Gis Applications In Agrometeorology

A GIS generally refers to a description of the characteristics and tools used in the organization and management of geographical data. The term GIS is currently applied to computerised storage, processing and retrieval systems that have hardware and software specially designed to cope with geographically referenced spatial data and corresponding informative attribute. Spatial data are commonly in the form of layers that may depict topography or environmental elements. Nowadays, GIS technology...

Factors Of Soil Erosion

The soil erosion process is modified by biophysical environment comprising soil, climate, terrain and ground cover and interactions between them (Figure 4). Soil erodibility - susceptibility of soil to agent of erosion - is determined by inherent soil properties e.g., texture, structure, soil organic matter content, clay minerals, exchangeable cations and water retention and transmission properties. Climatic erosivity includes drop size distribution and intensity of rain, amount and frequency...

References

Agro-ecological zoning using crop growth simulation models characterization of wheat environments of India, pages 97-109. In Systems Approaches for Agricultural Development, Vol. 2. (Penning de Vries, F.W.T., Teng, P. and Metselaar, K. eds.), Kluwer Academic Publishers, Dordrecht, The Netherlands. Aggarwal, P.K., Kalra, N., Bandhyopadhyay, S.K., Pathak, H., Sehgal, V.K., Kaur, R., Rajput, T.B.S., Joshi, H.C., Choudhary, R. and Roetter, R. 1998. Exploring agricultural land...

Role of Climate Change in Crop Modeling

In recent years there has been a growing concern that changes in climate will lead to significant damage to both market and non-market sectors. The climate change will have a negative effect in many countries. But farmers adaptation to climate change-through changes in farming practices, cropping patterns, and use of new technologies will help to ease the impact. The variability of our climate and especially the associated weather extremes is currently one of the concerns of the scientific as...

Soil Erosion And Processes

Soil erosion is a three stage process (1) detachment, (2) transport, and (3) deposition of soil. Different energy source agents determine different types of erosion. There are four principal sources of energy physical, such as wind and water, gravity, chemical reactions and anthropogenic, such as tillage. Soil erosion begins with detachment, which is caused by break down of aggregates by raindrop impact, sheering or drag force of water and wind. Detached particles are transported by flowing...

Introduction

Remote sensing (RS), also called earth observation, refers to obtaining information about objects or areas at the Earth's surface without being in direct contact with the object or area. Humans accomplish this task with aid of eyes or by the sense of smell or hearing so, remote sensing is day-today business for people. Reading the newspaper, watching cars driving in front of you are all remote sensing activities. Most sensing devices record information about an object by measuring an object's...

Interpretation of WV Imagery

Water vapor imagery is derived from radiation at wavelengths around 6-7 m. Though this is not an atmospheric window, it is part of the spectrum where water vapor is the dominant absorbing gas. It has a strong absorption band centered on 6.7 m. In regions of strong absorption, most of the radiation reaching the satellite originates high in the atmosphere. The stronger the absorption, the higher is the originating level of the emission that ultimately reaches the satellite. As the Relative...

Satellite Sensor System

Most remote sensing instruments (sensors) are designed to measure photons. The fundamental principle underlying sensor operation centers on what happens in a critical component - the detector. This is the concept of the photoelectric effect (for which Albert Einstein, who first explained it in detail, won his Nobel Prize). This, simply stated, says that there will be an emission of negative particles (electrons) when a negatively charged plate of some appropriate light-sensitive material is...

Satellite Remote Sensing

Remote sensing provides spatial coverage by measurement of reflected and emitted electromagnetic radiation, across a wide range of wavebands, from the earth's surface and surrounding atmosphere. The improvement in technical tools of meteorological observation, during the last twenty years, has created a favourable substratum for research and monitoring in many applications of sciences of great economic relevance, such as agriculture and forestry. Each waveband provides different information...

Electromagnetic Radiation And The Electromagnetic Spectrum

EMR is a dynamic form of energy that propagates as wave motion at a velocity of c 3 x 1010 cm sec. The parameters that characterize a wave motion are wavelength (A,), frequency (v) and velocity (c) (Fig. 2). The relationship between the above is Figure 2 Electromagnetic wave. It has two components, Electric field E and Magnetic field M, both perpendicular to the direction of propagation Figure 2 Electromagnetic wave. It has two components, Electric field E and Magnetic field M, both...

The Commission for Agricultural Meteorology CAgM of WMO Remote Sensing and GIS

Agricultural meteorology had always been an important component of the National Meteorological Services since their inception. A formal Commission for Agricultural Meteorology (CAgM) which was appointed in 1913 by the International Meteorological Organization (IMO), became the foundation of the CAgM under WMO in 1951. The WMO Agricultural Meteorology Programme is coordinated by CAgM. The Commission is responsible for matters relating to applications of meteorology to agricultural cropping...

Linking Crop Simulation Models To Rs Inputs

The use of remotely sensed information to improve crop model accuracy was proposed as early as two decades ago by Wiegand et al. (1979) and Richardson et al. (1982). They suggested using spectrally derived LAI either as direct input to physiological crop model or as an independent check to model calculation for its re-initialization. The main advantage of using remotely sensed information is that it provides a quantification of the actual state of crop for large area using less labour and...

Image Fusion Techniques

The satellites cover different portions of the electromagnetic spectrum and record the incoming radiations at different spatial, temporal, and spectral resolutions. Most of these sensors operate in two modes multispectral mode and the panchromatic mode. The panchromatic mode corresponds to the observation over a broad spectral band (similar to a typical black and white photograph) and the multispectral (color) mode corresponds to the observation in a number of relatively narrower bands. For...

Basic Concept Of Gps Receiver And Its Components

The main components of a GPS receiver are shown in Fig. 10. These are - RF section with signal identification and signal processing - Micro-processor for receiver control, data sampling and data processing - User interface, command and display panel Figure 10 Major components of a GPS receiver Figure 10 Major components of a GPS receiver Sensitive antenna of the GPS receiver detects the electromagnetic wave signal transmitted by GPS satellites and converts the wave energy to electric current...

Output Grid

Figure 12 A local function multiplies the input grid by the multiplier grid to produce the output grid Local functions are not limited to arithmetic computations. Trigonometric, exponential, and logarithmic and logical expressions are all acceptable for defining local functions. Focal functions process cell data depending on the values of neighboring cells. For instance, computing the sum of a specified neighborhood and assigning the sum to the corresponding cell of the output grid is the focal...

Per cent Hopper Development undergone

Similar to egg incubation this model (Figure 18) calculates per cent development of hopper through various instars using daily air temperature. Like egg incubation per cent development undergone per day is integrated over the requested period and the value is returned. Here the inputs required are date of sighting of hoppers in the field along with approximate development till that time and the date on which percent development is sought. For generalization the model uses the growth curve of DL...

Policy management

The policy management is one very useful application of crop simulation models. The issues range from global (impacts of climate change on crops) to field level (effect of crop rotation on soil quality) issues. Thornton et al. (1997) showed that in Burkina Faso, crop simulation modeling using satellite and ground-based data could be used to estimate millet production for famine early warning which can allow policy makers the time they need to take appropriate steps to ameliorate the effects of...

Rayleigh Scattering

Rayleigh scattering predominates where electromagnetic radiation interacts with particles that are smaller than the wavelength of the incoming light. The effect of the Rayleigh scattering is inversely proportional to the fourth power of the wavelength. Shorter wavelengths are scattered more than longer wavelengths. In the absence of these particles and scattering the sky would appear black. In the context of remote sensing, the Rayleigh scattering is the most important type of scattering. It...

Brij Bhushan Meteorology

Anderson, F. and Hollingsworth, A. 1988. Typhoon bogus observations in the ECMWF data assimilation systems. Bhatia, R.C., Brij Bhushan and Rajeswara Rao, V. 1999. Application of water vapour imagery received from INSAT-2E. Current Science, 76 1448-1450. Brueske, K.F. and C.S. Velden, 2000. Tropical cyclone intensity estimation using the NOAA-KLM series AMSU Preliminary results and future prospects. Preprints, 24th Conf. Hurr. Trop. Meteor., Fort Lauderdale, FL, Amer. Meteor. Soc., p. 258-259....

Regional Cooperation in Forest Fire Management

Beginning in 1992, as a consequence of the regional smog problems caused by land-use fires, member states of the Association of South East Asian Nations (ASEAN) created joint activities to encounter problems arising from transboundary haze pollution. ASEAN workshops held in Balikpapan (1992) and Kuala Lumpur (1995) summarized the problems and urged appropriate initiatives. The ASEAN Conference on Transboundary Pollution and the Sustainability of Tropical Forests is one of the first important...

Remote Sensing For Droughts

Monitoring and assessment of drought through remote sensing and GIS depend on the factors that cause drought and the factors of drought impact. Based on the causative factors, drought can be classified into Meteorological, Hydrological and Agricultural droughts. An extensive survey of the definition of droughts by WMO found that droughts are classified on the basis of (i) rainfall, (ii) combinations of rainfall with temperature, humidity and or evaporation, (iii) soil moisture and crop...

Results and Discussion

The output FCD map generated from the semi-expert system (Fig. 11) is sliced in to five density classes and same density stratification is also followed in object oriented image analysis (image segmentation) (Fig. 12) and visual image interpretation of digital data. Details of each density class are shown in the Table 6. Overall analysis of forest canopy density in all the cases indicates that majority of the forests in the study area have canopy closure of 40 to 80 . However, some deviation...

Rn 1A Rs EaRl Es a Ts4

Figure 5 (1) FCC ( Ch2, Ch1, Ch1, R,G,B) (2) Vegetation proportion image (3) Surface emissivity image and (4) Surface Temperature image - derived from processings of NOAA - AVHHR data ( southern India) Figure 5 (1) FCC ( Ch2, Ch1, Ch1, R,G,B) (2) Vegetation proportion image (3) Surface emissivity image and (4) Surface Temperature image - derived from processings of NOAA - AVHHR data ( southern India) where, A is surface albedo Rs is the incident short wave radiation (w m2) Ea is the atmospheric...

Solar Radiation

Incoming solar radiation is the primary source of energy for plant photosynthesis. Solar radiation also plays a key role in evapotranspiration. Visible observations from satellites provide an excellent source of information about the amount of solar radiation reaching the plant canopy. A measurement of solar energy reflected to space from earth-atmosphere system immediately specifies the maximum amount of solar energy that can be absorbed at the surface. Incoming solar radiation can be known by...

Son i oss PRFnim on

Qgis Python Flowchart

Sml miHPivflii nii nmii Tfliiinii nf ih m rni xjuatvrflliiWlft Sml miHPivflii nii nmii Tfliiinii nf ih m rni xjuatvrflliiWlft Figure 6 Factors of USLE and model predicted erosional soil loss (Bhogabati Watershed, Kolhapur District, Maharashtra, India) Figure 6 Factors of USLE and model predicted erosional soil loss (Bhogabati Watershed, Kolhapur District, Maharashtra, India) Figure 7 Flow diagram of methodology of soil erosion modeling using MMF model Figure 7 Flow diagram of methodology of...

Spatial Modelling Techniques for Forest Fire Risk Assessments

The study attempted to give insight in the use of RS and GIS for fire management. Spatial modelling and analysis have been done in GIS environment for identification of areas prone to fire risk and subsequently response routes were suggested for extinguishing forest fires (Jain et al., 1996 and Porwal et al., 1997). Some of the necessary components contributing to the fire behaviour viz., fuel (vegetation types), topography (slope and aspect etc.) and the causes of fire (i.e., roads and...

Stages in Remote Sensing

Emission of electromagnetic radiation, or EMR (sun self- emission) Transmission of energy from the source to the surface of the earth, as well as absorption and scattering Interaction of EMR with the earth's surface reflection and emission Transmission of energy from the surface to the remote sensor Figure 1 Remote Sensing process Data transmission, processing and analysis Forest Grass Bare Soil Paved Built-up Area Water Road Figure 1 Remote Sensing process Data transmission, processing and...

Temperature and Humidity Profiles Sounding

Temperature and moisture structures of earth's atmosphere are some of the most significant factors that influence the weather and climate patterns on the local as well as on global scale. The vertical structure of temperature and humidity is retrieved by satellite sounders that operate in infrared and microwave frequencies. Sounders use the principle of gaseous absorption for the retrieval of temperature and humidity profiles. For the retrieval of temperature, absorption spectra of some...

The expanded spacebased component of the world weather watchs global observing system

Several initiatives since 2000 with regard to WMO satellite activities have culminated in an expansion of the space-based component of the Global Observing System to include appropriate Research and Development (R& D) satellite missions. The recently established WMO Consultative Meetings on High-Level Policy on Satellite Matters have acted as a catalyst in each of these interwoven and important areas. First was the establishment of a new series of technical documents on the operational use...

Thermal Scanner

Many multispectral (MSS) systems sense radiation in the thermal infrared as well as the visible and reflected infrared portions of the spectrum. However, remote sensing of energy emitted from the Earth's surface in the thermal infrared (3 m to 15 m) is different from the sensing of reflected energy. Thermal sensors use photo detectors sensitive to the direct contact of photons on their surface, to detect emitted thermal radiation. The detectors are cooled to temperatures close to absolute zero...

Types Of Models

Depending upon the purpose for which it is designed the models are classified into different groups or types. Of them a few are a. Statistical models These models express the relationship between yield or yield components and weather parameters. In these models relationships are measured in a system using statistical techniques (Table 1). Example Step down regressions, correlation, etc. b. Mechanistic models These models explain not only the relationship between weather parameters and yield,...

Using Gis For Spatial Analysis

Spatial analysis in GIS involves three types of operations Attribute Query-also known as non-spatial (or spatial) query, Spatial Query and Generation of new data sets from the original database (Bwozough, 1987). The scope of spatial analysis ranges from a simple query about the spatial phenomenon to complicated combinations of attribute queries, spatial queries, and alterations of original data. Attribute Query Requires the processing of attribute data exclusive of spatial information. In other...

Variogram

A variogram is calculated from the variance of pairs of points at different separation. For several distance classes or lags, all point pairs are identified which matches that separation and the variance is calculated. Repeating this process for various distance classes yields a variogram. These functions can be used to measure spatial variability of point data but also of maps or images. Spatial Auto-correlation of Point Data The statistical analysis referred to as spatial auto-correlation,...

Vector Based Spatial Data Analysis

Output is point coverage with additional attributes. Logical Operators Overlay analysis manipulates spatial data organized in different layers to create combined spatial features according to logical conditions specified in Boolean algebra with the help of logical and conditional operators. The logical conditions are specified with operands (data elements) and operators (relationships among data elements). Note In vector overlay, arithmetic operations are performed with the help of logical...

Weather Data For Modeling

The national meteorological organizations provide weather data for crop modeling purposes through observatories across the globe (Sivakumar et al., 2000). In many European countries weather records are available for over 50 years. In crop modeling the use of meteorological data has assumed a paramount importance. There is a need for high precision and accuracy of the data. The data obtained from surface observatories has proved to be excellent. It gained the confidence of the people across the...

Wmo Space Programme

The World Meteorological Organization, a specialized agency of the United Nations, has a membership of 187 states and territories (as of June 2003). Amongst the many programmes and activities of the organization, there are three areas which are particularly pertinent to the satellite activities To facilitate world-wide cooperation in the establishment of networks for making meteorological, as well as hydrological and other geophysical observations and centres to provide meteorological services...

Case Study On Agroecological Zoning In Mountain Ecosystem

Sustainable development of mountain regions is a challenging task because the areas have highly diverse and fragile ecosystems. One of the most striking characteristics of mountains is their spatial variability. This makes the planning of the use of natural resources in the mountains more complex than any other area. In view of this, the present study was conducted in part of Kumaon Himalayas (latitudes 28o45' to 30o00'N, longitude 78o45' to 80o15') to demonstrate the use of remote sensing and...

Spot Series of Satellite

French Government in joint programme with Sweden and Belgium undertook the development of Systeme Pour l'Observation de la Terre (SPOT) program. Conceived and designed by the French Center National d'Etudes Spatiales (CNES), SPOT has developed into a large-scale international programme with ground receiving stations and data distribution outlets located in more than 30 countries. It is also the first system to have pointable optics. This enables side-to-side off-nadir viewing capabilities, and...

Multispectral Scanning Principle

Image Whiskbroom Pushbroom Scanner

Cameras and their use for aerial photography are the simplest and oldest of sensors used for remote sensing of the Earth's surface. Cameras are framing systems (Figure 5a), which acquire a near-instantaneous snapshot of an area of the Earth's surface. Camera systems are passive optical sensors that use a lens (or system of lenses collectively referred to as the optics) to form an image at the focal plane, the aerial image plane at which an image is sharply defined. Many electronic (as opposed...

Image Classification

The overall objective of image classification is to automatically categorize all pixels in an image into land cover classes or themes. Normally, multispectral data are used to perform the classification, and the spectral pattern present within the data for each pixel is used as numerical basis for categorization. That is, different feature types manifest different combination of DNs based on their inherent spectral reflectance and emittance properties. The term classifier refers loosely to a...

Data Models

Layers And Coverages

Conversion of real world geographical variation into discrete objects is done through data models. It represents the linkage between the real world domain of geographic data and computer representation of these features. Data models discussed here are for representing the spatial information. Data models are of two types Raster and Vector. In raster type of representation of the geographical data, a set of cells located by coordinate is used each cell is independently addressed with the value...

Image Rectification And Registration

Geometric distortions manifest themselves as errors in the position of a pixel relative to other pixels in the scene and with respect to their absolute position within some defined map projection. If left uncorrected, these geometric distortions render any data extracted from the image useless. This is particularly so if the information is to be compared to other data sets, be it from another image or a GIS data set. Distortions occur for many reasons. For instance distortions occur due to...

Pft [ErM E x 100

P( ) Spectral reflectance (reflectivity) at a particular wavelength. Er(A,) Energy of wavelength reflected from object Ej( ) Energy of wavelength incident upon the object The plot between p(X) and X is called a spectral reflectance curve. This varies with the variation in the chemical composition and physical conditions of the feature, which results in a range of values. The spectral response patterns are averaged to get a generalized form, which is called generalized spectral response pattern...

Few Successfully Used Models In Agrometeorology

Large scale evolution of computers since 1960 allowed to synthesize detailed knowledge on plant physiological processes in order to explain the functioning of crops as a whole. Insights into various processes were expressed using mathematical equations and integrated in simulation models. In the beginning, models were meant to increase the understanding of crop behaviour by explaining crop growth and development in terms of the understanding physiological mechanisms. Over the years new insights...