Improving reference evapotranspiration (ETo) calculation under limited data conditions in the Tropical Andes

2020 ◽  
Author(s):  
Cristina Vásquez ◽  
Mario Córdova ◽  
Galo Carrillo ◽  
Rolando Célleri
Keyword(s):  
Reference Evapotranspiration ◽  
Estimation Error ◽  
Simulation Models ◽  
Weather Conditions ◽  
Tropical Andes ◽  
Local Conditions ◽  
The Andes ◽  
Correct Determination ◽  
Highly Correlated ◽  
The Impact

<p>The correct determination of reference evapotranspiration (ET<sub>o</sub>) is fundamental for countless scientific and management applications such as closing the catchment water balance, the planning of irrigation schemes, and for simulation models. Nevertheless, the records of weather variables are often not available or incomplete. This usually happens when a sensor breaks or malfunctions due to severe weather conditions, lack of maintenance or electronic failure, which leads to data loss and consequently makes it hard to estimate ET<sub>o</sub>. Frequently, that is the case in mountain regions where meteorological sensors are subject to harsh environmental conditions as in the Andes. In case of missing data, the only solution is to estimate the required variable using a given equation. Therefore, these equations need to be calibrated to specific local conditions. The aim of this study was to calibrate and validate equations to estimate Solar Radiation (R<sub>s</sub>) on daily and monthly scales and to evaluate the impact of using these estimations for the calculation of ET<sub>o</sub> through the Penman Monteith (PM) equation in an Andean altitudinal gradient in the páramo ecosystem. The páramo occupies the upper portion of the northern Andes, where the tussock grasslands are the dominant vegetation. In addition, this ecosystem provides essential environmental services for inter-Andean cities. We used six years of observations (2013–2019) from the Quinoas Ecohydrological Observatory. This Observatory has four meteorological stations: Toreadora (3955 m a.s.l), Virgen Cajas (3626 m a.s.l), Chirimachay (3298 m a.s.l) and Balzay (2610 m a.s.l). We evaluated five models to estimate R<sub>s</sub> based on the maximum and minimum daily air temperature. A calibration was performed for each weather station and a simultaneous calibration for the entire gradient. We used four years of data for calibration and validation of the R<sub>s</sub> model, and two years to evaluate the impact on ET<sub>o</sub> calculations. We found that all models yielded estimations that are highly correlated with the observed data. However, no model was able to capture high R<sub>s</sub> values, greater than 185.4 W m<sup>-2</sup> (16 MJ m<sup>-2</sup> d<sup>-1</sup>), found in cloud-free days. The best model to estimate R<sub>s</sub> was the locally calibrated Chen model, which showed a mean error of 2.9 W m<sup>-2 </sup>(0.25 MJ m<sup>-2</sup> d<sup>-1</sup>).  Estimated R<sub>s</sub> values reduced the estimation error of PM-ET<sub>o</sub> and, thus, allows its application for further studies.</p>

scholarly journals Tropical Andes Radar Precipitation Estimates Need High Temporal and Moderate Spatial Resolution

Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 1038 ◽  
Author(s):  
Mario Guallpa ◽  
Johanna Orellana-Alvear ◽  
Jörg Bendix
Keyword(s):  
Spatial Resolution ◽  
Temporal Resolution ◽  
Time Resolution ◽  
Weather Radar ◽  
Radar Data ◽  
Rain Gauge ◽  
Tropical Andes ◽  
The Andes ◽  
Significant Difference ◽  
The Impact

Weather radar networks are an excellent tool for quantitative precipitation estimation (QPE), due to their high resolution in space and time, particularly in remote mountain areas such as the Tropical Andes. Nevertheless, reduction of the temporal and spatial resolution might severely reduce the quality of QPE. Thus, the main objective of this study was to analyze the impact of spatial and temporal resolutions of radar data on the cumulative QPE. For this, data from the world’s highest X-band weather radar (4450 m a.s.l.), located in the Andes of Ecuador (Paute River basin), and from a rain gauge network were used. Different time resolutions (1, 5, 10, 15, 20, 30, and 60 min) and spatial resolutions (0.5, 0.25, and 0.1 km) were evaluated. An optical flow method was validated for 11 rainfall events (with different features) and applied to enhance the temporal resolution of radar data to 1-min intervals. The results show that 1-min temporal resolution images are able to capture rain event features in detail. The radar–rain gauge correlation decreases considerably when the time resolution increases (r from 0.69 to 0.31, time resolution from 1 to 60 min). No significant difference was found in the rain total volume (3%) calculated with the three spatial resolution data. A spatial resolution of 0.5 km on radar imagery is suitable to quantify rainfall in the Andes Mountains. This study improves knowledge on rainfall spatial distribution in the Ecuadorian Andes, and it will be the basis for future hydrometeorological studies.

scholarly journals Data-Driven Simulation for Evaluating the Impact of Lower Arrival Aircraft Separation on Available Airspace and Runway Capacity at Tokyo International Airport

Aerospace ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 165
Author(s):  
Katsuhiro Sekine ◽  
Furuto Kato ◽  
Kota Kageyama ◽  
Eri Itoh
Keyword(s):  
Simulation Models ◽  
Weather Conditions ◽  
Air Traffic ◽  
Data Driven ◽  
Wake Turbulence ◽  
Automation Systems ◽  
Delay Times ◽  
Simulation Results ◽  
The Impact ◽  
Terminal Area

Although the application of new wake turbulence categories, the so-called “RECAT (wake turbulence category re-categorization)”, will realize lower aircraft separation minima and directly increase runway throughput, the impacts of increasing arrival traffic on the surrounding airspace and arrival traffic flow as a whole have not yet been discussed. This paper proposes a data-driven simulation approach and evaluates the effectiveness of the lower aircraft separation in the arrival traffic at the target airport. The maximum runway capacity was clarified using statistics on aircraft types, stochastic distributions of inter-aircraft time and runway occupancy time, and the levels of the automation systems that supported air traffic controllers’ separation work. Based on the estimated available runway capacity, simulation models were proposed by analyzing actual radar track and flight plan data during the 6 months between September 2019 and February 2020, under actual operational constraints and weather conditions. The simulation results showed that the application of RECAT would reduce vectoring time in the terminal area by 7% to 10% under the current airspace and runway capacity when following a first-come first-served arrival sequence. In addition, increasing airspace capacity by 10% in the terminal area could dramatically reduce en-route and takeoff delay times while keeping vectoring time the same as under the current operation in the terminal area. These findings clarified that applying RECAT would contribute to mitigating air traffic congestion close to the airport, and to reducing delay times in arrival traffic as a whole while increasing runway throughput. The simulation results demonstrated the relevance of the theoretical results given by queue-based approaches in the authors’ past studies.

Climate disparity versus risk management: destination demand analysis

2016 ◽  
Vol 8 (5) ◽  
pp. 560-568
Author(s):  
Parikshat Singh Manhas
Keyword(s):  
Climate Change ◽  
Secondary Data ◽  
Weather Conditions ◽  
Climatic Conditions ◽  
Policy Implications ◽  
Local Conditions ◽  
Content Type ◽  
Impact Of Climate Change ◽  
Travel Decisions ◽  
The Impact

Purpose The purpose of this paper is to study the relationship between tourism and climate change and, hence, to understand the impact of climate change on tourist destinations. Design/methodology/approach A conceptual analysis of secondary data was extracted and analyzed. The framework and policy implications for the study were obtained from online secondary data and by interaction with representatives of a state authority. Findings The findings from the study show that the impact of climate change on tourism is likely to manifest itself in a number of different ways according to local conditions. Climate and weather are connected with tourism and recreational activities. The paper shows the importance of climate for tourism because climate itself is an attraction. Climate and weather are among the most important attributes to influence tourist decision-making. Changing the climate and weather conditions of any destination may affect the tourists’ comfort and travel decisions, and due to the changing demand pattern and tourist flows, tourism businesses and host communities suffer. Cancellation of any trip due to bad weather causes dissatisfaction and those affected may avoid visiting the destination again. Temperature is also one of the most important climate variables in the analysis of tourism demands as it affects comfort. Originality/value This original piece of work suggests that climatic conditions control destination choice and this influences the tourism demands for a given destination.

Spatial Variations in Weather Conditions and Wine Prices in Bordeaux

2006 ◽  
Vol 1 (2) ◽  
pp. 114-124 ◽  
Author(s):  
Sébastien Lecocq ◽  
Michael Visser
Keyword(s):  
Weather Conditions ◽  
Jel Classification ◽  
Spatial Variations ◽  
Weather Station ◽  
Weather Variables ◽  
Local Data ◽  
Local Conditions ◽  
Model Based ◽  
The Impact ◽  
The Relationship

AbstractThe purpose of this paper is to study the impact of weather conditions on prices of Bordeaux wines. Unlike previous studies (based on data from the main weather station in Mérignac), we use climatological variables from many local stations. Two models are compared: one where prices are related to Mérignac weather conditions, and one where prices are related to local conditions (weather variables measured in the station the nearest to the château). Although a (non-nested) test suggests that the model based on local data is better, the two specifi cations lead to very similar results. This is reassuring news for researchers interested in the relationship between weather and prices, but who do not have access to spatial variations in climate. (JEL Classification: Q19)

scholarly journals Impact of Weather Conditions on Travel Demand – The Most Common Research Methods and Applied Models

2020 ◽  
Vol 32 (5) ◽  
pp. 711-725
Author(s):  
Dragana Petrović ◽  
Ivan Ivanović ◽  
Vladimir Đorić ◽  
Jadranka Jović
Keyword(s):  
Research Methods ◽  
Travel Demand ◽  
Weather Conditions ◽  
Travel Behaviour ◽  
Transport Systems ◽  
Small Samples ◽  
Local Conditions ◽  
Modal Split ◽  
Demand Models ◽  
The Impact

This paper presents an overview of the applied research methodologies and developed travel demand models that take weather impact into account. The paper deals with trip generation and modal split as elements of travel demand that best describe changes in the travel behaviour in different weather conditions. The authors herein emphasize the importance of research in local conditions in all climate zones, especially in areas where climate and modal split characteristics are different from those in common research areas. This review is designed as a brief guide on how the impact of weather can be explored in order to encourage conducting research even in the countries where there is no systematic traffic and travel data collection. The stated adaptation technique followed by the panel household travel surveys may be particularly appropriate for those countries. It is concluded that small budgets should not be considered an obstacle, because it is possible to draw reliable conclusions based even on small samples. Moreover, modern research methods enable a cheaper survey process together with the possibility of obtaining higher quality of results. The increasing popularity of research in this field should contribute to the creation of more resilient transport systems all over the world. A special contribution of this paper is the review of research studies carried out in central, western and southern Europe and not mentioned in any review paper before.

Prospects of spring wheat cultivation in the conditions of arid Volga region

2020 ◽  
pp. 28-33
Author(s):  
Valery Genadievich Popov ◽  
Andrey Vladimirovich Panfilov ◽  
Yuriy Vyacheslavovich Bondarenko ◽  
Konstantin Mikhailovich Doronin ◽  
Evgeny Nikolaevih Martynov ◽  
...  
Keyword(s):  
Spring Wheat ◽  
Soil Layer ◽  
Weather Conditions ◽  
Volga Region ◽  
Mineral Fertilizers ◽  
Climate Conditions ◽  
Wheat Cultivation ◽  
Forest Belts ◽  
Clear Differentiation ◽  
The Impact

The article analyzes the experience of the impact of the system of forest belts and mineral fertilizers on the yield of spring wheat, including on irrigated lands. Vegetation irrigation is designed to maintain the humidity of the active soil layer from germination to maturation at the lower level of the optimum-70-75%, and in the phases of tubulation-earing - flowering - 75-80% NV. However, due to the large differences in zones and microzones of soil and climate conditions and due to the weather conditions of individual years, wheat irrigation regimes require a clear differentiation. In the Volga region in the dry autumn rainfalls give the norm of 800-1000 m3/ha, and in saline soils – 1000-1300 and 3-4 vegetation irrigation at tillering, phases of booting, earing and grain formation the norm 600-650 m3/ha. the impact of the system of forest belts, mineral fertilizers on the yield of spring wheat is closely tied to the formation of microclimate at different distances from forest edges.

The Impact of High-Speed Rail on the Spatial Structure of Chinese Urban Agglomerations

2020 ◽  
Vol 46 (3) ◽  
pp. 379-397
Author(s):  
Chunyang Wang
Keyword(s):  
High Speed ◽  
River Delta ◽  
City Size ◽  
High Speed Rail ◽  
Local Conditions ◽  
Urban Agglomerations ◽  
Large Cities ◽  
Spatial Systems ◽  
Economic Concentration ◽  
The Impact

This paper measures the spatial evolution of urban agglomerations to understand be er the impact of high-speed rail (HSR) construction, based on panel data from fi ve major urban agglomerations in China for the period 2004–2015. It is found that there are signi ficant regional diff erences of HSR impacts. The construction of HSR has promoted population and economic diff usion in two advanced urban agglomerations, namely the Yang e River Delta and Pearl River Delta, while promoting population and economic concentration in two relatively less advanced urban agglomerations, e.g. the middle reaches of the Yang e River and Chengdu–Chongqing. In terms of city size, HSR promotes the economic proliferation of large cities and the economic concentration of small and medium-sized cities along its routes. HSR networking has provided a new impetus for restructuring urban spatial systems. Every region should optimize the industrial division with strategic functions of urban agglomeration according to local conditions and accelerate the construction of inter-city intra-regional transport network to maximize the eff ects of high-speed rail across a large regional territory.

scholarly journals Ontogenetic shift in the trophic role of the invasive killer shrimp Dikerogammarus villosus: a stable isotope study

2021 ◽  
Author(s):  
Francesco Mancini ◽  
Raffaele De Giorgi ◽  
Alessandro Ludovisi ◽  
Salvatrice Vizzini ◽  
Giorgio Mancinelli
Keyword(s):  
Dietary Habits ◽  
Trophic Position ◽  
Ecological Impact ◽  
Central Italy ◽  
Local Conditions ◽  
Dikerogammarus Villosus ◽  
Isotopic Signatures ◽  
Depth Analysis ◽  
Stable Isotope Study ◽  
The Impact

AbstractThe introduction of the amphipod Dikerogammarus villosus in European fresh waters is to date recognized as a threat to the integrity of invaded communities. Predation by D. villosus on native benthic invertebrates is assumed as the key determinant of its ecological impact, yet available information describe the species as a primary consumer as well as a carnivore depending on local conditions. Here, we assessed the trophic position (TP) of D. villosus in Lake Trasimeno, a recently invaded lentic system in central Italy, using the CN isotopic signatures of individuals captured in winter spanning two orders of magnitude in body size. TP estimations were compared with those characterizing the native amphipod Echinogammarus veneris and other representative invertebrate predators. On average, D. villosus showed a trophic position higher than E. veneris, and comparable with that of odonate nymphs. An in-depth analysis revealed that large-sized individuals had a trophic position of 3.07, higher than odonates and close to that of the hirudinean predator Erpobdella octoculata, while small-sized specimens had a trophic position of 2.57, similar to that of E. veneris (2.41). These findings indicate that size-related ontogenetic shifts in dietary habits may per se vary the nature of the interaction between Dikerogammarus villosus and native invertebrates from competition to predation. Information collated from published isotopic studies corroborated the generality of our results. We conclude that intra-specific trophic flexibility may potentially amplify and make more multifaceted the impact of the species on other invertebrate species in invaded food webs.

scholarly journals Energy Performance Assessment of Innovative Building Solutions Coming from Construction and Demolition Waste Materials

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1226
Author(s):  
Beatriz Fraga-De Cal ◽  
Antonio Garrido-Marijuan ◽  
Olaia Eguiarte ◽  
Beñat Arregi ◽  
Ander Romero-Amorrortu ◽  
...  
Keyword(s):  
Thermal Insulation ◽  
Energy Demand ◽  
Energy Savings ◽  
Flow Analysis ◽  
Weather Conditions ◽  
Energy Performance ◽  
Construction And Demolition Waste ◽  
The European Union ◽  
Demolition Waste ◽  
The Impact

Prefabricated solutions incorporating thermal insulation are increasingly adopted as an energy conservation measure for building renovation. The InnoWEE European project developed three technologies from Construction and Demolition Waste (CDW) materials through a manufacturing process that supports the circular economy strategy of the European Union. Two of them consisted of geopolymer panels incorporated into an External Thermal Insulation Composite System (ETICS) and a ventilated façade. This study evaluates their thermal performance by means of monitoring data from three pilot case studies in Greece, Italy, and Romania, and calibrated building simulation models enabling the reliable prediction of energy savings in different climates and use scenarios. Results showed a reduction in energy demand for all demo buildings, with annual energy savings up to 25% after placing the novel insulation solutions. However, savings are highly dependent on weather conditions since the panels affect cooling and heating loads differently. Finally, a parametric assessment is performed to assess the impact of insulation thickness through an energy performance prediction and a cash flow analysis.

scholarly journals Earthworm Abundance Changes Depending on Soil Management Practices in Slovenian Vineyards

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1241
Author(s):  
Stanko Vršič ◽  
Marko Breznik ◽  
Borut Pulko ◽  
Jesús Rodrigo-Comino
Keyword(s):  
Management Practices ◽  
Human Impacts ◽  
Soil Layer ◽  
Soil Management ◽  
Weather Conditions ◽  
Soil Tillage ◽  
Soil Biodiversity ◽  
Straw Mulch ◽  
Green Cover ◽  
The Impact

Earthworms are key indicators of soil quality and health in vineyards, but research that considers different soil management systems, especially in Slovenian viticultural areas is scarce. In this investigation, the impact of different soil management practices such as permanent green cover, the use of herbicides in row and inter-row areas, use of straw mulch, and shallow soil tillage compared to meadow control for earthworm abundance, were assessed. The biomass and abundance of earthworms (m2) and distribution in various soil layers were quantified for three years. Monitoring and a survey covering 22 May 2014 to 5 October 2016 in seven different sampling dates, along with a soil profile at the depth from 0 to 60 cm, were carried out. Our results showed that the lowest mean abundance and biomass of earthworms in all sampling periods were registered along the herbicide strip (within the rows). The highest abundance was found in the straw mulch and permanent green cover treatments (higher than in the control). On the plots where the herbicide was applied to the complete inter-row area, the abundance of the earthworm community decreased from the beginning to the end of the monitoring period. In contrast, shallow tillage showed a similar trend of declining earthworm abundance, which could indicate a deterioration of soil biodiversity conditions. We concluded that different soil management practices greatly affect the soil’s environmental conditions (temperature and humidity), especially in the upper soil layer (up to 15 cm deep), which affects the abundance of the earthworm community. Our results demonstrated that these practices need to be adapted to the climate and weather conditions, and also to human impacts.

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