DYNAMIC-SPATIAL MANAGEMENT OF COASTAL AQUIFERS

We analyze the management of a coastal aquifer under seawater intrusion using distributed control methods. The aquifer's state is taken as the water head elevation, which varies with time and in space since extraction, natural recharge and lateral water flows vary with time and in space. The water head, in turn, induces a temporal-spatial seawater intrusion process, which changes the volume of fresh water in the aquifer. Under reasonable conditions we show that the optimal state converges to a steady state process that is constant in time. We characterize the optimal steady state process in terms of a standard control problem (in space) and offer a tractable algorithm to solve for it.distributed control, groundwater, optimal exploitation, seawater intrusion, Resource /Energy Economics and Policy, C61, C62, Q25,

Farm Output, Non-Farm Income, and Commercialization in Rural Georgia

This article examines the decision of farmers to sell part of their farm output on the market, using data from the Republic of Georgia. A two-level empirical model is used, in which endowments and resource allocation decisions determine farm output and non-farm income, and these in turn determine market participation. We found, as expected, that farm output affects market participation positively, while non-farm income affects it negatively. Landholdings have an indirect positive effect on market participation, through its positive effect on farm output. Education has a negative effect on market participation, mainly through its positive effect on non-farm income.commercialization, market participation, farm output, non-farm income, resource allocation, Agricultural Finance, Farm Management,

ON A POLITICAL SOLUTION TO THE NIMBY CONFLICT

Political Economy,

A Structural Land-Use Analysis of Agricultural Adaptation to Climate Change: A Proactive Approach

This article proposes a proactive approach for analyzing agricultural adaptation to climate change based on a structural land-use model wherein farmers maximize profit by allocating their land between crop-technology bundles. The profitability of the bundles is a function of four technological attributes via which climate variables‟ effect is channeled: yield potential; input requirements; yields' sensitivity to input use; and farm-level management costs. Proactive adaptation measures are derived by identifying the technological attributes via which climate variables reduce overall agricultural profitability, despite adaptation by land reallocation among bundles. By applying the model to Israel, we find that long-term losses stem from yield potential reductions driven by forecasted increases in temperature, implying that adaptation efforts should target more heat-tolerant crop varieties and technologies.adaptation, agricultural land use, climate change, crop-technology bundles, Land Economics/Use,

Development of Individual Farming in Georgia: Descriptive Analysis and Comparisons

The purpose of this paper is to examine the situation of individual farms in Georgia using a survey conducted in 2003, in comparison to a similar survey conducted in 1996. The basic issue investigated is the progress of the land individualization process, and the consequences of this process for the development of the agricultural sector, and more generally for the well-being of farm families and rural poverty. We found significant changes in the farm sector. In particular, average landholdings have increased, mainly through leasing of plots. There is more specialization, with some farmers not producing at all and others expanding. Profits and income have deteriorated markedly, and many producers did not even sell their produce on the market. Those producers who leased land were much more likely to sell their produce on the market and they also had higher incomes and relied less on off-farm income and social assistance payments. Still, fewer than 15% of the farmers lease land. While the average age of the population has increased, the level of schooling declined. This indicates a possible “brain drain” process of selective outmigration. Another worrying implication of the income situation is the increase in the incidence of child labor. These findings indicate that the potential of increased land transactions is still there, and a continuing specialization process that will enable successful farmers to acquire more land could improve the economic well-being of farm families even in a period of depressed produce prices.Individual Farming, Georgia

LAND REFORM AND RURAL WELL BEING IN THE REPUBLIC OF GEORGIA: 1996-2003

Land reform was launched in the Republic of Georgia in 1992, about a year after the country gained its independence from the Soviet Union. While an impressive land individualization process has been in effect since then, the pace and the performance of this process are far from satisfactory. This is due to a combination of institutional and economic constraints. We use comparable survey data from 1996 and 2003 and show that the land reform has been progressing mainly through land leasing. This allows successful farm households to expand their farming operation and improve their well-being. Land documentation doesn’t seem to yield the expected results, and the blame may be on less than sufficient labor and credit opportunities. We conclude that there is scope for continuing the process of land reform in Georgia, but this has to be accompanied by measures to develop rural credit and labor markets.Community/Rural/Urban Development, Land Economics/Use,

Analysis and Modeling of Wastewater Reuse Externalities in African Agriculture

Wastewater reuse has been identified to alleviate freshwater scarcity, improve crop yield and sustain the environment. This study analysed and modeled wastewater reuse externalities in the context of African agriculture. Data were retrieved from FAO-AQUASTAT (2015). Descriptive statistics and correlation analyses were performed to analyse the potentials of wastewater and determine the relationship between the environmental implications of treated effluent respectively. Cost-Benefit Analysis (CBA) and Stochastic frontier cost functions were modeled for estimating the economic/environmental trade-offs of wastewater reuse and costs of wastewater treatment. The descriptive results indicated that Northern Africa, which is the most vulnerable region, has the greatest potentials of wastewater reuse. The quantity of effluent from treatment plants was inversely proportional to the treatment capacity between Northern and Southern Africa. Correlation analysis results show that "area of land salinized" had a highly positive significant correlation with the quantity of treated wastewater used (r=0.69). CBA was modeled to account for treatment cost, health cost, cost of soil reclamation, aquifer damage cost, increased crop yield and aquifer recharge. A conceptual Stochastic Frontier Model (SFM) was also developed in this research as no previous studies took into account inefficiency parameters (negative externalities) accompanied with wastewater reuse. African regions living above water-poverty line must however not wait till when freshwater will become a limiting resource. The significance of salinity in this study calls for the use of appropriate agronomic practices to remediate saline soils. Stochastic frontier is recommended to be applied to empirical data for further studies considering the valuation of externalities. In conclusion, this study puts wastewater on the policy agenda by emphasizing its impacts in agriculture. Keywords: Wastewater, Africa, Externalities, Cost-benefit analysis and Stochastic frontier model

INTEGRATED DRAINWATER MANAGEMENT IN IRRIGATED AGRICULTURE

Drainwater management strategies include source control, reuse, treatment, and evaporation ponds; questions of interest are efficient management, policy instruments, and sustainability. A high level of source control is indicated absent reuse due to the relatively high cost of evaporation ponds; this is accomplished largely through high uniformity/high cost irrigation systems. With reuse, the primary form of source control is reduction in land area devoted to freshwater production; the released land goes to reuse production. Reuse appears as an economically promising solution to the drainage problem. A high level of net returns is achieved while maintaining overall hydrologic balance in the system. Economic efficiency and hydrologic balance may be attained through pricing or market schemes. With pricing, growers are charged for deep percolations flows, while reuse and evaporation pond operators are paid for extractions. With markets, permit supply is generated by extractions from the water table, while permit demand is generated by deep percolation. Competitive equilibrium exists, is efficient, and implies hydrologic balance. The analysis suggests that a high level of agricultural production may be possible for some period of time while still maintaining environmental quality.Resource /Energy Economics and Policy,

MICROECONOMICS OF IRRIGATION WITH SALINE WATER

Water management and reuse at the field level are analyzed under saline, limited drainage conditions. A function relating crop yield and deep percolation flows to applied water and salinity concentration is developed. This function fits simulated data well and is tractable for theoretical and empirical analysis of irrigation economics. With a single irrigation source, irrigation water for cotton and tomatoes at first increases and the decreases with salt concentration. Drain-water reuse is found to be an efficient strategy in events of high surface-water prices and costly solutions to drainage-related environmental problems. However, blending freshwater and drainage appears plausible only under surface water scarcityResource /Energy Economics and Policy,