Research
Job Market Paper
Silver Bullets: Cloud Seeding and Water Resources in California
Abstract: Management of water resources is a complex decision-making process, especially in drought-susceptible regions where water scarcity poses a serious constraint to energy production, agriculture, and urban water distribution. Weather modification, such as cloud seeding, has been used in many contexts, including the Middle East, southern Europe, North Africa, China, and the US to ease water shortages and stabilize natural fresh water supplies, by increasing precipitation and streamflow. Cloud seeding has become a contentious issue, leading to both international conflict and concerns about the effectiveness of implemented programs. In this paper, I use a non-linear difference-in-differences framework to estimate the effects of California’s long-running cloud seeding programs on precipitation to help understand the role of precipitation enhancement projects as a tool in water resources management. I find that cloud seeding increases precipitation by 57%, with significant heterogeneity between projects. This additional water comes at a cost of $7/acre-foot. Estimating the effects of individual events for Santa Barbara reveals that the precipitation enhancement program covering the Upper Santa Ynez and the Huasna-Alamo watersheds increases precipitation by 26% in the target areas at an average cost of $5.6/acre-foot. The varying effectiveness of cloud seeding suggests that results of a program in a specific area might not be extrapolated to justify the investment in a new precipitation enhancement program in a different area. These results provide guidance on the contexts in which cloud seeding programs may be viable, along with estimating potential deleterious impacts to neighboring communities.
Research Papers
Irrigation Adoption and Crop Choice Adaptation
Abstract: This paper investigates how farmers alter their production practices in response changes in public irrigation infrastructure. I consider the construction of the Koga dam in northwest Ethiopia in 2011. I combine data on crop choice, irrigation, and farm characteristics from the World Banks Living Standards Measurement Study with climate and topographical data to estimate the short-run and long-run effect of the Koga dam on farm-level irrigation access and crop choice. I use a differences-in-differences approach to estimate the effect on irrigation and a multinomial logit discrete choice model to characterize crop choice. I find little effect on irrigation two years post-construction but observe an increase of 6.4% in probability of irrigation in areas with dam access four years post-construction. For crop choice, my estimates imply dam access leads to an initial 3.5% increase in the likelihood of planting cereals, growing to an effect of 6.9% after four years. Results suggest that the large-scale irrigation scheme increases the likelihood of irrigation adoption. The policy intervention also increases the likelihood of choosing cereals, oilseeds, and spices, whereas participation in extension programs increases the likelihood of increasing cereals production.
Economic Impacts of Climate Change on Agriculture and Water Resources in Morocco
Abstract: Climate change presents a major challenge with adverse impacts on sustainable economic development, especially in developing regions such as North Africa. Projected reduced rainfall with increased spatiotemporal irregularity will aggravate water scarcity in this region. Water resources shortages will particularly affect agriculture, the most climate-sensitive economic sector, in terms of agricultural production and incomes. This paper examines the impacts of climate change on water resources and on the agricultural value-added at a regional level in Morocco. Using a dynamic integrated hydro-agro- economic optimization model, I represent the relationship between conjunctive water use and agricultural production in the upstream part of the Oum-Rbia water basin, with a spatial water distribution network of water flows, balances and constraints. The model maximizes the total profit of water use by agricultural producers within the study region, which are primarily constrained by water availability. Simulations are conducted regarding projected changes in climatic and hydrologic variables. Results indicate a total gross margin reduction of 7%. In irrigated areas, production is roughly maintained at the same level as in the “business as usual” scenario but irrigation water quantities increase significantly, by up to 20%. Groundwater use buffers the increase in surface water shortages in agricultural perimeters that use surface water and groundwater conjunctively. Therefore, the groundwater head is reduced in all aquifers as a consequence of climate change. Finally, the economic value of water is greater under climate change scenario compared to “business as usual”, especially in irrigated areas that only use springs (+18%).