Download or read book Estimating Crop Water Requirements of a Command Area Using Multispectral Video Imagery and Geographic Information Systems written by Rashid H. Ahmed and published by . This book was released on 1997 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dissertation Abstracts International written by and published by . This book was released on 1998 with total page 662 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book American Doctoral Dissertations written by and published by . This book was released on 1997 with total page 806 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Spatial Methodology for Estimation of Crop Water Requirements written by Mansoor Ahmed Hashmi and published by . This book was released on 1993 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Estimating water requirements and water storage requirements for farms community and backyard gardens and for large irrigation systems A user manual for PLANWAT Version 1 2 3b and a CD ROM to install this program written by Pieter van Heerden and published by IWMI. This book was released on 2004 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt: Water storage / Water requirements / Water harvesting / Irrigation management / Irrigated farming / Estimation / Irrigation requirements / Computer software / Computer models

Download or read book Monitoring Crops Water Needs at High Spatio temporal Resolution by Synergy of Optical thermal and Radar Observations written by Abdelhakim Amazirh and published by . This book was released on 2019 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optimizing water management in agriculture is essential over semi-arid areas in order to preserve water resources which are already low and erratic due to human actions and climate change. This thesis aims to use the synergy of multispectral remote sensing observations (radar, optical and thermal data) for high spatio-temporal resolution monitoring of crops water needs. In this context, different approaches using various sensors (Landsat-7/8, Sentinel-1 and MODIS) have been developed to provide information on the crop Soil Moisture (SM) and water stress at a spatio-temporal scale relevant to irrigation management. This work fits well the REC "Root zone soil moisture Estimates at the daily and agricultural parcel scales for Crop irrigation management and water use impact: a multi-sensor remote sensing approach" (http://rec.isardsat.com/) project objectives, which aim to estimate the Root Zone Soil Moisture (RZSM) for optimizing the management of irrigation water. Innovative and promising approaches are set up to estimate evapotranspiration (ET), RZSM, land surface temperature (LST) and vegetation water stress through SM indices derived from multispectral observations with high spatio-temporal resolution. The proposed methodologies rely on image-based methods, radiative transfer modelling and water and energy balance modelling and are applied in a semi-arid climate region (central Morocco). In the frame of my PhD thesis, three axes have been investigated. In the first axis, a Landsat LST-derived RZSM index is used to estimate the ET over wheat parcels and bare soil. The ET modelling estimation is explored using a modified Penman-Monteith equation obtained by introducing a simple empirical relationship between surface resistance (rc) and a RZSM index. The later is estimated from Landsat-derived land surface temperature (LST) combined with the LST endmembers (in wet and dry conditions) simulated by a surface energy balance model driven by meteorological forcing and Landsat-derived fractional vegetation cover. The investigated method is calibrated and validated over two wheat parcels located in the same area near Marrakech City in Morocco. In the next axis, a method to retrieve near surface (0-5 cm) SM at high spatial and temporal resolution is developed from a synergy between radar (Sentinel-1) and thermal (Landsat) data and by using a soil energy balance model. The developed approach is validated over bare soil agricultural fields and gives an accurate estimates of near surface SM with a root mean square difference compared to in situ SM equal to 0.03 m3 m-3. In the final axis a new method is developed to disaggregate the 1 km resolution MODIS LST at 100 m resolution by integrating the near surface SM derived from Sentinel-1 radar data and the optical-vegetation index derived from Landsat observations. The new algorithm including the S-1 backscatter as input to the disaggregation, produces more stable and robust results during the selected year. Where, 3.35 °C and 0.75 were the lowest RMSE and the highest correlation coefficient assessed using the new algorithm.

Download or read book Estimating Farm and Landscape Water Use at the Rural urban Interface Using Remote Sensing and Geographic Information Systems written by Fayek A. Farag and published by . This book was released on 2003 with total page 622 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Evaluating Spatial and Temporal Variations in Sub field Level Crop Water Demands written by Travis Wiederstein and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Existing Variable Rate Irrigation (VRI) practices use soil electrical conductivity, historical yields, and topographic maps to delineate variable rate zones. However, these methods are not conducive to tracking within season variability in crop water demands. With increasing remote sensing data availability, in-season maps of crop coefficients and evapotranspiration (ET) may help inform variable rate irrigation schedules. Although, the amount of spatial and temporal variation in crop coefficients at the sub-field level has not been widely researched. This study aims to compare subfield ET estimates from two remote sensing platforms and quantify spatial and temporal variations in sub-field level ET. Vegetation indices and reference ET data were collected at Kansas State University's Southwest Research Extension Center (SWREC) and two Water Technology Farms during the 2020 corn growing season. Weekly maps of the normalized difference vegetation index (NDVI) and the soil-adjusted vegetation index (SAVI) from manned aerial imagery were combined with empirical equations to estimate both basal and combined crop coefficients at a 1-meter resolution. These coefficients were combined with local reference ET estimates, aggregated to a 30-meter resolution, and compared to the Landsat Provisional Actual Evapotranspiration dataset. Finally, actual ET estimates from aerial images were aggregated using K-means clustering and stationary variable speed zones to determine if there is enough variation in actual ET at the sub-field level to build variable rate irrigation schedules. An equivalence test demonstrated that the aerial imagery and Landsat data sources produce significantly different crop coefficient estimates. However, the two datasets were moderately correlated with Pearson's product-moment correlation coefficients ranging from -0.95 at the SWREC to 0.63 and 0.86 at the two Water Technology Farms. Both the aerial imaging and Landsat datasets showed high variability in crop coefficients during the first 5-6 weeks after emergence, with these coefficients becoming more spatially uniform later in the growing season. These crop coefficients may help irrigators make more informed irrigation management decisions during the growing season. However, more research is needed to validate these remotely sensed ET estimates and integrate them into an irrigation decision support system.

Download or read book Advances in the technology of estimating crop water requirements an aid to improved water management written by W R. Rangeley and published by . This book was released on 1977 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Guidelines for Predicting Crop Water Requirements written by J. Doorenbos and published by . This book was released on 1977 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: This publication is intended to provide guidance in determining crop water requirements and their application in planning, design and operation of irrigation projects; Part I.1 presents suggested methods to derive crop water requirements. The use of four well-known methods for determining such requirements is defined to obtain reference crop evapotranspiration (ETo), which denotes the level of evapotranspiration for different set of climatic data. To derive the evapotranspiration for a specific crop, relationships between crop evapotranspiration (ETcrop) and reference crop evapotranspiration (ETo) are given in Part I.2 for different crops, stages of growth, length of growing season and prevailing climatic conditions. The effect of local conditions on crop water requirements is given in Part I.3; this includes local variation in climate, advection, soil water availability and agronomic and irrigation methods and practices. Calculation procedures are presented together with examples. A detailed discussion on selection and calibration of the presented methodologies together with the data sources is given in Appendix II. A computer programme on applying the different methods is given in Appendix III. Part II discusses the application of crop water requirements data in irrigation project planning, design and operation. Part II. 1 deals with deriving the field water balance, which in turn forms the basis for predicting seasonal and peak irrigation supplies for general planning purposes. Attention is given to irrigation efficiency and water requirements for cultural practices and leaching of salts. In Part II. 2 methods are presented to arrived at field and scheme supply schedules with emphasis towards the field water balance and field irrigation management. Criteria are given for operating the canal system using different methods of water delivery, and for subsequent design parameters of the system. Suggestions are made in Part II. 3 on refinement of field and project supply schedules once the project is in operation. The presented guidelines are based on measured data and experience obtained covering a wide range of conditions. Local practical, technical, social and economic considerations will, however, affect the planning criteria selected. Therefore caution and a critical attitude should still be taken when applying the presented methodology.

Download or read book Estimation of Water Balance and Crop Water Requirements written by Tathir Ahmad Usmani and published by LAP Lambert Academic Publishing. This book was released on 2012 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: Agriculture provides the basis of sustenance for the population.But the challenge of maintaining a balance between human numbers and the capacity to produce food increases day by day.Furth more global climate change seems to make intra-annual rainfall distributions more erratic and inter-annual variations less predictable, resulting in greater uncertainty and risk for agriculture.Irrigation Scheduling according to crop water requirement at different stages not only minimizes the chances of under or over watering but also helpful to boost up crop output per unit of water.Apart of that it also gives idea to farmers and irrigation managers about the quantity of water needed to deliver to meet the peak demand of water.Present study is an attempt in this regard in which Water Balance according to Thornthwaite's method of Potential Evapotranspiration and Crop Water Requirements for different stages are computed on the basis of Penman-Monteith model for the study area of Samastipur, Bihar.These are the methods that require minimum effort and give maximum dividend.Hope that this book envisioned as a reference for those working in the field of achieving more crop per drop of water

Download or read book Assessing On farm Water use Efficiency written by and published by . This book was released on 2005 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Crop Water Requirements written by J. Doorenbos and published by . This book was released on 1992 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: This publication is intended to provide guidance in determining crop water requirements and their application in planning, design and operation of irrigation projects; Part I.1 presents suggested methods to derive crop water requirements. The use of four well-known methods for determining such requirements is defined to obtain reference crop evapotranspiration (ETo), which denotes the level of evapotranspiration for different set of climatic data. To derive the evapotranspiration for a specific crop, relationships between crop evapotranspiration (ETcrop) and reference crop evapotranspiration (ETo) are given in Part I.2 for different crops, stages of growth, length of growing season and prevailing climatic conditions. The effect of local conditions on crop water requirements is given in Part I.3; this includes local variation in climate, advection, soil water availability and agronomic and irrigation methods and practices. Calculation procedures are presented together with examples. A detailed discussion on selection and calibration of the presented methodologies together with the data sources is given in Appendix II. A computer programme on applying the different methods is given in Appendix III. Part II discusses the application of crop water requirements data in irrigation project planning, design and operation. Part II. 1 deals with deriving the field water balance, which in turn forms the basis for predicting seasonal and peak irrigation supplies for general planning purposes. Attention is given to irrigation efficiency and water requirements for cultural practices and leaching of salts. In Part II. 2 methods are presented to arrived at field and scheme supply schedules with emphasis towards the field water balance and field irrigation management. Criteria are given for operating the canal system using different methods of water delivery, and for subsequent design parameters of the system. Suggestions are made in Part II. 3 on refinement of field and project supply schedules once the project is in operation. The presented guidelines are based on measured data and experience obtained covering a wide range of conditions. Local practical, technical, social and economic considerations will, however, affect the planning criteria selected. Therefore caution and a critical attitude should still be taken when applying the presented methodology.

Download or read book Estimate of Water Requirements of Crops written by Byron Richard Tomlinson and published by . This book was released on 1951 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Earth Resources written by and published by . This book was released on 1985 with total page 594 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book NASA SP written by and published by . This book was released on 1962 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Crop Water Requirements Imperial Valley written by David Inouye and published by . This book was released on 1981 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: