WHEN WILL ALL THE LIVESTOCK IN AUSTRALIA BE ONE CLONE?

Satellite remote sensing has been a valuable tool in providing a complete and synoptic geographical coverage of water quality in fresh water systems. The principal benefit of satellite remote sensing for inland water quality monitoring is the production of synoptic views without the need of costly in situ sampling. In addition spatial and temporal variations of water quality and trophic state in fresh water bodies such as dams and reservoirs can be mapped and assessed using satellite remotely sensed imagery. Satellite remote sensing techniques may also be used to design or improve in situ sampling monitoring programmes by locating appropriate sampling points based on the qualitative results obtained directly from the satellite images. A further benefit is the capability of establishing spectral statistical relationships of satellite data with water quality parameters. Cyprus is made attractive by the frequency of high cloud-free imagery availability and moreover due to the fact that a single Landsat Thematic Mapper (TM) or Enhanced Thematic Mapper (ETM+) image of Cyprus covers almost the entire island. This paper examines the potential of using satellite remote sensing for the qualitative assessment of water quality in inland water bodies such as dams in Cyprus; including evaluation on spatial, temporal water quality variations and finally an assessment on trophic stat

The use of earth observation methods for estimating regional crop evapotranspiration and yield for water footprint accounting

Remote sensing can efficiently support the quantification of crop water requirements included in the goal of assessing water footprints, which is to analyse how human activities or specific products relate to issues of water scarcity and pollution and identify how activities and products can become more sustainable from a water perspective. Remote sensing techniques have become popular in estimating actual crop evapotranspiration and hence crop water requirements in recent decades due to the advantages they offer to users, e.g. low cost, regional data and use of maps instead of point measurements as well as saving time. The use of earth observation data supports models' accuracy in the procedure for assessing water footprint, since no average values are used: instead, users have real values for the specific parameters. The present study provides two examples of how remote sensing techniques are used essentially for estimating evapotranspiration along with crop yield, two basic parameters, for assessing water footprint. Two different case studies have been illustrated to define the methodology proposed, which refers to Mediterranean conditions and can be applied after inferring the necessary field data of each crop. The first case study refers to the application of Surface Energy Balance Algorithm for Land (SEBAL) for estimating evapotranspiration, while the second refers to the Crop Yield prediction. Both elements, such as evapotranspiration and crop yield, are vital for water footprint accounting. Firstly, the SEBAL was adopted, under the essential adaptations for local soil and meteorological conditions for estimating groundnut water requirements. Landsat-5 TM, Landsat-7 Enhanced Thematic Mapper+ and Landsat 8 OLI images were used to retrieve the required spectral data. The SEBAL model is enhanced with empirical equations regarding crop canopy factors, in order to increase the accuracy of crop evapotranspiration estimation. Maps were created for evapotranspiration (ET) using the SEBAL modified model for the area of interest. The results were compared with measurements from an evaporation pan, used as a reference. Statistical comparisons showed that the modified SEBAL can predict ETc in a very effective and accurate way and provide water footprint modellers with high-level crop water data. Yield prediction plays a vital role in calculating water footprint. Having real values rather than taking reference (or averaged) values from FAO is an advantage that Earth Observation means can provide. This is very important in econometric or any other prediction models used for estimating water footprint because using average data reduces accuracy. In this context, crop and soil parameters along with remotely sensed data can be used to develop models that can provide users with accurate yield estimations. In a second step, crop and soil parameters along with the normalized difference vegetation index were correlated to examine whether crop yield can be predicted and to define the actual time-window to predict the yield. Statistical and remote sensing techniques were then applied to derive and map a model that can predict crop yield. The algorithm developed for this purpose indicates that remote sensing observations can predict crop yields effectively and accurately. Using the statistical Student's t test, it was found that there was no statistically significant difference between predicted and real values for crop yield

DIACHRONIC STUDY OF CROP SPECTRAL RESPONSE

Η ΔΙΑΤΡΙΒΗ ΑΦΟΡΑ ΤΟΝ ΔΙΑΧΡΟΝΙΚΟ ΠΡΟΣΔΙΟΡΙΣΜΟ ΤΩΝ ΦΑΣΜΑΤΙΚΩΝ ΧΑΡΑΚΤΗΡΙΣΤΙΚΩΝ (ΥΠΟΓΡΑΦΩΝ ΚΑΙ ΔΕΙΚΤΩΝ ΒΛΑΣΤΗΣΗΣ) ΤΩΝ ΚΑΛΛΙΕΡΓΕΙΩΝ ΣΙΤΑΡΙΟΥ, ΒΑΜΒΑΚΙΟΥ, ΚΑΛΑΜΠΟΚΙΟΥ ΚΑΙ ΤΕΥΤΛΩΝ, ΣΤΗΝ ΠΕΡΙΟΧΗ ΛΑΡΙΣΑΣ, ΜΕ ΣΚΟΠΟ ΤΗΝ ΔΙΑΚΡΙΣΗ ΚΑΙ ΑΝΑΓΝΩΡΙΣΗ ΤΟΥΣ ΜΕ ΤΗΛΕΠΙΣΚΟΠΗΣΗ. ΓΙΑ ΤΟΝ ΣΚΟΠΟ ΑΥΤΟ ΧΡΗΣΙΜΟΠΟΙΗΘΗΚΑΝ ΦΟΡΗΤΑ ΕΠΙΓΕΙΑ ΑΚΤΙΝΟΜΕΤΡΑ ΣΤΟ ΟΡΑΤΟ ΚΑΙ ΥΠΕΡΥΘΡΟ ΦΑΣΜΑ, ΚΑΤΑ ΤΗΝ ΔΙΑΡΚΕΙΑ ΜΙΑΣ ΚΑΛΛΙΕΡΓΗΤΙΚΗΣ ΠΕΡΙΟΔΟΥ. ΕΠΙΣΗΣ ΥΠΟΛΟΓΙΣΤΗΚΑΝ ΚΑΙ ΜΕΛΕΤΗΘΗΚΑΝ ΣΤΑΤΙΣΤΙΚΕΣ ΠΑΡΑΜΕΤΡΟΙ ΤΩΝ ΣΧΕΣΕΩΝ ΜΕΤΑΞΥ ΦΑΣΜΑΤΙΚΩΝ ΚΑΙ ΜΕΤΕΩΡΟΛΟΓΙΚΩΝ ΔΕΔΟΜΕΝΩΝ ΜΕ ΣΤΟΙΧΕΙΑ ΤΩΝ ΚΑΛΛΙΕΡΓΕΙΩΝ(ΥΨΟΣ ΚΑΙ ΔΙΑΜΕΤΡΟΣ ΚΟΜΗΣ) ΚΑΙ ΤΟΥ ΕΔΑΦΟΥΣ. ΙΔΙΑΙΤΕΡΗ ΜΕΛΕΤΗ ΑΠΟΤΕΛΕΣΑΝ ΟΙ ΣΧΕΣΕΙΣ ΤΩΝ ΦΑΣΜΑΤΙΚΩΝ ΚΑΙ ΜΕΤΕΩΡΟΛΟΓΙΚΩΝ ΔΕΔΟΜΕΝΩΝ ΜΕ ΤΗΝ ΔΙΑΦΟΡΟΠΟΙΗΣΗ ΤΟΥ ΟΓΚΟΥ ΤΗΣ ΒΙΟΜΑΖΑΣ ΤΟΥ ΣΙΤΑΡΙΟΥ ΣΕ ΔΙΑΧΡΟΝΙΚΗ ΒΑΣΗ, ΠΟΥ ΜΕΛΕΤΗΘΗΚΑΝ ΣΕ ΤΡΙΕΤΕΣΠΕΙΡΑΜΑ, ΟΙ ΟΠΟΙΕΣ ΟΔΗΓΟΥΝ ΣΤΗΝ ΠΡΟΓΝΩΣΗ ΤΗΣ ΑΝΑΜΕΝΟΜΕΝΗΣ ΑΠΟΔΟΣΗΣ.THIS THESIS CONCERNS THE DIACHRONIC SPECIFICATION OF THE SPECTRAL CHARACTERISTICS (SIGNATURES AND VEGETATION INDICES) OF WHEAT, COTTON, MAIZE AND SUGARBEET CROPS, IN LARISSA AREA, GREECE, AIMING TO THEIR IDENTIFICATION AND DISCRIMINATION USING REMOTE SENSING TECHNIQUES. FOR THESE PURPOSES HAND-HELD PORTABLE RADIOMETERS WERE USED, IN THE VISIBLE AND NEAR INFRARED, DURING A CROP PERIOD. ALSO, STATISTICAL PARAMETERS OF THE RELATIONSHIPS BETWEEN SPECTRAL AND METEOROLOGICAL DATA WITH CROP ELEMENTS (CANOPY HEIGHT AND DIAMETER) AND SOIL PROPERTIES, WERE STUDIED AND CALCULATED. A SPECIAL STUDY OF THE RELATIONSHIPS OF THE SPECTRAL AND METEOROLOGICAL DATA WITH THE WHEAT BIOMASS DIFFERENTIATION DURING ATHREE- YEAR EXPERIMENT WAS CARRIED OUT, LEADING TO YIELD PREDICTION

Mapping potato crop height and leaf area index through vegetation indices using remote sensing in Cyprus

This paper aims to model leaf area index (LAI) and crop height to spectral vegetation indices (VI), such as normalized difference vegetation index (NDVI) and soil adjusted vegetation index (SAVI), and weighted difference vegetation index (WDVI). The intended purpose is to create empirical statistical models to support evapotranspiration algorithms applied under the current conditions in the island of Cyprus. Indeed, a traditionally agricultural area was selected in the Mandria Village in the Paphos District area in Cyprus, where one of the island's main exported crops, potatoes, are cultivated. A GER-1500 field spectroradiometer was used in this study in order to retrieve the necessary spectrum data of the different crops for estimating the VI’s. A field campaign was undertaken with spectral measurements of LAI and crop height using the Sun-Scan canopy analyzer, acquired simultaneously with the spectroradiometric measurements between March and April of 2008 and 2009. Regarding the measurements, the phenological cycle of potatoes was followed. Several regression models have been applied to relate LAI/crop height and the three indices. It was found that the best fitted vegetation index to both LAI and crop height was WDVI. When LAI was regressed against WDVI for potatoes, the determination coefficient (R2) was 0.72, while for crop height R2 reached 0.78. Two Landsat TM-5 images acquired simultaneously during the spectroradiometric and LAI and crop height measurements are used to validate the proposed regression model. From the whole analysis it was found that the modeled results are very close to real values. This fact enables the specific empirical models to be used in the future for hydrological purposes.The authors would like to express their appreciation to Cyprus Research Promotion Foundation (www.research.org.cy), European Union (Regional Development Funds), and the Cyprus University of Technology for their funding support. Thanks are given to the Remote Sensing Laboratory of the Department of Civil Engineering and Geomatics at the Cyprus University of Technolog

Retrieving visibility values using satellite remote sensing

The recent development of satellite meteorology has allowed us to estimate spatially and frequently number of basic meteorological parameters. This paper presents the proposed methodology for retrieving visibility values based on the application of the darkest pixel atmospheric correction algorithm on satellite image data. The method is based on the use of the radiative transfer calculations followed by some key assumptions. Landsat-5 TM band 1 images (0.45–0.52 ?m) have been used to determine the visibility value for each image date. A direct comparison between the measured visibility data from the airport meteorological stations with the determined visibility data was performed showing high correlation values. Indeed, by relating the determined visibility data with those measured on the Heathrow Airport station in the West London (UK), a correlation coefficient of r2 = 0.97 has been found with the observed significance for the regression model to be less than 0.05, for four multi-temporal images acquired on 1985 and 1986. The algorithm has been tested also to Landsat TM images of the Paphos Airport area in Cyprus with satisfactory agreement between the visibilities measured at the meteorological station and those found from the images. The algorithm presented may be useful for assessing the atmospheric conditions of satellite images and also can assist the improvement and effectiveness of the available atmospheric correction algorithms.<br/

Satellite remote sensing for water quality assessment and monitoring-an overview on current concepts, deficits and future tasks

The aim of this study is to give an overview of the current state of monitoring water quality issues and the application experience with the approaches provided by using satellite remote sensing as an effective monitoring tool for such studies. It is pointed out that the current in-situ techniques must be replaced by satellite remote sensing techniques due to their cost effectiveness and benefits of providing synoptic coverage of the area under investigation. Today satellite remote sensing can provide much needed information-for example, on some aspects of water quality where access is difficult or where a large area needs to be surveyed and the cost of a ground survey would be too high. Satellite Remote Sensing was found to be a valuable tool of assessing multi-temporal changes, spatial variations and synoptic coverage of water quality as described in this paper by citing the example of the Cyprus Island in which a Landsat TM or ETM image covers almost the entire island. Indeed, the benefit of using only one snapshot and assessing water quality for all the inland water bodies is highlighted

A Modified SEBAL Modeling Approach for Estimating Crop Evapotranspiration in Semi-arid Conditions

Remote sensing methods are becoming attractive to estimate crop evapotranspiration, as they cover large areas and can provide accurate and reliable estimations; intensive field monitoring is also not required, although some ground-truth measurements can be helpful in interpreting satellite images. For the purposes of this paper, modeling and remote sensing techniques were integrated for estimating actual evapotranspiration of groundnuts (Arachishypogaea, L.) that is cultivated near Mandria Village in Paphos District of Cyprus. The Surface Energy Balance Algorithm for Land (SEBAL) was adopted for the first time in Cyprus, employing the essential adaptations for local soil and meteorological conditions. Landsat-5 TM and 7 ETM+ images were used to retrieve the needed spectral data. The SEBAL model is enhanced with empirical equations determined as part of the present study, regarding crop canopy factors, in order to increase its accuracy. Maps of ETa were created using the SEBAL modified model (CYSEBAL) for the area of interest. The results have been compared to the measurements from an evaporation pan (which was used as a reference) and those of the original SEBAL model. The statistical comparison has shown that the modified SEBAL yields results that are comparable to those of the evaporation pan. T-test application has revealed that the statistical difference between SEBAL and CYSEBAL is significant and quite crucial, especially in a place with limited surface and underground water resources

Defining the Landsat TM/ETM+ and CHRIS/PROBA spectral regions in which turbidity can be retrieved in inland waterbodies using field spectroscopy

This article describes the results obtained by an existing campaign in which in situ spectroradiometric measurements using a GER1500 field spectroradiometer, Secchi disk depth, and turbidity measurements (using a portable turbidity meter) were acquired at Asprokremmos Reservoir in Paphos District, Cyprus. Field spectroradiometric and water quality data span 18 sampling campaigns during the period May 2010–October 2010. By applying several regression analyses between ‘In-Band’ mean reflectance values against turbidity values for all spectral bands corresponding to Landsat TM/ETM+ (Bands 1 to 4) and CHRIS/PROBA (Bands A1 to A62), the highest correlation was found for Landsat TM/ETM+ Band 3 (R2 = 0.85) and for CHRIS/PROBA Bands A30 to A32 (R2 = 0.90)

Monitoring water quality parameters for Case II waters in Cyprus using satellite data

Remote sensing technology has been widely used for monitoring water quality parameters such as suspended solids (turbidity), Secchi Disk, chlorophyll, and phosphorus. Suspended matter plays an important role in water quality management of several inland- (such as lakes and reservoirs) and coastal-water bodies and can be used to estimate the Trophic State Index of different water bodies. However synoptic information on water quality parameters at a systematic basis is difficult to be obtained from routine in situ monitoring programs since suspended matter, phosphorus, and chlorophyll are spatially inhomogeneous parameters. To meet this need, an integrated use of Landsat satellite images, in situ data and water quality models can be used. Several algorithms were developed at a previous stage using water quality data collected during the in situ sampling campaigns taken place in 2010 and 2011 over Asprokremmos Reservoir (Paphos District) for the assessment of turbidity, Secchi Disk, and Trophic State Index fluctuations using spectroradiometric data. Remotely sensed data were atmospherically corrected and water quality models for the estimation of both the turbidity- and Secchi Disk- concentrations were further calibrated using in situ data for the case of Asprokremmos Reservoir and several coastal over Cyprus coastline (Limassol and Paphos District Areas). This methodology can be used as a supporting monitoring tool for water management authorities "gaining"? additional information regarding the spatial and temporal alterations of the turbidity- and Secchi Disk- concentrations and the Trophic State Index values over several Case II water bodies