Inclusive Multiple Model Using Hybrid Artificial Neural Networks for Predicting Evaporation

Predicting evaporation is essential for managing water resources in basins. Improvement of the prediction accuracy is essential to identify adequate inputs on evaporation. In this study, artificial neural network (ANN) is coupled with several evolutionary algorithms, i.e., capuchin search algorithm (CSA), firefly algorithm (FFA), sine cosine algorithm (SCA), and genetic algorithm (GA) for robust training to predict daily evaporation of seven synoptic stations with different climates. The inclusive multiple model (IMM) is then used to predict evaporation based on established hybrid ANN models. The adjusting model parameters of the current study is a major challenge. Also, another challenge is the selection of the best inputs to the models. The IMM model had significantly improved the root mean square error (RMSE) and Nash Sutcliffe efficiency (NSE) values of all the proposed models. The results for all stations indicated that the IMM model and ANN-CSA could outperform other models. The RMSE of the IMM was 18, 21, 22, 30, and 43% lower than those of the ANN-CSA, ANN-SCA, ANN-FFA, ANN-GA, and ANN models in the Sharekord station. The MAE of the IMM was 0.112 mm/day, while it was 0.189 mm/day, 0.267 mm/day, 0.267 mm/day, 0.389 mm/day, 0.456 mm/day, and 0.512 mm/day for the ANN-CSA, ANN-SCA, and ANN-FFA, ANN-GA, and ANN models, respectively, in the Tehran station. The current study proved that the inclusive multiple models based on improved ANN models considering the fuzzy reasoning had the high ability to predict evaporation.

Dry Matter Production and Nutrient Uptake of Coloured Capsicum Hybrids (Capsicum annuum var. grossum L.) as Influenced by Different Irrigation Levels under Shade Net

Aim: The experiment was aimed at evaluating the influence of different irrigation levels on dry matter production and nutrient uptake of coloured capsicum hybrids. Study Design: Split plot design with three replications Place and Duration of Study: Horticultural farm, College of Agriculture, Rajendranagar, Hyderabad during rabi 2018-19. Methodology: The experiment was laid out in split plot design and the treatments comprises of four irrigation levels viz., drip irrigation at 0.4, 0.6, 0.8 and 1.0 Epan as main treatments and three hybrids viz., Indra (green), Orobelle (yellow), Bomby (red) as sub treatments and replicated thrice. The recommended dose of nutrients were 100:80:60 N, P2O5 and K2O kg ha-1 and entire dose of P2O5 was applied as basal, N and K2O was applied through venturi meter as fertigation on three days interval from 9 to 153 DAT. The crop was transplanted at 45 cm × 40 cm spacing in September under a green shade net. Irrigation scheduling was done based on daily evaporation data recorded from USWB class ‘A’ pan evaporimeter. The cumulative daily evaporation during crop growth period was 737.5 mm. Quantity of water applied including special operations of 26 mm and effective rainfall during crop growth period were 245.3, 392.0, 546.5 and 698.5 mm and 58.6, 64.2, 74.6, 82.6 mm out of 127.4 mm of rainfall for 100, 80, 60 and 40 per cent irrigation treatments, respectively as per water balance method. Bed size was 7.6 m × 0.9 m. Results: Significantly higher yield (47.50 t ha-1) was recorded with drip irrigation at 1.0 Epan than rest of the treatments. Indra recorded significantly higher yield (40.27 t ha-1) than other two hybrids. The interaction effect between drip irrigation levels and hybrids was not significant on Dry Matter Production and N, P & K uptakes and economics of capsicum. DMP and nutrient uptake were significantly higher with drip irrigation at 1.0 Epan than 0.8, 0.6 and 0.4 Epan throughout the crop growth over other drip irrigation levels. Among hybrids, Indra recorded significantly higher DMP and nutrient uptake than other two hybrids.

Evaporation over glacial lakes in Antarctica

The water cycle in glacier hydrological networks is not well known in Antarctica. We present the first evaluations of evaporation over a glacial lake located in the Schirmacher oasis, Dronning Maud Land, East Antarctica. Lake Zub/Priyadarshini is a shallow lake of the epiglacial type, and it is ice free for almost two months in summer (December–February). We evaluated evaporation over the ice free surface of Lake Zub/Priyadarshini using various methods including the eddy covariance (EC) method, the bulk aerodynamic method, and Dalton type empirical equations. The evaporation was estimated on the basis of data collected during a field experiment in December–February, 2017–2018, and regular observations at the nearest meteorological site. The EC was considered as the most accurate method providing the reference estimates for the evaporation over the lake surface. The EC method suggests that the mean daily evaporation was 3.0 mm day−1 in January, 2018. The bulk-aerodynamic method, based on observations at the lake shore as an input, yielded a mean daily evaporation of 2.3 mm day−1 for January. One of the Dalton type equations was better in estimating the summer mean evaporation, but the bulk aerodynamic method was much better in producing the day-to-day variations in evaporation. The summer evaporation over the ice-free Lake Zub/Priyadarshini exceeded the summer precipitation by a factor of 10. Hence, evaporation is a major term of the water balance of glacial lakes. Evaluation of the evaporation products of ERA5 reanalysis clearly demonstrated the need to add glacial lakes in the surface scheme of ERA5. Presently the area-averaged evaporation of ERA5 is strongly underestimated in the lake-rich region studied here.

Estimation of Water Loss Due to Evaporation in the El Cazadero Dam, Mexico, during a Drought

In Mexico, large dams have been a critical component of the water supply. However, the places where they can be built are scarcer every day, a situation that adds to the high costs and social conflicts that they cause. Much of the water stored in dams is lost due to evaporation, so technological alternatives are currently being investigated to reduce it. Regarding the determination of evaporated volumes, data obtained with evaporimeters do not represent actual evaporation, being necessary to apply theoretical models in combination with field measurements to reach better approximations. The main objective of this research is to calculate the water evaporation in the El Cazadero dam located in the State of Zacatecas, Mexico, through Penman’s semi-empirical equation using data from the El Cazadero or 32006 weather station. The study area was selected due to its aridity and recurring drought problems that affect water availability. Evaporation results obtained from applying the theoretical model are compared with those reported by the weather station, showing a good correlation. In addition, results of the average daily evaporation are used to determine the approximate volume of water evaporated in the hydrological year between November 2010 and October 2011, when a severe drought occurred, whose magnitude and economic value indicates the necessity to carry out more research on this subject and propose public policies to develop and implement technological alternatives that mitigate this phenomenon.

Aplicability of sap flow data in hydrological modeling

Статья содержит результаты моделирования стока малого речного бассейна в верховьях р. Уссури с использованием оригинальных данных о стволовом сокодвижении, пересчитанных в объем воды, транспирируемый древостоем. В теплый период 2019 г. на территории Верхнеуссурийского стационара ФНЦ биоразнообразия наземной биоты Восточной Азии ДВО РАН проведен комплекс наблюдений за компонентами влагооборота, позволивший накопить необходимый массив данных для гидрологического моделирования. В дополнение к традиционным водно-балансовым измерениям проводился мониторинг транспирации на основе системы датчиков регистрации водотока в стволах деревьев. Полученные данные точечных наблюдений распространены на масштаб водосбора (площадь около 3.1 км2). Показано, что в теплых и сухих условиях объем суточного суммарного испарения с малого речного бассейна может достигать 8.5 тыс. м3, что больше объема речного стока за тот же период в 5–6 раз, а во время выпадения дождей транспирация деревьев уменьшается практически до нуля. Для расчета водного баланса изучаемого объекта использована гидрологическая модель HBV (Hydrologiska Byråns Vattenbalansavdelning). Ряды суточной потенциальной эвапотранспирации, рассчитанные на основе широко используемых методов Пенмана-Монтейса и Одина, применены в HBV как входные данные. Расчетные суточные значения испарения, по сравнению с полученными на основе данных стволового сокодвижения, оказались выше в 1.5–2 раза, разница сумм испарения за весь теплый период года достигает слоя 100 мм и более. При этом надежной связи между расчетными значениями суточного испарения и измерениями не было обнаружено. Сделан вывод, что использование приборных данных о стволовом сокодвижении в составе входных переменных в гидрологическую модель повышает качество расчетов стока. The article deals with the experience of applying an alternative method for quantifying evapotranspiration volume as input to the hydrological model to simulate runoff of a small catchment located in the upper reaches of the Ussuri River. In the warm period of 2019 at the territory of the Verkhneussuriyskiy station of the Federal Scientific Center of the East Asia Terrestrial Biodiversity (FEB RAS), a set of field measurements was carried out. The measured data were used to calibrate the HBV hydrological model (Hydrologiska Byråns Vattenbalansavdelning). In addition to traditional water-balance measurements, there was assessed the evapotranspiration rate based on sap flow measurements eliminating other parts of water losses. The Tissue Heat Balance technique was applied to measure a sap flow in some individual trees. After that, the obtained data were scaled up to the catchment area (3.1 km2). It is shown that in warm and dry weather conditions, the volume of daily total evaporation from a small catchment can reach 8.5 ths.m3 that is 5-6 times more than the river runoff volume over the same period. During the rainfall events, the transpiration rate in trees decreases to almost zero. To compare the obtained results with the modelled ones, the potential evapotranspiration was also calculated based on well-known Penman-Monteith’s and L. Oudin’s methods that forced HBV model as input. Based on hydrological simulations, these methods overestimated the actual daily evaporation volume up to 2 times in comparison with the sap flow data, and the difference for the warm season reaches 100 mm and more. No reliable relationship was found between the calculated values of daily evaporation rate and the conventionally “measured” ones. Basically, runoff simulations quality was improved while using evapotranspiration volume assessed with the sap flow data. We conclude that water balance via HBV simulations is quite different depending on applied evapotranspiration method. In this case, overestimated volume of evapotranspiration by Penman-Monteith and L. Oudin methods leads to excessive water extraction from the HBV soil moisture storage. If it’s actually not correct, long-term runoff simulations would result in wrong water balance and error accumulation.

CubeSats deliver new insights into agricultural water use at daily and 3 m resolutions

Earth observation has traditionally required a compromise in data collection. That is, one could sense the Earth with high spatial resolution occasionally; or with lower spatial fidelity regularly. For many applications, both frequency and detail are required. Precision agriculture is one such example, with sub-10 m spatial, and daily or sub-daily retrieval representing a key goal. Towards this objective, we produced the first cloud-free 3 m daily evaporation product ever retrieved from space, leveraging recently launched nano-satellite constellations to showcase this emerging potential. Focusing on three agricultural fields located in Nebraska, USA, high-resolution crop water use estimates are delivered via CubeSat-based evaporation modeling. Results indicate good model agreement (r2 of 0.86–0.89; mean absolute error between 0.06 and 0.08 mm/h) when evaluated against corrected flux tower data. CubeSat technologies are revolutionizing Earth observation, delivering novel insights and new agricultural informatics that will enhance food and water security efforts, and enable rapid and informed in-field decision making.

Records of Surface Meteorological Elements and their Applications in Alexandria Eastern Harbour, Egypt

The surface meteorological elements, namely: air temperature, wind regime (speed and direction), dew point temperature, relative humidity and atmospheric pressure were considered; to describe the general meteorological conditions over Alexandria Eastern Harbour (AEH). These conditions were then applied to calculate some important physical properties of the Harbour’s surface waters: sea surface temperature (SST), the evaporation rates and the net surface heat flux. The period of investigation extended from 01.01.2019 to 31.12.2020. The air temperature distribution over AEH reflected a seasonal variability with higher values in spring/summer and lower records in autumn/winter. The dominant wind direction was NNW with more than 40% occurrence and the average wind speed was 4.11 m/s. The inverse relationship between atmospheric pressure and air temperature was clear. The SST over the study period showed the same seasonal pattern in the air temperature. The mean daily evaporation from AEH surface water follows the pattern of air temperature variations to a considerable extent. The maximum mean monthly evaporation of 14 cm (0.14 m) occurred in July and August, while the minimum of 6 cm (0.06 m) occurred in January. This was associated with a volume loss of 0.389x106 m3 in July and of 0.171x106 m3 in January from AEH surface waters. The solar radiation (Qs) reached its maximum value in May (383 Wm-2) and its lowest value in September (258 Wm-2). The net surface heat in AEH (Qnet) showed a gain in four successive months: March-June, and a loss in the remaining period: July-September. Keywords: Alexandria Eastern Harbour

CATCHMENT RUNOFF MODELING APPLYING SAP FLOW DATA (CASE OF THE UPPER USSURI RIVER)

Представлены результаты использования данных полевых наблюдений для моделирования речного стока малого водосбора в верховьях р.Уссури. В качестве входного потока данных в гидрологическую модель HBV об эвапотранспирации применены оригинальные данные о стволовом сокодвижении, пересчитанные в объем влаги, транспирируемого древостоем. Показано, что расчетные методы определения эвапотранспирации (Пенмана-Монтейса и Л.Одина) завышают оценки испарения: разница с данными стволового сокодвижения достигает 100 мм слоя за теплый период. Надежной связи между расчетными значениями суточного испарения и измерениями не обнаружено. Выявлено повышение качества расчетов стока при использовании данных стволового сокодвижения в качестве входного потока в гидрологическую модель. The results of applying the field observation data for hydrological modeling in the Upper Ussuri river are presented. The original data of sap flow measurements (recalculated to the evapotranspiration volume of forest stand) was used as input to the HBV model. It is shown that the calculation methods for determining evapotranspiration (Penman-Monteith and L.Oudin) overestimate the daily evaporation volume. In comparison with sap flow data difference reach 100 mm during the warm period. No reliable relationship was found between the calculated values of daily evaporation and measurements. An increase in the quality of runoff calculations is reported while using data from stem sap flow as an input to a hydrological model.