Department of Geography and Spatial Sciences
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Geography provides a unique spatial perspective that seeks to explain patterns of differences and commonality across the human and natural environment. Housed within the College of Earth, Ocean, and Environment, the department has nationally and internationally recognized faculty engaged in cutting edge research and offering exciting educational opportunities for both undergraduate and graduate students.
The department houses the Office of the State Climatologist of Delaware and the Delaware Environmental Observing System (DEOS). DEOS collects real-time information on all facets of the region's environment for use by everyone from environmental scientists to emergency management professionals to the general public. We also work with the Delaware Geographic Alliance, an organization of teachers and others interested in strengthening geographic learning in Delaware's K-12 classrooms.
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Item Adaptation to compound climate risks: A systematic global stocktake(iScience, 2023-02-17) Simpson, Nicholas P.; Williams, Portia Adade; Mach, Katharine J.; Berrang-Ford, Lea; Biesbroek, Robbert; Haasnoot, Marjolijn; Segnon, Alcade C.; Campbell, Donovan; Musah-Surugu, Justice Issah; Joe, Elphin Tom; Nunbogu, Abraham Marshall; Sabour, Salma; Meyer, Andreas L.S.; Andrews, Talbot M.; Singh, Chandni; Siders, A.R.; Lawrence, Judy; van Aalst, Maarten; Trisos, Christopher H.; The Global Adaptation Mapping Initiative TeamHighlights: • Compound climate impacts are particularly hard to adapt to • Compound vulnerabilities and exposures constrain adaptation capabilities • Inappropriate responses to climate change can lead to maladaptation • Compound impacts can have cascading effects on response options Summary: This article provides a stocktake of the adaptation literature between 2013 and 2019 to better understand how adaptation responses affect risk under the particularly challenging conditions of compound climate events. Across 39 countries, 45 response types to compound hazards display anticipatory (9%), reactive (33%), and maladaptive (41%) characteristics, as well as hard (18%) and soft (68%) limits to adaptation. Low income, food insecurity, and access to institutional resources and finance are the most prominent of 23 vulnerabilities observed to negatively affect responses. Risk for food security, health, livelihoods, and economic outputs are commonly associated risks driving responses. Narrow geographical and sectoral foci of the literature highlight important conceptual, sectoral, and geographic areas for future research to better understand the way responses shape risk. When responses are integrated within climate risk assessment and management, there is greater potential to advance the urgency of response and safeguards for the most vulnerable. Graphical abstract at: https://doi.org/10.1016/j.isci.2023.105926Item An Analytical Approach for Levee Underseepage Analysis(Elsevier B. V., 2012) Meehan, Christopher L.; Benjasupattananan, Sittinan; Meehan, Christopher L., Benjasupattananan, Sittinan; Meehan, Christopher L.Levee underseepage analyses are commonly performed to assess the risk of erosion and piping of levee foundation soils. They are also commonly used to estimate the quantity of seepage that is expected to pass beneath a levee over time, and to assess the risk of excessively high pore pressures at various points in the foundation. A variety of approaches have historically been utilized to perform steady-state underseepage analyses in levees, including flow-nets, closed-form analytical solutions, and numerical techniques such as finite difference or finite element analyses. This paper provides a derivation of a series of closed-form \blanket theory" analytical equations that can be used to perform a levee underseepage analysis. This derivation starts from a generic confined flow analytical solution, of the type that is common in groundwater flow analyses. The solution is then extended to simulate semiconfined flow beneath a levee in a shallow aquifer. Equations are presented for calculating total head and seepage quantity values for different model boundary conditions. A typical example problem is used to compare the analytical equations that are derived with the analytical equations that are presented in the US Army Corps of Engineers (USACE) levee design manual. The results provide validation for both the equations that are presented and the conventional USACE analytical design approach. Using the results from the example problem, general guidance and suggestions are provided for designers that use closed-form analytical approaches for modeling levee underseepage.Item Antarctic sea-ice thickness and volume estimates from ice charts between 1995 and 1998(International Glaciological Society, 2015-10-01) Bernstein, E. Rachel; Geiger, Cathleen A.; DeLiberty, Tracy L.; Lemcke-Stampone, Mary D.; E. Rachel BERNSTEIN, Cathleen A. GEIGER, Tracy L. DeLIBERTY, Mary D. LEMCKE-STAMPONE; Bernstein, E. Rachel; Geiger, Cathleen A.; DeLiberty, Tracy L.This work evaluates two distinct calculations of central tendency for sea-ice thickness and quantifies the impact such calculations have on ice volume for the Southern Ocean. The first calculation, area-weighted average thickness, is computed from polygonal ice features and then upscaled to regions. The second calculation, integrated thickness, is a measure of the central value of thickness categories tracked across different scales and subsequently summed to chosen regions. Both methods yield the same result from one scale to the next, but subsequent scales develop diverging solutions when distributions are strongly non-Gaussian. Data for this evaluation are sea-ice stage-ofdevelopment records from US National Ice Center ice charts from 1995 to 1998, as proxy records of ice thickness. Results show regionally integrated thickness exceeds area-weighted average thickness by as much as 60% in summer with as few as five bins in thickness distribution. Year-round, the difference between the two calculations yields volume differences consistently >10%. The largest discrepancies arise due to bimodal distributions which are common in ice charts based on current subjective-analysis protocols. We recommend that integrated distribution be used for regional-scale sea-ice thickness and volume estimates from ice charts and encourage similar testing of other large-scale thickness data archives.Item Assessing and addressing the global state of food production data scarcity(Nature Reviews Earth & Environment, 2024-02-20) Kebede, Endalkachew Abebe; Abou Ali, Hanan; Clavelle, Tyler; Froehlich, Halley E.; Gephart, Jessica A.; Hartman, Sarah; Herrero, Mario; Kerner, Hannah; Mehta, Piyush; Nakalembe, Catherine; Ray, Deepak K.; Siebert, Stefan; Thornton, Philip; Davis, Kyle FrankelFood production data — such as crop, livestock, aquaculture and fisheries statistics — are critical to achieving multiple sustainable development goals. However, the lack of reliable, regularly collected, accessible, usable and spatially disaggregated statistics limits an accurate picture of the state of food production in many countries and prevents the implementation of effective food system interventions. In this Review, we take stock of national and international food production data to understand its availability and limitations. Across databases, there is substantial global variation in data timeliness, granularity (both spatially and by food category) and transparency. Data scarcity challenges are most pronounced for livestock and aquatic food production. These challenges are largely concentrated in Central America, the Middle East and Africa owing to a combination of inconsistent census implementation and a global reliance on self-reporting. Because data scarcity is the result of technical, institutional and political obstacles, solutions must include technological and policy innovations. Fusing traditional and emerging data-gathering techniques with coordinated governance and dedicated long-term financing will be key to overcoming current obstacles to sustained, up-to-date and accurate food production data collection, foundational in promoting and monitoring progress towards healthier and more sustainable food systems worldwide.Item Assessing urban heat-related adaptation strategies under multiple futures for a major U.S. city(Climatic Change, 2021-02-27) Rohat, Guillaume; Wilhelmi, Olga; Flacke, Johannes; Monaghan, Andrew; Gao, Jing; van Maarseveen, Martin; Dao, HyUrban areas are increasingly affected by extreme heat in the face of climate change, while the size and vulnerability of exposed populations are shifting due to economic development, demographic change, and urbanization. In addition to the need to assess future urban heat-related health risks, there is also an increasing need to design adaptation strategies that will be effective under varying levels of socioeconomic development and climate change. We use the case study of Houston, Texas, to develop and demonstrate a scenario-based approach to explore the effectiveness of both autonomous and planned heat-related adaptations under multiple plausible futures. We couple a heat risk model with urban climate projections (under the Representative Concentration Pathways) and vulnerability projections (under locally extended Shared Socioeconomic Pathways) to investigate the impact of different adaptation strategies under multiple scenario combinations. We demonstrate that, in the context of Houston, community-based adaptation strategies aiming to reduce social isolation are the most effective and the least challenging to implement across all plausible futures. Scenario-based approaches can provide local policymakers with context-specific assessments of possible adaptation strategies that account for uncertain futures.Item Atmospheric Drivers Associated with Extreme Snow Ablation and Discharge Events in the Susquehanna River Basin: A Climatology(Journal of Applied Meteorology and Climatology, 2023-11-02) Suriano, Zachary J.; Henderson, Gina R.; Arthur, Julia; Harper, Kricket; Leathers, Daniel J.Extreme snow ablation can greatly impact regional hydrology, affecting streamflow, soil moisture, and groundwater supplies. Relatively little is known about the climatology of extreme ablation events in the eastern United States, and the causal atmospheric forcing mechanisms behind such events. Studying the Susquehanna River basin over a 50-yr period, here we evaluate the variability of extreme ablation and river discharge events in conjunction with a synoptic classification and global-scale teleconnection pattern analysis. Results indicate that an average of 4.2 extreme ablation events occurred within the basin per year, where some 88% of those events resulted in an increase in river discharge when evaluated at a 3-day lag. Both extreme ablation and extreme discharge events occurred most frequently during instances of southerly synoptic-scale flow, accounting for 35.7% and 35.8% of events, respectively. However, extreme ablation was also regularly observed during high pressure overhead and rain-on-snow synoptic weather types. The largest magnitude of snow ablation per extreme event occurred during occasions of rain-on-snow, where a basinwide, areal-weighted 5.7 cm of snow depth was lost, approximately 23% larger than the average extreme event. Interannually, southerly flow synoptic weather types were more frequent during winter seasons when the Arctic and North Atlantic Oscillations were positively phased. Approximately 30% of the variance in rain-on-snow weather type frequency was explained by the Pacific–North American pattern. Evaluating the pathway of physical forcing mechanisms from regional events up through global patterns allows for improved understanding of the processes resulting in extreme ablation and discharge across the Susquehanna basin. Significance Statement The purpose of this study is to better understand how certain weather patterns are related to extreme snowmelt and streamflow events and what causes those weather patterns to vary with time. This is valuable information for informing hazard preparation and resource management within the basin. We found that weather patterns with southerly winds were the most frequent patterns responsible for extreme melt and streamflow, and those patterns occurred more often when the Arctic and North Atlantic Oscillations were in their “positive” configuration. Future work should consider the potential for these patterns, and related impacts, to change over time.Item Between paranoia and possibility: Diverse economies and the decolonial imperative(Transactions of the Institute of British Geographers, 2022-02-13) Naylor, Lindsay; Thayer, NathanHere we reflect on diverse economies scholarship following Gibson-Graham's call to adopt performative practices for other worlds. Urging scholars to move from paranoia to possibility through weak theory methodology, their call provided momentum for work on economic difference that sustained critiques of capitalocentrism launched in 1996. In this clarion call to read for difference and possibility, a diverse economies framing facilitated a wholesale rejection of strong theory and paranoia. As a subdiscipline in the making, diverse economies scholars are challenged and critiqued as we seek to develop the framework and apply it to economic activities that exist within, alongside, and outside capitalism. Creating the language of diverse economies is continuous; here we consider a geopolitics of knowledge production in reading economic practice for difference, challenging the disuse of strong theory. We argue for deeper engagement with the power imbalances present in building liveable worlds, putting diverse economies and decolonial theory in conversation to address power and strike a balance between paranoia and possibility.Item Beyond the Green Revolution: A roadmap for sustainable food systems research and action(Environmental Research Letters, 2022-09-29) Davis, Kyle Frankel; Dalin, Carole; Kummu, Matti; Marston, Landon; Pingali, Prabhu; Tuninetti, MartaThe Green Revolution produced remarkable achievements in increasing food supply while leading to a suite of compromises for economic, social, and environmental outcomes [1]—including ongoing needs for rural development [2], persistent widespread malnutrition [3] and the transgression of multiple planetary boundaries [4]. To sustainably meet the grand challenge of feeding a growing and more affluent population in the coming decades, there is wide recognition that food system transitions must build upon the benefits of past food system advances while overcoming their many shortcomings [5–7]—a problem further complicated by an increasingly interconnected food system [8–11] and its interactions with a changing climate [12–14]. Food system actors—including policy makers, corporations, farmers, and consumers—must meet this challenge while considering potentially conflicting priorities [15], such as environmental sustainability, economic viability, nutrition and human health, and resilience to climate change and other environmental and socio-political disruptions. Successfully navigating this deep and growing complexity to meet multiple goals simultaneously—while avoiding or minimizing tradeoffs (e.g. [16])—is the crux of achieving sustainable and resilient food systems. New thinking is needed to shed light on the solutions for food system sustainability and the pathways to its realization, including overcoming political economy constraints to effective policy change. Here we take the pulse of our emerging understanding of food system sustainability—drawing from new food systems work in this Focus Issue—and outline three key aims to guide future research and action.Item Closing the Infrastructure Gap for Decarbonization: The Case for an Integrated Mineral Supply Agreement(Environmental Science and Technology, 2022-11-15) Ali, Saleem H.; Kalantzakos, Sophia; Eggert, Roderick; Gauss, Roland; Karayannopoulos, Constantine; Klinger, Julie; Pu, Xiaoyu; Vekasi, Kristin; Perrons, Robert K.Significant amounts of feedstock metals will be required to build the infrastructure for the green energy transition. It is currently estimated, however, that the world may be facing an “infrastructure gap” that could prevent us from meeting United Nations Sustainable Development Goal targets. Prior investigations have focused on the extractive aspects of the mining industry to meet these targets and on looming bottlenecks and regional challenges in these upstream market segments. Scant attention has been paid to the downstream processing segments of the raw materials value chain, which also has a high degree of market concentration. Growing international tensions and geopolitical events have resulted in a shift toward “reshoring” and “near-shoring” of mining processing capabilities as regional powers attempt to make metal supply chains more secure. While increasing resilience, these shifts can also dilute the overall effectiveness of the global mining supply network and subsequently hamper the world’s ability to close the green energy infrastructure gap. We argue that broadening the remit of the International Renewable Energy Agency (IRENA) to include coordinating these mission-critical metal processing functions can mitigate these issues. The G20 is one potential forum for enabling an integrated mineral processing agreement under the auspices of IRENA.Item Coincident buoy- and SAR-derived surface fluxes in the western Weddell Sea during Ice Station Weddell 1992(American Geophysical Union, 2005) Drinkwater, M. R.; Geiger, Cathleen A.; Geiger, Cathleen A., Drinkwater, M. R.; Geiger, Cathleen A.We examine sea ice kinematics relevant to surface fluxes using ERS-1 synthetic aperture radar (SAR) images coincident with buoys in the western Weddell Sea in austral autumn of 1992. Careful matching of temporal and spatial scales shows that buoy- and SAR-derived velocities differ in root-mean-square error (RMSE) by 0.6 cm s(-1) and 7.80 degrees in magnitude and direction, respectively. These values represent agreements of 91.3% and 92.7%, respectively, and correspond to instrument uncertainties. Scaling analysis shows that shear matching is best at the smallest scales (<= 5 km), while divergence is better represented at scales of 40 km and larger. Sensitivity to error propagation shows lower agreement for divergence (47.4%; RMSE = 7.46 x 10-(8) s(-1)), but we find these results sufficient for integrated surface flux comparisons. Using a toy model, we test the effects of aliasing in surface flux determination. The results show that variability associated with storms, ocean tides, inertial oscillations, and other high-frequency forcing affects integrated sea ice growth rates along this continental slope location. Integrated salt and new ice production rates computed from buoys are found to be two times larger than those computed from ERS-1 SAR motion products. We show that these differences in salt and ice production rates result primarily from inadequate temporal resolution of heat flux variability and sea ice divergence. Comparison with other studies shows that the problem is widespread, thereby impacting the modeling of sea ice mass balance and variability. The small-scale processes cited here have significant ramifications for larger scales and the global thermohaline circulation.Item Comparison of Extreme Coastal Flooding Events between Tropical and Midlatitude Weather Systems in the Delaware and Chesapeake Bays for 1980–2019(Journal of Applied Meteorology and Climatology, 2022-04-26) Callahan, John A.; Leathers, Daniel J.; Callahan, Christina L.Coastal flooding is one of the most costly and deadly natural hazards facing the U.S. mid-Atlantic region today. Impacts in this heavily populated and economically significant region are caused by a combination of the location’s exposure and natural forcing from storms and sea level rise. Tropical cyclones (TCs) and midlatitude (ML) weather systems each have caused extreme coastal flooding in the region. Skew surge was computed over each tidal cycle for the past 40 years (1980–2019) at several tide gauges in the Delaware and Chesapeake Bays to compare the meteorological component of surge for each weather type. Although TCs cause higher mean surges, ML weather systems can produce surges just as severe and occur much more frequently, peaking in the cold season (November–March). Of the top 10 largest surge events, TCs account for 30%–45% in the Delaware and upper Chesapeake Bays and 40%–45% in the lower Chesapeake Bay. This percentage drops to 10%–15% for larger numbers of events in all regions. Mean sea level pressure and 500-hPa geopotential height (GPH) fields of the top 10 surge events from ML weather systems show a low pressure center west-southwest of “Delmarva” and a semistationary high pressure center to the northeast prior to maximum surge, producing strong easterly winds. Low pressure centers intensify under upper-level divergence as they travel eastward, and the high pressure centers are near the GPH ridges. During lower-bay events, the low pressure centers develop farther south, intensifying over warmer coastal waters, with a south-shifted GPH pattern relative to upper-bay events. Significance Statement Severe coastal flooding is a year-round threat in the U.S. mid-Atlantic region, and impacts are projected to increase in magnitude and frequency. Research into the meteorological contribution to storm surge, separate from mean sea level and tidal phase, will increase the scientific understanding and monitoring of changing atmospheric conditions. Tropical cyclones and midlatitude weather systems both significantly impact the mid-Atlantic region during different times of year. However, climate change may alter the future behavior of these systems differently. Understanding the synoptic environment and quantifying the surge response and subbay geographic variability of each weather system in this region will aid in public awareness, near-term emergency preparation, and long-term planning for coastal storms.Item Comparison of thermal modeling, microstructural analysis, and Ti-in-quartz thermobarometry to constrain the thermal history of a cooling pluton during deformation in the Mount Abbot Quadrangle, CA(American Geophysical Union, 2017-03-30) Nevitt, Johanna M.; Warren, Jessica M.; Kidder, Steven; Pollard, David D.; Johanna M. Nevitt, Jessica M. Warren, Steven Kidder, and David D. Pollard; Warren, Jessica M.Granitic plutons commonly preserve evidence for jointing, faulting, and ductile fabric development during cooling. Constraining the spatial variation and temporal evolution of temperature during this deformation could facilitate an integrated analysis of heterogeneous deformation over multiple length-scales through time. Here, we constrain the evolving temperature of the Lake Edison granodiorite within the Mount Abbot Quadrangle (central Sierra Nevada, CA) during late Cretaceous deformation by combining microstructural analysis, titanium-in-quartz thermobarometry (TitaniQ), and thermal modeling. Microstructural and TitaniQ analyses were applied to 12 samples collected throughout the pluton, representative of either the penetrative ‘‘regional’’ fabric or the locally strong ‘‘fault-related’’ fabric. Overprinting textures and mineral assemblages indicate the temperature decreased from 400–5008C to <3508C during faulting. TitaniQ reveals consistently lower Ti concentrations for partially reset fault-related fabrics (average: 1264 ppm) than for regional fabrics (average: 31612 ppm), suggesting fault-related fabrics developed later, following a period of pluton cooling. Uncertainties, particularly in TiO2 activity, significantly limit further quantitative thermal estimates using TitaniQ. In addition, we present a 1-D heat conduction model that suggests average pluton temperature decreased from 5858C at 85 Ma to 3328C at 79 Ma, consistent with radiometric age data for the field. Integrated with the model results, microstructural temperature constraints suggest faulting initiated by 83 Ma, when the temperature was nearly uniform across the pluton. Thus, spatially heterogeneous deformation cannot be attributed to a persistent temperature gradient, but may be related to regional structures that develop in cooling plutons.Item Competition for water induced by transnational land acquisitions for agriculture(Nature Communications, 2022-01-26) Chiarelli, Davide Danilo; D’Odorico, Paolo; Müller, Marc F.; Mueller, Nathaniel D.; Davis, Kyle Frankel; Dell’Angelo, Jampel; Penny, Gopal; Rulli, Maria CristinaThe ongoing agrarian transition from smallholder farming to large-scale commercial agriculture promoted by transnational large-scale land acquisitions (LSLAs) often aims to increase crop yields through the expansion of irrigation. LSLAs are playing an increasingly prominent role in this transition. Yet it remains unknown whether foreign LSLAs by agribusinesses target areas based on specific hydrological conditions and whether these investments compete with the water needs of existing local users. Here we combine process-based crop and hydrological modelling, agricultural statistics, and georeferenced information on individual transnational LSLAs to evaluate emergence of water scarcity associated with LSLAs. While conditions of blue water scarcity already existed prior to land acquisitions, these deals substantially exacerbate blue water scarcity through both the adoption of water-intensive crops and the expansion of irrigated cultivation. These effects lead to new rival water uses in 105 of the 160 studied LSLAs (67% of the acquired land). Combined with our findings that investors target land with preferential access to surface and groundwater resources to support irrigation, this suggests that LSLAs often appropriate water resources to the detriment of local users.Item COVID-19, Social Distancing, and an Ethic of Care: Rethinking Later-Life Care in the U.S.(ACME: An International E-Journal for Critical Geographies, 2021-12-16) Kim, Nari; Naylor, LindsayIn 2020, the novel coronavirus (COVID-19) disrupted life around the globe. In the United States, governors issued state of emergency orders and mandated shelter-in-place and social distancing measures. While these measures are important, they ignore the nuances of risk for vulnerable groups, such as older adults. Moreover, social distancing measures made more visible the reality that many patients in care homes often die in isolation. In this commentary, we argue that a rethinking of later-life care is necessary and to understand this need, that critical geographers should expand on how we evaluate care. Here we start from a space of radical care ethics to examine the emotional experience of place and the role it should play in how we think about later-life care. Reflecting on state-mandated social distancing, we show that the current system of geriatric care in the United States does not promote dignified living for older adults and how older adults’ complex emotions are ignored in current later-life care. We conclude by recommending that the emotional experiences of place must be taken into consideration for scholars examining place-based later-life care of older adults.Item Critical facility accessibility and road criticality assessment considering flood-induced partial failure(Sustainable and Resilient Infrastructure, 2022-11-25) Gangwal, Utkarsh; Siders, A. R.; Horney, Jennifer; Michael, Holly A.; Dong, ShangjiaThis paper examines communities’ accessibility to critical facilities such as hospitals, emergency medical services, and emergency shelters when facing flooding. We use travel speed reduction to account for flood-induced partial road failure. A modified betweenness centrality metric is also introduced to calculate the criticality of roads for connecting communities to critical facilities. The proposed model and metric are applied to the Delaware road network under 100-year floods. This model highlights the severe critical facility access loss risk due to flood isolation of facilities. The mapped post-flooding accessibility suggests a significant travel time increase to critical facilities and reveals disparities among communities, especially for vulnerable groups such as long-term care facility residents. We also identified critical roads that are vital for post-flooding access to critical facilities. The results of this research can help inform targeted infrastructure investment decisions and hazard mitigation strategies that contribute to equitable community resilience enhancement.Item Crop harvests for direct food use insufficient to meet the UN’s food security goal(Nature Food, 2022-05-12) Ray, Deepak K.; Sloat, Lindsey L.; Garcia, Andrea S.; Davis, Kyle F.; Ali, Tariq; Xie, WeiRising competition for crop usage presents policy challenges exacerbated by poor understanding of where crops are harvested for various uses. Here we create high-resolution global maps showing where crops are harvested for seven broad use categories—food, feed, processing, export, industrial, seed and losses. Yields for food crops are low relative to other crop-use categories. It is unlikely, given current trends, that the minimum calorie requirement to eliminate projected food undernourishment by 2030 will be met through crops harvested for direct food consumption, although enough calories will be harvested across all usages. Sub-Saharan African nations will probably fall short of feeding their increased population and eliminating undernourishment in 2030, even if all harvested calories are used directly as food.Item Crop switching can enhance environmental sustainability and farmer incomes in China(Nature, 2023-03-16) Xie, Wei; Zhu, Anfeng; Ali, Tariq; Zhang, Zhengtao; Chen, Xiaoguang; Wu, Feng; Huang, Jikun; Davis, Kyle FrankelAchieving food-system sustainability is a multidimensional challenge. In China, a doubling of crop production since 1990 has compromised other dimensions of sustainability1,2. Although the country is promoting various interventions to enhance production efficiency and reduce environmental impacts3, there is little understanding of whether crop switching can achieve more sustainable cropping systems and whether coordinated action is needed to avoid tradeoffs. Here we combine high-resolution data on crop-specific yields, harvested areas, environmental footprints and farmer incomes to first quantify the current state of crop-production sustainability. Under varying levels of inter-ministerial and central coordination, we perform spatial optimizations that redistribute crops to meet a suite of agricultural sustainable development targets. With a siloed approach—in which each government ministry seeks to improve a single sustainability outcome in isolation—crop switching could realize large individual benefits but produce tradeoffs for other dimensions and between regions. In cases of central coordination—in which tradeoffs are prevented—we find marked co-benefits for environmental-impact reductions (blue water (−4.5% to −18.5%), green water (−4.4% to −9.5%), greenhouse gases (GHGs) (−1.7% to −7.7%), fertilizers (−5.2% to −10.9%), pesticides (−4.3% to −10.8%)) and increased farmer incomes (+2.9% to +7.5%). These outcomes of centrally coordinated crop switching can contribute substantially (23–40% across dimensions) towards China’s 2030 agricultural sustainable development targets and potentially produce global resource savings. This integrated approach can inform feasible targeted agricultural interventions that achieve sustainability co-benefits across several dimensions.Item Culturally appropriate shifts in staple grain consumption can improve multiple sustainability outcomes(Environmental Research Letters, 2021-11-24) Wei, Dongyang; Davis, Kyle FrankelDiets exercise great influence over both human and environmental health. While numerous efforts have sought to define and identify sustainable diets, there remains a poor understanding of the extent to which such shifts are feasible when taking into account local dietary preferences. Accounting for 40% of dietary calories and 46% of global cropland, cereals offer an important food group by which culturally appropriate dietary shifts may achieve large sustainability benefits. Here we combine country-specific information on dietary cereal supply with nutrient content values, CO2 nutrient penalties, and environmental footprints to quantify the outcomes of adopting two feasible dietary shifts—maximizing the share of C4 cereals (e.g. maize, millet, sorghum) based on historical shares and increasing the share of whole grains. Our results show that increasing the share of whole grains can increase nutrient supply (+7% protein, +37% iron, +42% zinc) and overcome the nutrient-depleting effects of elevated CO2 (eCO2) and that maximizing the share of C4 cereals can substantially reduce environmental burden (−12% greenhouse gas emissions, −11% blue water demand), particularly in Africa and the Middle East. We also find that a combination of the two strategies would likely produce strong co-benefits between increased nutrient supply and reduced environmental impacts with mixed outcomes for offsetting the effects of eCO2. Such simultaneous improvements are particularly important for food insecure regions such as West Africa and Southeast Asia. These findings demonstrate important opportunities to identify sustainable diets that incorporate local preferences and cultural acceptability. Such considerations are essential when developing demand-side solutions to achieve more sustainable food systems.Item Daily reservoir inflow forecasting using weather forecast downscaling and rainfall-runoff modeling: Application to Urmia Lake basin, Iran(Journal of Hydrology: Regional Studies, 2022-12-01) Meydani, Amirreza; Dehghanipour, Amirhossein; Schoups, Gerrit; Tajrishy, MassoudStudy region: This study develops the first daily runoff forecast system for Bukan reservoir in Urmia Lake basin (ULB), Iran, a region suffering from water shortages and competing water demands. Study focus: A weather forecast downscaling model is developed for downscaling large-scale raw weather forecasts of ECMWF and NCEP to small-scale spatial resolutions. Various downscaling methods are compared, including deterministic Artificial Intelligence (AI) techniques and a Bayesian Belief Network (BBN). Downscaled precipitation and temperature forecasts are then fed into a rainfall-runoff model that accounts for daily snow and soil moisture dynamics in the sub-basins upstream of Bukan reservoir. The multi-objective Particle Swarm Optimization (MOPSO) method is used to estimate hydrological model parameters by maximizing the simulation accuracy of observed river flow (NSEQ) and the logarithm of river flow (NSELogQ) in each sub-basin. New hydrological insights for the region: Results of the weather forecast downscaling model show that the accuracy of the BBN is greater than the various deterministic AI methods tested. Calibration results of the rainfall-runoff model indicate no significant trade-off between fitting daily high and low flows, with an average NSEQ and NSELogQ of 0.43 and 0.63 for the calibration period, and 0.54 and 0.57 for the validation period. The entire forecasting system was evaluated using inflow observations for years 2020 and 2021, resulting in an NSE of 0.66 for forecasting daily inflow into Bukan reservoir. The inflow forecasts can be used by policymakers and operators of the reservoir to optimize water allocation between agricultural and environmental demands in the ULB. Graphical Abstract: Available at https://doi.org/10.1016/j.ejrh.2022.101228Item Detection of climate transitions and discontinuities by Hurst rescaling(International Journal of Climatology, 2021-12-20) Legates, David R.; Outcalt, Samuel I.The method of Outcalt et al., based on work developed originally by Hurst, is re-examined to evaluate its efficacy in delineating changes in trends and identifying regime shifts in climatic-related time series. This technique is based on the concept of the normalized rescaled running sum where temporal changes in the Hurst exponent can be used to identify climatic trends from one regime to another as each regime has a characteristic distribution that differs from the statistical characteristics of the complete time series. An examination of the temporal change in the amplitude of the normalized rescaled running sum can be used as a method to identify these regime changes, which may be either real (i.e., a true climatic shift) or induced (i.e., through a change in measurement bias, station location, or other nonclimatic influence). Examples shown here focus on examining time series of the Pacific Decadal Oscillation, Arctic thaw depth, the Northern Hemisphere snow cover extent, treeflow data from Lees Ferry (AZ), North Atlantic tropical cyclone frequency, and central England air temperatures.