EP Ratio Research Articles

Correcting Thornthwaite potential evapotranspiration using a global grid of local coefficients to support temperature-based estimations of reference evapotranspiration and aridity indices

Abstract. Thornthwaite’s formula is globally an optimum candidate for large scale applications of potential evapotranspiration and aridity assessment at different climates and landscapes since it has the lower data requirements compared to other methods and especially from the ASCE-standardized reference evapotranspiration (former FAO-56), which is the most data demanding method and is commonly used as benchmark method. The aim of the study is to develop a global database of local coefficients for correcting the formula of monthly Thornthwaite potential evapotranspiration (Ep) using as benchmark the ASCE-standardized reference evapotranspiration method (Er). The validity of the database will be verified by testing the hypothesis that a local correction coefficient, which integrates the local mean effect of wind speed, humidity and solar radiation, can improve the performance of the original Thornthwaite formula. The database of local correction coefficients was developed using global gridded temperature and Er data of the period 1950–2000 at 30 arc-sec resolution (~1 km at equator) from freely available climate geodatabases. The correction coefficients were produced as partial weighted averages of monthly Er / Ep ratios by setting the ratios’ weight according to the monthly Er magnitude and by excluding colder months with monthly values of Er or Ep can be assessed using the following link: https://doi.pangaea.de/10.1594/PANGAEA.932638 (Aschonitis et al., 2021).

Silicone rubber reinforced by self-welded short glass fibers: Effect of resin viscosity on preferential segregation

Self-organization of mesoscopic materials (≥10 μm) using capillary forces is an attractive strategy to assemble small objects into ordered structures. In this report, a small amount of epoxy resin (EP) is added as a “solder” in glass fibers (GFs)-reinforced silicone rubber (SR). The randomly dispersed GFs are found spontaneously self-welded into a three-dimensional GF-EP network under the driving force of capillarity. We center on investigating the effects of viscosity ratio of EP to SR (λ) and the matrix viscosity (ηm) on the size of EP domain, the encapsulation ratio (NEP) of EP on GF and the morphology evolution of self-welded GF scaffolds. NEP increases with decreasing ηm of the SR matrix. At a given matrix, enlarging the viscosity difference of EP from SR seems to maximize NEP. More interestingly, decreasing ηm can not only increase NEP, but also promote preferential segregation at the junction points of GFs. We confirm that NEP increases because of the viscosity-related enlargement of the EP domain size. The self-welded rigid GF-EP scaffolds mechanically support the SR matrix, thus providing a new strategy for the design of high-strength and pressure-resistant functional rubber composite materials.

Melt Processable Novolac Cyanate Ester/Biphenyl Epoxy Copolymer Series with Ultrahigh Glass-Transition Temperature.

The rapid progress in silicon carbide (SiC)-based technology for high-power applications expects an increasing operation temperature (up to 250 °C) and awaits reliable packaging materials to unleash their full power. Epoxy-based encapsulant materials failed to provide satisfactory protection under such high temperatures due to the intrinsic weakness of epoxy resins, despite their unmatched good adhesion and processability. Herein, we report a series of copolymers made by melt blending novolac cyanate ester and tetramethylbiphenyl epoxy (NCE/EP) that have demonstrated much superior high-temperature stability over current epoxies. Benefited from the aromatic, rigid backbone and the highly functional nature of the monomers, the highest values achieved for the copolymers are as follows: glass-transition temperature (Tg) above 300 °C, decomposition onset above 400 °C, and char yield above 45% at 800 °C, which are among the highest of the known epoxy chemistry by far. Moreover, the high-temperature aging (250 °C) experiments showed much reduced mass loss of these copolymers compared to the traditional high-temperature epoxy and even the pure NCE in the long term by suppressing hydrolysis degradation mechanisms. The copolymer composition, i.e., NCE to EP ratio, has found to have profound impacts on the resin flowability, thermomechanical properties, moisture absorption, and dielectric properties, which are discussed in this paper with in-depth analysis on their structure-property relationships. The outstanding high-temperature stability, preferred and adjustable processability, and the dielectric properties of the reported NCE/EP copolymers will greatly stimulate further research to formulating robust epoxy molding compounds (EMCs) or underfill for packaging next-generation high-power electronics.

Effects of epoxy resin crosslinking networks on stereocomplexation of poly(l‐lactic acid)/poly(d‐lactic acid) racemic blends

AbstractIn contrast to existing methods that add specific substances to poly(l‐lactic acid)/poly(d‐lactic acid) racemic blends to enhance stereocomplexation, in this study, a crosslinkable epoxy resin (EP) was introduced into a racemic blend. The results showed that, when the mass ratio of EP to racemic blend was 0.2:1 (EP:racemic blend = 0.2), regardless of the amount of diethylenetriamine (DETA) curing agent, homo‐crystals in the racemic blend were essentially inhibited. With a fixed EP content, a 0.05:1 DETA to EP mass ratio resulted in a homogeneous poly(l‐lactic acid)/poly(d‐lactic acid)/EP/DETA mixture. Uniformly dispersed EP network promoted the stereocomplexation of the racemic blend from the melt, but delayed the lamellar thickening of the stereocomplex crystals during heating. Thus, the constrained chain diffusion caused by the uniformly dispersed EP network was likely responsible for these contradictory results. Introducing uniformly dispersed network into poly(l‐lactic acid)/poly(d‐lactic acid) racemic blends is presumably a promising approach for gaining more insight into poly(lactic acid) stereocomplexation. © 2020 Society of Industrial Chemistry

The Mediating Effect of EPS on the Relationship between ROE and Stock Prices of 15 Banks Listed on Indonesia Stock Exchange

This research is descriptive which collects and presents data from financial statements from 2014 - 2018 by taking ROE and EPS data as independent variables and stock prices as the dependent variable. Measurement scales used statistical scales such as regression analysis test, f test, and t-test. The results showed that 15 bank sector companies as a place of this research had good management performance and performed their functions well, it can be seen from the ratio of ROE and EPS. From the test results based on the regression analysis test, f test, and t-test, the results are obtained that the contribution of ROE to changes in the Stock price is 25.8%, with EPS mediation, the contribution of ROE and EPS to changes in the Stock price is found to be 47.2% and the change in the value of R-Square change of 0.219 or 21.9%. Significant test results indicate a significant effect between ROE on Stock prices. This can be seen from the F-test value of 26,668 and significant value of 0,000 at α = 0.05 or 5% and with the presence of EPS mediation, the effect of ROE and EPS on the stock price is significant with a significant level of 0,000 at α = 0.05 or 5% with F -The existence of EPS mediation, it was found that ROE and Stock’s Prices have a significant effect of 0.019 at a significant level of 5%. Thus any change in ROE will change to an increase in Stock Price by 0.236 significantly.Therefore, because ROE and the Stock price have significant value, EPS does not fully mediate the effect of ROE and the stock pricetest 34,129.

FAKTOR YANG MEMPENGARUHI HARGA SAHAM PERUSAHAAN GARMEN DAN TEKSTIL DI BEI

The objective of this research is to obtain empirical evidence about the effect of EPS, Profitability and Current Ratio toward Share Price. This research uses secondary data. The object of this research is garment and textile companies listed in the Indonesia Stock Exchange (IDX) during the year 2014-2018. This research is conducted with 16 garment and textile companies as the sample. Furthermore, data collection techniques used in this research is purposive sampling that is processed using Statistical Package for the Social Sciences (SPSS) ver 24.0 program. The results of this research show that EPS has a significant effect toward Share Price, at the same time Profitability and Current Ratio do not have significant effect toward Share Price

PENGARUH PER EPS ROA DAN DER TERHADAP HARGA SAHAM LQ45 DI BURSA EFEK INDONESIA

Effect of PER, EPS, ROA, and DER towards LQ45 share price in the Indonesia Stock Exchange. Under the guidance of Dr. Makmur, SE., M.SI as Supervisor I and Mr. Eko A. Widyanto, SE., M.SA as Advisor II. This study aims to determine the effect of variable PER, EPS, ROA, and DER towards LQ45 share price in the Indonesia Stock Exchange. Data collection techniques are the methods of documentation. For testing instrument using classical assumption test and test statistics. As for the technique of data analysis using multiple linear regression for the variables used four variables, the F test and t test. The results showed that the variables PER (X1), EPS (X2), ROA (X3) and DER (X4) simultaneously significant effect on stock prices LQ45 Indonesian Stock Exchange Securities (Y). Analysis result simultaneously can explaine that EPS ratio take positive effect and significant on stock prices LQ45 in Indonesia Stock Exchange.

Content matters: Cyclic effects on women's voices depend on social context

Women's voices reportedly sound more attractive during the fertile days compared to the non-fertile days of their menstrual cycle. Here we investigated whether the speech content modulates the cyclic changes in women's voices. We asked 72 men and women to rate how interested they were in getting to know the speaker based on her voice. Forty-two naturally cycling women were recorded once during the late follicular phase (high fertility) and once during the luteal phase (low fertility) while speaking sentences of neutral and social content. Listeners were more interested in getting to know the speakers when hearing sentences with social content. Furthermore, raters were more interested in getting to know the speakers when these were recorded in the late follicular than in the luteal phase, but only in sentences with social content. Notably, levels of reproductive hormones (EP ratio) across the cycle phases did not significantly predict the preference for late follicular voices, but echoing the perceptual ratings, there was a significant EP ratio x speech content interaction. Phonetic analyses of mean fundamental frequency (F0) revealed a main effect of menstrual cycle phase and speech content but no interaction. Employing an action-oriented task, the present study extends findings of cycle-dependent voice changes by emphasising that speech content critically modulates fertility effects.

Characterization of the dough rheological and steamed bread fortified with extruded purple sweet potato flour

ABSTRACT Addition of purple sweet potato flour has a negative effect on the technological characteristics of steamed bread. The present study researches the potential of extruded purple sweet potato flour (EP) in improving the quality of composite dough and steamed bread. Compared to unextruded purple sweet potato flour (UP), addition of EP significantly increased dough thermal temperatures and decreased the freezable water content, indicating that it enhanced the binding of dough components with water molecules. The rheological properties of dough height, extensibility, configuration ratio, and deformation energy of EP added dough were similar to wheat dough. Moreover, steamed bread made from EP had higher specific volume, lower hardness, and chewiness than their elaborated from UP. Furthermore, the total polyphenol content and antioxidant activity of EP were significantly improved in comparison with the UP and wheat steamed bread. In conclusion, results mightily suggest that the addition of extruded purple sweet potato flour could be an effective way of enhancing the technological and nutritional of composite steamed bread.

The Effect of Mergers on Financial Performance PT. Bank Woori Saudara Indonesia 1906, Tbk

The Mergers are carried out by the companies to get a number of benefits. Mutually beneficial conditions will occur if the merger activities carried out can create the synergy, which finally, it is expected to improve the company's performance. This study aims to determine whether the financial performance after the merger has changed or not. The financial ratios studied are financial ratios four years after the merger and before the merger. This research was conducted by quantitative methods, by taking data from PT. Bank Woori Saudara Indonesia 1906, Tbk, which has merged in 2014 and has engaged in banking financial services. Sampling in this study uses quota sampling. the data is obtained from one bank, that is, a bank which has merged. The parametric test used to answer the hypothesis in this study was the Paired Sample T-Test. The results of this study indicate that in partial testing of the seven financial ratios, there was a significant difference in the ratio of BR and EPS, while the CAR, TATO, NPM, ROI, and ROE ratios showed no significant differences. So the merger process carried out by banks does not show a significant difference because the synergy has not yet been achieved after the merger.

Dampak Kinerja Keuangan dan Pengungkapan Corporate Social Responsibility (CSR) terhadap Nilai Perusahaan

The development of a company will illustrate the increasing asset of a company that will describe the value of a company. Company value can be reflected from financial performance (EPS, ROA and NPM) as well as corporate social responsibility (CSR) disclosure. In this research firm value is analyzed with financial performance data and corporate CSR in 5th interval from year 2011 to 2015. Based on research that has been done show that financial performance proxy with ratio of EPS, ROA and NPM partially only NPM which have significant influence, where The company's value will increase 2,207 if the company's net income is generated high. In addition, corporate value is also proxied with the disclosure of social responsibility (CSR), in this study CSR does not significantly influence. Corporate performance and social responsibility disclosure simultaneously based on the research that has been done have an ef ect on simultaneously and significantly. This is indicated by the value of testing the value of F - Calculate is greater than the value of F - Table. The test results obtained value F - count 3.079, the value when compared with the value of t - table has a larger value, for t - table produced with df = 4 and N = 54 of 2.54. This indicates that financial performance simultaneously / simultaneously af ect the value of the company. And based on the result of testing the significance value of 0,024 <0,05, this result indicate that financial performance and disclosure of social responsibility significantly influence company value.

Energy budgeting of crop-livestock-poultry integrated farming system in irrigated ecologies of eastern India

The purpose of this study was to determine energy input, output and energy use efficiency of an acre land based crop-livestock-poultry IFS model, developed at ICAR-Research Complex for Eastern Region, Patna during 2012–16. In the current investigation, total energy input in the experimental one-acre integrated farming model was calculated to be 45.08 GJ and total energy output obtained as 102.54 GJ, and resulted in energy use efficiency ratio as 2.27. Also, it was analysed that total energy input was required utmost for the goat rearing, i.e. 24.84 GJ/20 goats/year followed by field crops, vegetable, green fodders, fruits, poultry and mushroom cultivation. In the current IFS model labour, diesel and electrical energy inputs were required maximum in field crops. The direct and indirect energy sources were calculated and found to be invested utmost in field crops and goat rearing as 2.98 GJ and 24.53 GJ, respectively. Similarly, renewable and non-renewable energy sources were utilized in goat rearing and field crops as 24.39 GJ and 6.99 GJ, respectively. Moreover, energy use efficiency ratio was estimated highest in fodder crops (8.66) and lowest from goat rearing (0.17). It was found that goatry and poultry farming are of least energy efficient agricultural production systems, because they produced negative energy mileage. The energy use efficiency ratio for the main output has shown that green fodders and field crops yielded better energy productivity. The net energy gain was recorded maximum from field crops. The energy profitability analysis revealed that green fodders’ cultivation was most profitable in terms of energy and produced EP ratio as 7.66 followed by field crops and vegetables, respectively.

Investigations of the Influence of Polystyrene Foamed Granules on the Properties of Lightweight Concrete

Abstract This paper deals with the behaviour of cement paste upon the addition of crushed polystyrene foam. Crushed polystyrene foam waste with a fill density of 13.97 kg/m3 and hydrated lime were used to prepare the foam. Three different types of samples S-1, S-2, and S-3 were prepared to observe the behaviour of cement pastes after the addition of different doses of foam in constant water/cement ratio. The volumetric ratio of EPS and cement paste were 1: 1.294; 1: 0.863; and 1: 0.647. In each type of sample, 0.28 water/cement ratio is maintained. Slump test was carried out in the fresh state and it has been found slump value was decreasing by increasing foam content in concrete sample. On the 7th and 28th day of curing process, the compressive strength test was carried out. Compressive strength and density of concrete samples also decreasing by addition of higher foam content. In addition, water absorption test and microscopic analysis tests were carried out on the 28th day of curing process. It has been found from the study that samples thermal conductivity is working proportionally.

Source Analysis of Post-Blasting Events Recorded in Deep Copper Mine, Poland

Seismic and rock burst hazard is a very important factor that has to be considered in seismically active mining areas. Several different methods are used to decrease seismic activity in mines. Among others, an active prevention method known as destress blasting, is considered the most effective technique. The aim of this work is to find possible influences of such active prevention on observed seismic activity recorded in the established waiting time after blasts. Using technological knowledge and seismic data recorded by an underground seismic network, we estimated several parameters that characterize sources provoked by blasting works and compared them with the parameters obtained for spontaneous, non-provoked mining tremors. According to our studies the source mechanisms of post-blasting seismicity are characterized by the similar non-DC part of the full moment tensor whereas the source mechanisms of spontaneous events are not characterized by any specific features. On the other hand non-provoked seismicity presents lowest values of apparent stress. Also ES to EP ratio suggest some differences between events occurred immediately after blasting (up to 30 s) and the rest dataset. We believe that these parameters could be considered valuable tools supporting established safety time limitations after active prevention.

Piezoresistive Nanomechanical Humidity Sensors Using Internal Stress In-Plane of Si-Polymer Composite Membranes

This article presents the design and fabrication process of a highly miniaturized nanomechanical Si-polymer composite membrane-type internal-stress sensor (MIS) with piezoresistive elements for humidity detection. The 500-μm2 area dimension sensor consists of a thin Si-polymer composite membrane supported by two piezoresistive Si beams. The composite membrane is fabricated as follows: First, 1-μm-wide width Si slits with 1 μm separation gaps are formed by using photolithography and deep reactive-ion etching, and then, the Si slits are filled with a functional polymer (methyl methacrylate based acrylate resin: OLESTERTMQ155). This composite device acts as an absorber of vapor molecules and, consequently, generates stress. The fabricated sensor in a humidity-controlled chamber shows a relative resistance change Δ R / R device = 0.6% for 58% relative humidity (RH) change and a highly linear steady response of 5.2 mV/%RH up to 70% RH change with sensing resolution of 0.5% humidity. The measured polymer expansion ratio of ep = 2.4 × 10−3 is consistent with the theoretical estimation using the weight fraction of water adsorbed in the polymer.

EXPERIMENTAL STUDY ON UNCONFINED COMPRESSIVE STRENGTH OF SOIL AND EPS PARTICLES MIXTURES

This paper aims to study the density, strength and deformation characteristics of soil and EPS particles mixtures that is a type of light weight soil. It carried out the density tests and unconfined compressive strength tests of the mixed soil with different cement content, EPS content, age and water content. The results show the following findings. When volume ratio of EPS particals is 20% to 60%, the density range of the light weight soil is about 0.64g·cm-3~1.46g·cm-3. The amount of EPS particles has the greatest impact on the light weight soil density. When the volume rate of EPS particles is increased by 10%, the density of EPS particles light weight soil is decreased by about 0.15g·cm-3~0.23g·cm-3, which shows that it is feasible to realize the light weight of mixed soil by adding EPS particles. Cement content and water content have less influence on density of light weight soil. But age has little effect on density of light weight soil. In addition, when the volume ratio of EPS is 50%, the density of light weight soil is similar to that of water. The range of unconfined compressive strength of EPS particles light weight soil in this test is 103.2 kPa~1359.0 kPa, while the unconfined compressive strength of plain soil is 79.98 kPa. So it can be stated that the light soil in the proportioning of this test has better strength properties relative to the plain soil. The unconfined compressive strength of light weight soil increases exponentially with the increase of cement content. However, the larger the volume ratio of EPS particles, the smaller the unconfined compressive strength and the linear relationship between them. In the case of more than the optimal water content, with the increase of water content, the relationship between the unconfined compressive strength is reduced exponentially. The increase of age makes the unconfined compressive strength increase in hyperbolic form. The stress-strain relationship characteristics of EPS particles light weight soil are mainly characterized by strain softening type. However, the increase of water content and the increase of the content of EPS particles can make the stress-strain relationship curves of the light weight soil change gradually to the hardening type. Damage strain and average deformation model are used to describe the deformation characteristics of soil. The damage strain of light weight soil decreases with the increase of cement content, but the volume ratio of EPS particle is opposite. The greater the water content, the greater the damage strain of light weight soil. However, the increase of the age makes the damage strain of the sample decrease. When the volume ratio of EPS particles is more than 50%, the damage strain of light weight soil is greatly increased, and its brittleness is obviously weakened. The average deformation modulus is a parameter to characterize the stiffness of EPS particles light weight soil. The larger the cement content, the larger the average deformation modulus of light weight soil. However, the average deformation modulus of light weight soil decreases linearly with the increase of the volume ratio of EPS particles. The increase of water content can reduce the stiffness of light weight soil, and the longer the age, the greater the stiffness.

ANALISIS LAPORAN KEUANGAN PERUSAHAAN SUB SEKTOR HOTEL, RESTORAN DAN PARIWISATA YANG TERDAFTAR DI BEI TAHUN 2014–2016

<div><em>are also used by investors to analyze companies in forecasting profits, forecasting dividends and forecasting stock prices. Analysis of financial statements is then used to compare companies with other companies in the same industry. The purpose of this study is to determine the analysis of liquidity ratios, activity ratios, solvabilities ratios, profitability ratios of hotels, restaurants, and tourism sub-sectors listed on the Indonesia Stock Exchange in 2014-2016 in order to compare the company's financial performance so that it can take future decisions.</em><em>The research method used is descriptive analysis of the results of data analysis of financial statement analysis. The results obtained from the analysis of the financial statements of companies that have the best CR are PT MNC Land Tbk. The company has the best TATO ratio is PT Bayu Buana Tbk. The ratio of DER, the best company is PT Pembangunan Graha Lestari Indah Tbk while the profitability analysis with NPM ratio, the best company in 2014, PT MNC land Tbk, in 2015 PT Pembangunan Jaya Ancol Tbk and 2016 again PT MNC </em><em><em>Land Tbk. If investors see the EPS ratio in 2014 and 2015 we recommend that PT Pembangunan Jaya Ancol Tbk and 2016 PT MNC Land Tbk.</em></em><p><strong><em>Keywords</em></strong><strong><em>: </em></strong><em>Current Ratio, Total Assets Turn Over, Total Debt to Equity Ratio, Net Profit Margin, Earning per Share</em>.</p></div>

Simultaneous nitrification, denitrification and phosphorus removal in an aerobic granular sludge sequencing batch reactor with high dissolved oxygen: Effects of carbon to nitrogen ratios

Simultaneous nitrification, denitrification and phosphorus removal (SNDPR) using aerobic granules is a promising approach in water treatment. The present work investigated the effects of influent carbon to nitrogen (N) ratios (20, 10, and 4) on the SNDPR performance in aerobic granular sequencing batch reactors (AGSBR) under high aeration rate. Results revealed that granules remained long-term stability when the DO concentration was 7–8 mg/L. With the decline of COD/N ratios, the denitrification efficiency was reduced due to the accumulation of nitrate, although the removal of COD and TP remained stable with good efficiency. Rising concentration of ammonia N led to the increase of PN/PS ratio of EPS as well as the protein types according to the results of 3D-EEM fluorescence spectroscopy. MiSeq pyrosequencing technology indicated that the decreasing ratio of COD/N under high DO concentration contributed to accumulation of GAOs and DNPAOs rather than PAOs.

Extending Class A pan evaporation for a shallow lake to simulate the impact of littoral sediment and submerged macrophytes: a case study for Keszthely Bay (Lake Balaton, Hungary)

Class A pan evaporation rate, Ep with sediment cover (S) and submerged aquatic macrophytes (Ps) was analysed in a temperate freshwater shallow lake at Keszthely (Hungary), over three growing seasons between 2014 and 2016. The aim was to identify the importance of this water body’s natural components (S and Ps) on Ep. Measured Ep together with reference E of Shuttleworth (E0) and the FAO-56 equation ET were also derived. Pan coefficient, Ka for filled in pans with S and Ps were computed as the ratio of Ep of the planted pan (Ps/S) and Ep. Ka values determined on-site were tested in the estimation of E for an open water body, namely Keszthely Bay of Lake Balaton. Overall seasonal mean evaporation rate was lower for Ep (3.2 ± 1.05 mm day−1) than the seasonal daily average Ep of S (3.7 ± 1.16 mm day−1) and the Ep of Ps (4.0 ± 1.28 mm day−1). Interannual variation of Ep was controlled by variations in seasonal air temperature, Ta. Data of the wet 2014 season showed a significant suppression of Ep, and this was related to humid and cooler weather conditions causing late emergence and early senescence of the submerged macrophytes (Potamogeton perfoliatus L., Myriophyllum spicatum L. and Najas marina L.) at Keszthely Bay. Overall seasonal mean Ka was greater than 1.0 as determined for the three-season time period in pans with S and Ps (Kas: 1.14 ± 0.04; Kap: 1.20 ± 0.05). Except for a previous study from our group (Anda et al., 2016, J Hydrol 542: 615–626) over a two-season period, no such ratio or coefficients have been published, until now. The dominant component of the energy balance was latent heat flux, which accounted for more than 60% of net radiation in Keszthely Bay, depending on Class A pan filling (S and Ps). Diurnal variation in heat storage of the pan also changed due to the occurrence of sediment cover and macrophytes inside the evaporimeters. The most important daily meteorological variables were used to develop the Ep model and to validate S and Ps. Our results show that linear models, even with more input variables, performed better than tree-based models with respect to mean absolute errors (MAE), root mean square errors (RMSE) and determination coefficient (R2) in predicting daily Ep of S and Ps. The use of pan coefficients Kas and Kap increased seasonal E of Keszthely Bay by 4.2, 14.4 and 17.1% during the 2014–2016 seasons, respectively. Total seasonal increments for Keszthely Bay (surface area is about 39 km2) accounted for 0.97, 4.31 and 3.91 million m3 throughout 2014–2016, respectively. In the warmer seasons, an increasing trend in the growth of Keszthely Bay’s E was detected. These results indicate that Class A pan Ep rates need to be modified to take into account sediment cover and submerged macrophytes to derive open water E. This approximation may lend additional credit to the estimation of E in lakes. Given that appropriate estimation of E can effectively impact the management of an ecologically functional lake’s water, maintaining the proper water level and quality can contribute to the sustainability of lakes in the long run.

Simulation of Pan Evaporation and Application to Estimate the Evaporation of Juyan Lake, Northwest China under a Hyper-Arid Climate

Because of its nature, lake evaporation (EL) is rarely measured directly. The most common method used is to apply a pan coefficient (Kp) to the measured pan evaporation (Ep). To reconstruct the long sequence dataset of Ep, this study firstly determined the conversion coefficients of Ep of two pans (φ20 and E601, each applied to a different range of years) measured synchronously at the nearest meteorological station during the unfrozen period through 1986 to 2001, and then Ep was estimated by the PenPan model that developed to the Class A pan and applied to quantify the EL of the Juyan Lake, located in the hyper-arid area of northwest China. There was a significantly linear relationship between the E601 and φ20 with the conversion coefficients of 0.60 and 0.61 at daily and monthly time scales, respectively. The annual Ep based on monthly conversion coefficients was estimated at 2240.5 mm and decreased by 6.5 mm per year, which was consistent with the declining wind speed (U) during the 60 years from 1957 to 2016. The Ep simulated by the PenPan model with the modified net radiation (Rn) had better performance (compared to Ep measured by E601) than the original PenPan model, which may be attributed to the overestimated Rn under the surface of E601 that was embedded in the soil rather than above the ground similar to the Class A and φ20. The measured monthly EL and Ep has a significantly linear relationship during the unfrozen period in 2014 and 2015, but the ratio of Ep to EL, i.e., Kp varied within the year, with an average of 0.79, and was logarithmically associated with U. The yearly mean EL with full lake area from 2005 to 2015 was 1638.5 mm and 1385.6 mm, calculated by the water budget and the PenPan model with the modified Rn, respectively; the latter was comparable to the surface runoff with an average of 1462.9 mm. In conclusion, the PenPan model with the modified Rn has good performance in simulating Ep of the E601, and by applying varied Kp to the model we can improve the estimates of lake evaporation.