Drought Scenarios Research Articles

Genome-Wide Analysis of Yield in Europe: Allelic Effects Vary with Drought and Heat Scenarios.

Assessing the genetic variability of plant performance under heat and drought scenarios can contribute to reduce the negative effects of climate change. We propose here an approach that consisted of (1) clustering time courses of environmental variables simulated by a crop model in current (35 years × 55 sites) and future conditions into six scenarios of temperature and water deficit as experienced by maize (Zea mays L.) plants; (2) performing 29 field experiments in contrasting conditions across Europe with 244 maize hybrids; (3) assigning individual experiments to scenarios based on environmental conditions as measured in each field experiment; frequencies of temperature scenarios in our experiments corresponded to future heat scenarios (+5°C); (4) analyzing the genetic variation of plant performance for each environmental scenario. Forty-eight quantitative trait loci (QTLs) of yield were identified by association genetics using a multi-environment multi-locus model. Eight and twelve QTLs were associated to tolerances to heat and drought stresses because they were specific to hot and dry scenarios, respectively, with low or even negative allelic effects in favorable scenarios. Twenty-four QTLs improved yield in favorable conditions but showed nonsignificant effects under stress; they were therefore associated with higher sensitivity. Our approach showed a pattern of QTL effects expressed as functions of environmental variables and scenarios, allowing us to suggest hypotheses for mechanisms and candidate genes underlying each QTL. It can be used for assessing the performance of genotypes and the contribution of genomic regions under current and future stress situations and to accelerate breeding for drought-prone environments.

Synthetic Drought Scenario Generation to Support Bottom-Up Water Supply Vulnerability Assessments

AbstractExploratory simulation allows analysts to discover scenarios in which existing or planned water supplies may fail to meet stakeholder objectives. These robustness assessments rely heavily on the choice of plausible future scenarios, which, in the case of drought management, requires sampling or generating a streamflow ensemble that extends beyond the historical record. This study develops a method to modify synthetic streamflow generators by increasing the frequency and severity of droughts for the purpose of exploratory modeling. To support management decisions, these synthetic droughts can be related to recent observed droughts of consequence for regional stakeholders. The method approximately preserves the spatial and temporal correlation of historical streamflow in drought-adjusted scenarios. The approach is demonstrated in a bottom-up planning context using an urban water portfolio design problem in North Carolina, a region whose water supply faces both climate and population pressures. Synth...

Land-use response to drought scenarios and water policy intervention in Lijiang, SW China

As a part of the Asian highlands, Lijiang, in the northwest of Yunnan Province, China, is threatened by climate-induced drought and an increasing water demand by tourism development. Understanding local farmers’ land-use options in response to drought and policy intervention is crucial for future adaptation strategies. We assessed farmers’ land-use options and the socio-economic factors affecting decisions under drought and water policy scenarios using household surveys. From the total of 174 households surveyed, whether under a drought scenario or a drought scenario with water policy intervention, we found that respondents preferred land-use options focusing on four choices: keep current pattern; keep crops, but reduce areas; abandon farming; rent out farmlands. Findings suggest that there is a growing pattern of agricultural abandonment for urban jobs as a strategy to cope with climate change impacts. The results identified a total of five socio-economic factors that have a significant effect on the households’ land-use options. These factors are important for the households’ land-use decisions and could prevent people from altering their livelihood strategies. We provide some specific recommendations which could enhance local households’ potential adaptation to drought, as well as for effective management of water to prevent potential conflicts in the design or implementation of water policy with the local community.

French summer droughts since 1326 CE: a reconstruction based on tree ring cellulose <i>δ</i><sup>18</sup>O

Abstract. The reconstruction of droughts is essential for the understanding of past drought dynamics and can help evaluate future drought scenarios in a changing climate. This article presents a reconstruction of summer droughts in France based on annually resolved, absolutely dated chronologies of oxygen isotope ratios (δ18O) in tree ring cellulose from Quercus spp. Samples were taken from living trees and timber wood from historic buildings at two sites: Fontainebleau (48°23′ N, 2°40′ E; 1326–2000 CE) and Angoulême (45°44′ N, 0°18′ E; 1360–2004 CE). Cellulose δ18O from these sites proved to be a good proxy of summer climate, as the trees were sensitive to temperature and moisture availability. However, offsets in average δ18O values between tree cohorts necessitated a correction before joining them to the final chronologies. Using the corrected δ18O chronologies, we developed models based on linear regression to reconstruct drought, expressed by the standardized precipitation evapotranspiration index (SPEI). The significant correlations between the SPEI and cellulose δ18O (r ≈ −0.70), as well as the verification of the models by independent data support the validity of these reconstructions. At both sites, recent decades are characterized by increasing drought. Fontainebleau displays dominantly wetter conditions during earlier centuries, whereas the current drought intensity is not unprecedented in the Angoulême record. While the δ18O chronologies at the two studied sites are highly correlated during the 19th and 20th centuries, there is a significant decrease in the correlation coefficient between 1600 and 1800 CE, which indicates either a weaker climate sensitivity of the tree ring proxies during this period, or a more heterogeneous climate in the north and the south of France. Future studies of tree ring isotope networks might reveal if the seasonality and spatial patterns of past droughts can explain this decoupling. A regional drought reconstruction based on a combination of the two sites shows good agreement with historical records of grape harvest dates in France, which provide another proxy of summer climate.

Is Change in Ovary Carbon Status a Cause or a Consequence of Maize Ovary Abortion in Water Deficit during Flowering?

Flower or grain abortion causes large yield losses under water deficit. In maize (Zea mays), it is often attributed to a carbon limitation via the disruption of sucrose cleavage by cell wall invertases in developing ovaries. We have tested this hypothesis versus another linked to the expansive growth of ovaries and silks. We have measured, in silks and ovaries of well-watered or moderately droughted plants, the transcript abundances of genes involved in either tissue expansion or sugar metabolism, together with the concentrations and amounts of sugars, and with the activities of major enzymes of carbon metabolism. Photosynthesis and indicators of sugar export, measured during water deprivation, suggested sugar export maintained by the leaf. The first molecular changes occurred in silks rather than in ovaries and involved genes affecting expansive growth rather than sugar metabolism. Changes in the concentrations and amounts of sugars and in the activities of enzymes of sugar metabolism occurred in apical ovaries that eventually aborted, but probably after the switch to abortion of these ovaries. Hence, we propose that, under moderate water deficits corresponding to most European drought scenarios, changes in carbon metabolism during flowering time are a consequence rather than a cause of the beginning of ovary abortion. A carbon-driven ovary abortion may occur later in the cycle in the case of carbon shortage or under very severe water deficits. These findings support the view that, until the end of silking, expansive growth of reproductive organs is the primary event leading to abortion, rather than a disruption of carbon metabolism.

Moving the Conversation on Climate Change and Inequality to the Local: Socio-ecological Vulnerability in Agricultural Tanzania.

Climate change is expected to shift seasonality in Tanzania, while smallholder farmers' livelihoods and the economy rely upon the success of rainfed agriculture. However, we should not a priori assume doomsday climate vulnerability scenarios of drought and devastation in the rural global South nor, on the other hand, that farmers will optimally employ local knowledge for effective adaptation. Drawing from qualitative fieldwork in two Tanzanian communities, I question these grand narratives of devastation and local adaptive capacity and introduce an approach that brings inequality to the center. Poorer nations are most vulnerable to climate change, but they are not homogenous and neither are the smallholder farmers living within them. I present evidence on the crucial context-specific dimensions of socio-ecological vulnerability for these smallholder farmers-1) water resources and access to them; 2) agricultural knowledge, including farmers' own knowledge and their interactions with sources like government-run agricultural extension and NGOs; and 3) existing drought-coping strategies-and the heterogeneity among farmers across these dimensions. Ultimately, this case demonstrates how climate change can reproduce existing inequalities within nations by drawing upon how farmers currently respond to drought as evidence. I present the difficult and somewhat bleak contexts within which the farmers are coping, but also illustrate the agency that farmers exhibit in response to these conditions and the adaptive capacity they possess. Finally, I call for more sub-national research on climate and inequality by sociologists and draw connections among within-nation inequality, climate change, and agricultural development initiatives.

Projecting Droughts in the Purview of Climate Change under RCP 4.5 for the Coastal Districts of South India

Background: Global warming and the resultant changes in climate may add the risk for human survival. To understand and simulate the temporal and spatial pattern of the impacts in the form of the drought, this local study over Kancheepuram district was carried out. Methods: Dynamical downscaling using RegCM4.4 model under the IPCC's latest RCP 4.5 emission trajectory was used to project future drought scenario for the end of 21st century compared to the reference period 1971-2000. Simulated rainfall data was used to derive Standardized Precipitation index for drought assessments. Results: The projected increment in the mean day time and night time temperature was 2.3oC to 2.5oC respectively. With this the drought situations are also expected to increase towards the end of 21st century .The frequency of moderately dry ( SPI values in the range of 1 to -1.49) drought situations are projected to be more in future. As per the projections, there is going to be 3 to 23% increase in the number of drought days in blocks covering the south east parts of the district such as Tiruporur, Tirukalikundram and Lathur. Application: Mainstreaming of appropriate drought proofing adaptations into developmental planning is the need of the time to enhance its resilience as far the key sectors like agriculture and water management.

Temporal analysis of rainfall (1871–2012) and drought characteristics over a tropical monsoon-dominated State (Kerala) of India

Summary The climate of Kerala is controlled by the monsoon, and the analysis of rainfall and drought scenario, for a period of 141 years (1871–72 to 2011–12), reveals a decreasing trend in southwest monsoon, and increasing trends for post-monsoon-, winter- and pre-monsoon-rainfall. The inconsistent periodicity (2–8 years) of annual- and seasonal-rainfall agrees with the periodicity of El-Nino Southern Oscillation (ENSO). The annual rainfall shows an irregular distribution, and is concentrated roughly in half of the year, which is due to the monsoon-driven climatic seasonality. The rainfall concentration at annual-, southwest monsoon-, and winter-scales exhibits significant decreasing trends, implying decline in the degree of irregularity in annual- and seasonal-rainfall. Temporal distribution as well as severity of the drought events have been analyzed using various drought indicators. The drought pattern is not only related to the rainfall trends, but also to the rainfall concentration (or monthly rainfall heterogeneity). The decreasing rainfall during southwest monsoon contributes to short-term meteorological droughts, which have serious implications on the agricultural sector and water resources of Kerala, while the increasing rainfall during other seasons helps to reduce the drought severity.

Drought-Stressed Tomato Plants Trigger Bottom-Up Effects on the Invasive Tetranychus evansi.

Climate change will bring more drought periods that will have an impact on the irrigation practices of some crops like tomato, from standard water regime to deficit irrigation. This will promote changes in plant metabolism and alter their interactions with biotic stressors. We have tested if mild or moderate drought-stressed tomato plants (simulating deficit irrigation) have an effect on the biological traits of the invasive tomato red spider mite, Tetranychus evansi. Our data reveal that T evansi caused more leaf damage to drought-stressed tomato plants (≥1.5 fold for both drought scenarios). Mite performance was also enhanced, as revealed by significant increases of eggs laid (≥2 fold) at 4 days post infestation (dpi), and of mobile forms (≥2 fold and 1.5 fold for moderate and mild drought, respectively) at 10 dpi. The levels of several essential amino acids (histidine, isoleucine, leucine, tyrosine, valine) and free sugars in tomato leaves were significantly induced by drought in combination with mites. The non-essential amino acid proline was also strongly induced, stimulating mite feeding and egg laying when added to tomato leaf disks at levels equivalent to that estimated on drought-infested tomato plants at 10 dpi. Tomato plant defense proteins were also affected by drought and/or mite infestation, but T. evansi was capable of circumventing their potential adverse effects. Altogether, our data indicate that significant increases of available free sugars and essential amino acids, jointly with their phagostimulant effect, created a favorable environment for a better T. evansi performance on drought-stressed tomato leaves. Thus, drought-stressed tomato plants, even at mild levels, may be more prone to T evansi outbreaks in a climate change scenario, which might negatively affect tomato production on area-wide scales.

Constraint satisfaction problem based on flow graph to study the resilience of inland navigation networks in a climate change context

The T-Ten European program aims at optimizing the transport logistics in Europe by promoting alternative transport modes. Navigation transport offers a competitive and environmentally friendly alternative. Hence, it is foresaw an increase of the navigation transport demand that it will be necessary to accommodate. This will be very challenging particularly in a global change context where less available water resource is expected. A constraint satisfaction problem based on flow graph is proposed in this paper to study the resilience of inland navigation networks against increase of the navigation demand and extreme events. Drought and flood scenarios are simulated considering an network composed of five interconnected navigation reaches. The results show that the designed tools are well adapted to the resilience study of inland navigation networks.

Pasture intake and milk production of dairy cows rotationally grazing on multi-species swards

Increasing plant species diversity has been proposed as a means for enhancing annual pasture productivity and decreasing seasonal variability of pasture production facing more frequent drought scenarios due to climate change. Few studies have examined how botanical complexity of sown swards affects cow performance. A 2-year experiment was conducted to determine how sward botanical complexity, from a monoculture of ryegrass to multi-species swards (MSS) (grasses-legumes-forb), affect pasture chemical composition and nutritive value, pasture dry matter (DM) intake, milk production and milk solids production of grazing dairy cows. Five sward species: perennial ryegrass (L as Lolium), white clover and red clover (both referred to as T as Trifolium because they were always sown together), chicory (C as Cichorium) and tall fescue (F as Festuca) were assigned to four grazing treatments by combining one (L), three (LT), four (LTC) or five (LTCF) species. Hereafter, the LT swards are called mixed swards as a single combination of ryegrass and clovers, whereas LTC and LTCF swards are called MSS as a combination of at least four species from three botanical families. The experimental area (8.7 ha) was divided into four block replicates with a mineral nitrogen fertilisation of 75 kg N/ha per year for each treatment. In total, 13 grazing rotations were carried out by applying the same grazing calendar and the same pasture allowance of 19 kg DM/cow per day above 4 cm for all treatments. Clover represented 20% of DM for mixed and MSS swards; chicory represented 30% of DM for MSS and tall fescue represented 10% of DM for LTCF swards. Higher milk production (+1.1 kg/day) and milk solids production (+0.08 kg/day) were observed for mixed swards than for ryegrass swards. Pasture nutritive value and pasture DM intake were unaffected by the inclusion of clover. Pasture DM, organic matter and NDF concentrations were lower for MSS than for mixed swards. Higher milk production (+0.8 kg/day), milk solids production (+0.04 kg/day) and pasture DM intake (+1.5 kg DM/day) were observed for MSS than for mixed swards. These positive effects of MSS were observed for all seasons, but particularly during summer where chicory proportion was the highest. In conclusion, advantages of grazing MSS on cow performance were due to the cumulative effect of improved pasture nutritive value and increased pasture DM intake that raised milk production and milk solids production.

Reconnaissance Drought Index Based Evaluation of Meteorological Drought Characteristics in Bundelkhand

Among all the different types of extreme events drought is considered to be the most hazardous in terms economic losses and number of people being affected by its impacts, mainly due to the various complexities involved. Since it is rather difficult to predict and forecast droughts with a reasonable degree of certainty, the drought management aspects are also very complex and needs to be fine-tuned with the spatial and temporal variation of drought characteristics. It is therefore mandatory to evaluate the drought characteristics effectively for development of operative action oriented drought management plans. Generally there are many techniques available for the measurement of drought characteristics; however the drought indices can be effectively used to identify the characteristics of various types of droughts including the meteorological, hydrological and agricultural droughts. TheReconnaissance Drought Index (RDI) have been applied to evaluate the characteristics of the meteorological drought in Bundelkhand region located in central India. RDI has been used by many researchersfor identifying the drought characteristics as it is more suited to arid and semi-arid areas. The RDI uses precipitation as well as potential evapotranspiration (PET) and can also be used to analyse the climate change impacts on the drought scenario of a region.ThePenman-Monteith method has been used to estimate the PET. The spatio-temporal variation of drought in Bundelkhand has been investigated and it is found that every drought events has its own characteristics in terms of its areal extent, its progression, withdrawal and severity.

Periphytic algae in a floodplain lake and river under low water conditions

Abstract Drought events will become more frequent due the climate change. In floodplains, periphytic algae are responsible for part of the primary production, are the principal source of organic carbon deposition, play an important role in mineralization and nutrient cycling, and are the base of the food web for many organisms. As algae distribution in aquatic environments is a strong indicator of physical and chemical conditions of the sites, we aimed to determine the structure of periphytic algae in lentic and lotic environments during drought conditions and to uncover the main local abiotic factors in community structuring. We hypothesized diatoms would be more frequent than green algae and desmids at both sites, due to their resistance characteristics, and that higher periphyton algal richness, density and diversity would occur in the lake due to the greater availability of nutrients and the absence of flow. The study was carried out in the Finado Raimundo lake and the Ivinhema river in the Upper Paraná river floodplain during the low water period of 2011. Petioles of the aquatic macrophyte Eichhornia azurea (Sw.) Kunth were used as a substrate for periphytic algae. We found a total of 171 species, 104 species in the lake and 80 in the river. Diatoms were predominant at both sites due to their strategic traits, and between sites, there were different patterns in the periphytic algal community structure, owing to the distinctive physical and chemical characteristics of the lake and the river. Achnanthidium minutissimum (Kützing) Czarnecki and Nitzschia palea (Kützing) W. Smith were the most abundant species in both environments. Our results showed patterns of periphytic algae in a floodplain during drought conditions, which will assist in understanding their structuring during future drought scenarios.

Identification of adaptation traits to drought in collections of maize landraces from southern Europe and temperate regions

Breeding maize for drought tolerance is becoming a major challenge in a context of climate changes and restricted irrigation. Gene banks contain underused genetic resources and adaptation traits for drought tolerance may be present in some populations originating from dry regions. We screened, under contrasted water regimes in dry-Mediterranean climate, populations originating from dry cropping zones in Southern Europe, and other populations from temperate regions with a good combining ability for yield and good agronomic features under drought scenarios in a previous study. We evaluated 78 populations for leaf growth, anthesis-silking interval, number of ears per plant, number of kernels per plot, and grain yield in the presence and absence of water stress, in field conditions, over 2 years. Maximum grain yield and the sensitivity of grain yield to water deficit were highly variable. Positive correlations between sensitivity and performance in well-watered conditions were found for yield and number of kernels. Landraces originating from dry regions were generally less sensitive to water stress and had a limited grain yield potential, with variability observed even among accessions from the same survey area. However, some of them had a relatively high yield under stress conditions. During screening for traits associated with the maintenance of grain yield under conditions of water limitation, we identified sources of drought tolerance in breeding populations and landraces from temperate areas as well as in landraces collected in dry regions, indicating large reservoir of native traits in collections for breeding for drought-prone environments.

Annually resolved late Holocene paleohydrology of the southern Sierra Nevada and Tulare Lake, California

AbstractHere we present 2000 year long, annually resolved records of streamflow for the Kings, Kaweah, Tule, and Kern Rivers in the southwestern Sierra Nevada of California and consequent lake‐level fluctuations at Tulare Lake in the southern San Joaquin Valley. The integrated approach of using moisture‐sensitive tree ring records from the Living Blended Drought Atlas to reconstruct annual discharge and then routing this discharge to an annual Tulare Lake water balance model highlights the differences between these two types of paleoclimate records, even when subject to the same forcing factors. The reconstructed streamflow in the southern Sierra responded to yearly changes in precipitation and expressed a strong periodicity in the 2–8 year range over most of the reconstruction. The storage capacity of Tulare Lake caused it to fluctuate more slowly, masking the 2–8 year streamflow periodicity and instead expressing a strong periodicity in the 32–64 year range over much of the record. Although there have been longer droughts, the 2015 water year represents the driest in the last 2015 years and the 2012–2015 drought represents the driest 4 year period in the record. Under natural conditions, simulated Tulare Lake levels would now be at about 60 m, which is not as low as what occurred multiple times over the last 2000 years. This long‐term perspective of fluctuations in climate and water supply suggests that different drought scenarios that vary in terms of severity and duration can produce similar lake‐level responses in closed lake basins.

Selecting an Efficient Adaptation Level to Uncertain Water Scarcity by Coupling Hydrological Modeling and Economic Valuation

Water planners are increasingly in need of raising more complete information on the hydrological and economic consequences of water management in order to take adequate decisions to secure water supply in the future. This paper combines a scenario-based modeling of future impacts on water availability at basin level with economic valuation to answer the following questions: Which is the most cost-effective adaptation strategy? Is adaptation bringing net benefits to society as opposed to no adaptation? How to select an efficient adaptation level, if any, when facing uncertainty on which future scenario will apply? The model integrates cost-effectiveness analysis of adaptation measures, monetary valuation of avoided scarcity impacts and hydrologic modeling. By testing a set of cost-effective strategies at basin level in several potential short-term drought scenarios, we identify the most efficient strategy that should be implemented by water planners. The model is applied to the Llobregat river, in north-east Spain.

A new framework for evaluating the impacts of drought on net primary productivity of grassland

This paper presented a valuable framework for evaluating the impacts of droughts (single factor) on grassland ecosystems. This framework was defined as the quantitative magnitude of drought impact that unacceptable short-term and long-term effects on ecosystems may experience relative to the reference standard. Long-term effects on ecosystems may occur relative to the reference standard. Net primary productivity (NPP) was selected as the response indicator of drought to assess the quantitative impact of drought on Inner Mongolia grassland based on the Standardized Precipitation Index (SPI) and BIOME-BGC model. The framework consists of six main steps: 1) clearly defining drought scenarios, such as moderate, severe and extreme drought; 2) selecting an appropriate indicator of drought impact; 3) selecting an appropriate ecosystem model and verifying its capabilities, calibrating the bias and assessing the uncertainty; 4) assigning a level of unacceptable impact of drought on the indicator; 5) determining the response of the indicator to drought and normal weather state under global-change; and 6) investigating the unacceptable impact of drought at different spatial scales. We found NPP losses assessed using the new framework were more sensitive to drought and had higher precision than the long-term average method. Moreover, the total and average losses of NPP are different in different grassland types during the drought years from 1961–2009. NPP loss was significantly increased along a gradient of increasing drought levels. Meanwhile, NPP loss variation under the same drought level was different in different grassland types. The operational framework was particularly suited for integrative assessing the effects of different drought events and long-term droughts at multiple spatial scales, which provided essential insights for sciences and societies that must develop coping strategies for ecosystems for such events.

Risk analysis of sustainable urban drainage and irrigation

Urbanization, by creating extended impervious areas, to the detriment of vegetated ones, may have an undesirable influence on the water and energy balances of urban environments. The storage and infiltration capacity of the drainage system lessens the negative influence of urbanization, and vegetated areas help to re-establish pre-development environmental conditions. Resource limitation, climate, leading to increasing water scarcity, demographic and socio-institutional shifts promote more integrated water management. Storm-water harvesting for landscape irrigation mitigates possible water restrictions for the urban population in drought scenarios. A new probabilistic model for sustainable rainfall drainage, storage and re-use systems was implemented in this study. Risk analysis of multipurpose storage capacities was generalized by the use of only a few dimensionless parameters and applied to a case study in a Mediterranean-type climate, although the applicability of the model is not restricted to any particular climatic type.

Functional Traits and Water Transport Strategies in Lowland Tropical Rainforest Trees

Understanding how tropical rainforest trees may respond to the precipitation extremes predicted in future climate change scenarios is paramount for their conservation and management. Tree species clearly differ in drought susceptibility, suggesting that variable water transport strategies exist. Using a multi-disciplinary approach, we examined the hydraulic variability in trees in a lowland tropical rainforest in north-eastern Australia. We studied eight tree species representing broad plant functional groups (one palm and seven eudicot mature-phase, and early-successional trees). We characterised the species’ hydraulic system through maximum rates of volumetric sap flow and velocities using the heat ratio method, and measured rates of tree growth and several stem, vessel, and leaf traits. Sap flow measures exhibited limited variability across species, although early-successional species and palms had high mean sap velocities relative to most mature-phase species. Stem, vessel, and leaf traits were poor predictors of sap flow measures. However, these traits exhibited different associations in multivariate analysis, revealing gradients in some traits across species and alternative hydraulic strategies in others. Trait differences across and within tree functional groups reflect variation in water transport and drought resistance strategies. These varying strategies will help in our understanding of changing species distributions under predicted drought scenarios.

Can diversity in root architecture explain plant water use efficiency? A modeling study

Drought stress is a dominant constraint to crop production. Breeding crops with adapted root systems for effective uptake of water represents a novel strategy to increase crop drought resistance. Due to complex interaction between root traits and high diversity of hydrological conditions, modeling provides important information for trait based selection. In this work we use a root architecture model combined with a soil-hydrological model to analyze whether there is a root system ideotype of general adaptation to drought or water uptake efficiency of root systems is a function of specific hydrological conditions. This was done by modeling transpiration of 48 root architectures in 16 drought scenarios with distinct soil textures, rainfall distributions, and initial soil moisture availability. We find that the efficiency in water uptake of root architecture is strictly dependent on the hydrological scenario. Even dense and deep root systems are not superior in water uptake under all hydrological scenarios. Our results demonstrate that mere architectural description is insufficient to find root systems of optimum functionality. We find that in environments with sufficient rainfall before the growing season, root depth represents the key trait for the exploration of stored water, especially in fine soils. Root density, instead, especially near the soil surface, becomes the most relevant trait for exploiting soil moisture when plant water supply is mainly provided by rainfall events during the root system development. We therefore concluded that trait based root breeding has to consider root systems with specific adaptation to the hydrology of the target environment.