Temat: canopy cover - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Calibration and Evaluation of Aquacrop for Maize (Zea Mays L.) under Different Irrigation and Cultivation Methods
Autorzy:: Hassan, Diaa Fliah
Ati, Alaa Salih
Neima, AbdulKhalik Saleh
Powiązania:: https://bibliotekanauki.pl/articles/2027849.pdf
Data publikacji:: 2021
Wydawca:: Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:: Aquacrop
sprinkler irrigation
canopy cover
maize
Opis:: Crop models of simulation are utilised effectively to evaluate the management of irrigation strategies which help in managing the water use. The aim of this study was to verify the validity of the Aquacrop model of maize under the surface and sprinkler irrigation systems, and a cultivation system, borders and furrows, and for two varieties of Maze (Fajr and Drakma) at two different sites in Iraq, i.e. the Babylon and Al-Qadisiyah governorates. The current study conducted an experiment to evaluate the Aquacrop model capacity in simulating canopy cover (CC), biomass (B), dry yield, harvest index (HI), and water productivity (WP). The results of RMSE, R2, MAE, d, NSE, CC, Pe indicated good results and high compatibility between the measured and simulated values. The highest achieved results were identical to the method of sprinkler irrigation due to the decrease in the amount of water consumed and the furrows cultivation method as the aerial roots were covered and the cultivar was Drakma. The highest values for the statistical data were $R^2$ (90 and 96%), RMSE (0.60, 0.73), MAE (0.5, 0.67), d (0.97, 0.97), NSE (0.87, 0.90), for the Babylon and Al-Qadisiyah sites, respectively. As for the CC values, they were very compatible with the values of $R^2$ and ranged between (92–99)%. The prediction error was Pe and minor errors were found. Thus, the Aquacrop model can be used reliably to evaluate the effectiveness of proposed irrigation management strategies for maize.
Źródło:: Journal of Ecological Engineering; 2021, 22, 10; 192-204
2299-8993
Pojawia się w:: Journal of Ecological Engineering
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Relationship between forest canopy and natural regeneration in the subalpine spruce-larch forest (north-east Italy)
Autorzy:: Marchi, A.
Paletto, A.
Powiązania:: https://bibliotekanauki.pl/articles/38768.pdf
Data publikacji:: 2010
Wydawca:: Instytut Badawczy Leśnictwa
Tematy:: relationship
forest canopy
natural regeneration
subalpine forest
spruce-larch forest
canopy closure
canopy cover
Italy
Opis:: The authors describe the difference between canopy cover (proportion of the forest floor covered by the vertical projection of the tree crowns) and canopy closure (proportion of sky hemisphere obscured by vegetation when viewed from a single point) and the respective ground-based estimation techniques focused on two types of densiometer (GRS tube and spherical). The data collected in the field were used to analyse the relationship between forest canopy and natural regeneration in two subtypes of subalpine larch-spruce forests. The results indicate that in the first subtype characterized by a high fertility and a high canopy cover (around 62%), the level of natural regeneration is low (115 stems per hectare) and it is nearly exclusively composed by spruce [Picea abies (L.) Karst.]. For the second subtype characterized by a low fertility and a medium canopy cover (around 49%) the natural regeneration is rather dense (650 stems per hectare). At last the authors evidence a insignificant difference between the data of forest canopy collected by different ground-based estimation techniques (+0.7% using spherical densiometer compared to using GRS tube densiometer).
Źródło:: Folia Forestalia Polonica. Series A . Forestry; 2010, 52, 1
0071-6677
Pojawia się w:: Folia Forestalia Polonica. Series A . Forestry
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Czynniki wpływające na gęstość chmury punktów „leżących na gruncie” lotniczego skanowania laserowego na przykładzie danych pochodzących z projektu ISOK
Factors influencing ground point density from AirborneLaser Scanning – a case study with ISOK Project data
Autorzy:: Maślanka, M.
Powiązania:: https://bibliotekanauki.pl/articles/345800.pdf
Data publikacji:: 2016
Wydawca:: Polskie Towarzystwo Informacji Przestrzennej
Tematy:: ISOK
znormalizowany numeryczny model pokrycia terenu
numeryczny model terenu
numeryczny model pokrycia terenu
zwarcie drzewostanu
normalized Digital Surface Model
digital terrain model (DTM)
Digital Surface Model
canopy cover
Opis:: Obszary gęsto pokryte roślinnością charakteryzują się obniżoną gęstością chmury punktów „leżących na gruncie”. Wpływa to negatywnie na odwzorowanie szczegółów terenowych na danym obszarze. W Polsce w latach 2011 - 2015 pozyskano dane lotniczego skanowania laserowego w ramach projektu Informatyczny Systemu Osłony Kraju (ISOK) przed nadzwyczajnymi zagrożeniami. Ze względu na coraz częstsze wykorzystanie tych danych do generowania NMT, należy ocenić czynniki wpływające na gęstość chmury punktów pod obszarami gęsto pokrytymi roślinnością. Praca przedstawia przykład takiej oceny. W pierwszym etapie wykonano modele rastrowe: gęstości chmury punktów, procentowego udziału punktów gruntu, liczby szeregów, NMT, nachylenia terenu, kąta skanowania, zwarcia drzewostanów i znormalizowanego numerycznego modelu pokrycia terenu (zNMPT). W dalszej części dla punktów testowych przeprowadzono analizę związków między zmiennymi na podstawie wielkości z wygenerowanych modeli oraz obiektów wektorowych. W wyniku przeprowadzonych badań stwierdzono, że gęstość chmury punktów warunkowana jest głównie przez zwarcie drzewostanów, wysokość szaty roślinnej i kąt skanowania, przy czym pewien wpływ na kształtowanie się gęstości chmury punktów ma również nachylenie terenu oraz liczba szeregów.
Areas covered with vegetation are characterized by a lower density of ground points. This issue has a negative impact on the accuracy of terrain representation and terrain details that could be detected. Country-wide ALS data was delivered in Poland within the ISOK Project (the IT System of the Country’s Protection against Extreme Hazards) between 2011 and 2015. Considering the increasing use of this data in the process of generation of Digital Terrain Models (DTM), factors affecting the density of ground points in areas covered with vegetation should be carefully assessed. During the first step various raster models were generated: the point cloud density, the percentage of ground points, the point source number, the slope, the scan angle, the canopy cover, the DTM and the normalized Digital Surface Model (nDSM). In the next step statistical analysis of relations between variables, basing on values from generated models and vector objects, was performed. The results showed that the density of ground points is mainly determined by the canopy cover, the forest height and the scan angle; however it is also influenced by the slope and the point source number.
Źródło:: Roczniki Geomatyki; 2016, 14, 4(74); 511-519
1731-5522
2449-8963
Pojawia się w:: Roczniki Geomatyki
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Porównanie oceny zwarcia drzewostanu za pomocą metody wizualnej i zwarciomierza
Comparison of visual estimation of the canopy cover with the canopyscope assessment
Autorzy:: Chmura, D.
Salachna, A.
Sierka, E.
Powiązania:: https://bibliotekanauki.pl/articles/989315.pdf
Data publikacji:: 2016
Wydawca:: Polskie Towarzystwo Leśne
Tematy:: lesnictwo
drzewostany
fitosocjologia
zwarcie drzewostanu
metody oceny
metoda wizualna
metoda kanopiskopowa
kanopiskop
zwarciomerz zob.kanopiskop
canopy closure
ocular estimate cover
phytosociology
Opis:: he visual estimates of tree canopy cover belong to the fundamental measurements of analytical features of forest phytocoenoses. However, it is the subjective method, which results in error difficult to control. The objective of the research was to present a canopyscope and to compare results of canopy cover estimation using it with visual estimates. We conducted several experiments in oak−hornbeam, pine and spruce forest stands in southern Poland. We engaged in fieldwork well− and less−experienced students, i.e. biologists skilled in methods of phytosociology and students of nature engineering as well as three professional phytosociologists. They performed a comparative research in terms of correlation analyses, analysis of coefficients of variation and intra−class correlation (ICC) between−observers and between−methods using both ways of canopy cover estimates. The correlation between canopyscope score and results of visual estimates was highest in the group of phytosociologists (rs=0.82, p<0.001) followed by well−experienced students (rs=0.72, p<0.001) and less−experienced persons (rs=0.62, p<0.001). For purpose of comparison of both methods two variants of visual method were applied: optional visual cover estimate, and adjusted visual method where percentage cover of tree layer was noted using 4% intervals likewise in canopyscope method. The results of visual estimate method were characterized by more than threefold higher variation (CV%=9.72 and CV%=9.46 for optional variant and adjusted variant respectively) in comparison with canopy−scope method (CV%=2.26) in repeating measurements on the same plot. In terms of repeatability, analysis yielded 0.873 (p<0.0001) and 0.622 (p=0.00682) values of ICC for canopyscope and adjusted visual estimate respectively between two phytosociologists. The result of intra−class correlation for comparison between methods within each rater separately revealed low and non−significant value of ICC. We suggest using canopyscope because this method is more precise, reliable and repeatable than visual estimation. Moreover, canopyscope is easier and more convenient to use when compared to objective methods as hemispherical photography of tree canopy and image analysis.
Źródło:: Sylwan; 2016, 160, 06; 475-481
0039-7660
Pojawia się w:: Sylwan
Dostawca treści:: Biblioteka Nauki

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