Evapotranspiration assessments from drone-based thermography - a method comparison in an oil palm plantation and a look ahead

2020 ◽  
Author(s):  
Alexander Röll ◽  
Florian Ellsäßer ◽  
Christian Stiegler ◽  
Tania June ◽  
Hendrayanto Hendrayanto ◽  
...  
Keyword(s):  
Land Use ◽  
Energy Balance ◽  
Eddy Covariance ◽  
Spatial Resolution ◽  
Oil Palm ◽  
Reference Method ◽  
Net Radiation ◽  
Near Surface ◽  
Oil Palm Plantation ◽  
Deming Regression

<p>Evapotranspiration (ET) is a key flux in hydrological cycles; it is affected by both climate and land-use change. A recent study across 42 study sites in four land-use types in lowland Sumatra (Indonesia) reported that local and regional transpiration are on the rebound due to the high water use and continuing expansion of oil palm plantations. Conventional ET assessment methods such as satellite-based thermography or the eddy covariance (EC) technique lack the high spatial resolution and spatial replicability, respectively, that are required for ET assessments in dynamic and heterogeneous, mosaic-like landscapes. For such assessments of ET, near-surface airborne thermography offers new opportunities for studies with high numbers of spatial replicates and in a fine spatial resolution. In our study, we tested drone-based thermography and the subsequent application of three energy balance models (DATTUTDUT, TSEB-PT, DTD) using the widely accepted EC technique as a reference method. The study site was a mature oil palm plantation in lowland Sumatra. For 61 flight missions, latent heat flux estimates of the DATTUTDUT model with measured net radiation agreed well with eddy covariance measurements (r²=0.85; MAE=47; RMSE=60) across variable weather conditions and daytimes. Confidence intervals for slope and intercept of a Deming regression suggest no difference between drone-based and eddy covariance method, thus indicating interchangeability. TSEB-PT and DTD yielded agreeable results, but all three models are highly sensitive to the configuration in which net radiation is assessed. Overall, we conclude that drone-based thermography with energy-balance modeling is a reliable method complementing available methods for ET studies. It offers promising, additional opportunities for fine grain and spatially explicit studies. Further steps in the near future will include the testing and if necessary calibrating of the method across different biomes as well as ecological applications.</p>

scholarly journals Predicting evapotranspiration from drone-based thermography – a method comparison in a tropical oil palm plantation

2020 ◽  
Author(s):  
Florian Ellsäßer ◽  
Christian Stiegler ◽  
Alexander Röll ◽  
Tania June ◽  
Alexander Knohl ◽  
...  
Keyword(s):  
Energy Balance ◽  
Eddy Covariance ◽  
Oil Palm ◽  
Method Comparison ◽  
Reference Method ◽  
Net Radiation ◽  
Eddy Covariance Method ◽  
Near Surface ◽  
Oil Palm Plantation ◽  
Deming Regression

Abstract. For the assessment of evapotranspiration, near-surface airborne thermography offers new opportunities for studies with high numbers of spatial replicates and in a fine spatial resolution. We tested drone-based thermography and the subsequent application of three energy balance models (DATTUTDUT, TSEB-PT, DTD) using the widely accepted eddy covariance technique as a reference method. The study site was a mature oil palm plantation in lowland Sumatra, Indonesia. For the 61 flight missions, latent heat flux estimates of the DATTUTDUT model with measured net radiation agreed well with eddy covariance measurements (r² = 0.85; MAE = 47; RMSE = 60) across variable weather conditions and daytimes. Confidence intervals for slope and intercept of a model II Deming regression suggest no difference between drone-based and eddy covariance method, thus indicating interchangeability. TSEB-PT and DTD yielded agreeable results, but all three models are sensitive to the configuration of the net radiation assessment. Overall, we conclude that drone-based thermography with energy-balance modeling is a reliable method complementing available methods for evapotranspiration studies. It offers promising, additional opportunities for fine grain and spatially explicit studies.

scholarly journals Predicting evapotranspiration from drone-based thermography – a method comparison in a tropical oil palm plantation

2021 ◽  
Vol 18 (3) ◽  
pp. 861-872
Author(s):  
Florian Ellsäßer ◽  
Christian Stiegler ◽  
Alexander Röll ◽  
Tania June ◽  
Alexander Knohl ◽  
...  
Keyword(s):  
Energy Balance ◽  
Eddy Covariance ◽  
Oil Palm ◽  
Turbulent Transport ◽  
Reference Method ◽  
Balance Model ◽  
Net Radiation ◽  
Near Surface ◽  
Oil Palm Plantation ◽  
Deming Regression

Abstract. For the assessment of evapotranspiration, near-surface airborne thermography offers new opportunities for studies with high numbers of spatial replicates and in a fine spatial resolution. We tested drone-based thermography and the subsequent application of the DATTUTDUT energy balance model using the widely accepted eddy covariance technique as a reference method. The study site was a mature oil palm plantation in lowland Sumatra, Indonesia. For the 61 flight missions, latent heat flux estimates of the DATTUTDUT (Deriving Atmosphere Turbulent Transport Useful To Dummies Using Temperature) model with measured net radiation agreed well with eddy covariance measurements (r2 = 0.85; MAE = 47; RMSE = 60) across variable weather conditions and times of day. Confidence intervals for slope and intercept of a model II Deming regression suggest no difference between drone-based and eddy covariance methods, thus indicating interchangeability. The DATTUTDUT model is sensitive to the configuration of the net radiation assessment. Overall, we conclude that drone-based thermography with energy balance modeling is a reliable method complementing available methods for evapotranspiration studies. It offers promising, additional opportunities for fine grain and spatially explicit studies.

scholarly journals Surface Temperature and Heat Fluxes: Comparison between Natural Forest and Oil Palm Plantation in Jambi Province Using Surface Energy Balance Algorithm for Land (SEBAL)

Agromet ◽  
2019 ◽  
Vol 33 (2) ◽  
pp. 62-70
Author(s):  
Salis Deris Artikanur ◽  
Tania June
Keyword(s):  
Heat Flux ◽  
Energy Balance ◽  
Surface Temperature ◽  
Oil Palm ◽  
Surface Energy Balance ◽  
Sensible Heat Flux ◽  
Canopy Cover ◽  
Heat Fluxes ◽  
Net Radiation ◽  
Oil Palm Plantation

One of the leading commodities that has contributed a lot of income for Indonesia is oil palm. Oil palm plantations in Jambi are widespread, affecting the energy balance and surface temperature. This study aims to compare surface temperature and heat fluxes of oil palm plantation with different ages, how is the difference between forest and oil palm plantation, and to analyze the effect of oil palm planting on micro-climate change in Jambi. Using the Surface Energy Balance Algorithm for Land (SEBAL), it was found that in Jambi, young oil palm (2 years old) had higher surface temperatures of 2oC compared with adult oil palm (19 years old). While the surface temperature of the adult oil palm plant is slightly higher than natural forest that is 0.5oC. The increase of the age of oil palm followed by the increase of plant height (h), Canopy Cover (CC), and surface roughness which resulted in the increase of NDVI value and the cooling effect around the plantation so that the surface temperature (Ts) decreased as indicated by equation TS = 27.00 - 0.1581h - 0.0317CC and NDVI = 0.1335 + 0.00892h + 0.00096CC. The sensible heat flux (H) is affected by surface temperature, roughness length, friction velocity, and aerodynamic resistance of the plant. The highest H value is in the oil palm plantation near Brimob which is 282 W/m2. Latent heat flux (LE) is the remainder of the net radiation minus the flux of the soil and the flux feels. The highest LE value is in the oil palm plantation of Pompa Air Village which is 710 W/m2. Substantially ground heat flux (G) is affected by net radiation, NDVI, surface temperature, and albedo. The highest value of G is in PT Pisifera Persada oil palm plantation of 98 W/m2.Keywords: NDVI, net radiation, sensible heat flux, latent heat flux, Canopy Cover

scholarly journals Inter-comparison of two land-surface models applied at different scales and their feedbacks while coupled with a regional climate model

2012 ◽  
Vol 16 (3) ◽  
pp. 1017-1031 ◽  
Author(s):  
F. Zabel ◽  
W. Mauser ◽  
T. Marke ◽  
A. Pfeiffer ◽  
G. Zängl ◽  
...  
Keyword(s):  
Land Use ◽  
Land Surface ◽  
Regional Climate ◽  
Moderate Increase ◽  
Net Radiation ◽  
Land Surface Models ◽  
Near Surface ◽  
Temporal Behaviour ◽  
Surface Models ◽  
The Alps

Abstract. Downstream models are often used in order to study regional impacts of climate and climate change on the land surface. For this purpose, they are usually driven offline (i.e., 1-way) with results from regional climate models (RCMs). However, the offline approach does not allow for feedbacks between these models. Thereby, the land surface of the downstream model is usually completely different to the land surface which is used within the RCM. Thus, this study aims at investigating the inconsistencies that arise when driving a downstream model offline instead of interactively coupled with the RCM, due to different feedbacks from the use of different land surface models (LSM). Therefore, two physically based LSMs which developed from different disciplinary backgrounds are compared in our study: while the NOAH-LSM was developed for the use within RCMs, PROMET was originally developed to answer hydrological questions on the local to regional scale. Thereby, the models use different physical formulations on different spatial scales and different parameterizations of the same land surface processes that lead to inconsistencies when driving PROMET offline with RCM output. Processes that contribute to these inconsistencies are, as described in this study, net radiation due to land use related albedo and emissivity differences, the redistribution of this net radiation over sensible and latent heat, for example, due to different assumptions about land use impermeability or soil hydraulic reasons caused by different plant and soil parameterizations. As a result, simulated evapotranspiration, e.g., shows considerable differences of max. 280 mm yr−1. For a full interactive coupling (i.e., 2-way) between PROMET and the atmospheric part of the RCM, PROMET returns the land surface energy fluxes to the RCM and, thus, provides the lower boundary conditions for the RCM subsequently. Accordingly, the RCM responses to the replacement of the LSM with overall increased annual mean near surface air temperature (+1 K) and less annual precipitation (−56 mm) with different spatial and temporal behaviour. Finally, feedbacks can set up positive and negative effects on simulated evapotranspiration, resulting in a decrease of evapotranspiration South of the Alps a moderate increase North of the Alps. The inconsistencies are quantified and account for up to 30% from July to Semptember when focused to an area around Milan, Italy.

scholarly journals Effects of long-term mixed land use of human settlement and oil palm plantation on the groundwater quality of ex-promontory land

2014 ◽  
Vol 8 (7) ◽  
pp. 01-09
Author(s):  
SitiZulaikha Othman ◽  
◽  
Roslan Hashim ◽  
Mohamad FaizalTajulBaharuddin ◽  
Sharifah Mohamad
Keyword(s):  
Land Use ◽  
Groundwater Quality ◽  
Oil Palm ◽  
Human Settlement ◽  
Oil Palm Plantation ◽  
Mixed Land Use

scholarly journals Assessment of fertility status of soils under land use types in Egbema Area, Imo State, Nigeria

2020 ◽  
Vol 17 (2) ◽  
pp. 1-13
Author(s):  
C. Chikere-Njoku
Keyword(s):  
Land Use ◽  
Bulk Density ◽  
Soil Ph ◽  
Oil Palm ◽  
Fallow Land ◽  
Cultivated Land ◽  
Fertility Status ◽  
Oil Palm Plantation ◽  
Land Use Types ◽  
Land Use System

The study was conducted to investigate fertility status under four different land use types (oil palm plantation, pineapple orchard, cassava cultivated land and fallow land use system) in Umuekem, Ohaji/Egbema of Imo State, Nigeria. Composite samples were collected from various depths (10-15cm, 15-30cm, 30-45cm) across these land use patterns and analyzed in the laboratory using the standard procedure. Data generated were subjected to statistical analysis. Results obtained showed significant differences (p ≥ 0.05) in silt-clay ratio, bulk density, total porosity, water holding capacity, soil pH, organic carbon, available phosphorus, TN and ECEC across the four land use types studied. The soils were predominantly loamy sand surface and sandy clay loam in the subsoil exception of pineapple orchard with sandy loam topsoil over sandy clay loam subsoil. The silt clay ratio (SCR) showed ranges of 0.10-0.30, 0.10-0.36, 0.07 – 0.30, and 0.06- 0.20 in land use types of oil palm plantation, pineapple orchard, cassava cultivated land and fallow land respectively. The bulk density ranged of (1.61 – 1.77 g/cm3) for oil palm, (1.34 – 1.58 g/cm3) for pineapple (1.42 – 1.49 g/cm3) cassava and (1.45 – 1.48 g/cm3) in forest land use system. The soils of the four land use types were generally acidic. The mean values of soil pH (H20) were oil palm plantation (5.11), pineapple orchard (5.03), cassava cultivated land (5.35) and fallow land (5.40). The soil pH recorded low variation in all the land use types. The organic carbon and total nitrogen recorded high variation (>52.57% < 85.67%, >79.19 < 95.77) in all the different land use types. Calcium-magnesium ratio (Ca: Mg) recorded high variation (37.36%) in forest land use system, low variation (18.77%) in pineapple orchard and moderate in cassava (27.51%) and oil palm plantation (28.23). The low Ca: Mg ratio inhibits uptake and causes Ca deficiency thereby resulting in low fertility status of the soil. C: P recorded high variation (≥ 53.77% ≤ 77.73%) in all the studied land use types. O.C correlated positively and highly significant with available phosphorus, ECEC and T.N. The findings also indicated that bulk density correlated positively with ECEC and percentage base saturation. It is recommended that land use approach should be adopted for effective and sustainable management of the soil fertility. Keywords: Fertility status, Soils, Land use types

scholarly journals Faktor Penentu Produksi pada Perkebunan Rakyat Kelapa Sawit di Kabupaten Mamuju Utara

2019 ◽  
Vol 9 (1) ◽  
pp. 58
Author(s):  
Dimas Deworo Puruhito ◽  
Jamhari Jamhari ◽  
Slamet Hartono ◽  
Irham Irham
Keyword(s):  
Land Use ◽  
Data Analysis ◽  
Oil Palm ◽  
Land Area ◽  
Function Model ◽  
Family Labor ◽  
Oil Palm Plantation ◽  
Average Production ◽  
Npk Fertilizer

There are three patterns of smallholder oil palm plantation in North Mamuju regency, ie plasma, IGA (Income Generating Activity), and mandiri (independent). Independent smallholder plantations are plantations managed by the community themselves without the involvement of others. While the partnership patterns can be divided into plasma and IGA. The partnership is a form of fostering of smallholders plantations by large private plantation in this area. This study aims to determine the amount of oil palm production on smallholder plantations and the factors that affect. The research was conducted in North Mamuju Regency, West Sulawesi Province which has the widest smallholder oil palm plantation in Sulawesi Island with various pattern. Four villages in two sub-districts were chosen purposively consideration with having three patterns of smallholder plantations. The sampling of farmers using snowball method after stratification in each pattern. Selected 35 plasma farmers, 70 IGA farmers, and 55 independent farmers. Data analysis was performed with Cobb-Doulas function model in the normalized logarithm, using Eviews 6 software. The findings are the average production of 56,840 kg, with productivity of 20,300 kg/ha. Input of land area, NPK fertilizer, age of oil palm crops, outside family labor, frequency of estate sanitation and distance of estate to river is the determinant input to production. Input land area is found as the most elastic input. However, land use for oil palm plantations should still refer to existing legislation.

Air mixing and sub-canopy advection in an oil palm plantation in Indonesia

2020 ◽  
Author(s):  
Christian Stiegler ◽  
Tania June ◽  
Alexander Knohl
Keyword(s):  
Eddy Covariance ◽  
Oil Palm ◽  
Gross Primary Production ◽  
Air Flow ◽  
Accurate Information ◽  
Night Time ◽  
Oil Palm Plantation ◽  
Stable Conditions ◽  
Air Mixing ◽  
Eddy Covariance Measurements

&lt;p&gt;In tall vegetation canopies, such as forest or oil palm monoculture plantations, the below-canopy airflow can be influenced by the local topography and thereby cause horizontal exchange of the below-canopy air. Especially during night time, calm weather conditions may result in the formation of an isolated layer near the surface, which is decoupled from the above-canopy air layer. When decoupling and below-canopy horizontal air flow occurs, there is a high potential that above-canopy measured carbon dioxide (CO&lt;sub&gt;2&lt;/sub&gt;) fluxes based on eddy covariance measurements might not represent the true ecosystem CO&lt;sub&gt;2&lt;/sub&gt; flux as below-canopy respiration might be undetected by the eddy covariance system. Nevertheless, eddy covariance data are frequently used as the reference for fluxes of tall vegetation ecosystems or for validation of modelling approaches estimating gross primary production (GPP) and net ecosystem exchange (NEE). It is therefore important to have accurate information on air mixing, decoupling and sub-canopy drainage flow to understand the complex CO&lt;sub&gt;2&lt;/sub&gt; exchange behaviour in tall vegetation ecosystems.&lt;/p&gt;&lt;p&gt;In this context, we investigate wind and micrometeorological dynamics of a mature oil palm monoculture plantation (tropical lowland, Jambi Province, Sumatra, Indonesia). We use data from above- and below-canopy eddy covariance and micrometeorological measurements within the oil palm plantation to assess the wind dynamics and the strength of the turbulent mixing as an estimator for the degree of coupling. Further, we explore the potential implications of decoupling and horizontal below-canopy flow on the above-canopy derived NEE.&lt;/p&gt;&lt;p&gt;Preliminary results show that wind is generally weak in the oil palm plantation. Using a breakpoint analysis, the correlation of below- and above-canopy standard deviation of vertical wind speed (&amp;#963;&lt;sub&gt;w&lt;/sub&gt;) derived from sonic eddy covariance measurements below (2.4 m height) and above the canopy (22 m height), we identified a site-specific &amp;#963;&lt;sub&gt;w&lt;/sub&gt; threshold of 0.11 m s&lt;sup&gt;-1&lt;/sup&gt; (below-canopy) and 0.26 m s&lt;sup&gt;-1&lt;/sup&gt; (above-canopy) above which the atmospheric conditions are in fully coupled state. During the day, unstable conditions dominate over stable conditions while in the twilight hours and during the night, the reverse is the case. Below-canopy wind comes mostly from south-eastern directions during both day and night, and tends to blow independently from wind above the canopy for conditions with above-canopy u* &lt; 0.3 m s&lt;sup&gt;-1&lt;/sup&gt;. Based on the above-canopy eddy covariance NEE measurements and on the direction difference (&amp;#916;WD) between above- and below-canopy wind, we observe a threshold of ~70&amp;#176; &amp;#916;WD above which the two layers might be decoupled. Below-canopy air flow might therefore influence the above-canopy NEE detections, biasing carbon balance estimates.&lt;/p&gt;

scholarly journals Components of near-surface energy balance derived from satellite soundings – Part 1: Net available energy

2014 ◽  
Vol 11 (8) ◽  
pp. 11825-11861 ◽  
Author(s):  
K. Mallick ◽  
A. Jarvis ◽  
G. Wohlfahrt ◽  
G. Kiely ◽  
T. Hirano ◽  
...  
Keyword(s):  
Energy Balance ◽  
Surface Energy ◽  
Surface Energy Balance ◽  
Surface Radiation ◽  
Net Radiation ◽  
Heat Accumulation ◽  
Simple Method ◽  
Ground Truth Data ◽  
Near Surface ◽  
Available Energy

Abstract. This paper introduces a relatively simple method for recovering global fields of near-surface net available energy (the sum of the sensible and latent heat flux or the difference between the net radiation and surface heat accumulation) using satellite visible and infra-red products derived from the AIRS (Atmospheric Infrared Sounder) and MODIS (MOderate Resolution Imaging Spectroradiometer) platforms. The method focuses on first specifying net surface radiation by considering its various shortwave and longwave components. This was then used in a surface energy balance equation in conjunction with satellite day–night surface temperature difference to derive 12 h discrete time estimates of surface, system heat capacity and heat accumulation, leading directly to retrieval for surface net available energy. Both net radiation and net available energy estimates were evaluated against ground truth data taken from 30 terrestrial tower sites affiliated to the FLUXNET network covering 7 different biome classes. This revealed a relatively good agreement between the satellite and tower data, with a pooled root mean square deviation of 98 and 72 W m−2 for net radiation and net available energy, respectively, although both quantities were underestimated by approximately 25 and 10%, respectively relative to the tower observations. Analysis of the individual shortwave and longwave components of the net radiation revealed the downwelling shortwave radiation to be the main source of this systematic underestimation.

scholarly journals Plant Diversity in Different Land Use Types at The Peat Hidrological Unit (PHU) of Mendahara – Batanghari River, Jambi Province

2019 ◽  
Vol 24 (2) ◽  
pp. 141-151
Author(s):  
Aji Nuralam Dwisutono ◽  
Sri Wilarso Budi ◽  
Istomo Istomo
Keyword(s):  
Land Use ◽  
Plant Diversity ◽  
Oil Palm ◽  
Secondary Forest ◽  
Land Use Changes ◽  
Coffee Plantation ◽  
Coffee Plantations ◽  
Oil Palm Plantation ◽  
Melastoma Malabathricum ◽  
Tropical Peatlands

The characteristics of tropical peatlands are still able to form a high diversity of plants. Conversion of tropical peatlands affects the composition of plants. The aim of this study was to find out effect of land use changes to the composition and diversity of plants in the Peat Hydrological Unit (PHU) Mendahara - Batanghari River. The research was conducted in three land use categories, namely secondary forest, coffee plantation, and oil palm plantation (subdivided into oil palm plantation 1 and oil palm plantation 2). In each study location, sample lane 20 m x 200 m were made. Overall, we found 77 species of plants. The results showed   number of plant species decreased due to changes of land use. There are 51 - 53 species of plants in secondary forest areas (out of a total of 58 species) that are not found in oil palm and coffee plantations areas. Differences in composition were also shown in the low value of community similarity (<50%). In the oil palm and coffee plantation areas, plant communities tend to be dominated by pioneer plants such as Melicope lunu-ankenda, Coffea liberica, Macaranga triloba, and Melastoma malabathricum. Secondary forest was dominated by plants species that characterize peatlands such as Tetramerista glabra, Parastemon urophyllus, Knema percoriacea, Litsea costalis var. nidularis and Madhuca motleyana. Changes in land use also reduce the level of diversity (H 'and R) at various levels of growth. Whereas in the oil palm and coffee plantation areas tend to form uniform stands (indicated through index E which describes the abundance distribution in community and index C which describes the dominance of species). Generally, the distribution pattern of plants is clumped. Uniform distribution was found in K. percoriacea and L. costalis var. nidularis. Keywords: land use changes, peatland characteristics, plant composition, plant diversity

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