A MODIFIED CALIBRATION APPROACH FOR RATIO ESTIMATOR IN STRATIFIED SAMPLING

Calibration is a technique for the adjustment of the original design weight to improve the precision of the survey. There is a dearth of information on calibration approach adapted for survey such that the survey cost is put into consideration. This research work developed a modified calibration approach for improving survey precision by considering the cost function. Data set on vegetable and tobacco productions (metric tonnes) were considered for this study. The data were obtained from the website of Food and Agriculture Organization. Data used was stratified based on geographical location. The population under study was divided into subpopulation of units, these subpopulations were non-overlapping homogenous sub- group. Observations were drawn within each stratum by simple random sampling with optimum allocation procedure. The proposed estimator was derived and used to determine the linear weight estimator of population parameters. The statistical properties of the derived estimator was examined. Using Lagrange multiplier, Mean Square Error and Relative Efficiency was obtained. The proposed estimator is found to be efficient

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Tree Cover Estimation in Global Drylands from Space Using Deep Learning

Remote Sensing ◽

10.3390/rs12030343 ◽

2020 ◽

Vol 12 (3) ◽

pp. 343 ◽

Cited By ~ 3

Author(s):

Emilio Guirado ◽

Domingo Alcaraz-Segura ◽

Javier Cabello ◽

Sergio Puertas-Ruíz ◽

Francisco Herrera ◽

...

Keyword(s):

Forest Cover ◽

Global Scale ◽

Classification Model ◽

Tree Cover ◽

System Modelling ◽

Earth System ◽

Visual Interpretation ◽

Food And Agriculture ◽

Food And Agriculture Organization ◽

The Cost

Accurate tree cover mapping is of paramount importance in many fields, from biodiversity conservation to carbon stock estimation, ecohydrology, erosion control, or Earth system modelling. Despite this importance, there is still uncertainty about global forest cover, particularly in drylands. Recently, the Food and Agriculture Organization of the United Nations (FAO) conducted a costly global assessment of dryland forest cover through the visual interpretation of orthoimages using the Collect Earth software, involving hundreds of operators from around the world. Our study proposes a new automatic method for estimating tree cover using artificial intelligence and free orthoimages. Our results show that our tree cover classification model, based on convolutional neural networks (CNN), is 23% more accurate than the manual visual interpretation used by FAO, reaching up to 79% overall accuracy. The smallest differences between the two methods occurred in the driest regions, but disagreement increased with the percentage of tree cover. The application of CNNs could be used to improve and reduce the cost of tree cover maps from the local to the global scale, with broad implications for research and management.

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International Whaling Commission

International Organization ◽

10.1017/s0020818300024498 ◽

1957 ◽

Vol 11 (4) ◽

pp. 701-702 ◽

Cited By ~ 2

Keyword(s):

Soviet Union ◽

International Association ◽

Substantial Reduction ◽

The United States ◽

International Whaling Commission ◽

Food And Agriculture ◽

Food And Agriculture Organization ◽

The Soviet Union ◽

Scientific Papers ◽

The Cost

The eighth annual meeting of the International Whaling Commission took place in London July 16–20, 1956, under the chairmanship of Dr. G. J. Lienesch (Netherlands). All seventeen contracting governments, with the exception of Brazil, were represented, with observers from Italy, Portugal, the Food and Agriculture Organization (FAO), the International Council for the Exploration of the Sea, and the International Association of Whaling Companies. During the deliberations the Commission 1) received from the Bureau of International Whaling Statistics data on the operations and the catch for the past season; 2) received various scientific papers concerning the stocks of whales, and almost unanimously favoring a substantial reduction in the catch in view of evidence that the stock was declining, recommended that the catch for future seasons should not exceed 15,000 blue whale units, and, with one dissentient, recommended that the limit should be reduced in the 1956–1957 season to 14,500 blue whales; 3) after examining the returns rendered in respect of infractions of the whaling regulations, noted that, in general, there had been a decrease over the previous year; 4) received further confirmation from the Commissioner of the Soviet Union of the use of fenders of porous rubber to replace the present use of whale carcases for this purpose; 5) allocated an equivalent of $1400 towards the cost of whale marking; and 6) requested the United States to prepare a protocol for the amendment of the convention requiring every factory ship to have on board two inspectors who were generally of the same nationality as the flag of the ship, to permit consideration of a scheme to appoint independent observers in addition to the national inspectors.

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Estimation of the Evapotranspiration and Crop Coefficients of Bell Pepper Using a Removable Weighing Lysimeter: A Case Study in the Southeast of Spain

Sustainability ◽

10.3390/su13020747 ◽

2021 ◽

Vol 13 (2) ◽

pp. 747

Author(s):

Laura Ávila-Dávila ◽

José Miguel Molina-Martínez ◽

Carlos Bautista-Capetillo ◽

Manuel Soler-Méndez ◽

Cruz Octavio Robles Rovelo ◽

...

Keyword(s):

Research Work ◽

Bell Pepper ◽

Crop Water ◽

Water Requirements ◽

Crop Water Requirements ◽

Food And Agriculture ◽

Food And Agriculture Organization ◽

Precise Knowledge ◽

Crop Coefficients ◽

Weighing Lysimeter

Water use efficiency is essential in semiarid regions of Spain, and it can be achieved through a precise knowledge of the real crop water requirements (CWR). The Food and Agriculture Organization of the United Nations (FAO) offers standardized crop coefficients to establish the CWR. However, these coefficients can change due to different conditions, such as climatic variations and cultivation practices. In this work, the evapotranspiration (ETClys) and crop coefficients (KClys) of bell pepper were obtained with a compact removable weighing lysimeter between February and August for two crop seasons (2019 and 2020). ETClys was determined from the water balance, and the KClys values were determined as the ratio of the crop evapotranspiration, measured on the removable weighing lysimeter, and the reference evapotranspiration. The KClys average values for the bell pepper in the initial, middle, and final stages were 0.57, 1.06, and 0.80, respectively. KC regression models were obtained as a function of the fraction thermal units, achieving a maximum correlation of 0.67 (R2). In general, the KC values obtained in this research work were lower in the initial and in the final stages and larger in the middle stage in comparison with the FAO-56 values and other research works values in semiarid conditions. The bell pepper yield increased by 7.72% in 2019 and by 3.49% in 2020 compared to the yield reported by the Ministry of the Environment and Rural and Marine Areas of the Spanish Government in 2019 and with a minimum water loss through drainage. The results in this work can help farmers to determine the crop water requirements and to improve the system efficiency in semiarid locations with similar conditions to those in the study.

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COST BENEFITS ANALYSIS OF PH.D EDUCATION IN NIGERIA

International Journal of Research -GRANTHAALAYAH ◽

10.29121/granthaalayah.v9.i6.2021.3970 ◽

2021 ◽

Vol 9 (6) ◽

pp. 104-112

Author(s):

Ebenezer Taiwo ADU ◽

Oyedokun Samuel AJAYI

Keyword(s):

Random Sampling ◽

Descriptive Analysis ◽

Research Work ◽

Simple Random Sampling ◽

Cost Benefits ◽

The Cost ◽

The University

This research work examined the cost benefits of Ph. D in Nigeria. It was a descriptive design of a survey type. The population of the study was all the lecturers and Ph. students of the University of Ado-Ekiti, Nigeria, 150 Lecturers and students were selected through simple random sampling and techniques. Two sets of research instruments were used one for the lecturers and the second one for the students currently undergoing Ph. . The validity of the instruments was done with the use of content, construct and face . Descriptive analysis was used to the data collected. The results showed that the cost of Ph. was higher compare to lower degrees, the prospect cadre for Ph. was high and that the financial and other benefits of Ph.D holders were higher than other degrees.

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The Impact of Felling Method, Bunch Size, Slope Degree and Skidding Area on Productivity and Costs of Skidding in a Eucalyptus Plantation

Croatian journal of forest engineering ◽

10.5552/crojfe.2021.879 ◽

2021 ◽

Vol 42 (3) ◽

Author(s):

Ricardo Hideaki Miyajima ◽

Danilo Simões ◽

Paulo Torres Fenner ◽

Gislaine Cristina Batistela

Keyword(s):

Operating Cycle ◽

Operator Experience ◽

Eucalyptus Plantation ◽

Technical Performance ◽

Food And Agriculture ◽

Food And Agriculture Organization ◽

Machine Cost ◽

The Cost ◽

The Impact ◽

Cost Components

Grapple skidder is a machine designed for the extraction of tree bunches after felling. Several factors influence its technical performance and costs such as terrain slope, operator experience time, machine type, and the size of tree bunches for each operating cycle, among others. Thus, it becomes necessary to weigh the variables that most influence the productivity and costs of the grapple skidder. So, the main objective was evaluated according to the influence of bunch size using two feller bunchers with distinct technical characteristics, two slope classes and two skidding areas on the productivity and machine production cost in a Eucalyptus plantation. For the analysis of the productivity, the study of time and method was applied and the scheduled machine cost per hour was based on the Food and Agriculture Organization of the United Nations methods. When analyzing the results, it was found that the operational elements moving without load (MWoL) and moving with load (MWL) were the ones that spend the most time in the operational cycle of the grapple skidder. Among the cost components, monetary expenditure on fuel and operator labor were the most influential in the scheduled machine cost per hour. In conclusion, the tree bunches and slope class influenced the productivity and, consequently, the cost of the skidding operation.

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Sahelian countries face acute hunger crisis

Emerald Expert Briefings ◽

10.1108/oxan-db233763 ◽

2018 ◽

Keyword(s):

Climate Change ◽

Rural Economy ◽

Acute Malnutrition ◽

Content Type ◽

Crisis Prevention ◽

Food And Agriculture ◽

Food And Agriculture Organization ◽

Food Shortages ◽

The Cost

Subject Food shortages and insecurity in the Sahel. Significance The UN Food and Agriculture Organization (FAO), the UN Children's Fund (UNICEF) and the World Food Programme (WFP) warned in May that 1.6 million children are in danger of acute malnutrition and 5.0 million people are in need of food assistance in the Sahel and parts of West Africa. Drought and conflict have left 7.1 million people in the Sahel in need of food aid, the Food Crisis Prevention Network (RPCA) warned in April. Pastoral societies are severely affected. The range of food shortages and socio-economic crises in the Sahel reflects the region’s vulnerability to annual drought and long-term climate change, as well as challenges posed by insecurity. Impacts France will emphasise counter-terrorism even though the cost of fighting terrorism undermines the Sahel’s capacity to avert food crises. The region will remain vulnerable to annual droughts. Long-term climate change will threaten the sustainability of the rural economy upon which the majority of the population still depend.

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Analysing the Structure of the Global Wheat Trade Network: An ERGM Approach

Agronomy ◽

10.3390/agronomy10121967 ◽

2020 ◽

Vol 10 (12) ◽

pp. 1967

Author(s):

Ester Gutiérrez-Moya ◽

Sebastián Lozano ◽

Belarmino Adenso-Díaz

Keyword(s):

Land Surface ◽

Geographical Location ◽

Graph Model ◽

Trade Network ◽

Random Graph Model ◽

Food And Agriculture ◽

Food And Agriculture Organization ◽

Exponential Random Graph ◽

Inference Methods ◽

The Relationship

This paper studies the relationship between wheat trading countries using both descriptive and statistical inference methods for complex networks. The global Wheat Trade Network (WTN) and its evolving topological characteristics is analysed for the periods 2009–2013 and 2014–2018, using the Food and Agriculture Organization (FAO) data. The network characterisation measures in both periods are rather stable. There are some differences, however, in the magnitude of some measures (e.g., connectivity or disassortativity), and a higher degree of inequality in the distribution of the number of partners and the distribution of trade volume in the period 2014–2018. An Exponential Random Graph Model (ERGM) has been applied to identify significant determinants associated with the presence/absence of trade links between countries. The results indicate that wheat trade links are driven mainly by country openness, reciprocity (mutual importer-exporter relationship), whether the exporting country is US or Canada and the geographical location of importer and exporter. Other factors, such as the economic size of the importing country, if the importing country is US or Canada and the land surface of the exporting country also contribute less to capture interlinkages of WTN.

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Irrigation Estimates from Remote Sensing Soil Moisture: A District-Scale Analysis in Spain

10.5194/egusphere-egu21-2914 ◽

2021 ◽

Author(s):

Jacopo Dari ◽

Pere Quintana-Seguí ◽

María José Escorihuela ◽

Vivien Stefan ◽

Renato Morbidelli ◽

...

Keyword(s):

Remote Sensing ◽

Soil Moisture ◽

Primary Source ◽

Data Sets ◽

Crop Evapotranspiration ◽

Data Set ◽

North East ◽

The North ◽

Food And Agriculture ◽

Food And Agriculture Organization

<p>Irrigation represents a primary source of anthropogenic water consumption, whose effects impact on the natural distribution of water on the Earth&#8217;s surface and on food production. Over anthropized basins, irrigation often represents the missing variable to properly close the hydrological balance. Despite this, detailed information on the amounts of water actually applied for irrigation is lacking worldwide. In this study, a method to estimate irrigation volumes applied over a heavily irrigated area in the North East of Spain through high-resolution (1 km) remote sensing soil moisture is presented. Two DISPATCH (DISaggregation based on Physical And Theoretical scale CHange) downscaled data sets have been used: SMAP (Soil Moisture Active Passive) and SMOS (Soil Moisture and Ocean Salinity). The SMAP experiment covers the period from January 2016 to September 2017, while the SMOS experiment is referred to the time span from January 2011 to September 2017. The irrigation amounts have been retrieved through the SM2RAIN algorithm, in which the guidelines provided in the FAO (Food and Agriculture Organization) paper n.56 about the crop evapotranspiration have been implemented for a proper modeling of the crop evapotranspiration. A more detailed analysis has been performed in the context of the SMAP experiment. In fact, the spatial distribution and the temporal occurrence of the irrigation events have been investigated. Furthermore, the loss of accuracy of the irrigation estimates when using different sources for the evapotranspiration data has been assessed. In order to do this, the SMAP experiment has been repeated by forcing the SM2RAIN algorithm with several evapotranspiration data sets, both calculated and observed. Finally, the merging of the results obtained through the two experiments has produced a data set of almost 7 years of irrigation estimated from remote sensing soil moisture.</p>

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Effect of Feller-Buncher Model, Slope Class and Cutting Area on the Productivity and Costs of Whole Tree Harvesting in Brazilian Eucalyptus Stands

Forests ◽

10.3390/f12081092 ◽

2021 ◽

Vol 12 (8) ◽

pp. 1092

Author(s):

Ricardo Hideaki Miyajima ◽

Paulo Torres Fenner ◽

Gislaine Cristina Batistela ◽

Danilo Simões

Keyword(s):

Food And Agriculture ◽

Eucalyptus Forest ◽

Food And Agriculture Organization ◽

Individual Volume ◽

Machine Cost ◽

The Individual ◽

The Cost ◽

Whole Tree Harvesting ◽

Model Slope ◽

Slope Class

The operational productivity and costs of tree felling operations can be influenced by several factors, among which, the machine characteristics, slope class, the cutting area and the individual volume of the trees stand out. Thus, the main objective of the present study was to analyze the productivity and production cost for two feller-bunchers with different technical characteristics operating in a eucalyptus forest. The productivity was calculated from a time study and the factors analyzed were two feller-buncher models, two slope classes, and two cutting areas. The machine cost per scheduled hour was based on the methodology of the Food and Agriculture Organization of the United Nations. Analysis of the results showed that the felling and turn operational elements occupied the most time in the operational cycle of feller-bunchers. The machine cost per scheduled hour was USD 69.69 h−1 for feller-buncher 1 and USD 102.03 h−1 for feller-buncher 2. In conclusion, the distinct technical characteristics of feller-bunchers were found to influence the productivity and, consequently, the cost, of the felling operation during the harvesting of whole eucalyptus trees.

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An Improved Forest Structure Data Set for Europe

Remote Sensing ◽

10.3390/rs14020395 ◽

2022 ◽

Vol 14 (2) ◽

pp. 395

Author(s):

Christoph Pucher ◽

Mathias Neumann ◽

Hubert Hasenauer

Keyword(s):

Structure Data ◽

Forest Structure ◽

Large Scale ◽

Remote Sensing Data ◽

Inventory Data ◽

Data Set ◽

European Forests ◽

Food And Agriculture ◽

Food And Agriculture Organization ◽

European Forest

Today, European forests face many challenges but also offer opportunities, such as climate change mitigation, provision of renewable resources, energy and other ecosystem services. Large-scale analyses to assess these opportunities are hindered by the lack of a consistent, spatial and accessible forest structure data. This study presents a freely available pan-European forest structure data set. Building on our previous work, we used data from six additional countries and consider now ten key forest stand variables. Harmonized inventory data from 16 European countries were used in combination with remote sensing data and a gap-filling algorithm to produce this consistent and comparable forest structure data set across European forests. We showed how land cover data can be used to scale inventory data to a higher resolution which in turn ensures a consistent data structure across sub-regional, country and European forest assessments. Cross validation and comparison with published country statistics of the Food and Agriculture Organization (FAO) indicate that the chosen methodology is able to produce robust and accurate forest structure data across Europe, even for areas where no inventory data were available.

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