The production of specialty crops in the Pacific Northwest is an economically important industry and one that is likely to be heavily impacted by rising temperatures and decreasing snowpack associated with climate change. The purpose of this study was to interview small-scale specialty crop farmers in Oregon's Willamette Valley and Central Coast Range to understand how they are experiencing climate change and what information they are using to make farm-management decisions related to the climate. Semi-structured interviews were conducted with seven specialty crop farmers on farms in Corvallis, OR or at the Corvallis Farmers' Market. The farmers believe that factors such as high temperatures earlier in the growing season, hotter temperatures, increased weather variability, and decreased precipitation are impacting their farms. The interviewed farmers employ multiple strategies to manage the risk of their work, which include incorporating heterogeneity and flexibility into their management, using irrigation and sheltering infrastructure to control the microclimates for crops, and selecting different crops or crop varieties. When considering the information sources farmers use when making decisions about climate and weather, some farmers use short-term weather forecasts, but none rely on longer-term forecasts. As the farmers in this study are all concerned about climate change, having accessible information for the upcoming season and future climate could be helpful if they believe that long-term forecasts are credible.

Decision makers and water managers throughout New England desire to understand how development and land-use change, especially under a changing climate, will affect high flows, flooding, and stormwater. We use the New England Landscape Futures (NELF) project to demonstrate the potential for translating participatory scenarios to simulations of land use and land cover and the resulting effects on streamflow. In addition to projecting recent trends, four other landscape scenarios were co-designed through a structured process that engaged over 150 stakeholders and scientists from throughout New England. Daily streamflows were simulated with the Soil and Water Assessment Tool (SWAT) to investigate how high flows vary among the scenarios for the less developed Cocheco River watershed in southeast New Hampshire and the more urbanized Charles River watershed in eastern Massachusetts. The hydrologic response of each land-use scenario was simulated for both historic weather (1999-2017) and downscaled weather for 2049-2067 from the CCSM 4.0-RCP 8.5 model-pathway from the Community Earth System Model. Differences among the land-use scenarios led to no differences in average annual water yield and ET. Loss of forest and increase in urban area reduces the baseflow contribution to streamflow while increasing storm runoff. This shift in partitioning did not affect the frequency of high flows (5% exceedence). The increase in runoff did lead to a concomitant increase in the average annual maximum flow, and the effect is larger in the Charles River watershed than in the Cocheco. Under the future climate, a combination of increased precipitation and decreased potential evaporation results in increased streamflow relative to the scenarios modeled with the historic weather. As a fraction of precipitation, surface runoff remains the same, and baseflow increases. The frequency of high flows increases, with the 5%-exceedence flow (under historical weather) being met or exceeded 8-9% of the days. Annual maximum flows also increased for the future climate, and the effects of land-use change and climate on annual maximum flows are comparable. These water-related results fit into a larger framework for evaluating ecosystem services associated with socially relevant landscape scenarios.

Advances in understanding of stratified-shear turbulence have been made over the last several decades through ocean measurements, which typically quantify net turbulent quantities, and through laboratory and direct numerical simulations (DNS), which have sufficient resolution to investigate the internal dynamics of individual instabilities. Stratified shear layer thicknesses in these environments can range from cms for laboratory and DNS studies to 100s of m in ocean environments, complicating extrapolation of results between environments. This study provides a direct comparison of field measurements from oceanic stratified shear environments with laboratory flows, demonstrating that non-dimensional turbulent quantities at ocean scales can fall several orders of magnitude below laboratory values for similar bulk Richardson numbers, , suggesting that scale plays a critical role. Here, the dependence of the non-dimensional turbulence intensity, expressed as , on a layer Reynolds number, , is evaluated via a ratio of the shear layer thickness, , to the Kolmogorov turbulence length scale,η. Using a mechanistically driven, empirical approach a parameterization for turbulence is defined in parameter space, and by extension, - parameter space. The mechanisms invoke a “building block” approach to initiation of stratified shear turbulence, which explains the presence of turbulence values exceeding the critical value of the gradient Richardson number, , and increases in at low . The results describe a new “turbulent geography” in the – plane that can build intuition about stratified shear turbulence and facilitate interpretation of ocean measurements in comparison to laboratory experiments and modeling.

The appearance of alluvial channel networks is similar to that of trees and their roots what have self-similarity. In the process of a fluvial evolution, alluvial channels are inner-shaping, adjust to achieve a stable equilibrium state, and form some channel patterns that establish balance relationships between the parameters of the local turbulence field of the channel flow and the supplies of the water discharge, sediment transport rate and sediment composition in a river basin. Therefore, the characteristic dimension lΩ of the representing eddy of the turbulence field of the channel flow and the dynamic characteristic length ld of a catchment are supposed to respectively represent the local dynamic factor and the dynamic factor stream along. The geometric dimension of the cross section of a channel is deduced. And then, it is clarified that the self-similarity equation of cross section morphology has similarity relationship conjugated with the self-similarity equation of the widths of a channel network. One of the hydraulic geometry relationship equations reveals that the nominal dimension lΩ and the gravitational acceleration g have the same effects on shaping channel patterns in the fluvial processes. Finally, the governing equations for channels in regime are derived. It is considered that the regime situation can be regarded approximately to that of the bankfull water level of channels, and exponential relationship equations of channels in regime are given systematically. All the results of the study are consistent with the actual statistical data of the channels of Songhua River Basin.

We develop a Hamiltonian Monte Carlo (HMC) sampler which solves a multi-parameter elastic full-waveform inversion (FWI) in a probabilistic setting for the first time. This gives novel access to the full posterior distribution for this type of highly non-linear inverse problem. Typically, FWI has focused on using gradient descent methods with proper regularization to iteratively update models to a minimum misfit value. Non-uniqueness and uncertainties are mostly in this approach. Bayesian inversions offer an alternative by assigning a probability to each model in model space given some data and prior constraints. The drawback is the need to evaluate a very large number of models. Random walks from Markov chains counter this effect by only exploring regions of model space where probability is significant. HMC method additionally incorporates gradient information, i.e. local structure, typically available for numerical waveform tomography experiments. So far, HMC has only been implented for acoustic FWI. We implement HMC for multiple 2D elastic FWI set-ups. Using parallelized wave propagation code, wavefields and kernels are computed on an regular numerical grid and projected onto basis functions. These gradients are subsequently used to explore the posterior space of different target models using HMC. The free parameters in these experiments are P and S velocity, and density. Although simulating Hamiltonian dynamics in the resulting phase space is approximated numerically, the results of the Markov chain are nevertheless very insightful. No prior tuning of kernels, data or model space is required, under the constraint that the sampler is properly tuned. After a burn in phase during which the mass matrix is iteratively optimized, the Markov chain is run on multiple nodes. After approximately 100,000 samples (combined from all nodes) the Markov chain mixes well. The resulting samples give access to the full posterior distribution, including the mean and maximum-likelihood models, conditional probabilities, inter-parameter correlations and marginal distributions.

The dynamic balance of sediment elevating and settling in the turbulence field of a river channel is an outcome of two aspects: one is the cycling process of the bursting and weeping of a turbulence that makes the sediment suspend from the channel bed surface in the turbulence field; the other is the gravity of the Earth that makes the sediment fall down. In order to quantitatively express the turbulent flow functions such as the bursting and sweeping, momentum transfer and energy consumption onset of turbulence, and the ability to suspend sediment in the turbulence field, the nominal eddy named “Ω” eddy, as a representative eddy in the turbulence field, is defined and endows it with the functions, whose spatial dimension moving along the water depth in the turbulence field is 3/2 and nominal dimension and quantity are derived. Then, the momentum principle of water and sediment movement in turbulent field is established. For the dynamic balance state of sediment suspending in the turbulent flow field, an energy relationship for the sediment suspending is derived, which is proved that 25% of the vertical (gravity direction) component of the momentum in turbulent field is transferred to sediment particles for jumping and suspending. Thus, the formula of sediment carrying capacity of the channel water flow is derived which does not need to be calibrated by observed data and can be directly used for the calculation of sediment transportation. The study has both theoretical significance and engineering value.

Mercury is a notorious pollutant causing severe nerve diseases. This metal has a semi-volatile nature under the STP condition, therefore, it is emitted to atmosphere as gaseous elemental mercury (GEM) from variety of sources, such as the ocean surface, volcanoes, and fossil fuel combustion. Because of the long atmospheric life time, mercury is transported for long distance and spreads globally, consequently ubiquitous in the natural environment. The current global model for mercury cycle assumes that oxidation is a predominant pathway for the removal of GEM from the atmosphere. To the best of our knowledge, however, none of heterogeneous uptake of GEM by atmospheric water, such as cloud, fog, and rain droplets, has been evaluated to date. For more accurate understanding of the mercury cycle, the evaluation of this process is necessary. We conducted laboratory experiments to evaluate GEM uptake by artificial atmospheric water. The experiments were carried out using a 3 L glass cell. 500 mL of acidified water was transferred into the cell, and approximately 50 to 10 ng m-3 of GEM gas mixture was continuously flowed into and out of the open space above the solution in the cell. After a definite time the solution was quantitatively analyzed for mercury to investigate the uptake. At this presentation preliminary results of the uptake experiments will be presented.

To improve surface mass balance (SMB) estimates for the Greenland Ice Sheet (GrIS), we develop a spatially and temporally high resolution polar regional climate model combining the Japan Meteorological Agency Non-Hydrostatic atmospheric Model and the Snow Metamorphism and Albedo Process model (NHM–SMAP). At present, the horizontal resolution of the model is set to be 5 km with the temporal interval of 1-hour. The model forced by the Japanese 55year Reanalysis (JRA-55) has been evaluated in the GrIS during the 2011–2014 mass balance years using in-situ surface meteorological and stake measurement data [1]. Results show that the model reproduced the measured features of the GrIS climate, diurnal variations, and even a meso-scale strong wind event. In particular, it reproduces the GrIS surface melt area extent well. Recently, near real-time calculations with the model are conducted operationally. Here we introduce the concept and framework of the model, then present performance of the model from various aspects. In addition, some new results from the operational near-real time calculations will be shown and discussed. Reference [1] Niwano et al. (2018) NHM-SMAP: Spatially and temporally high resolution non-hydrostatic atmospheric model coupled with detailed snow process model for Greenland Ice Sheet. The Cryosphere, 12, 635-655, doi:10.5194/tc-12-635-2018.

Water security hinges on water storage. Although the public and water resources planners habitually look to surface reservoirs for storage solutions, by far the largest ‘space’ to store water is underground. The very nature of freshwater distribution on Earth foreshadows future water storage solutions, as 97% of all circulating freshwater globally is in groundwater. Similarly, although 140 surface reservoirs in California can store 52 km3(42 MAF), in the Central Valley aquifer system there is room for another ~170 km3(~140 MAF) owing to past depletion. Despite the state’s Mediterranean climate in which nearly all of the precipitation occurs between November and March when demand is lowest, historically massive snow storage and spring-summer snow melt synchronized well with surface reservoir replenishment during April-July. This system built around snow storage as a means of mitigating winter flood threats and delaying runoff until the beginning of the peak demand season is clearly demonstrating significant vulnerabilities to climate change and drought. Climate warming has already produced decades of declining snowmelt runoff, making surface reservoir storage more difficult. Moreover, as demonstrated during the 2012-16 drought, in the face of droughts longer than a few years, the surface storage offers inadequate long-term water security. This fact, the fact that California during pre-development times of the last millennium experienced far longer droughts, and ongoing climate change clearly indicate the need for a different strategy that more fully leverages both surface and subsurface storage. Kocis and Dahlke (2017) show that increasing winter runoff during wet and normal years provide enough high-magnitude flows to support a strategy of diverting flood flows for groundwater storage. This “flood-MAR” (managed aquifer recharge) approach will require a massive change in winter water and land management that exploits recharge opportunities on irrigated farm lands and in areas with suitable soils and subsurface geology. A case study in the American-Cosumnes Rivers portion of the Central Valley shows how total system water storage can be increased dramatically through diversion of high-magnitude flows and reoperation of both the surface and subsurface reservoirs including economic incentives.

Climate change is forcing the ski industry to modify snow-making strategies and facility operations. Over-summer snow storage is an adaptation successfully employed by high-elevation and/or high-latitude ski centers in Europe, Canada, and Asia. The process involves stockpiling winter snow and storing it beneath insulation (e.g., wood chips) through summer. Current methods are empirically-based with few studies quantifying snowmelt through summer or comparing insulation strategies. In this project, we evaluate the feasibility of over-summer snow storage in Vermont, northeastern North America. Soil temperatures were recorded since June 2017 with sensors 5, 20, 50 cm and 1 m below the ground surface. In March 2018, two, 200 m3 snow piles were covered in plastic and wood chips; we monitored their volume bi-weekly through the melt season using terrestrial LiDAR. We also measured air to snow temperature gradients under various insulation materials: rigid foam, open cell foam, and wet wood chips, all with and without reflective coverings. Away from snow piles, ground temperatures at 1 m depth were ~7C in spring 2017, rising to 12C in summer, and falling to just above 0C in winter. As depth decreased, ground temperature became more responsive to air temperature; ground temperature lagged air temperature at all depths. Below summer snow piles, soil temperature at all depths remained near freezing through the summer as cold meltwater percolated into the ground. Snow was lost from each pile at a similar rate (~1.3 m3 day-1) from late March to mid-June; melt then accelerated slightly in response to increased air temperature, solar radiation, and humidity. Large crevasses formed in both piles along the edge of the plastic sheeting which exposed snow to direct sunlight. Temperature was at or above 10C over the snow below both rigid foam and open-cell foam with a strong diurnal variation, regardless of the addition of a reflective blanket. Beneath wet wood chips covered with a reflective blanket, temperature remained close to freezing even though air temperature was > 30C. There was no diurnal variation, indicating that wood chips effectively buffered thermal swings. It appears that a reflective surface over >20cm of wet wood chips is most effective at minimizing summer snow melt in humid, northeastern North America.

The Earth’s crystalline inner core (IC) solidifies from the liquid Fe alloy of the outer core (OC), which releases latent heat and light elements sustaining the geodynamo. Variability in solidification regime at the inner core boundary (ICB) may result in compositional and thermal multi-scale mosaic of the IC surface and dissimilarity of its hemispheres. Both the mosaic and hemisphericity are poorly constrained, not least due to a lack of available sampling by short-period reflected waves. Measured amplitude ratio of seismic phases of PKiKP and PcP reflected, respectively, off the inner and outer boundary of the liquid core, yields direct estimate of the ICB density jump. This parameter is capable of constraining the inner – outer core compositional difference and latent energy release, but is not well known (0.2–1.2 g/cub cm), and its distribution is obscure. Travel time measurements of PKiKP and PcP waveforms can be useful in terms of getting an insight into fine structure of ICB and its topography. We analyse a new representative sample of pre-critical PKiKP/PcP differential travel times and amplitude ratios that probes the core’s spots under Southeastern Asia and South America . We observe a statistically significant systematic bias between the measurements collected in western and eastern hemispheres, and carefully examine its origin. Separating the effects of core-mantle boundary (CMB) and ICB on the measured differentials is particularly challenging and we acknowledge that a whole class of physically valid models involving D” heterogeneities and lateral variation in lower mantle attenuation can be addressed to account for the observed hemisphericity. However, we find that variance in PKiKP-PcP differential travel times measured above the epicentral distance of 16 degrees is essentially due to mantle heterogeneities. Analysis of data below this distance indicates the ICB density jump under Southeastern Asia can be about 0.3 g/cub. cm, which is three times as small as under South America where also the thickness of the liquid core can be by 1-3 km in excess of the one in the East. The findings are interpretable as evidence for IC hemispherical asymmetry whereby crystallization dominates in the West and melting in the East (and not vice versa) or in terms of two disconnected mosaic patches with contrasting properties.

We investigate electron whistler wave activity in the flux pile-up region of an asymmetric reconnection event at the magnetopause. The ~140Hz waves are right-hand polarized with a wave normal angle of ~20 degrees and track the magnetic field strength, consistent with electron whistler waves. Poynting flux direction indicates that the waves were generated at the reconnection site. The waves modulated the flux of 500eV electrons propagating parallel and anti-parallel to the magnetic field, as observed by EDI. Only two of four MMS spacecraft observe similar wave activity, suggesting that the waves are isolated within a narrow flux tube. While it is not possible to use the wave telescope technique, current density produced by 500eV electrons provides a means of estimating the parallel wave vector, k, from a single spacecraft. In addition, we fit the FPI electron parallel energy distribution with a kappa function then use Liouville mapping with 500eV EDI electrons to determine the parallel wave potential, 𝝓, and electric field, E. Combining this with the wave normal angle and Poynting flux direction provides an estimate for the perpendicular components of k and E.

The concept of an Interstellar Probe (ISP) offers an intriguing combination of scientific break-throughs in several disciplines. These include a global view of our heliosphere, unperturbed sampling of the interstellar medium, discoveries of Kuiper Belt Objects, and many others. The current mission concept of the ISP aims at reaching a distance of 1000 au away from the Sun within this century, far beyond the heliopause at roughly 100-200 au. In this presentation, we investigate basic requirements for an Energetic Neutral Atom (ENA) instrument onboard the ISP for the energy range between 10 eV and 5 keV. An ENA is produced when a fast ion exchanges its charge with an ambient neutral atom. The resulting ENA leaves the source region on a straight trajectory, no longer influenced by electromagnetic fields. This allows an ENA camera to image the ion distribution of remote plasma regions. We calculate the energy spectrum of heliospheric ENAs an observer would see from a given vantage point inside or outside the heliopause. Since the global shape of the heliosphere is unknown yet, we use two analytical models to derive proton flowlines for two different heliospheric shapes: the Parker model [Parker 1961] modified with a termination shock and the analytical representation of a full MHD model [Röken et al. 2015, Kleimann et al. 2017]. The ENA intensity then is the line-of-sight integral of proton density times the local density of neutral hydrogen times the charge-exchange cross-section. We disregard any other neutral species inside the heliosphere and we only consider protons as source for ENAs. The proton populations included are the supersonic solar wind and pickup ions inside the termination shock and the shocked solar wind and pickup ions between termination shock and heliopause. The calculated ENA intensities are first compared to the globally distributed ENA flux measured by the Interstellar Boundary Explorer and Cassini in the inner solar system in the energy range from 10 eV to 55 keV. We then proceed to calculate the ENA intensity as seen by an observer at other positions near or beyond the heliopause. These predictions can serve as a rough guideline for the mission concept of ISP: which trajectory offers the most interesting view on the heliosphere in ENAs and which technical requirements should a low-energy ENA imager meet?

A direct comparison of hydrometeor types (HMT) from state-of-the-art hydrometeor classification schemes (HMC) with modelled hydrometeors (ICOL-LAM, operational weather predictions model of the German Weather Service) is challenging, e.g. due to different HMT definitions and numbers and difficulties to identify dominant types in mixtures of hydrometeors. A comparison of published HMCs even revealed significant differences between the membership functions used for the same hydrometeor types (Figure 1), emphasizing again the high uncertainty in scattering simulations for ice hydrometeors because of their complex geometries, dielectric properties, and largely unknown size and orientation distributions. The HMCs were applied to perturbed polarimetric variables observed by the X-band Radar in Bonn (BoXPol) to test their robustness against measurement errors and show that especially in the regions with solid precipitation misclassification in hydrometeor typing occurs often. Thus, a dual strategy to evaluate the hydrometeor type representation in ICON-LAM is presented: i) Classification after clustering of the data is assumed to reduce the sensitivity of the decision to the uncertainty of scattering simulations. First an agglomerative hierarchical clustering of the radar pixels based on their similarity in multi-dimensional polarimetric signatures is applied, and afterwards for each identified cluster a comparison of the distributions of polarimetric moments with scattering simulations or membership functions for different HMT is performed. ii) A direct comparison of multivariate simulated and observed distributions of polarimetric moments. These comparisons will be performed for different heights and/or space-time subsets, and for clusters with similar HMT in the model and the observations as identified with the advanced radar-based hydrometeor classification scheme. Results for a set of case studies observed with the polarimetric X-band radar composite in Bonn, Germany, will be presented.

The basaltic effusive eruption at Mt. Fagradalsfjall began on March 19, 2021, ending a 781-year hiatus on Reykjanes Peninsula, Iceland. By late September 2021, 32 near real-time photogrammetric surveys were completed using satellite and airborne images, usually processed within 3–6 hours. The results provide unprecedented temporal data sets of lava volume, thickness, and effusion rate. This enabled rapid assessment of eruption evolution and hazards to populated areas, important infrastructure, and tourist centers. The mean lava thickness exceeds 30 m, covers 4.8 km2 and has a bulk volume of 150 ± 3 × 106 m3. The March–September mean effusion rate is 9.5 ± 0.2 m3/s, ranging between 1–8 m3/s in March–April and increasing to 9–13 m3/s in May–September. This is uncommon for recent Icelandic eruptions, where the highest discharge usually occurs in the opening phase.

Sediment fluxes at the estuary-sea interface modulate estuary morphologies and impact particle matter exchanges between marine and continental sources along the land-sea continuum. However, meteorological forcing (e.g., extreme events) and human activities (e.g., estuary deepening) drive pressures on estuary physical functioning, hence threatening estuarine habitats and their ecosystem services. There is an increasing societal need to better predict the potential trajectories of estuarine sediment fluxes resulting from natural and anthropogenic pressures. Nevertheless, it is difficult to derive generalizations from site-specific studies; thus, multi-site approaches appear necessary to move toward a global conceptualization of estuarine sediment transfers. This study explores 10-year numerical hindcasts of three contrasted macrotidal estuaries (Gironde, Loire, and Seine estuaries; France) to disentangle the relative contributions of hydrometeorological and morphological forcing on net sediment fluxes between estuaries and coastal seas. Our results highlight that intense wave events induce fine sediment (≤100 μm) export to the sea but coarser sediment (≥210 μm) import within the estuary. Remarkably, moderate to large river flows support mud import within the estuary. In addition, the Seine Estuary morphological changes due to human activities (i.e., estuary deepening and narrowing) increase fine sediment import within the estuary, shifting the estuary from an exporting to importing system. We propose a conceptualization of mud flux response to river flow and wave forcing, as well as anthropogenic pressures. It provides valuable insights into particle transfers along the land-sea continuum, contributing to a better understanding of estuarine ecosystem trajectories under global changes.

Cyclostratigraphy’s near 100% success rate in statistical cycle identification suggests confirmation bias; absence of cyclicity is not regarded as a possible outcome. Vaughan et al 2011 (VBS) showed that the usual methods of estimating confidence levels (CLs) admit numerous false cycle detections, but in subsequent debate it is asserted that the corrections recommended by VBS do not apply in cyclostratigraphy because they lead to rejection of the expected orbital periods. Is there a deeper problem? VBS particularly criticised universal failure to correct CLs for the unavoidably multiple nature of significance tests of power spectra. However, the multiple-test problem is compounded by assumptions of unlimited freedom to vary procedures to allow for properties of individual datasets. Statistical analysis in cyclostratigraphy operates in a large variable-space, both of target hypotheses (many orbital cycles and combinations thereof), and of procedures (many pre- and syn-processing options). Each of the many data-contingent choices made before and during spectral analysis and significance-testing implies the existence of alternatives: in effect, the reported analysis is only one of many. Given that multiple experiments will eventually achieve a positive result purely by chance, unadjusted significance thresholds will result in large numbers of spurious cycle identifications, a possible explanation for observed success rates. Additional multiplicity is implied by the practice of treating CLs as a guide, rather than as a definitive signal:noise discriminator; treating CLs as movable (or even optional) negates the concept that the particular dataset is just one realisation of many permitted by the noise model; without pre-selection of a CL the statistics are meaningless. Suggestions for practical improvements include: better hypothesis formulation (with attention to the prior probability of signal preservation in an unreliable recording medium); more care in discriminating between the exploratory (hypothesis-setting) and confirmatory (hypothesis-testing) modes of data analysis; advance definition of analytical protocols; and publication of all results whether positive or negative. Reference: Vaughan et al 2011: doi:10.1029/2011PA002195.

Brazil is one of the richest countries in water resources and is currently the second largest global supplier of food and agricultural products. Furthermore, more than 70% of Brazilian energy comes from hydropower. Therefore, to ensure water availability for future generations it is necessary to consider the Nexus thinking (water, food, energy, ecosystem service, and social aspects integrated) in the country. However, few studies have been developed considering the Nexus thinking in Brazil. Understanding the interconnected risks and vulnerability to these sectors under climatic change conditions is crucial for the development of sustainable resources management plans and for mitigating competition among them. Here, we assess the Food-Energy-Water Nexus considering climate and land cover and land use changes (LCLUC) scenarios in the São Francisco river basin. This basin is the third largest basin in Brazil and supplies water to approximately 14 million inhabitants, with the Metropolitan Region of Belo Horizonte being the most populous area. The São Francisco river has been used for water supply, irrigation, agriculture and transportation by waterways, but its preponderant use is for hydroelectric power generation. However, this basin has been suffering from LCLUC and drought that has plagued the region since 2012. In addition, part of the river flow has been diverted due to the transposition of the São Francisco river to supply water to the semi-arid region of Brazil. We will calibrate and evaluate the Soil and Water Assessment Tool (SWAT) using hydrometeorological data from 1972 to 2017. We will also use LCLUC scenarios from the OTIMIZAGRO model and regional climate change models (HadGEM2-ES and MIROC5, RCP 4.5 and 8.5). Then, we will compute the demands of water by different sectors and integrate water availability and demand to reach an optimal water use based on the Nexus thinking. Our results will provide decision-makers with information regarding the risks and trade-offs and will support water resources management decisions in order to allocate scarce water resources toward food or energy.