, partial demand systems, and consumer's surplus measures

In practice, complete demand systems are not estimated. Rather, either an incomplete demand system is estimated, or separability is invoked and a partial demand system is estimated. This paper considers the relationship between the conventional compensating variation (equivalent variation) and the corresponding welfare measure that can be derived from a partial demand system and the current budget allocation to the separable group. Even assuming the separability assumption invoked is appropriate, these partial measures provide, in general, only a limited amount of information about the compensating variation and no information about the equivalent variation. Great care is therefore needed when using partial welfare measures to evaluate policy.     

Seepage from deep bedded and poultry litter systems

The work reported indicates that there could be a potential of ground water pollution by NO3-N from turkey facilities built on both sandy and clay soils. At four different depths (30.54, 61.08, 91.62, and 122.16 cm), the NO3-N levels for the clay soil were 1572, 497, 66, and 28 ppm, and those for the sandy soil were 293, 425, 324, and 164 ppm, respectively. No significant P increases were observed but there did exist a significant increase of K in the topsoil for both clay and sandy turkey structures. The results show that swine hoop houses with less than three or four years of age may not pose a threat to groundwater pollution due to the leaching of nutrients. The only dairy feedlot sampled in this study, although it has been used for more than 20 years, did not show leaching of NO3-N and P. However, it did show a significantly elevated concentration of potassium in the topsoil, as compared to the background sample. More sites should be investigated to verify this.     

The demand for site-specific recreational activities: A characteristics approach

A model of constrained utility maximizing behavior is developed to explain how a representative individual allocates his ski days among alternative sites. The physical characteristics of the ski areas and the individual's skiing ability are explicit arguments in the utility function; the budget allocation is given along with the parametric costs to ski (including travel costs, entrance fees, equipment costs, and the opportunity cost of his time). Shares (a site's share being the proportion of ski days that the individual spends at that site) are derived and assumed multinomially distributed, a stochastic specification which maintains the inherent properties of the shares. Maximum likelihood estimation confirms the basic hypothesis that costs, ability, and characteristics all are important determinants of the sites' shares. The model explains a large proportion of the skier's allocation of ski days. A multinomial logit model of skier behavior is also developed and maximum likelihood estimates of its parameters are obtained. Examination of the summary statistics from my model and the logit model indicates that my model predicts the skier's choice of sites better than the logit model.     

Climate change adaptation: factors influencing Chinese smallholder farmers’ perceived self-efficacy and adaptation intent

Understanding how individuals perceive their ability to adapt to climate change is critical to understanding adaptation decision-making. Drawing on a survey of 483 smallholder farmer households in the Loess Plateau region of China, we examine the factors that shape smallholder farmer perceptions of their ability to adapt to climate change and their stated intent to do so. We apply a proportional odds ordered logistic regression model to identify the role that determinants of adaptive capacity play in shaping smallholders’ perceived self-efficacy and adaptation intent. Our study provides further evidence that self-efficacy beliefs are a strong, positive predictor of adaptation intent. Our study suggests that human capital, information and technology, material resources and infrastructure, wealth and financial capital, and institutions and entitlements all play an important role in shaping smallholder perceived self-efficacy, while state-society dependencies may reduce smallholder perceived self-efficacy. In addition, our study suggests that perceiving climate change risks and impacts do not necessarily lead to an intention to adapt. Overall, our findings highlight the importance of incorporating both the objective determinants of smallholders’ adaptive capacity and their subjective perceptions of these objective determinants into future climate change adaptation programs and policies in order to facilitate adaptive actions. Identifying factors that cause individuals to have a low estimation of their adaptive ability may allow planned adaptation interventions to address these perceived limitations and encourage adaptive behavior.     

Estimating the benefits and costs to mountain bikers of changes in trail characteristics,access fees,and site closures: choice experiments and benefits transfer

Mountain biking is an increasingly popular leisure pursuit. Consequences are trail degradation and conflicts with hikers and other users. Resource managers often attempt to resolve these problems by closing trails to mountain biking. In order to estimate the impact of these developments, a model has been devised that predicts the effects of changes in trail characteristics and introduction of access fees, and correlates these with biker preference on trail selection. It estimates each individual's per-ride consumer's surplus associated with implementing different policies. The surplus varies significantly as a function of each individual's gender, budget, and interest in mountain biking. Estimation uses stated preference data, specifically choice experiments. Hypothetical mountain bike trails were created and each surveyed biker was asked to make five pair-wise choices. A benefit-transfer simulation is used to show how the model and parameter estimates can be transferred to estimate the benefits and costs to mountain bikers in a specific area.     

Spatial variation and ontogenic shifts in the isotopic composition of Mediterranean littoral fishes

Stable carbon and nitrogen isotope signatures have been determined for littoral fishes from three localities in the Balearic Islands (NW Mediterranean) for trophic assessment. Variation in the isotopic composition was examined at multiple levels: the individual organism, individual populations (ontogenetic variation) and at area effects (different islands). Cluster analyses based on ¹³C and ¹⁵N resulted in two very different dendrograms for the fish assemblages from Menorca and Formentera. In both schemes, congeners of the genera Diplodus and Labrus did not cluster together, suggesting that closely related species do not necessarily feed on similar foods. Significant differences in ¹⁵N were detected between locations for Scorpaena porcus, Scorpaena scrofa and Sciaena umbra, and significant differences in ¹³C were detected for Scorpaena porcus and Scorpaena scrofa. Overall there were significant spatial differences in the trophic position of littoral fishes among the three Balearic Islands, and fishes from Palma, Mallorca tended to feed at a higher trophic level than fishes from either Menorca and Formentera. Large-scale geographic comparisons, using earlier data from three sites in western Mallorca and in Corsica revealed that throughout the western Mediterranean generally, the average trophic level of fishes differs remarkably little. However, large discrepancies were observed in ¹⁵N for individual species, notably Scorpaena porcus, D. annularis, D. vulgaris and Serranus scriba. ¹³C composition of fishes did not seem to change greatly among the locations, although marked discrepancies were observed for D. puntazzo and Mullus surmuletus. Given the large-scale patterns we have observed, it is possible that the extent of multichannel omnivory which has been purported to exist in complex aquatic systems, may have been greatly overstated. Regression of ¹⁵N and ¹³C with fish body size revealed clear and significant trends for some species. In particular, ¹⁵N appeared to increase with body length in the macrocarnivorous fishes Scorpaena porcus, Scorpaena scrofa, Serranus scriba and Sciaena umbra. Trends were less apparent in animals which feed primarily on small benthic invertebrates, notably the four Diplodus species (D. vulgaris, D. sargus, D. annularis, D. puntazzo), and the labrids Labrus viridis and L. merula.Communicated by J.P. Thorpe, Port Erin     

What Is Consumer′s Surplus Per Day of Use, When Is It a Constant Independent of the Number of Days of Use, and What Does It Tell Us about Consumers Surplus?

An individual′s consumer′s surplus per day of use for a change in the price of recreational site is the price change, so it is a constant, independent of the number of days of use. Consumer′s surplus per day of use for a change in a site′s characteristics is not, in general, a constant. When a constant compensating variation per day of use exists, it multiplied by the number of days at the site in the original state (proposed state) bounds the compensating variation, CV, from below (above). The average of these two approximations is an almost second-order approximation to the CV. Simulations indicate the approximation biases can be large.