Variability in the water footprint of arable crop production across European regions

201

Priority questions in multidisciplinary drought research

Addressing timely and relevant questions across a multitude of spatio-temporal scales, state-of-the-art interdisciplinary drought research will likely increase in importance under projected climate change. Given the complexity of the various direct and indirect causes and consequences of a drier world, scientific tasks need to be coordinated efficiently. Drought-related research endeavors ranging from individual projects to global initiatives therefore require prioritization. Here, we present 60 priority questions for optimizing future drought research. This topical catalogue reflects the experience of 65 scholars from 21 countries and almost 20 fields of research in both natural sciences and the humanities. The set of drought-related questions primarily covers drought monitoring, impacts, forecasting, climatology, adaptation, as well as planning and policy. The questions highlight the increasingly important role of remote sensing techniques in drought monitoring, importance of drought forecasting and understanding the relationships between drought parameters and drought impacts, but also challenges of drought adaptation and preparedness policies

Sources of remote sensing data used for estimating variables in environmental change studies in agriculture

Abstract. The paper presents the contribution of satellit

Thermal stress in the northern Carpathians and air circulation

In mountain areas, air circulation plays a major role in the forming of the climate. This paper examines how it influences thermal stress in the northern Carpathians. The Niedźwiedź’s classification of air circulation was applied. Thermal stress was assessed by Universal Thermal Climate Index (UTCI). Daily meteorological and circulation data for the period 1986–2015 were used for 20 stations in Poland, Slovakia and Ukraine. Air circulation was found to have a significant impact on thermal stress. The highest UTCI values are observed at Ca+Ka (centre of the high and anticyclonic wedge or ridge of high pressure) and the lowest values at N+NE and W+NW circulation; at the Southward stations, UTCI is higher than in the Northward ones; thermoneutral days are more frequent on the southward than on the northward slopes; during N+NE, E+SE and W+NW circulation and for heat stress days, the greatest thermal privilege of the southward slopes is observed at E+SE, S+SW, Ca+Ka and Cc+Bc (centre of low and through of low pressure) types of circulation

Can Agrometeorological Indices of Adverse Weather Conditions Help to Improve Yield Prediction by Crop Models?

The impact of adverse weather conditions (AWCs) on crop production is random in both time and space and depends on factors such as severity, previous agrometeorological conditions, and plant vulnerability at a specific crop development stage. Any exclusion or improper treatment of any of these factors can cause crop models to produce significant under- or overestimates of yield. The analysis presented in this paper focuses on a range of agrometeorological indices (AMI) related to AWCs that might affect real yield as well as simulated yield. For this purpose, the analysis addressed four indicators of extreme temperatures and three indicators of dry conditions during the growth period of maize and winter wheat in Austria, Croatia, Serbia, Slovakia, and Sweden. It is shown that increases in the number and intensity of AWCs cannot be unambiguously associated with increased deviations in simulated yields. The identified correlations indicate an increase in modeling uncertainty. This finding represents important information for the crop modeling community. Additionally, it opens a window of opportunity for a statistical (“event scenario”) approach based on correlations between agrometeorological indices of AWCs and crop yield data series. This approach can provide scenarios for certain locations, crop types, and AWC patterns and, therefore, improve yield forecasting in the presence of AWCs

Pedestrian Walking Behavior Revealed through a Random Walk Model

This paper applies method of continuous-time random walks for pedestrian flow simulation. In the model, pedestrians can walk forward or backward and turn left or right if there is no block. Velocities of pedestrian flow moving forward or diffusing are dominated by coefficients. The waiting time preceding each jump is assumed to follow an exponential distribution. To solve the model, a second-order two-dimensional partial differential equation, a high-order compact scheme with the alternating direction implicit method, is employed. In the numerical experiments, the walking domain of the first one is two-dimensional with two entrances and one exit, and that of the second one is two-dimensional with one entrance and one exit. The flows in both scenarios are one way. Numerical results show that the model can be used for pedestrian flow simulation

Priority for climate adaptation measures in European crop production systems

To date, assessing the adaptive measures to climate change effects on cropping systems have generally been based on data from field trials and crop models. This strategy can only explore a restricted number of options with a limited spatial extent. Therefore, we designed a questionnaire that incorporated both qualitative and quantitative aspects of climate change adaptation in the agricultural sector. The questionnaire was distributed to experts from 15 European countries to map both the observed and planned climate adaptive measures in general and for five major crops (wheat, oilseed rape, maize, potato, and grapevine) in six environmental zones (EnZs) across Europe. In northern Europe, changed timing of field operations and introduction of new crops and cultivars were the already observed as the main adaptations to a longer growing season and reduced low-temperature stress under climate change. Farmers in central and southern Europe were mainly changing water and soil management as well as adopting drought-tolerant cultivars to cope with increasing evapotranspiration and higher variability and lower predictability of rainfall. Crop protection, crop insurance, and early warning/forecast systems were considered effective ways to reduce the economic losses from increased climate-related risks and extremes. The risks and associated adaptation measures vary for different crops in different EnZs. Across Europe, changes in field operation practices, fertilisation regime, crop protection, and cultivar selection are expected to be the most prominent adaptive measures under future projected climate change. In southern and central Europe, improved irrigation systems, changing cropping systems, and revised environmental regulations and subsidy schemes are being introduced as part of adaptation planning due to the projected warmer and drier climate. In northern Europe, there are also considerations of changing landscape and environmental regulations to cope with increasing rainfall variability and changing cropping practices due to longer growing seasons. The thorough understanding of the observed and foreseen adaptations in the different zones will be helpful for supporting decision making at both farm and policy levels across Europe