Global irrigated area mapping: Overview and recommendations

Mapping / Data collection / Data storage and retrieval / Water harvesting / Irrigated sites / Climate / Satellite surveys / Evaporation / Food production / Sustainability / Soil water / Models

A Review of Landsat TM/ETM based Vegetation Indices as Applied to Wetland Ecosystems

A review of vegetation indices as applied to Landsat-TM and ETM+ multispectral data is presented. The review focuses on indices that have been developed to produce biophysical information about vegetation biomass/greenness, moisture and pigments.In addition, a set of biomass/greenness and moisture content indices are tested in a Mediterranean semiarid wetland environment to determine their appropriateness and potential for carrying redundant information.The results indicate that most vegetation indices used for biomass/greenness mapping produce similar information and are statistically well correlated.

Mapping Annual Riparian Water Use Based on the Single-Satellite-Scene Approach

The accurate estimation of water use by groundwater-dependent riparian vegetation is of great importance to sustainable water resource management in arid/semi-arid regions. Remote sensing methods can be effective in this regard, as they capture the inherent spatial variability in riparian ecosystems. The single-satellite-scene (SSS) method uses a derivation of the Normalized Difference Vegetation Index (NDVI) from a single space-borne image during the peak growing season and minimal ground-based meteorological data to estimate the annual riparian water use on a distributed basis. This method was applied to a riparian ecosystem dominated by tamarisk along a section of the lower Colorado River in southern California. The results were compared against the estimates of a previously validated remotely sensed energy balance model for the year 2008 at two different spatial scales. A pixel-wide comparison showed good correlation (R2 = 0.86), with a mean residual error of less than 104 mm·year-1 (18%). This error reduced to less than 95 mm·year-1 (15%) when larger areas were used in comparisons. In addition, the accuracy improved significantly when areas with no and low vegetation cover were excluded from the analysis. The SSS method was then applied to estimate the riparian water use for a 23-year period (1988–2010). The average annual water use over this period was 748 mm·year-1 for the entire study area, with large spatial variability depending on vegetation density. Comparisons with two independent water use estimates showed significant differences. The MODIS evapotranspiration product (MOD16) was 82% smaller, and the crop-coefficient approach employed by the US Bureau of Reclamation was 96% larger, than that from the SSS method on average

Remote and field level quantification of vegetation covariates for malaria mapping in three rice agro-village complexes in Central Kenya

<p>Abstract</p> <p>Background</p> <p>We examined algorithms for malaria mapping using the impact of reflectance calibration uncertainties on the accuracies of three vegetation indices (VI)'s derived from QuickBird data in three rice agro-village complexes Mwea, Kenya. We also generated inferential statistics from field sampled vegetation covariates for identifying riceland <it>Anopheles arabiensis </it>during the crop season. All aquatic habitats in the study sites were stratified based on levels of rice stages; flooded, land preparation, post-transplanting, tillering, flowering/maturation and post-harvest/fallow. A set of uncertainty propagation equations were designed to model the propagation of calibration uncertainties using the red channel (band 3: 0.63 to 0.69 μm) and the near infra-red (NIR) channel (band 4: 0.76 to 0.90 μm) to generate the Normalized Difference Vegetation Index (NDVI) and the Soil Adjusted Vegetation Index (SAVI). The Atmospheric Resistant Vegetation Index (ARVI) was also evaluated incorporating the QuickBird blue band (Band 1: 0.45 to 0.52 μm) to normalize atmospheric effects. In order to determine local clustering of riceland habitats <it>Gi*(d) </it>statistics were generated from the ground-based and remotely-sensed ecological databases. Additionally, all riceland habitats were visually examined using the spectral reflectance of vegetation land cover for identification of highly productive riceland <it>Anopheles </it>oviposition sites.</p> <p>Results</p> <p>The resultant VI uncertainties did not vary from surface reflectance or atmospheric conditions. Logistic regression analyses of all field sampled covariates revealed emergent vegetation was negatively associated with mosquito larvae at the three study sites. In addition, floating vegetation (-ve) was significantly associated with immature mosquitoes in Rurumi and Kiuria (-ve); while, turbidity was also important in Kiuria. All spatial models exhibit positive autocorrelation; similar numbers of log-counts tend to cluster in geographic space. The spectral reflectance from riceland habitats, examined using the remote and field stratification, revealed post-transplanting and tillering rice stages were most frequently associated with high larval abundance and distribution.</p> <p>Conclusion</p> <p>NDVI, SAVI and ARVI generated from QuickBird data and field sampled vegetation covariates modeled cannot identify highly productive riceland <it>An. arabiensis </it>aquatic habitats. However, combining spectral reflectance of riceland habitats from QuickBird and field sampled data can develop and implement an Integrated Vector Management (IVM) program based on larval productivity.</p

Modelos simples para estimar cobertura de suelo agrícola a partir de imágenes MODIS: aplicación a la zona central de Córdoba (Argentina)

Las imágenes provenientes de sensores remotos constituyen una importante fuente de información sobre cultivos que puede utilizarse para obtener parámetros agronómicos. La soja (Glycine max (L.) Merrill) y el maíz (Zea mays L.) son los cultivos más importantes en Argentina, por área sembrada y réditos económicos producidos. En este trabajo se desarrollaron modelos matemáticos simples para evaluar porcentaje de cobertura de suelo por soja y maíz, a partir de diferentes índices de vegetación derivados del Moderate–resolution Imaging Spectroradiometer (MODIS). Los índices de vegetación considerados fueron: de diferencia normalizada (NDVI), Índice ajustado por el suelo SAVI, su modificación MSAVI, la Razón Simple (SR) y el índice perpendicular de vegetación (PVI). El comportamiento de los modelos fue muy bueno y los resultados mostraron que, excepto para SR, un modelo lineal puede predecir porcentaje de cobertura de suelo por soja y maíz, con valores de R2>0,86.Sociedad Argentina de Informática e Investigación Operativ

Modelos simples para estimar cobertura de suelo agrícola a partir de Imágenes MODIS: aplicación a la zona central de Córdoba (Argentina)

Ponencia presentada en 42º Jornadas Argentinas de Informática (JAiiO). V Congreso Argentino de AgroInformática (CAI). Córdoba, Argentina, 16 al 20 de septiembre de 2013Las imágenes provenientes de sensores remotos constituyen una importante fuente de información sobre cultivos que puede utilizarse para obtener parámetros agronómicos. La soja (Glycine max (L.) Merrill) y el maíz (Zea mays L.) son los cultivos más importantes en Argentina, por área sembrada y réditos económicos producidos. En este trabajo se desarrollaron modelos matemáticos simples para evaluar porcentaje de cobertura de suelo por soja y maíz, a partir de diferentes índices de vegetación derivados del Moderate?resolution Imaging Spectroradiometer (MODIS). Los índices de vegetación considerados fueron: de diferencia normalizada (NDVI), Índice ajustado por el suelo SAVI, su modificación MSAVI, la Razón Simple (SR) y el índice perpendicular de vegetación (PVI). El comportamiento de los modelos fue muy bueno y los resultados mostraron que, excepto para SR, un modelo lineal puede predecir Porcentaje de cobertura de suelo por soja y maíz, con valores de R2>0,86.Fil: Bocco, Mónica. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; Argentina.Fil: Ovando, Gustavo Gabriel. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; Argentina.Fil: Sayago, Silvina. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; Argentina.Fil: Willington, Enrique. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; Argentina

Modelos simples para estimar cobertura de suelo agrícola a partir de imágenes MODIS: aplicación a la zona central de Córdoba (Argentina)

Las imágenes provenientes de sensores remotos constituyen una importante fuente de información sobre cultivos que puede utilizarse para obtener parámetros agronómicos. La soja (Glycine max (L.) Merrill) y el maíz (Zea mays L.) son los cultivos más importantes en Argentina, por área sembrada y réditos económicos producidos. En este trabajo se desarrollaron modelos matemáticos simples para evaluar porcentaje de cobertura de suelo por soja y maíz, a partir de diferentes índices de vegetación derivados del Moderate–resolution Imaging Spectroradiometer (MODIS). Los índices de vegetación considerados fueron: de diferencia normalizada (NDVI), Índice ajustado por el suelo SAVI, su modificación MSAVI, la Razón Simple (SR) y el índice perpendicular de vegetación (PVI). El comportamiento de los modelos fue muy bueno y los resultados mostraron que, excepto para SR, un modelo lineal puede predecir porcentaje de cobertura de suelo por soja y maíz, con valores de R2>0,86.Sociedad Argentina de Informática e Investigación Operativ

Spectral Characteristics and Mapping of Rice Fields using Multi-Temporal Landsat and MODIS Data: A Case of District Narowal

Availability of remote sensed data provides powerful access to the spatial and temporal information of the earth surface Real-time earth observation data acquired during a cropping season can assist in assessing crop growth and development performance As remote sensed data is generally available at large scale rather than at field-plot level use of this information would help to improve crop management at broad-scale Utilizing the Landsat TM ETM ISODATA clustering algorithm and MODIS Terra the normalized difference vegetation index NDVI and enhanced vegetation index EVI datasets allowed the capturing of relevant rice cropping differences In this study we tried to analyze the MODIS Terra EVI NDVI February 2000 to February 2013 datasets for rice fractional yield estimation in Narowal Punjab province of Pakistan For large scale applications time integrated series of EVI NDVI 250-m spatial resolution offer a practical approach to measure crop production as they relate to the overall plant vigor and photosynthetic activity during the growing season The required data preparation for the integration of MODIS data into GIS is described with a focus on the projection from the MODIS Sinusoidal to the national coordinate systems However its low spatial resolution has been an impediment to researchers pursuing more accurate classification results and will support environmental planning to develop sustainable land-use practices These results have important implications for parameterization of land surface process models using biophysical variables estimated from remotely sensed data and assist for forthcoming rice fractional yield assessmen

Application of Artificial Neural Network (ANN) to Predict Soil Organic Matter Using Remote Sensing Data in Two Ecosystems

Concern over global problems induced by rising CO2 has prompted attention on the role of forests and pastures as carbon ‘storage’ because forests and pastures store a large amount of carbon in vegetation biomass and soil. Soil organic matter (SOM) plays a critical role in soil quality and has the potential to cost-effectively mitigate the detrimental effects of rising atmospheric CO2 and other greenhouse gas emissions that cause global warming and climate change(Causarano-Medina, 2006). SOM, an important source of plant nutrients is itself influenced by land use, soil type, parent material, time, climate and vegetation (Loveland &Webb, 2003). Important climatic factors influencing SOM include rainfall and temperature. Within the same isotherm, the SOM content increases with increase in rainfall regime. For the same isohyet, the SOM content...............