scholarly journals Why has catchment evaporation increased in the past 40 years? A data-based study in Austria

2018 ◽  
Author(s):  
Doris Duethmann ◽  
Günter Blöschl
Keyword(s):  
Soil Moisture ◽  
Vegetation Index ◽  
Global Radiation ◽  
The Past ◽  
Available Energy ◽  
Vegetation Activity ◽  
Regional Evapotranspiration ◽  
Monteith Equation ◽  
Term Data

Abstract. Global warming has increased regional evapotranspiration in many parts of the world in the last decades, but the drivers of these increases are widely debated. Part of the difficulty lies in the scarcity of high-quality long term data on evapotranspiration. In this paper, we analyze changes in catchment evapotranspiration estimated from the water balances of 156 catchments in Austria over the period 1977–2014 and attribute them to changes in atmospheric demand and available energy, vegetation, and soil moisture as possible drivers. Trend analyses suggest that evapotranspiration has significantly increased in 60 % of the catchments (p ≤ 0.05) with an average increase of 29 ± 14 mm y−1 decade−1 (±standard deviation) or 4.9 ± 2.3 % decade−1. A pooled pan evaporation series based on 22 stations has, on average, increased by 29 ± 5 mm y−1 decade−1 or 6.0 ± 1.0 % decade−1. Reference evaporation over the 156 catchments estimated by the Penman-Monteith equation has increased by 18 ± 5 mm y−1 decade−1 or 2.8 ± 0.7 % decade−1. Of these, 2.1 % are due to increased global radiation and 0.5 % due to increased air temperature according to the Penman-Monteith equation. A satellite-based vegetation index (NDVI) has increased by 0.02 ± 0.01 decade−1 or 3.1 ± 1.1 % decade−1. Estimates of reference evaporation accounting for changes in stomata resistance due to changes in NDVI indicate that the increase in vegetation activity has led to a similar increase in reference evaporation as changes in the climate parameters. A regression between trends in evapotranspiration and precipitation, as a proxy of soil moisture, yields a sensitivity of 0.30 ± 0.04 mm y−2 increase in evapotranspiration to 1  y−2 increase in precipitation. A synthesis of the data analyses suggests that 38 ± 13 % of the observed increase in catchment evapotranspiration can be directly attributed to increased atmospheric demand and available energy, 30 ± 12 % to increased vegetation activity, and 32 ± 5 % to increased soil moisture due to increases in precipitation.

scholarly journals Why has catchment evaporation increased in the past 40 years? A data-based study in Austria

2018 ◽  
Vol 22 (10) ◽  
pp. 5143-5158 ◽  
Author(s):  
Doris Duethmann ◽  
Günter Blöschl
Keyword(s):  
Vegetation Index ◽  
Global Radiation ◽  
Pan Evaporation ◽  
Average Increase ◽  
The Past ◽  
Available Energy ◽  
Vegetation Activity ◽  
Monteith Equation ◽  
Term Data

Abstract. Regional evaporation has increased in many parts of the world in the last decades, but the drivers of these increases are widely debated. Part of the difficulty lies in the scarcity of high-quality long-term data on evaporation. In this paper, we analyze changes in catchment evaporation estimated from the water balances of 156 catchments in Austria over the period 1977–2014 and attribute them to changes in atmospheric demand and available energy, vegetation, and precipitation as possible drivers. Trend analyses suggest that evaporation has significantly increased in 60 % of the catchments (p≤0.05) with an average increase of 29±14 mm yr−1 decade−1 (± standard deviation) or 4.9±2.3 % decade−1. Pan evaporation based on 24 stations has, on average, increased by 29±5 mm yr−1 decade−1 or 6.0±1.0 % decade−1. Reference evaporation over the 156 catchments estimated by the Penman–Monteith equation has increased by 18±5 mm yr−1 decade−1 or 2.8±0.7 % decade−1. Of these, 2.1 % are due to increased global radiation and 0.5 % due to increased air temperature according to the Penman–Monteith equation. A satellite-based vegetation index (NDVI) has increased by 0.02±0.01 decade−1 or 3.1±1.1 % decade−1. Estimates of reference evaporation accounting for changes in stomata resistance due to changes in the NDVI indicate that the increase in vegetation activity has led to a similar increase in reference evaporation as changes in the climate parameters. A regression between trends in evaporation and precipitation yields a sensitivity of a 0.22±0.05 mm yr−2 increase in evaporation to a 1 mm yr−2 increase in precipitation. A synthesis of the data analyses suggests that 43±15 % of the observed increase in catchment evaporation may be directly attributed to increased atmospheric demand and available energy, 34±14 % to increased vegetation activity, and 24±5 % to increases in precipitation.

scholarly journals ANALYSIS OF METEOROLOGICAL CONDITIONS SIGNIFICANT FOR SMALL AVIATION AND TRAINING FLIGHTS AT THE AIRFIELD “BALKHASH” FOR PLANNING AND FLIGHT SAFETY PURPOSES

2021 ◽  
Vol 2 (446) ◽  
pp. 62-67
Author(s):  
N. Dolzhenko ◽  
E. Mailyanova ◽  
I. Assilbekova ◽  
Z. Konakbay
Keyword(s):  
Meteorological Conditions ◽  
Flight Safety ◽  
The Past ◽  
The Republic ◽  
The Impact ◽  
And Training ◽  
Term Data ◽  
Small Aircraft

Cloudiness and range of visibility are the most significant flight conditions for aircraft. The impact of clouds and visibility on the safety of aircraft flights, especially small aircraft, cannot be overestimated. According to the Interstate Air Committee, Kazakhstan ranks second in the number of aviation disasters. The average age of a third of Kazakhstan's small aircraft is more than 30 years. Over the past few years, 14 air accidents have occurred in the Republic of Kazakhstan, 11 of them with small aircraft. In this work, we investigate long-term data on cloudiness and visibility at the most weather-favorable airfield in Balkhash, for the possibility of safe and economical flights of small aircraft and planning training flights.

scholarly journals An evaluation of ASCAT surface soil moisture products with in-situ observations in Southwestern France

2009 ◽  
Vol 13 (2) ◽  
pp. 115-124 ◽  
Author(s):  
C. Albergel ◽  
C. Rüdiger ◽  
D. Carrer ◽  
J.-C. Calvet ◽  
N. Fritz ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Surface Soil ◽  
Mountainous Area ◽  
Surface Soil Moisture ◽  
Water Index ◽  
In Situ Observations ◽  
Weather Stations ◽  
Term Data

Abstract. A long term data acquisition effort of profile soil moisture is currently underway at 13 automatic weather stations located in Southwestern France. In this study, the soil moisture measured in-situ at 5 cm is used to evaluate the normalised surface soil moisture (SSM) estimates derived from coarse-resolution (25 km) active microwave data of the ASCAT scatterometer instrument (onboard METOP), issued by EUMETSAT for a period of 6 months (April–September) in 2007. The seasonal trend is removed from the satellite and in-situ time series by considering scaled anomalies. One station (Mouthoumet) of the ground network, located in a mountainous area, is removed from the analysis as very few ASCAT SSM estimates are available. No correlation is found for the station of Narbonne, which is close to the Mediterranean sea. On the other hand, nine stations present significant correlation levels. For two stations, a significant correlation is obtained when considering only part of the ASCAT data. The soil moisture measured in-situ at those stations, at 30 cm, is used to estimate the characteristic time length (T) of an exponential filter applied to the ASCAT product. The best correlation between a soil water index derived from ASCAT and the in-situ soil moisture observations at 30 cm is obtained with a T-value of 14 days.

scholarly journals Phenological behavior of Atlas cedar (Cedrus atlantica) forest to snow and precipitation variability in Boutaleb and Babors Mountains, Algeria

2019 ◽  
Vol 21 (1) ◽  
Author(s):  
Khaled Missaoui ◽  
Rachid Gharzouli ◽  
Yamna Djellouli ◽  
Frençois Messner
Keyword(s):  
Time Series ◽  
Satellite Images ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Descriptive Analysis ◽  
Precipitation Variability ◽  
Monthly Precipitation ◽  
Cedrus Atlantica ◽  
The Past

Abstract. Missaoui K, Gharzouli R, Djellouli Y, Messner F. 2020. Phenological behavior of Atlas cedar (Cedrus atlantica)  forest to snow and precipitation variability in Boutaleb and Babors Mountains, Algeria. Biodiversitas 21: 239-245. Understanding the changes in snow and precipitation variability and how forest vegetation response to such changes is very important to maintain the long-term sustainability of the forest. However, relatively few studies have investigated this phenomenon in Algeria. This study was aimed to find out the response of Atlas cedar (Cedrus atlantica (Endl.) G.Manetti ex Carrière) forest in two areas (i.e Boutaleb and Babors Mountains) and their response to the precipitation and snow variability. The normalized difference vegetation index (NDVI) generated from satellite images of MODIS time series was used to survey the changes of the Atlas cedar throughout the study area well as dataset of monthly precipitation and snow of the province of Setif (northeast of Algeria) from 2000 to 2018. Descriptive analysis using Standarized Precipitation Index (SPI) showed the wetter years were more frequent in the past than in the last two decades. The NDVI values changes in both areas with high values were detected in Babors Mountains with statistically significant differences. Our findings showed important difference in Atlas cedar phenology from Boutaleb mountains to Babors Mountains which likely related to snow factor.

scholarly journals FAO-56 dual approach combined with multi-sensor remote sensing for regional evapotranspiration estimations

2013 ◽  
Vol 10 (6) ◽  
pp. 8117-8144
Author(s):  
R. Amri ◽  
M. Zribi ◽  
Z. Lili-Chabaane ◽  
C. Szczypta ◽  
J. C. Calvet ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Soil Moisture ◽  
North Africa ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Dual Approach ◽  
Semi Arid Region ◽  
Crop Coefficients ◽  
The University ◽  
Regional Evapotranspiration

Abstract. The aim of this paper is to use a dual, modified version of the FAO-56 methodology for the estimation of regional evapotranspiration. The proposed approach combines the FAO-56 technique with remote sensing. Two vegetation classes are considered in the evapotranspiration estimations. In the case of cereals, crop coefficients and cover fractions are estimated using relationships established with the Normalized Difference Vegetation Index (NDVI), retrieved from SPOT-VGT data. In order to characterize the soil, a relationship is established between evaporation and the retrieved soil moisture values, based on the ERS/WSC products developed by the University of Vienna. This approach is applied to a semi-arid region in central Tunisia (North Africa) and is validated over 1991–2007 period using simulations from the ISBA-A-gs physical SVAT model. The ISBA soil moisture outputs are validated using remotely sensed ERS/WSC products. Finally, a comparison is made between the ISBA and FAO approaches, for the same studied site.

scholarly journals Satellite-Observed Effects from Ozone Pollution and Climate Change on Growing-Season Vegetation Activity over China during 1982–2020

Atmosphere ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1390
Author(s):  
Zhaosheng Wang
Keyword(s):  
Climate Change ◽  
Remote Sensing ◽  
Large Scale ◽  
Vegetation Index ◽  
Growing Season ◽  
Ozone Pollution ◽  
Vegetation Growth ◽  
Vegetation Activity ◽  
The Impact

Remote sensing vegetation index data contain important information about the effects of ozone pollution, climate change and other factors on vegetation growth. However, the absence of long-term observational data on surface ozone pollution and neglected air pollution-induced effects on vegetation growth have made it difficult to conduct in-depth studies on the long-term, large-scale ozone pollution effects on vegetation health. In this study, a multiple linear regression model was developed, based on normalized difference vegetation index (NDVI) data, ozone mass mixing ratio (OMR) data at 1000 hPa, and temperature (T), precipitation (P) and surface net radiation (SSR) data during 1982–2020 to quantitatively assess the impact of ozone pollution and climate change on vegetation growth in China on growing season. The OMR data showed an increasing trend in 99.9% of regions in China over the last 39 years, and both NDVI values showed increasing trends on a spatial basis with different ozone pollution levels. Additionally, the significant correlations between NDVI and OMR, temperature and SSR indicate that vegetation activity is closely related to ozone pollution and climate change. Ozone pollution affected 12.5% of NDVI, and climate change affected 26.7% of NDVI. Furthermore, the effects from ozone pollution and climate change on forest, shrub, grass and crop vegetation were evaluated. Notably, the impact of ozone pollution on vegetation growth was 0.47 times that of climate change, indicating that the impact of ozone pollution on vegetation growth cannot be ignored. This study not only deepens the understanding of the effects of ozone pollution and climate change on vegetation growth but also provides a research framework for the large-scale monitoring of air pollution on vegetation health using remote sensing vegetation data.

Increased vulnerability of European ecosystems to two consecutive extreme summers

2021 ◽  
Author(s):  
Ana Bastos ◽  
René Orth ◽  
Markus Reichstein ◽  
Philippe Ciais ◽  
Nicolas Viovy ◽  
...  
Keyword(s):  
Central Europe ◽  
Land Surface ◽  
Vegetation Index ◽  
Legacy Effects ◽  
The Past ◽  
Surface Models ◽  
Summer Temperatures ◽  
The Impact ◽  
Observational Record

<p>Extreme summer temperatures in western and central Europe have become more frequent and heatwaves more prolonged over the past decades. The summer of 2018 was one of the driest and hottest in the observational record and led to losses in vegetation productivity in central Europe by up to 50%. Legacy effects from such extreme summers can affect ecosystem functioning over several years, as vegetation slowly recovers. In 2019 an extremely dry and hot summer was registered again in the region, imposing stress conditions at a time when ecosystems were still recovering from summer 2018.</p><p>Using Enhanced Vegetation Index (EVI) fields from MODIS, we evaluate how ecosystems in central Europe responded to the occurrence of two consecutive extreme summers. We find that only ca. 21% of the area negatively impacted by drought in summer 2018 fully recovered in 2019.</p><p>We find that the strongest EVI anomalies in 2018/19 diverge from the long-term relationships between EVI and climate, indicating an increase in ecosystem vulnerability to heat and drought events. Furthermore, 18% of the area showed a worsening of plant status during summer 2019 in spite of drought alleviation, which could be explained by interannual legacy effects from 2018, such as impaired growth and increased biotic disturbances.</p><p>Land-surface models do not simulate interannual legacy effects from summer 2018 and thereby underestimate the impact of drought in 2019 on ecosystems. The poor representation of drought-induced damage and mortality and lack of biotic disturbances in these models may result in an overestimation of the resilience and stability of temperate ecosystems in the future.</p>

The Role of Wearable Monitor for Healthcare

2016 ◽  
Vol 100 ◽  
pp. 159-165
Author(s):  
Toshiyo Tamura ◽  
Yuka Maeda ◽  
Masaki Sekine ◽  
Ming Huang
Keyword(s):  
Business Models ◽  
Daily Life ◽  
Healthcare Outcomes ◽  
The Past ◽  
Data Collection And Analysis ◽  
Healthcare Monitoring ◽  
Wearable Monitoring Systems ◽  
Term Data

Wearable monitor for healthcare was proposed in the late 1990s. Physiological monitoring in daily life has considerable potential for preventing and predicting diseases, without significant discomfort or inconvenience to the user. Over the past 25 years, wearable monitoring systems have been developed for health monitoring in daily life. In this presentation we will 1) review the devices used in wearable monitoring, including home use and clinical practice; 2) consider the evidence for their benefit in terms of healthcare outcomes; and 3) discuss long-term data collection and analysis using Big Data techniques. Furthermore, issues relating to the popularization of these devices are discussed, including regulation and business models. There are many promising devices available for wearable healthcare monitoring, and we propose ideas to popularize these devices.

scholarly journals An evaluation of ASCAT surface soil moisture products with in-situ observations in southwestern France

2008 ◽  
Vol 5 (4) ◽  
pp. 2221-2250 ◽  
Author(s):  
C. Albergel ◽  
C. Rüdiger ◽  
D. Carrer ◽  
J.-C. Calvet ◽  
N. Fritz ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Surface Soil ◽  
The Other ◽  
Mountainous Area ◽  
Surface Soil Moisture ◽  
Water Index ◽  
In Situ Observations ◽  
Term Data

Abstract. A long term data acquisition effort of profile soil moisture is currently underway at 13 automatic weather stations located in southwestern France. In this study, the soil moisture measured in-situ at 5 cm is used to evaluate the normalised surface soil moisture (SSM) estimates derived from coarse-resolution (25 km) active microwave data of the ASCAT scatterometer instrument (onboard METOP), issued by EUMETSAT for a period of 6 months (April–September) in 2007. The seasonal trend is removed from the satellite and in-situ time series by considering scaled anomalies. One station (Mouthoumet) of the ground network, located in a mountainous area, is removed from the analysis as very few ASCAT SSM estimates are available. No correlation is found for the station of Narbonne, which is close to the Mediterranean sea. On the other hand, the other 11 stations present significant correlation levels. The soil moisture measured in-situ at those stations, at 30 cm, is used to estimate the characteristic time length (T) of an exponential filter applied to the ASCAT product. The best correlation between a soil water index derived from ASCAT and the in-situ soil moisture observations at 30 cm is obtained with a T-value of 14 days.

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