Long-term phyto-, ornitho- and ichthyophenological time-series analyses in Estonia

1999 ◽  
Vol 42 (3) ◽  
pp. 119-123 ◽  
Author(s):  
Rein Ahas
Keyword(s):  
Time Series ◽  
Time Series Analyses

Availability and Sales of Alcohol in Four Canadian Provinces: A Time-Series Analysis

2005 ◽  
Vol 32 (3) ◽  
pp. 343-372 ◽  
Author(s):  
Björn Trolldal
Keyword(s):  
Time Series ◽  
Research Question ◽  
Pure Alcohol ◽  
Dependent Variables ◽  
Long Term Trends ◽  
Time Series Analyses ◽  
Canadian Provinces ◽  
Physical Availability ◽  
Total Sales

The research question addressed in the present study, with ARIMA time-series analyses, was the extent to which changes in economic and physical availability had an effect on sales of alcohol in four Canadian provinces during the second half of the 20th century. The annual sales, by type of beverage (spirits, wine and beer) as well as total sales, measured in pure alcohol per inhabitant age 15 and above in each province, were used as dependent variables in the analyses. The inhabitants' real disposable income, the real price of alcohol, and the number of on- and off-premise outlets per 100,000 inhabitants were used as independent variables. All the time-series were differenced to remove long-term trends. The main study period was 1951–2000. In some of the analyses the study periods were shorter, primarily due to lack of data. Changes in economic availability in general, and in price in particular, had larger effects on sales than physical availability. Among the beverages analyzed in the study, the demand for spirits was most sensitive to changes in availability. Economic availability had a greater effect on sales than the number of outlets. However, one might question to what extent the number of outlets really is a feasible measure of transaction costs associated with purchases of alcohol.

scholarly journals Long-term Soil Moisture Time Series Analyses based on Active Microwave Backscatter Measurements

2015 ◽  
Vol XL-7/W3 ◽  
pp. 545-550
Author(s):  
W. Wagner ◽  
C. Reimer ◽  
B. Bauer-Marschallinger ◽  
M. Enenkel ◽  
S. Hahn ◽  
...  
Keyword(s):  
Time Series ◽  
Soil Moisture ◽  
Microwave Frequencies ◽  
Vegetation Modelling ◽  
Time Series Analyses ◽  
Vegetation Parameters ◽  
Microwave Backscatter ◽  
Microwave Sensors ◽  
Modelling Approach

Active microwave sensors operating at lower microwave frequencies in the range from 1 to 10 GHz provide backscatter measurements that are sensitive to the moisture content of the soil. Thanks to a series of European C-band (5.3 GHz) scatterometers, which were first flown on board of the European Remote Sensing satellites ERS-1 and ERS-2, and later on board of MetOp-A and MetOp -B, we are now in the possession of a long-term soil moisture time series starting in 1991. The creation of globally consistent long-term soil moisture time series is a challenging task. The TU-Wien soil moisture algorithm is adopted to tackle these challenges. In this paper we present two methodologies that were developed to ensure radiometric stability of the European C-band scatterometers. The objective of sensor intra-calibration is to monitor and correct for radiometric instabilities within one scatterometer mission, while sensor inter-calibration aims to remove radiometric differences across several missions. In addition, a novel vegetation modelling approach is presented that enables the estimation of vegetation parameters for each day across several years to account for yearly to longer-term changes in vegetation phenology and land cover.

Trends and Characteristics of Hydrological Time Series in Finland

2003 ◽  
Vol 34 (1-2) ◽  
pp. 71-90 ◽  
Author(s):  
Veli Hyvärinen
Keyword(s):  
Time Series ◽  
Water Temperature ◽  
The South ◽  
Lake Ice ◽  
The North ◽  
Long Term Trends ◽  
Time Series Analyses ◽  
Water Stage ◽  
In The Beginning

Hydrological time series analyses made in Finland up to 2001 show the following: 1) Precipitation has been increasing in southern and central Finland, and also in the north in winter, during the period 1911-2000. There are, however, no harmonized analyses of areal precipitation to show the exact increase. 2) The annual maximum of the areal water equivalent of snow has been increasing in eastern and northern Finland but decreasing in the south and west during the period 1947-2001. 3) The winter runoff has generally been increasing strongly in southern and slightly in central Finland during the 20th century. In northern Lapland there are no signs of increase in winter or annual flow. Annual discharge in the south and west has also increased to some extent. 4) The existing analyses show no signs of long-term trends in annual evapotranspiration. 5) Long-term fluctuations of water stage have been observed in the major groundwater formations. 6) The series of the date of ice break-up in the river Tornionjoki - starting in 1693 – shows that in recent decades the ice cover of the river has broken up about two weeks earlier than in the beginning of the period. 6) Lake ice maximum thickness series show no noticeable trend. 7) Lake water temperature in south-eastern Finland seems to have been increasing slightly during the period starting in 1924; in central and northern Finland no trends in water temperature have been observed.

scholarly journals Calibration of a lumped karst system model and application to the Qachqouch karst spring (Lebanon) under climate change conditions

2020 ◽  
Vol 24 (9) ◽  
pp. 4275-4290
Author(s):  
Emmanuel Dubois ◽  
Joanna Doummar ◽  
Séverin Pistre ◽  
Marie Larocque
Keyword(s):  
Climate Change ◽  
Time Series ◽  
Karst Aquifer ◽  
Karst Aquifers ◽  
Flow Rates ◽  
Sustainable Water Management ◽  
Lumped Model ◽  
Time Series Analyses ◽  
Spring Flow

Abstract. Flow in complex karst aquifers is challenging to conceptualize and model, especially in poorly investigated areas, in semiarid climates, and under changing climatic conditions; however, it is necessary in order to implement long-term sustainable water management practices. Thus, the objectives of this work were to propose a calibration approach based on time series analyses for a karst aquifer and to assess the impact of climate change on spring discharge. Based on more than 3 years of high-resolution continuous monitoring, a semi-distributed lumped model was calibrated and validated for the Qachqouch karst spring, north of Beirut (Lebanon). Time series analyses and decomposition of spring hydrographs revealed that the system has a high regulatory function, with considerable storage capacity providing stable flow (minimum flow of 0.2 m3 s−1) during the dry season and with flow rates exceeding 10 m3 s−1 during the wet season, which is similar to other karst aquifers in the region. Based on this detailed understanding of the hydrodynamics of the system, the model geometry and parameters were validated. Three linear reservoirs were implemented to reproduce the combined contribution of the different flow components of the system. A satisfactory simulation (Nash–Sutcliffe efficiency coefficient, NSE, of 0.72) of the measured spring flow rates was obtained after calibration. Climate change conditions (+1 to +3 ∘C warming, −10 % to −30 % less precipitation annually, and the intensification of rain events) were added to a baseline climatic year to produce scenarios of expected spring flow responses. Results show that the Qachqouch karst aquifer is sensitive to decreasing rainfall, which is associated with more pronounced recessions, with flow rates decreasing by 34 % and 1-month longer dry periods. Because of the limited influence of snow on the spring flow rate, a warming climate has less impact on spring flow conditions than a reduction in precipitation. Although the model shows that increasing rainfall intensity induces larger floods, recessions, and shorter low-flow periods, the real impact of high-intensity precipitation events remains uncertain, as the model does not account for complex unsaturated and epikarstic processes. This work shows that calibrating a semi-distributed lumped model using time series analyses can be an efficient approach to improve simulations of complex karst aquifers, thereby providing useful models for long-term sustainable water management.

scholarly journals No Long-Term Decrease in Caterpillar Availability for Invertivorous Birds in Deciduous Forests in Hungary

Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1070
Author(s):  
Csaba Béla Eötvös ◽  
Anikó Hirka ◽  
László Gimesi ◽  
Gábor L. Lövei ◽  
Csaba Gáspár ◽  
...  
Keyword(s):  
Time Series ◽  
Time Windows ◽  
Light Trap ◽  
Forest Health ◽  
Deciduous Forests ◽  
Important Food ◽  
Time Series Analyses ◽  
Negative Impacts ◽  
Herbivore Pressure

Numerous recent studies report an alarming decrease in diversity, biomass, or abundance of arthropods in various habitats. Given that they are important food for other organisms, the ecological consequences of such a decline could be severe. We used data from the Hungarian Forestry Light Trap Network to examine whether the spring caterpillar biomass showed any long term (23–58 years) declining trend in oak-dominated forests. Light trap data for 43 selected macrolepidopteran species (suitable bird food in the larval stage) from six different locations were used for the estimation of the total available caterpillar biomass. Time series analyses showed strong year-to-year fluctuations, and over all locations and time windows there was an increasing rather than decreasing trend. The increase found at some locations may suggest increasing herbivore pressure and negative impacts on forest health. We conclude that foliage-feeding macrolepidopteran species with spring-developing larvae did not show a drastic decrease in recent decades, and food availability in the long term will not negatively influence the breeding success of birds in such forests.

Sign in / Sign up

Export Citation Format

Share Document