scholarly journals Spatial and seasonal patterns of precipitation in Greece: the terrain segmentation approach

2014 ◽  
Vol 16 (5) ◽  
pp. 988-997 ◽  
Keyword(s):  
Agricultural Land ◽  
Summer Precipitation ◽  
Winter Precipitation ◽  
Winter Period ◽  
Monthly Precipitation ◽  
Northern Greece ◽  
Agricultural Planning ◽  
Spatial And Seasonal Variation ◽  
Segmentation Approach ◽  
Spatio Temporal

<div> <p>The aim of the study is to investigate the spatial and seasonal variation of precipitation in Greece using multi-temporal data analysis techniques. Mean monthly precipitation grids of 1 km<sup>2</sup> resolution of the period 1950-2000 were used in the analysis. Cross correlation quantified spatio-temporal patterns which are summarized as follows a) the absolute correlations of precipitation versus elevation and longitude are minimized during the winter period, b) the latitude dependency of precipitation presents a seasonal shift where winter precipitation tends to be higher in northern Greece, while summer precipitation tends to be higher in southern Greece. Principal components analysis indicated that the first two components account for the 92.8% of variance in the spatio-temporal variability of precipitation in Greece. Cluster analysis segmented the terrain to 27 regions with distinct seasonal variability of precipitation. The majority of irrigated agricultural land (plains of Macedonia, Thessaly and Thrace) belong to clusters which present the lowest values of annual precipitation (&lt;600 mm year<sup>-1</sup>). The derivation of precipitation signatures for each region of Greece using the proposed terrain segmentation approach can support environmental decision and agricultural planning at a regional (country) scale in relation to water resources management.&nbsp;</p> </div> <p>&nbsp;</p>

scholarly journals Spatio-Temporal Analysis of Sheep and Goats Grazing in Different Forage Resources of Northern Greece

Hacquetia ◽  
2014 ◽  
Vol 13 (1) ◽  
pp. 205-213 ◽  
Author(s):  
Christakis Evangelou ◽  
Maria Yiakoulaki ◽  
Vasilios Papanastasis
Keyword(s):  
Agricultural Land ◽  
Small Ruminants ◽  
Farming Systems ◽  
Spatial Location ◽  
Temporal Analysis ◽  
Spatial And Temporal Patterns ◽  
Northern Greece ◽  
Sheep And Goats ◽  
Spatio Temporal ◽  
Extensive Farming

Abstract Grazing animals explore different forage resources to satisfy their daily nutrient needs, following specific spatial and temporal patterns throughout the year. In this study four different flocks of sheep and goats (two of each species) were selected to record their spatial location with a handheld GPS during spring, summer and winter. At the same time, three animals in each flock were followed to study their grazing activities by direct observation. These data with the time information and a detailed land use map were manipulated in a GIS to assign animal activities to different forage resources. Sheep and goats were travelling long distances (7.5 km and 9.0 km, respectively) to satisfy their nutritional needs throughout the year. They were found to graze in two main forage resources, rangelands (grasslands, shrublands and forest ranges) and agricultural land (fallow land, stubble fields and temporary pastures). Both grazer species spent significantly less time (P≤ 0.05) feeding in rangelands (38.9% & 18.1%) than in agricultural land (63.6% & 53.4%) during spring and summer. It appears that a heterogeneous landscape is necessary for supporting extensive farming systems of small ruminants since rangelands and agricultural land complement each other in providing forage throughout the year.

scholarly journals Validation of CHIRPS Precipitation Estimates over Taiwan at Multiple Timescales

2021 ◽  
Vol 13 (2) ◽  
pp. 254 ◽  
Author(s):  
Jie Hsu ◽  
Wan-Ru Huang ◽  
Pin-Yi Liu ◽  
Xiuzhen Li
Keyword(s):  
Annual Cycle ◽  
Interannual Variation ◽  
Winter Precipitation ◽  
Monthly Precipitation ◽  
Precipitation Estimation ◽  
Precipitation Estimates ◽  
Precipitation Variation ◽  
Global Precipitation ◽  
Multiple Timescale ◽  
Better Than

The Climate Hazards Group InfraRed Precipitation with Station data (CHIRPS), which incorporates satellite imagery and in situ station information, is a new high-resolution long-term precipitation dataset available since 1981. This study aims to understand the performance of the latest version of CHIRPS in depicting the multiple timescale precipitation variation over Taiwan. The analysis is focused on examining whether CHIRPS is better than another satellite precipitation product—the Integrated Multi-satellitE Retrievals for Global Precipitation Mission (GPM) final run (hereafter IMERG)—which is known to effectively capture the precipitation variation over Taiwan. We carried out the evaluations made for annual cycle, seasonal cycle, interannual variation, and daily variation during 2001–2019. Our results show that IMERG is slightly better than CHIRPS considering most of the features examined; however, CHIRPS performs better than that of IMERG in representing the (1) magnitude of the annual cycle of monthly precipitation climatology, (2) spatial distribution of the seasonal mean precipitation for all four seasons, (3) quantitative precipitation estimation of the interannual variation of area-averaged winter precipitation in Taiwan, and (4) occurrence frequency of the non-rainy grids in winter. Notably, despite the fact that CHIRPS is not better than IMERG for many examined features, CHIRPS can depict the temporal variation in precipitation over Taiwan on annual, seasonal, and interannual timescales with 95% significance. This highlights the potential use of CHIRPS in studying the multiple timescale variation in precipitation over Taiwan during the years 1981–2000, for which there are no data available in the IMERG database.

scholarly journals Increasing frequency of low summer precipitation synchronizes dynamics and compromises metapopulation stability in the Glanville fritillary butterfly

2015 ◽  
Vol 282 (1806) ◽  
pp. 20150173 ◽  
Author(s):  
Ayco J. M. Tack ◽  
Tommi Mononen ◽  
Ilkka Hanski
Keyword(s):  
Population Dynamics ◽  
Population Change ◽  
Temporal Dynamics ◽  
Summer Precipitation ◽  
Life History Stage ◽  
General Effect ◽  
Spatial Synchrony ◽  
Glanville Fritillary Butterfly ◽  
Spatio Temporal

Climate change is known to shift species' geographical ranges, phenologies and abundances, but less is known about other population dynamic consequences. Here, we analyse spatio-temporal dynamics of the Glanville fritillary butterfly ( Melitaea cinxia ) in a network of 4000 dry meadows during 21 years. The results demonstrate two strong, related patterns: the amplitude of year-to-year fluctuations in the size of the metapopulation as a whole has increased, though there is no long-term trend in average abundance; and there is a highly significant increase in the level of spatial synchrony in population dynamics. The increased synchrony cannot be explained by increasing within-year spatial correlation in precipitation, the key environmental driver of population change, or in per capita growth rate. On the other hand, the frequency of drought during a critical life-history stage (early larval instars) has increased over the years, which is sufficient to explain the increasing amplitude and the expanding spatial synchrony in metapopulation dynamics. Increased spatial synchrony has the general effect of reducing long-term metapopulation viability even if there is no change in average metapopulation size. This study demonstrates how temporal changes in weather conditions can lead to striking changes in spatio-temporal population dynamics.

scholarly journals AVALIAÇÃO DA DISPONIBILIDADE HÍDRICA NA SUB-BACIA DO BOI BRANCO ATRAVÉS DO BALANÇO HÍDRICO CLIMATOLÓGICO E DE CULTIVO

Irriga ◽  
2017 ◽  
Vol 22 (1) ◽  
pp. 1-17
Author(s):  
Mariana Alexandre de Lima Sales ◽  
RODRIGO MÁXIMO SÁNCHEZ ROMÁN ◽  
LEONOR RODRÍGUEZ SINOBAS ◽  
RAIMUNDO NONATO FARIAS MONTEIRO ◽  
JOÃO VICTOR RIBEIRO DA SILVA DE SOUZA
Keyword(s):  
Water Balance ◽  
Water Deficit ◽  
Environmental Planning ◽  
Water Cycle ◽  
Crop Coefficient ◽  
Monthly Precipitation ◽  
Agricultural Planning ◽  
Historical Series ◽  
Average Monthly Precipitation ◽  
E Mail

AVALIAÇÃO DA DISPONIBILIDADE HÍDRICA NA SUB-BACIA DO BOI BRANCO ATRAVÉS DO BALANÇO HÍDRICO CLIMATOLÓGICO E DE CULTIVO  MARIANA ALEXANDRE DE LIMA SALES1; RODRIGO MÁXIMO SÁNCHEZ ROMÁN2; LEONOR RODRÍGUEZ SINOBAS3; RAIMUNDO NONATO FARIAS MONTEIRO4; JOÃO VICTOR RIBEIRO DA SILVA DE SOUZA5. 1 Tecnóloga em Irrigação e Drenagem, Doutoranda em Agronomia (Irrigação e Drenagem) – FCA/UNESP. Rua José Barbosa de Barros, 1780, CEP 18610-307, Botucatu – SP, e-mail: [email protected] Eng. de Irrigação e Drenagem, Prof. Doutor FCA/UNESP. Rua José Barbosa de Barros, 1780, CEP 18610-307, Botucatu, SP. Fone: (14) 3711-7100. E-mail: [email protected] Eng. Agrônoma, Profa. Doutora ETSIA/UPM, Ciudad Universitaria, 28040 Madri, Espanha. e-mail: [email protected] Tecnólogo em Recursos Hídricos/Irrigação, Doutor em Agronomia (Irrigação e Drenagem) – FCA/UNESP. Rua José Barbosa de Barros, 1780, CEP 18610-307, Botucatu – SP, e-mail: [email protected] Eng. Agrônomo, Doutorando em Agronomia (Irrigação e Drenagem) – FCA/UNESP. Rua José Barbosa de Barros, 1780, CEP 18610-307, Botucatu – SP, e-mail: [email protected].  1 RESUMO Uma das formas de contabilizar a quantidade de água de um determinado sistema é por meio do balanço hídrico, o qual é uma importante ferramenta para o processo de avaliação do ciclo da água em uma determinada região. O objetivo deste trabalho foi determinar o balanço hídrico na sub-bacia hidrográfica do Boi Branco-SP, para servir como ferramenta ao planejamento hidroagrícola e ambiental da região. Para o balanço hídrico climatológico, utilizaram-se dados da série histórica da região (1971 a 1995). Os dados de evapotranspiração foram estimados pelo método de Thornthwaite. O balanço hídrico climatológico mostrou déficit hídrico total anual de 10,1 mm, e um excedente de 319,7 mm, tendo no mês de janeiro um excedente de 92,6 mm, para a precipitação média mensal; com a precipitação efetiva mensal com probabilidade de 75%, déficit hídrico no solo é de 238,8 mm e o excedente 56,8 mm. Quando se adiciona a esses dados os das culturas implantadas na área de estudo, como coeficiente de cultivo e fator de depleção da umidade do solo, observa-se que todas as culturas do estudo apresentaram déficit hídrico em todos os meses em que estiveram no campo. Palavras-chave: Planejamento hidroagrícola, capacidade de água disponível no solo, evapotranspiração.  SALES, M. A. L.; SÁNCHEZ-ROMÁN, R. M.; SONOBAS, L. R.; MONTEIRO, R. N. F.; SOUZA, J. V. R. S.ASSESSMENT OF WATER AVAILABILITY AT BOI BRANCO WATERSHED   THROUGH CLIMATIC WATER BALANCE AND GROWING  2 ABSTRACT One way to calculate the amount of water in a determined system is by means of the water balance, an important tool for the assessment of the water cycle in a specific region. The main goal of this work was to establish the water balance in the watershed Boi Branco-SP, so that it can be used as a tool for the hydro-agricultural and environmental planning of the region. For the climatic water balance, data of the historical series of the region (1971 - 1995) were used. Evapotranspiration data were estimated by the Thornthwaite method. The climatic water balance showed  total annual water deficit  of 10.1 mm, and surplus of 319.7 mm, with January presenting surplus  of  92.6 in the average monthly precipitation; given that the effective monthly precipitation presenting probability of 75%,  water deficit  in the soil  is 238.8 mm and surplus is 56.8 mm. When these data are added to the ones of the crop, as a crop coefficient and soil humidity depletion factor, it is observed that all crops studied showed water deficit  in all the months covered. Keyword: Water agricultural planning, water capability available in the soil, evapotranspiration.

scholarly journals Spatial Analysis of Seasonal Precipitation Using Various Interpolation Methods in the Euphrates Basin, Turkey

2021 ◽  
Author(s):  
Okan Mert Katipoğlu
Keyword(s):  
Spatial Distribution ◽  
Geographical Information Systems ◽  
Polynomial Interpolation ◽  
Estimation Method ◽  
Summer Precipitation ◽  
Winter Precipitation ◽  
Geographical Information ◽  
Seasonal Precipitation ◽  
Interpolation Methods

Abstract It is vital to accurately map the spatial distribution of precipitation, which is widely used in many fields such as hydrology, climatology, meteorology, ecology, and agriculture. In this study, it was aimed to reveal the spatial distribution of seasonal long-term average precipitation in the Euphrates Basin by using various interpolation methods. For this reason, Simple Kriging (SK), Ordinary Kriging (OK), Universal Kriging (UK), Ordinary CoKriging (OCK), Empirical Bayesian Kriging (EBK), Radial Basis Functions (Completely Regularized Spline (CRS), Thin Plate Spline (TPS), Multiquadratic, Inverse Multiquadratic (IM), Spline with Tensor (ST)), Local Polynomial Interpolation (LPI), Global Polynomial Interpolation (GPI), Inverse Distance Weighting (IDW) methods have been applied in the Geographical Information Systems (GIS) environment. Long-term seasonal precipitation averages between 1966 and 2017 are presented as input for the prediction of precipitation maps. The accuracy of the precipitation prediction maps created was based on root mean square error (RMSE) values obtained from the cross-validation tests. The method of precipitation by interpolation yielding the lowest RMSE was selected as the most appropriate method. As a result of the study, OCK in spring and winter precipitation, LPI in summer precipitation, and OK in autumn precipitation were determined as the most appropriate estimation method.

scholarly journals Assessment of Land Use and Vegetative Cover in Kano Metropolis (from 1975-2015) Employing GIS and Remote Sensing Technology

2020 ◽  
Vol 27 (2) ◽  
pp. 1-7
Author(s):  
M. Haruna ◽  
M.K. Ibrahim ◽  
U.M. Shaibu
Keyword(s):  
Remote Sensing ◽  
Land Use ◽  
Agricultural Land ◽  
Landsat 8 ◽  
Vegetative Cover ◽  
Gis And Remote Sensing ◽  
Remote Sensing Technology ◽  
Sensing Technology ◽  
Agricultural Planning ◽  
Bare Land

This study applied GIS and remote sensing technology to assess agricultural land use and vegetative cover in Kano Metropolis. It specifically examined the intensity of land use for agricultural and non agricultural purpose from 1975 – 2015. Images (1975, 1995 and 2015), landsat MSS/TM, landsat 8, scene of path 188 and 052 were downloaded for the study. Bonds for these imported scenes were processed using ENVI 5.0 version. The result indicated five classified features-settlement, farmland, water body, vegetation and bare land. The finding revealed an increase in settlement, vegetation and bare land between 1995 and 2015, however, farmland decreased in 2015. Indicatively, higher percentage of land use for non agricultural purposes was observed in recent time. Conclusively, there is need to accord surveying the rightful place and priority in agricultural planning and development if Nigeria is to be self food sufficient. Keywords: Geographic Information System, Agriculture, Remote sensing, Land use, Land cover

scholarly journals Precipitation Variations under a Changing Climate from 1961–2015 in the Source Region of the Indus River

Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1366
Author(s):  
Muhammad Rizwan ◽  
Xin Li ◽  
Kashif Jamal ◽  
Yingying Chen ◽  
Junaid Nawaz Chauhdary ◽  
...  
Keyword(s):  
Daily Precipitation ◽  
Source Region ◽  
Summer Precipitation ◽  
Heavy Precipitation ◽  
Winter Precipitation ◽  
Indus Basin ◽  
Indus River ◽  
Precipitation Characteristics ◽  
Daily Precipitation Data ◽  
Increasing Trends

The source region of the Indus River (SRIR), which is located in the Hindukush, Karakoram and Himalayan (HKH) mountainous range and on the Third Pole (TP), is very sensitive to climate change, especially precipitation changes, because of its multifarious orography and fragile ecosystem. Climate changes in the SRIR also have important impacts on social and economic development, as well as on the ecosystems of the downstream irrigation areas in Pakistan. This paper investigates the changes in precipitation characteristics by dividing the daily precipitation rate into different classes, such as light (0–10 mm), moderate (10.1–25 mm) and heavy precipitation (>25 mm). Daily precipitation data from gauging and non-gauging stations from 1961–2015 are used. The results of the analysis of the annual precipitation and rainy day trends show significant (p < 0.05) increases and decreases, respectively, while light and heavy precipitation show significant decreasing and increasing trends, respectively. The analysis of the precipitation characteristics shows that light precipitation has the highest number of rainy days compared to moderate or heavy precipitation. The analysis of the seasonal precipitation trends shows that only 18 stations have significant increasing trends in winter precipitation, while 27 stations have significant increasing trends in summer precipitation. Both short and long droughts exhibit increasing trends, which indicates that the Indus Basin will suffer from water shortages for agriculture. The results of this study could help policymakers cope with floods and droughts and sustain eco-environmental resources in the study area.

scholarly journals Overview of the Chemical and Isotopic Investigations of the Mareza Springs and the Zeta River in Montenegro

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 957
Author(s):  
Katarina Živković ◽  
Milan Radulović ◽  
Sonja Lojen ◽  
Mira Pucarević
Keyword(s):  
Seasonal Variations ◽  
Water Samples ◽  
Mean Transit Time ◽  
Karst Aquifer ◽  
Winter Period ◽  
Mountainous Area ◽  
Monthly Precipitation ◽  
Air Masses ◽  
Water Fraction ◽  
Stable Isotopic

The Mareza karst aquifer is the most important drinking water resource for the water supply system of the City of Podgorica, the capital of Montenegro. This study presents the first assessment for the determination of the Mareza catchment area. Water chemistry and stable isotopic composition (δ18O and δ2H) of monthly precipitation samples (as inputs) are presented, in order to determine the Local Meteoric Water Line (LMWL) for the study area, and to analyze the behavior of the karst spring Mareza (as output) and the Zeta River water. The possible impact of the river on the Mareza springs was also investigated. Stable isotope compositions were used to analyze the origin of the four springs of the Mareza aquifer. Seasonal variations of δ18O and δ2H values and deuterium excess (d excess) changes in precipitation are explained by the mixing of air masses, such that a Mediterranean source prevails in the winter period, while in the summer period, the area is rather under the influence of air mass originating from the Atlantic Ocean. All spring water samples have lower δ values than the local precipitation and they plot above the LMWL, which may indicate recharge at a higher altitude in the distant mountainous area. The d excess values of all water samples (higher than 10‰) indicate the prevalence of the Mediterranean as a moisture source. Based on the analysis of the seasonal variations of δ18O and δ2H in precipitation and the Mareza spring, it has been estimated that the groundwater mean transit time (MTT) is 92–129 days, and that the young water fraction (Fyw) amounts to 40.9%–53.3%. These values are typical for the strong karstic springs of highly karstified terrains.

Trends of the Degree-Day Factors in the mountainous regions

2020 ◽  
Author(s):  
Muhammad Fraz Ismail
Keyword(s):  
River Basin Management ◽  
Winter Precipitation ◽  
Indus Basin ◽  
Mountainous Regions ◽  
Degree Day ◽  
Air Temperatures ◽  
University Of Munich ◽  
University Of Applied Sciences ◽  
Spatio Temporal ◽  
Energy Balances

&lt;p&gt;&lt;strong&gt;Trends of the Degree-Day Factors in the mountainous regions&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;Muhammad Fraz Ismail&lt;sup&gt;1, 2&lt;/sup&gt;, Prof. Dr. &amp;#8211;Ing. Markus Disse&lt;sup&gt;1&lt;/sup&gt;, Prof. Dr. &amp;#8211;Ing. Wolfgang Bogacki&lt;sup&gt;2&lt;/sup&gt;,&lt;/p&gt;&lt;p&gt;Alexander Brandt&lt;sup&gt;3&lt;/sup&gt;, M. Larry Lopez C.&lt;sup&gt;3&lt;/sup&gt;&lt;/p&gt;&lt;p&gt;&lt;sup&gt;&amp;#160;&lt;/sup&gt;&lt;/p&gt;&lt;p&gt;&lt;sup&gt;1 &lt;/sup&gt;Chair of Hydrology and River Basin Management, Department of Civil, Geo and Environmental Engineering, Technical University of Munich.&lt;/p&gt;&lt;p&gt;&lt;sup&gt;2&lt;/sup&gt; Department of Civil Engineering, Koblenz University of Applied Sciences.&lt;/p&gt;&lt;p&gt;&lt;sup&gt;3 &lt;/sup&gt;Faculty of Agriculture, Yamagata University, Tsuruoka, Japan.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;Melt generated through snow and glaciers are considered to be a vital fresh water resource because they store the solid winter precipitation as then act as a reservoir to provide water when it is mostly needed i.e. during the summer season. Recently, a lot of studies based on hydrological modelling showed that the changing climate will adversely affect the snow and glacial melt patterns around the globe. Considering this situation it is quite critical to know more about these melting processes and the factors driving them.&lt;/p&gt;&lt;p&gt;Degree-day approach for simulating the flows generated through the snow and glacial melt has proved to be a handsome one because it uses the temperatures as an index variable to address the complex energy balances as well as its only dependency over the air temperatures to generate the melt make it feasible especially for the high mountainous data scare regions (e.g. Upper Indus Basin). Degree-day models use the Degree-Day Factor (DDF) as a &amp;#8216;key&amp;#8217; parameter which transforms one degree-day [&amp;#176;C.day&lt;sup&gt;-1&lt;/sup&gt;] into daily melt depth [mm.day&lt;sup&gt;-1&lt;/sup&gt;]. Literature enlightens that the DDF is not a constant parameter but it changes with the ripening of the snowpack.&lt;/p&gt;&lt;p&gt;In the present research, snow measurement datasets from three different locations e.g. Japan (Enshurin 173m a.s.l.), Germany (Brunnenkopfh&amp;#252;tte 1602m a.s.l.), and Pakistan (Deosai 4149m a.s.l.) have been collected and evaluated for the estimation of the DDFs. Initial findings show that there exists a considerable spatio-temporal variation of the DDFs. Which ranges from 0.3 &amp;#8211; 6.8 [mm&amp;#176;C&lt;sup&gt;-1&lt;/sup&gt; day&lt;sup&gt;-1&lt;/sup&gt;] in the German Alps, 0.2 &amp;#8211; 7.9 [mm&amp;#176;C&lt;sup&gt;-1&lt;/sup&gt; day&lt;sup&gt;-1&lt;/sup&gt;] in Yamagta Forest Japan and reaches &amp;#8805;10 [mm&amp;#176;C&lt;sup&gt;-1&lt;/sup&gt; day&lt;sup&gt;-1&lt;/sup&gt;] in the Himalayan ranges during the snowmelt season.&lt;/p&gt;&lt;p&gt;In general, the DDFs show an increasing trend during the snowmelt season at different elevations, which not only demonstrates the altitude influence on the variability of the DDFs but also links to changing snow densities. Latter suggests that the DDFs should not be taken as constant because it changes with the location and needs to be estimated for different regions.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;&amp;#160;&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;&lt;strong&gt;KEYWORDS&lt;/strong&gt;: Degree-Day Factor, Snow and glacial melt, Measurements&lt;/p&gt;

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