What are geotechnologies?

They are a set of techniques and scientific methods applied to the analysis, exploration, study, and conservation of natural resources, considering different scales and spatial information (geographic location). They are also used to study the landscape (topography, hydrography, geology, and geomorphology) and environmental variables (temperatures, rainfall, and solar radiation), analyze and assist the prevention of natural disasters (floods, earthquakes, and volcanic eruptions), and manage and monitor the human activity (infrastructure, agriculture and livestock, and socioeconomic data). This set of techniques is composed of hardware (satellites, cameras, GPS, computers) and software that can store and manipulate geographic information, and process digital images.

What is remote sensing?

It is the acquisition of information on an object through the analysis of data acquired by devices that are not in direct contact with the object under investigation. Such devices, which are known as remote sensors, are capable of capturing energy from the object and converting it into a signal that can be recorded in a format that is suitable for the extraction of information on the referred object. They can collect acoustic energy (sonars, seismographs, seismometers, etc.), gravitational energy (gravimeters) and electromagnetic energy (radiometers). They can be placed aboard Unmanned Aerial Vehicles (UAVs), different types of aircrafts, spaceships, orbital satellites, and space stations. Artificial satellites have remote sensors capable of passively or actively capturing electromagnetic energy reflected or emitted by objects or targets on Earth. After interacting with incident electromagnetic radiation (radiance), targets, or objects (vegetation, water resources, constructions, agricultural areas, etc.), they reflect this radiation (irradiance) differently, and this represents their spectral signature. The satellite sensors are capable of identifying the radiation reflected by each type of target or object, that is, they are capable of recognizing their spectral signatures.

What is geoprocessing?

It consists of the use of computational tools to manipulate and analyze geographic data. With the set of these tools integrated in Geographic Information Systems (GISs), one can analyze and cross data from different sources, facilitating the extration of information and decision-making.

What is a Geographic Information System (GIS)? 

The GIS is an example of geotechnology and represents the union between hardware and software that can store, analyze, and process georeferenced data. The GISs can contain digital raster (satellite images and aerial photos) or vector (points, lines, or polygons) files. The analysis of the information contained in a GIS enables the elaboration of maps, graphs, tables, and reports that digitally represent the real world. Each piece of stored data is associated with coordinates in two or three dimensions in space and relates to one given location in the globe.

How can a GIS be used for Agriculture? Are there free Geographic Information Systems?

One of the advantages of using a GIS is that it can work with immense databases and transform them into maps, which will be analyzed either individually or jointly with other maps and information to generate strategic knowledge. Within the scope of agricultural research, the GIS is used to: • Detect crop spatial patterns; • Elaborate maps that will assist in simulations and space modeling; • Search solutions to problems related to agriculture. There are free computational solutions for GISs. There are free and open-source commercial programs and packages available. It is up to the professional to evaluate the best solution to be used. Some of the more known free GISs are: • Quantum GIS • Spring. • GRASS. • gvSIG, amongst others.

What is a Global Positioning System (GPS) and how does it determine user locations?

It consists of a constellation of satellites that can determine the location and the positioning of a receptor (a vehicle, for instance) in any place on Earth's surface, at sea or in the air. The GPS locates the user through a procedure known as trilateration. Through radiofrequency signals, a receiving device is capable of determining their distance in relation to at least four satellites. Based on the satellite coordinates and the distances, it is possible to calculate the coordinates of the user's receiving device. There are two satellite-based global positioning systems: the American GPS and the Russian GLONASS. The European Union's Galileo and China's Compass systems are at implementation stages.

What is the importance of geotechnologies for the agricultural sector? What are the main applications of remote sensing in agriculture?

Geotechnologies are essential to support advances in the identification, qualification, quantification and monitoring of agricultural areas and natural resources, enabling the more effective, quick and precise generation of maps and analyses of geospatial information. Remote sensing is used to estimate planted areas, identify planted crops, and monitor the expansion and land use change of agricultural areas. A forecast for harvests at a national level can be made with data on water deficiency. Crop areas with nutritional deficiency, pest and disease outbreaks, low productivity, and low growth are also targeted by geotechnologies.

What are the main technologies, products and services that can be generated from the geotechnologies aimed at the agricultural sector?

The technologies are the algorithms (files with sets of rules) for the automatic identification of land use classes, plant development stages, pathologies, or differentiated needs for inputs, among others. In fact, there are methodologies that make use of given data and their respective spatial attributes, which can be developed and validated with the support of computer analysis tools to be applied in production systems, and thus supply decision-makers with strategic information. Future products will be the materialized results of the geotechnology and can comprise maps or other forms of spatial representation of data. Other examples include software, the Webgis, or equipment that uses or operates with geotechnologies or geoinformation.

How do farmers directly benefit from geotechnology products and services?

They can directly benefit from: credit to support production activities, obtained from zonings based on geotechnologies; the optimization of the use of natural resources and inputs through precision agriculture; the delimitation of areas and their internal divisions via satellite-based global positioning systems; crop management using soil and relief maps; conformance to environmental legislation, through mapping and spatialization of plant cover.

What is spatial planning? And what are zonings?

The term "spatial planning" is used to define the scientific discipline, the administrative technique, and the public policies aimed at the organization of land occupation, use, and change. Its purpose is to promote better uses of the spaces in accordance with ecological, social, and economic sustainability. It has a political nature, but also presents a technical aspect that is mainly manifested through the zonings, which establish the guidelines for the use and occupation of the territory.

Zonings are land use planning tools that comprise: the division of an area, region, or country in homogeneous territorial portions (zones); the characterization of these zones for different forms of use and occupation; and the establishment of differentiated guidelines for each zone.

What is the difference between land cover and land use and occupation?

Land cover is a place's physical cover. It expresses any material above the ground. Land use and occupation concern the way humans manage their territory, that is, their impact on the medium. Their study generates information to develop public policy. For example, in a given area the land cover can be the tree vegetation, while land use, forestry or fruit cropping.

What is the Territorial Management System?

It is a system to organize, store, and allow access to data of geographic interest, capable of supporting the decision-making of managers, planners, and users who have the need to analyze spacially identified and identifiable phenomena and their territorial connections. The Territorial Management Systems can be used for different audiences. If they have a user-friendly interface, they can facilitate access to information and to the generation of products, such as: maps based on consultations; area calculations; in addition to other metrics available, such as spread sheets, figures, etc.

How can a map of land use and cover help in spatial planning?

The map of land use and cover helps monitoring, quantifying, and qualifying the elements that cover the terrestrial surface, and makes a record of how society uses these elements throughout time. Through this type of mapping, it is possible to identify, for instance, if an area is covered by natural vegetation and if its use, based on the proximity of a water body and on the legislation, should be a Permanent Preservation Area. The data and the information obtained from the map of land use and cover can be used as the foundation for other analyses, to extract information that can help in planning, and in the establishment of public policies for a given region.

How can geotechnologies contribute to Brazilian land use planning and support public policy?

They can depict the dynamics of land use and territorial occupation . A geospatial vision of natural resources and human activities can contribute to understanding agricultural expansion, retraction, transition, and intensification processes. Geotechnologies have several applications for public policy, such as: • Agricultural climate risk zoning; • Agroecological zoning; • Ecological-economic zoning; • Environmental zoning; • Definition and evaluation of spatially-explicit sustainability and productivity indicators.

How can geotechnologies support the compliance with agricultural environmental legislation?

Geotechnologies support the compliance with environmental diagnoses of rural properties obtained from the interpretation of the landscapes observed in high resolution satellite images or aerial photos, with field checking. The process of rural property compliance must target the solution of the environmental/social/economic issues detected, aiming at long-term sustainability, job generation with social inclusion, and the continuity of economically viable activities.

Is the Rural Environmental Registration (Cadastro Ambiental Rural- CAR) part of such compliance?

Yes, it is. A georeferenced CAR is the first step towards environmental compliance and makes the use of a given rural property public come to public knowledge, in accordance with environmental legislation, with a focus on the recovery of legally protected areas, permanent preservation areas and legal reserves through the Environmental Regularization Program.

What is the importance of geotechnologies for hydrological studies? And what is the importance of watersheds in land use planning?

Geotechnology facilitates and improves hydrological studies by considering the spatial and/or time variation of hydrological variables. Remote sensing and GIS' increasing potential to promptly represent spatial and time information on watersheds (through soil use maps combined with topographical data) enable the development of hydrological models, which inform decision-making. An example is the study of the estimate of the amount of soil surface runoff, which produces important information regarding water infiltration into the soil and the recharge of underground aquifers. With Federal Law no. 9,433/1997 (BRAZIL, 1997), the watershed was adopted as a water resource planning unit, and hence it started to be of fundamental importance in the territorial management for agrosilvopastoral activities and for environmental studies.

Can Embrapa map all Brazilian agriculture via satellite images? It is possible to map family farming with satellite images?

Embrapa conducts several mappings of agriculture in Brazil via satellite images. The land use and land cover dynamics are used to map and monitor space-time interactions provoked by the processes of expansion, transition, intensification, and diversification of agricultural production in the country. The mappings of large-scale agriculture include short-cycle crops like: cotton, rice, maize, wheat, soybean; and long-cycle crops, such as: sugarcane, coffee, citrus, and forest crops that are more easily identified in view of the permanence of their spatial standard in the landscape. With regard to mapping family farming, high spatial resolution images, with resolution ranging from 50 cm to 5 m, already allow for the identification of areas with smallholdings, generally located within landscapes with more complex structure and diversified mosaics of land use and cover.

In addition to the mappings, what other geotechnologies apply to agriculture?

The use of geotechnologies makes it possible to conduct several analyses that are of interest to agriculture. For instance, Geographic Information Systems (GISs) can be used to identify areas of agricultural interest, i.e. with low declivity and specific types of soil and of climate conditions. Thus, the zoning of the area of interest can be obtained, identifying the places that are most suitable for the practice of agriculture and the places where it is not recommended. It is equally possible to make studies on: • Production logistics to identify areas that are close to consuming centers and means of transportation. • Identification and delimitation of preservation areas. • Studies to assess the impacts of erosion, among others. • Mapping urban forestry through quali-quantitative surveys of the urban forestation.

Are there geotechnologies that contribute to precision livestock farming?

Yes, there are. There is animal and herd geotraceability, which makes use of: Electronic equipment and a Global Positioning System (GPS). • The Geographic Information System (GIS) to interpret and characterize pastures. • GPS on animals and georeferenced information to interpret the distribution and spatial displacement of such animals, and to monitor their activities such as grazing, trajectory, rest, and rumination in light of the dietary supply and their preference in the pastures.

In forestry, can geotechnology help the planning of planted forests? Can it be applied to control pests? 

Yes, it can. The planning of a plantation, both in plain places and in uneven terrains, can be made by using 3D models, with the aid of geotechnologies. With regard to environmental issues, the plots can be planned with due respect to permanent preservation areas.

As for pest control, the use of vegetation indicators obtained through multispectral images can help technicians and researchers identify heterogeneity in the vegetation's response, indicating areas where the individuals can be suffering any type of stress, directly affecting vegetation vigor as expressed by the vegetation indicator. In these cases, one assumes that the areas where stress is identified are suffering some type of ant, fungal or other pest infestation.

Is it possible to have online access to agricultural socioeconomic data and to data on natural resources obtained through geotechnologies?

Embrapa Satellite Monitoring's Group on Strategic Territorial Intelligence (Grupo de Inteligência Territorial Estratégica - Gite), has numerical, cartographic and iconographic databases (aerial photos, satellite and radar images) with socioeconomic and natural resource data from all over Brazil, and which can be obtained through geotechnologies. The existing information in the Gite databases can help in the elaboration of syntheses and diagnoses for any Brazilian state or region in five dimensions: natural, agrarian, agricultural, socioeconomic and infrastructural aspects. The Group's services have contributed to the elaboration, application, monitoring, and assessment of public and private policies and investments in several production chains and Brazilian geoeconomic regions.
Users can find more information on www.embrapa.br/monitoramento-por-satelite.
Source: adapted from "500 perguntas e 500 respostas - Geotecnologias".