Budget Calculations Research Articles

Planning of Path Loss in Large Scale Signal Propagation Model at 5G Network by Using Linear Regression Methods

The generation of 4G network communication technology will gradually not be able to accommodate the community needs in the increasing data access speed. This research becomes very important to be one of many concepts in developing 5th network technology or 5G. Planning aims to observe the propagation model of 5G network signal to find the transmission path loss values using the mmWave signal propagation model, power link budget calculation, and analysis through linear regression. Based on the study results, the average path loss at 28 GHz and the line of sight and non-light of sight conditions for the Free-Space Reference Path Loss model are 97.7583 dB and 140.7436, while for the 73 GHz frequency each at 105.3378 and 131.6135 dB. Results of error standard deviation of linear regression models of the Reference Free-Space Path Loss at frequency 28 GHz conditions of line of sight and non-light of Sight 0.0636 and 0.7023 respectively, while the 73GHz frequency is 0.2855 and 0.5103, respectively.

Manganese dynamics in tidal basins of the Wadden Sea: Spatial/seasonal patterns and budget estimates

The concentrations of dissolved and particulate manganese (Mndiss and Mnpart) were studied in the Wadden Sea and adjacent estuaries to gain insights into spatial and regional differences, but also to assess the source function of the tidal basins for the open North Sea compared to river discharge. Ten transects across tidal basins of the southern and northern Wadden Sea as well as the estuaries of the rivers Elbe, Weser, and Ems were sampled. A case study in the tidal basin of Spiekeroog Island (southern Wadden Sea) was further used to evaluate seasonal and inter-annual Mn dynamics and the potential importance of deeper, groundwater-associated (up to 20 m sediment depth) Mn sources.In the estuaries and the Jade Bay, Mnpart is the predominant Mn fraction, whereas Mndiss is the major faction in the tidal basins. Higher Mndiss levels in the tidal basins of the southern compared to the northern Wadden Sea result from differences in tidal basin characteristics such as intertidal area and tidal asymmetry, influencing the extent of benthic-pelagic interaction and material import. Offshore-directed Mndiss fluxes exhibit less regional variability than Mndiss levels. Overall, the net export fluxes of total Mn from the tidal basins are variable but clearly exceed the river input for the considered summer situation. Annual Mndiss export fluxes, exemplified for the Spiekeroog tidal basin, exhibit high seasonal variations with highest fluxes during spring and late summer. Along with onshore material transport, budget calculations for the Spiekeroog tidal basin indicate that offshore-directed Mndiss fluxes are mainly controlled by surface and deep pore water discharge. Groundwater-associated Mn-rich pore waters in the deep sediments of the intertidal area are likely counteracting sedimentary Mn exhaustion on longer time scales.

The role of prior assumptions in carbon budget calculations

Abstract. Cumulative emissions budgets and net-zero emission target dates are often used to frame climate negotiations (Frame et al., 2014; Millar et al., 2016; Van Vuuren et al., 2016; Rogelj et al., 2015b; Matthews et al., 2012). However, their utility for near-term policy decisions is confounded by uncertainties in future negative emissions capacity (Fuss et al., 2014; Smith et al., 2016; Larkin et al., 2018; Anderson and Peters, 2016), in the role of non-CO2 forcers (MacDougall et al., 2015) and in the long-term Earth system response to forcing (Rugenstein et al., 2019; Knutti et al., 2017; Armour, 2017). Such uncertainties may impact the utility of an absolute carbon budget if peak temperatures occur significantly after net-zero emissions are achieved, the likelihood of which is shown here to be conditional on prior assumptions about the long-term dynamics of the Earth system. In the context of these uncertainties, we show that the necessity and scope for negative emissions deployment later in the century can be conditioned on near-term emissions, providing support for a scenario framework which focuses on emissions reductions rather than absolute budgets (Rogelj et al., 2019b).

Channel modelling of a cooker hob environment for smart kitchens

This study presents a study on the radio channel modelling for realising reliable wireless communication in kitchen environments. The study allows optimising the wireless communication between a cooking pot and the kitchen hood in a smart home's kitchen. The delay, angular and path loss characteristics of the wireless channel are obtained from channel sounding measurements. The authors compared path loss at frequencies 868 MHz, 2.4 and 5.25 GHz. The influence of the metallic pot on the antenna characteristics is assessed by measuring the radiation pattern of the antenna. The antenna gain increases when the antenna is placed next to the metallic pot. Based on the channel sounding measurements and antenna model, a two-ray channel model is proposed consisting of one line-of-sight component and a component caused by reflections on the hood and hob. For the validation of the proposed model, a narrowband patch antenna is designed and used for measurements in a real kitchen. The validation confirms the general applicability of the proposed method. The results of the joint channel and antenna model are used in link budget calculations. Via the link budget, the minimum required TX power to allow reliable wireless communication is calculated.

Pengaruh Faktor Finansial Dan Faktor Non Finansial Terhadap Kinerja Keuangan Pemerintah Desa

This study aims to determine the effect of Financial Factors (Original Village Income, Transfer Funds, Other Income, Village Expenditures and Extra Time Budget Calculation / SiLPA) and Non-Financial Factors (Area of Village Area, Number of Population, Size of Village Government, Educational Background of Village Head, and Term of Office village head) on the Financial Performance of the Village Government in the nagari in Tanah Datar District in 2016-2018. The data use secondary data. The sampling technique uses Simple Random Sampling method with a total sample of 47 villages with a period of time of 3 years. Analysis of the data using multiple linear regression analysis.The results showed that Original Village Income, Transfer Funds, and Size of Village Government had a negative and significant effect on the Financial Performance of the Village Government. Village Expenditures Government had a positive and significant effect on the Financial Performance of the Village Government. Other Income, Extra Time Budget Calculation/SiLPA, Area of Village Area, Number of Population, Educational Background of Village Head, and Term of Office village head had no effect onthe Financial Performance of the Village Government.

Channel and cut-bluff failure connectivity in a river system: Case study of the braided-wandering Belá River, Western Carpathians, Slovakia

Straightforward sediment transport is not common in nature and material is storage during transport and reworked by the same processed that lead to initial mass erosion. Despite the development of quantitative assessment by application high accuracy topography measurement, lack of conceptualisation and combination with precise elevation model changes is still missing. This paper presents a field-based channel-bluff connectivity study based on a sediment cascade approach. A TLS (terrestrial laser scanning) time-series database was generated by systematic monitoring of cut-bluff slope surface of the braided-wandering Belá River. The database was used to estimate volume changes and allowed to develop the conceptualisation model of coupling of cut-bluff slope based on spatial and temporal analyses of channel hydrology, gravity conditioned transformation of matter and a detailed of sediment budget calculations. Historical analyses have shown that a flow direction perpendicular to the slope is crucial to activate cut-bluff slope material movement and initiate a sediment cascade, as significant contributors of sediment into the river. Sediment supply to the channels correlates with the magnitude of flood events (maximum discharge, cumulative discharge, cumulative discharge higher than RI1.5, and duration of discharges higher than RI1.5) and lateral migration as a main factor controlling the behaviour of the cut-bluff slope-channel system. During the survey from March 2016 to November 2018, were transported 10,103 m3 (25,964 t) of fine-grained sediment into the river channel.

Analysis of Utilization Bandwidth and Power Transponder Extended C-Band On The Satellite Telkom 3S VSAT SCPC

On satellite communication systems, bandwidth and power are limited and expensive resources. Optimization of bandwidth and power utilization in Telkom 3S Satellite could be achieved if the ratio value of the percentage of bandwidth and power is 1: 1. The optimization conditions are influenced by the calculation of the link budget, the use of appropriate modulation and FEC settings. QPSK and 8-PSK modulation techniques with FEC used are ¾, 7/8, and 0.9 with a 9 m Hub antenna and VSAT SCPC with a diameter of 2.4 m and the same data rate of 1024 kbps. Based on the results of this research, the lower the modulation technique used, the lower the ratio of bandwidth and power. The most optimal FEC value to be used is 8-PSK modulation at FEC 0.93 with the resulting percentage is 97.25%, where the total carrier bandwidth generated is 93.415, and the amount of carrier power is 96.05, while the worst is modulation QPSK is at the FEC of 3/4 by producing a percentage of 35% which falls into the limited power category. Thus, the most appropriate modulation used on the Telkom 3S Satellite is the 8-PSK modulation with an FEC of 0.93.

Fractal inspired miniaturized wideband ingestible antenna for wireless capsule endoscopy

In this paper, a conformal wideband fractal implemented miniaturized antenna is presented for endoscopy capsule application over the 2450 MHz Industrial, Scientific and Medical (ISM) band. The thickness of the antenna is only 0.1 mm, which can be wrapped outside the capsule’s wall. By implementing Minkowski fractal geometry in the patch, the proposed antenna obtains significant size reduction. A cubical shape muscle phantom is considered for initial design with parametric studies. To realize a more practical scenario, effect of the internal electronic components inside the capsule is discussed in detail, and also the variation of antenna’s characteristics with respect to movement of capsule inside the gastro-intestinal (GI) tract has also been outlined. Further to study the bio-compatibility, specific absorption rate (SAR) of the proposed antenna is evaluated in different organs. The performance of the proposed antenna is experimentally validated by using a human phantom liquid mimicking the muscle tissue. From experimentation, it can be concluded that the antenna offers more than 30.6% fractional bandwidth in homogeneous tissue. Theoretically, the whole antenna assembly is electrically modeled and corresponding link budget calculation is accomplished. Link margin coming out from this study indicates the suitability of the proposed antenna in bio-medical applications.

The Role of a Tidal Flat–Saltmarsh System as a Source–Sink of Mercury in a Contaminated Coastal Lagoon Environment (Northern Adriatic Sea)

The Marano and Grado Lagoon (northern Adriatic Sea, Italy) is contaminated mainly by mercury (Hg) of mining and industrial origin. This work aims to investigate the sedimentary records of Hg of a tidal flat–saltmarsh (TF–S) system and to understand the role played by tidal fluxes in terms of the transport, accumulation and release of Hg due to the periodic flow of the tide. The complex history of the sources of Hg in the area of the TF–S system has resulted in several fluctuations of Hg in sediments over time; due to its higher sedimentation rate (1.3 cm year−1) than the subtidal areas of the Grado lagoon, the outer area of the TF–S system is more active in terms of accumulation (from 56 to 81 mg m−2 year−1) than the inner area. Fluxes were estimated at the mouth of a principal tidal creek by combining discrete hourly tidal flow measurements with weighed measurements of dissolved (DHg) and particulate (PHg) mercury obtained via water sample collection. Mercury, mainly in particulate form, is drained by the tidal creek from the marsh during a tidal semi-cycle. The highest flux of PHg was recorded during ebb tide in July (1071 mg). The calculation of the quantitative flows of PHg and DHg highlighted a tendency for Hg to be exported from the TF–S to the lagoon channel during a tidal semi-cycle. However, the results obtained here for the Hg fluxes do not allow for the depiction of a constant positive or negative budget as that found in the literature for macro-scale budget calculations at lagoon tidal inlets. A possible explanation for there being no constant trend in the PHg and DHg budget is that our TF–S system is located in a lagoon area where previous findings reported accretion or a balance situation between erosion and sedimentation processes.

Towards the closure of momentum budget analyses in the WRF (v3.8.1) model

Abstract. Budget analysis of a tendency equation is widely utilized in numerical studies to quantify different physical processes in a simulated system. While such analysis is often post-processed when the output is made available, it is well acknowledged that the closure of a budget is difficult to achieve without temporal and/or spatial averaging. Nevertheless, the development of errors in such calculations has not been systematically investigated. In this study, an inline budget retrieval method is first developed in the WRF v3.8.1 model and tested on a 2D idealized slantwise convection case with a focus on the momentum equations. This method extracts all the budget terms following the model solver, which gives a high accuracy, with a residual term always less than 0.1 % of the tendency term. Then, taking the inline values as truth, several offline budget analyses with different commonly used simplifications are performed to investigate how they may affect the accuracy of the estimation of individual terms and the resultant residual. These assumptions include using a lower-order advection operator than the one used in the model, neglecting grid staggering, or following a mathematically equivalent but transformed format of the governing equations. Errors in these post-processed analyses are found mostly over the area where the dynamics are the most active, thus impairing the subsequent physical interpretation. A maximum 99th percentile residual can reach >50 % of the concurrent tendency term, indicating the danger of neglecting the residual term as done in many budget studies. This work provides general guidance not only for budget diagnoses with the WRF model but also for minimizing the errors in post-processed budget calculations.

Development of thermal and deformation stability of Qinghai-Tibet Highway under sunny-shady slope effect in southern Tanglha region in recent decade

The Qinghai-Tibet Highway (QTH) crosses 528 km of a permafrost region in the Qinghai-Tibet Plateau, half of which has suffered freezing-thawing damage induced by the sunny-shady slope effect (SSSE), especially in the Southern Tanglha Region (STR). Given this problem, a continual field investigation was carried out in the STR to examine the types of damage and the development characteristics of the affected embankments. The investigation indicated that up to 60% of the damage featured an asymmetric specialty, mainly comprising uneven thaw deformation and longitudinal cracks. Furthermore, the long-term monitoring data taken from four observation sites in a recent decade, including the shallow soil temperature, ground temperature, freezing-thawing processes, and deformation, were used to analyze the thermal-deformation process of the embankments as well. Under the SSSE, the temperature fields of the embankments were characterized by the increase in ground temperature, the descent of the permafrost table, and the expansion of the thawing period in the sunny slopes during the operation period, representing several remarkable asymmetric phenomena. Specifically, the maximum difference between the annual average shallow soil temperatures of the sunny and shady slopes reached 3.17 °C. In addition, the permafrost table on the sunny slope side was about 1.0 m lower than that on the shady slope side because the thawing period is 1–2 months longer each year on the sunny slope side. Correspondingly, the asymmetric thermal state of the embankments led to varying degrees of asymmetric deformations. The heat budget calculation showed that the route direction was the most significant factor of influence on the SSSE. The embankment height was also seen to have a remarkable influence on the SSSE.

The first proposed of fiber to the home (FTTH) protection unit for clients scattered placement

This paper describes the design and analysis of protection schemes that it is not regular customers’ location in optical communication system network. Distance and number of customers with the design of optical point protection unit achievements are recognized as the user for a series of rings from CAPU-Ring 1 (Customer Access Protection Unit). CAPU-Ring 1 is made as a safety point of optics that will be placed on the prior user. This system is an optical spot that will be placed in a ring circuit for use in placement of clients scattered. Proposed construction of a series with a protection channel architecture is about designing CAPU-Ring 1 as optical nodes, condition and repair damage to the circuit, the power budget calculations, design in the simulation, and analysis of the node to node. Parameters outlined in this discussion are the relationship of each node optical output power, improving the system of the eye diagram to the distance and also increase the system working against the maximum optical node. Characterization of ring network protection architecture can be identified from the results of a simulation study.

Evidence of Eddy‐Enhanced Winter Chlorophyll‐a Blooms in Northern Arabian Sea: 2017 Cruise Expedition

AbstractThe temperature, salinity, and chlorophyll‐a (Chl‐a) profiles of the upper ocean (0–200 m) were measured during the China‐Pakistan Joint Expedition, 2017. The cruise track passed through an identified cyclonic eddy, and the multi‐disciplinary records thus verify the eddy contributions to winter blooms in the northern Arabian Sea (AS). The records show that the strength of upper blooms within the mixed layer is mainly dominated by surface phytoplankton biomass (the Chl‐a concentration), which increases simultaneously with the shallow mixed layer and uplifted thermocline. A composite analysis of eddy‐tracked sea level anomalies (SLA) and Chl‐a reveals the pumping and stirring effects that cyclonic eddies make to the ocean surface nutrient supply. Based on the high‐resolution Ocean General Circulation Model for the Earth Simulator (OFES) outputs, a mixed layer nitrogen budget calculation was subsequently conducted to quantify the contributions of mesoscale eddies to 10‐year climatological winter blooms. The results indicate that eddy flows are primary contributors to the increased nutrients in the coastal north AS during the mature period (usually in January and February) of the winter blooms, with a concentration histogram double that of convective mixing. The concentration decreases from the north to south, agreeing well with the seasonal northward nutrition gradient. This confirms that (i) the growth of nutrients over the northern AS, which is known to be triggered by convective mixing, would be further maintained by eddy‐induced advection; and (ii) higher concentration of nutrients would facilitate an easier response of Chl‐a to eddy dynamics.

Variation in forest landowners\u2019 management preferences reduces timber supply from Finnish forests

Key messageForest owners who maximize profitability with a low discount rate or whose management goals are related to conservation and recreation, rarely sell timber. These owners make it difficult to achieve the high harvesting targets of the growing bioeconomy sector of Finland. To increase timber supply, these landowners should be informed about alternative silvicultural methods.ContextThe round wood harvests from Finnish forests are increasing and approaching to the level of maximum sustainable cut. Cutting budget calculations assume that forests are harvested in an optimal way for national timber supply. The calculations ignore the variability of landowners’ forest management preferences.AimsThis study analyzed the effect of variation in the management objectives and silvicultural preferences of forest landowners on the forecasted timber supply from Finnish forests.MethodsForest owners were divided into savers (net present value maximized with a 1% discount rate), average owners (3% discount rate), and investors (5% discount rate). The owners of each group were further divided into three groups: those who allow only continuous cover management (12%), owners who use only rotation forest management (10%), and indifferent landowners who may use both silvicultural systems (78%). Scenarios were composed of management prescriptions that were optimized separately for the different groups of forest landowners.ResultsCompared to the even-flow timber drain scenario for rotation forest management (calculated without acknowledging the varying preferences of landowners), the scenario where the owners’ preferences varied decreased harvested volume by 15–19% during a 100-year calculation period. The main reason for the difference was the saver type of landowners who rarely sell timber.ConclusionIt was concluded that variation of the preferences of forest landowners may make it challenging to meet the increasing harvesting targets of the growing bioeconomy of Finland.

Sediment budget of high mountain stream channels in an arid zone (High Atlas mountains, Morocco)

In an arid zone the sediment budget is predominantly dependent on runoff, which is controlled mainly by the type of rainfall. Sediment budget calculation is one of the indirect methods of estimating channel morphodynamics. This method is advised here since it is not possible to directly measure this important hydrological indicator of environmental dynamics. This is because in small mountain catchments of an arid zone it is impossible to obtain flow rates due to factors such as the amount and size of transported rock debris, as well as the episodic and sudden nature of precipitation events. The research was conducted in 3 catchments (2.95 km2, 7.39 km2, 22.73 km2) situated within the boundaries of the basin of the upper Dades, on the southern slopes of the High Atlas in Morocco. The rivers of these catchments, tributaries to a trunk river Dades, are ephemeral and mostly bedrock depending on lithology of the geology. Three automatic weather stations were installed there. Precipitation events ≥ 10 mm (51 rains in 3 catchments) were used in the analysis. Simple rainfall typology (3 types) was devised for these events. During the research period seasonally repeated (6 times) measurements of topography were obtained from 21 cross-section profiles of streams of different order. These measurements formed a basis for calculating both the intensity of flow in ephemeral rivers (max 69,6 m/s) and the sediment budget. In 70% of analysed channel cross-sections erosion was dominant. The average change of the surface area of the cross-section profile is −82%. The maximum seasonal (between measurements) enlargement of the surface cross-section (erosion) is as high as 128%. The lower catchment, which is predominantly composed of conglomerates, distinctly shows the slightest changes of the cross-section profile surfaces, max 24%. The average volume of channel material displaced at the measurement point is 1.07 m3 (max 9.81 m3). There is evidence that not only high intensity rains, but also less intense but longer lasting rains, amounting to high precipitation totals (type C), may result in the highest channel sediment budgets. Differences between a catchment lithology composed of limestones and marlstones and that composed of conglomerates have only a minor impact on sediment budgets in the first and second order channels, whereas in the channels of the third and fourth order this impact is much higher. It was found that sediment budgets calculated for individual channels were higher for the catchments composed of limestones and marlstones, than for those composed of conglomerates, even though the catchments of different lithology may have had the same number of tributaries. This suggests that the sediment supply from slopes is comparatively larger in the catchments dominated by limestones and marlstones.

Finite-time circulation changes from topological rearrangement of distinguished curves and non-advective fluxes

A vorticity budget diagnoses the growth or decay of a vortex from advective transport, or non-advective fluxes such as those due to friction or vortex tilting. However, when a budget calculation is performed with respect to a fixed coordinate, errors may result from time-dependence of the flow, leading to disagreement between the vorticity tendency and the observed vorticity field. An adaptive Lagrangian coordinate resolves this problem, provided that the resulting Lagrangian structure does not become too complicated.In this study, a numerical simulation of Hurricane Nate (2011), the vorticity tendency is evaluated along distinguished material curves. There can be no net advective flux along a closed material curve, therefore, the total circulation tendency for a material region includes only the non-advective uxes acting along its boundary. A distinguished set of material curves (DMCs) associated with a distinguished hyperbolic trajectory (DHT) form a Lagrangian topology similar to that of a cat’s eye flow or “pouch” at each Eulerian snapshot. The time-dependence of velocities allows additional regions called lobes, which are formed by the intersections of DMCs, to exchange fluid across the vortex boundary by redefining the boundary.Because the vortex boundary changes, we refer to this redefinition of material boundary as “topological rearrangement”. The method is useful for unsteady cat’s-eye flows and more complex interactions of multiple waves, vortices and background shear. All advective changes of the vortex circulation are identified by exchanges of the lobes, and all non-advective uxes act between the vortex and either the lobes or environmental flow. The Lagrangian topology and combination of advective and non-advective uxes relative to the topology is used to describe the evolution of the circulation of Nate during its time of formation.

Assessment of groundwater recharge in carbonate aquifers based on a modified KARSTLOP–AHP method (case study: Dorfak region, Iran)

Determination of recharge from precipitation and its distribution in karst areas is of great importance in water budget calculations. Several multi-parameter weighting-rating methods have been proposed to determine the recharge into karst aquifers; one of the most precise methods used in this field is the KARSTLOP. It is always necessary that the weight of recharge estimation method becomes calibrated by new techniques due to the diversity conditions of each area. Therefore, in this study, the analytical hierarchy process (AHP) technique has been used as a powerful decision-helping subjective tool. Using this method, the weights of the original KARSTLOP method were modified and improved based on the comments from water experts in the area. The mean annual recharge in the study area was 27.5% and 34.5% for the KARSTLOP-AHO and KARSTLOP methods, respectively. The results of KARSTLOP–AHP method are in accordance with the discharge of selected springs in the study area and budget reports.

Miniaturised wideband ingestible antenna for wireless capsule endoscopy

This study demonstrates the development of an electrically small wideband antenna on silicon substrate targeting wireless capsule endoscopy application. Operating frequency is chosen as 915 MHz. Proposed antenna exhibits a wide frequency bandwidth of 300 MHz (750-1050 MHz) experimentally for a very compact size of 0.021 λ 0 × 0.021 λ 0 mm 2 . To simulate the realistic human body environment, `male Torso' model has been considered surrounding this miniaturised antenna. Different tissue properties have been considered during simulation by altering the electrical properties of the human phantom. For the practical experiment, `colon' tissue has been considered and fabricated prototype antenna is tested in this liquid. Further to study the bio-compatibility, specific absorption rate of the antenna is evaluated. Theoretically, the whole antenna assembly along with the phantom is modelled and corresponding link budget calculation is also accomplished to estimate carrier to noise ( C / N 0 ) ratio. Link margin coming out from this study indicates the suitability of the proposed antenna in biomedical applications. Orientation of the capsule in the gastrointestinal tract, effect of capsule material and the effect of capsule's in-side electronics upon antenna performance have been studied in this work. Experimentation reveals very promising results, which closely resembles with the predicted simulated values.

Total urban tree carbon storage and waste management emissions estimated using a combination of LiDAR, field measurements and an end-of-life wood approach

Climate action plans, with goals for carbon neutrality of cities, often rely on estimates of urban forest biomass and related annual carbon sequestration balanced against citywide carbon emissions. For these estimates to be successful, there is a need both for accurate quantification of urban tree populations and structure, and consideration of the net carbon sequestered when the fate of wood waste is factored in. This study provides a novel approach to providing a full city tree inventory for the city of Meran in northern Italy, using a combination of Light Detection and Ranging (LiDAR) and field techniques. Allometric equations, and the i-Tree application quantified the carbon storage in Meran as 8923 and 9213 Mg respectively, with an average carbon storage of 13.5 t/ha (5.47 kg C/m2). The percentage of traffic emissions sequestered annually is 0.61% falling to 0.17% when all emissions are considered. Differences between end-of-life wood management techniques were revealed, with burning with energy recovery for electricity being the most efficient with a carbon emissions/input ratio of 0.5. Landfill was the least efficient with a ratio of 121.9. The fate of this end-of-life wood has significant implications for carbon budget calculations in cities worldwide.

A study of the monsoonal hydrology contribution using a 8-yr record (2010–2018) from superconducting gravimeter OSG-060 at Djougou (Benin, West Africa)

SUMMARY We analyse a nearly 8-yr record (2010–2018) of the superconducting gravimeter OSG-060 located at Djougou (Benin, West Africa). After tidal analysis removing all solid Earth and ocean loading tidal contributions and correcting for the long-term instrumental drift and atmospheric loading, we obtain a gravity residual signal which is essentially a hydrological signal due to the monsoon. This signal is first compared to several global hydrology models (ERA, GLDAS and MERRA). Our superconducting gravimeter residual signal is also superimposed onto episodic absolute gravity measurements and to space gravimetry GRACE data. A further comparison is done using local hydrological data like soil moisture in the very superficial layer (0–1.2 m), water table depth and rainfall. The temporal evolution of the correlation coefficient between the gravity observation and both the soil moisture and the water table is well explained by the direct infiltration process of rain water together with the lateral transfer discharging the water table. Finally, we compute the water storage changes (WSC) using a simulation based on the physically based Parflow-CLM numerical model of the catchment, which solves the water and energy budget from the impermeable bedrock to the top of the canopy layer using the 3-D Richards equation for the water transfers in the ground, the kinematic wave equation for the surface runoff and a land surface model (CLM) for the energy budget and evapotranspiration calculation. This model forced by rain is in agreement with evapotranspiration and stream flow data and leads to simulated water storage changes that nicely fit to the observed gravity signal. This study points out the important role played by surface gravity changes in terms of a reliable proxy for water storage changes occurring in small catchments.