Review on estimation of evapotranspiration from remote sensing data: From empirical to numerical modeling approaches   总被引：5，自引：0，他引：5  

Dominique Courault  Bernard Seguin  Albert Olioso 《Irrigation and Drainage Systems》2005,19(3-4):223-249

Different methods have been developed to estimate evapotranspiration from remote sensing data, from empirical approaches such as the simplified relationship to complex methods based on remote sensing data assimilation along with SVAT models. The simplified relationship has been applied from small spatial scale using airborne TIR images to continental scale with NOAA data. Assimilation procedures often require remote sensing data over different spectral domains to retrieve input parameters which characterize surface properties such as albedo, emissivity or Leaf Area Index. A brief review of these different approaches is presented, with a discussion about the main physical bases and assumptions of various models. The paper reports also some examples and results obtained over the experimental area of the Alpilles Reseda project, where various types of models have been applied to estimate surface fluxes from remote sensing data.  相似文献   

Finding niches for whole-farm design models – contradictio in terminis?     

B. Sterk  M.K. van Ittersum  C. Leeuwis  W.A.H. Rossing  H. van Keulen  G.W.J. van de Ven 《Agricultural Systems》2006

Whole-farm design models quantitatively analyze the effects of a variety of potential changes at the farm system level. Science-driven technical information is confronted with value-driven objectives of farmers or other social groupings under explicit assumptions with respect to exogenous variables that are important drivers of agricultural systems (e.g., market conditions). Hence, farm design is an outcome of objective specification and the potential of a system. In recent publications, whole-farm design modelling has been proposed to enhance (farm) innovation processes. A number of operational modelling tools now offers the opportunity to assess the true potential of whole-farm design modelling to enhance innovation. In this paper, we demonstrate that it is not trivial to find niches for the application of goal-based farm models. Model outcomes appeared not to match questions of farm managers monitoring and learning from their own and other farmers’ practices. However, our research indicates that whole-farm design modelling possesses the capabilities to make a valuable contribution to reframing. Reframing is the phenomenon that people feel an urge to discuss and reconsider current objectives and perspectives on a problem. Reframing might take place in a situation (i) of mutually felt dependency between stakeholders, (ii) in which there is sufficient pressure and urgency for stakeholders to explore new problem definitions and make progress. Furthermore, our research suggests that the way the researcher enters a likely niche to introduce a model and/or his or her position in this niche may have significant implications for the potential of models to enhance an innovation process. Therefore, we hypothesize that the chances of capitalizing on modelling expertise are likely to be higher when researchers with such expertise are a logical and more or less permanent component of ongoing trajectories than when these researchers come from outside to purposefully search for a niche.  相似文献   

A quantitative approach to the Pruitt and Doorenbos version of the Penman equation     

Albert Weiss 《Irrigation Science》1983,4(4):267-275

Summary The Pruitt and Doorenbos version of the Penman equation developed from information given in Appendix II of FAO Irrigation and Drainage Paper No. 24 is calculated mainly from tables and is based on measurements made over a grass surface. Procedures are presented here to quantify these relationships, such as the calculation of net radiation, and to extend this approach to measurements made over alfalfa (Medicago sativa, L.). The latter was achieved by using a wind function that takes into account the height of the alfalfa and the use of mean rather than maximum relative humidity to calculate the correction factor used to take into account day and night weather conditions on calculated reference crop evapotranspiration. Using the above procedures, calculated values of evapotranspiration overestimated measured values from alfalfa by 13%. From data collected with an automated weather station near Broadwater, Nebraska, a much better agreement was obtained between these general procedures and a Penman equation with a locally derived- wind function. With greater utilization of low cost, automated weather stations for agricultural use, the procedures given for calculating reference crop evapotranspiration can easily be implemented in irrigation scheduling programs.Published as paper no. 6865, Journal Series, Nebraska Agricultural Experiment Station  相似文献   

Mitigating nitrous oxide emissions from agricultural soils by precision management     

Robert M. REES  Juliette MAIRE  Anna FLORENCE  Nicholas COWAN  Ute SKIBA  Tony van der WEERDEN  Xiaotang JU 《农业科学与工程前沿(英文版)》2020,7(1):75-80

Nitrous oxide (N₂O) emissions make up a significant part of agricultural greenhouse gas emissions. There is an urgent need to identify new approaches to the mitigation of these emissions with emerging technology. In this short review four approaches to precision managements of agricultural systems are described based on examples of work being undertaken in the UK and New Zealand. They offer the opportunity for N₂O mitigation without any reduction in productivity. These approaches depend upon new sensor technology, modeling and spatial information with which to make management decisions and interventions that can both improve agricultural productivity and environmental protection.  相似文献   

Hypovirulent effect of the Cryphonectria hypovirus 1 in British isolates of Cryphonectria parasitica     

Pedro Romon‐Ochoa  Caroline Gorton  Alex Lewis  Sietse van der Linde  Joan Webber  Ana Prez‐Sierra 《Pest management science》2020,76(4):1333-1343

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Mosquito repellent thermal stability,permeability and air volatility     

Antnio B Mapossa  Alcides Sitoe  Walter W Focke  Homa Izadi  Elizabeth L du Toit  Ren Androsch  Chanita Sungkapreecha  Elizabet M van der Merwe 《Pest management science》2020,76(3):1112-1120

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Variation in parasitoid attraction to herbivore-infested plants and alternative host plant cover mediate tritrophic interactions at the landscape scale     

Aartsma  Yavanna  Hao  Yueyi  Dicke  Marcel  van der Werf  Wopke  Poelman  Erik H.  Bianchi  Felix J. J. A. 《Landscape Ecology》2020,35(4):907-919

Landscape Ecology - Tritrophic interactions may be affected by local factors and the broader landscape context. At small spatial scales, carnivorous enemies of herbivorous insects use...  相似文献   

Projecting the suitability of global and local habitats for myrtle rust (Austropuccinia psidii) using model consensus     

H. A. Narouei-Khandan  S. P. Worner  S. L. H. Viljanen  A. H. C. van Bruggen  E. E. Jones 《Plant pathology》2020,69(1):17-27

Myrtle rust (caused by Austropuccinia psidii) affects more than 500 known host species in the Myrtaceae family. Three different modelling approaches (CLIMEX, MaxEnt and Multi-Model Framework) were used to project the habitat suitability for myrtle rust at both global and local scales. Current data on the global occurrence of myrtle rust were collected from online literature and expert solicitation. Long-term averages of climate data (1960–1990) were sourced from WorldClim and CliMond websites. Recent reports of myrtle rust in New Zealand were used for validation of model outputs but not in model training and testing. The model outputs were combined into a consensus model to identify localities projected to be suitable for myrtle rust according to two or three models (hotspots). In addition to the locations where the pathogen is currently present, all models successfully projected independent occurrence data in New Zealand suitable for establishment of the pathogen. Climate suitability for the pathogen was primarily related to temperature followed by rainfall in MaxEnt and the CLIMEX model. The results confirmed the optimum temperature range of this pathogen in the literature (15–25 °C). Additional analysis of the precipitation variables indicated that excessive rain (more than 2000 mm in warmest quarter of the year) combined with high temperatures (>30 °C) constrain pathogen establishment. The results of the current study can be useful for countries such as New Zealand, China, South Africa and Singapore where the pathogen has not fully spread or established.  相似文献   

Shortening the generation cycle in faba bean (Vicia faba) by application of cytokinin and cold stress to assist speed breeding     

Saeid Mobini  Hamid Khazaei  Thomas D. Warkentin  Albert Vandenberg 《Plant Breeding》2020,139(6):1181-1189

The aim of this study was to reduce the length of the breeding cycle for faba bean by accelerating seed setting. We examined the mode and time of exogenous 6-benzylaminopurine (BAP) (cytokinin) application, and cold treatments and their combinations in two faba bean genotypes. Acropetal node number of pod and seed set and pollen viability were recorded during the experiments. Application of BAP improved pollen germination. The application of 10^–5 M BAP 4 days after flowering increased seed set at the lower nodes. Cold treatment (8/4°C day/night for 2 days) after the onset of flowering induced the formation of more pods and faster pod set compared to the non-cold treatment. The time to first seed was significantly reduced, and pollen viability was increased in plants exposed to cold treatment. Increased pollen viability also showed a significant positive correlation with seed setting. The combinations of 10^–5 BAP and cold treatment together had similar and independent effects. These results will accelerate plant breeding in faba bean by providing additional tools for reducing generation time.  相似文献   

Improved detection of Mycobacterium tuberculosis and M. bovis in African wildlife samples using cationic peptide decontamination and mycobacterial culture supplementation     

Wynand J. Goosen  Lanie Kleynhans  Tanya J. Kerr  Paul D. van Helden  Peter Buss  Robin M. Warren  Michele A. Miller 《Journal of veterinary diagnostic investigation》2022,34(1):61

In South Africa, mycobacterial culture is regarded as the gold standard for the detection of Mycobacterium tuberculosis complex (MTBC) infection in wildlife even though it is regarded as “imperfect.” We compared a novel decontamination and mycobacterial culture technique (TiKa) to the conventional mycobacterium growth indicator tube (MGIT) system using known amounts of bacilli and clinical samples from MTBC-infected African buffaloes (Syncerus caffer), white rhinoceros (Ceratotherium simum), and African elephants (Loxodonta africana). Use of the TiKa-KiC decontamination agent on samples spiked with 10,000 to 10 colony forming units (cfu) of M. bovis (SB0121) and M. tuberculosis (H37Rv) had no effect on isolate recovery in culture. In contrast, decontamination with MGIT MycoPrep resulted in no growth of M. bovis samples at concentrations < 1,000 cfu and M. tuberculosis samples < 100 cfu. Subsequently, we used the TiKa system with stored clinical samples (various lymphatic tissues) collected from wildlife and paucibacillary bronchoalveolar lavage fluid, trunk washes, and endotracheal tube washes from 3 species with known MTBC infections. Overall, MTBC recovery by culture was improved significantly (p < 0.01) by using TiKa compared to conventional MGIT, with 54 of 57 positive specimens versus 25 of 57 positive specimens, respectively. The TiKa mycobacterial growth system appears to significantly enhance the recovery of MTBC members from tissue and paucibacillary respiratory samples collected from African buffaloes, African elephants, and white rhinoceros. Moreover, the TiKa system may improve success of MTBC culture from various sample types previously deemed unculturable from other species.  相似文献