Sequential Water Balance Research Articles

Agrometeorological water balance in the west of São Paulo State

The agriculture economic viability is a result of a correct planning and knowledge of the crop production environment. The level of meteorological information in the region can be improved through the water balance, making the agricultural planning more accurate. The objective of this study was to characterize the West of the São Paulo State through the agrometeorological water balance. Historical daily data from 1992 to 2021, from the meteorological station of the University of West Paulista in Presidente Prudente, São Paulo, were used in the study. The sequential water balance (deficit and excess of water in the soil) was evaluated during the agricultural season (from October to March) and off-season (from April to September). The annual water deficit was -303.2 mm, being -125.2 mm in the agricultural season and -178.0 mm in the off-season. The frequent occurrence of deficit in the region, in the beginning of spring and mainly during the autumn-winter, makes it necessary to adopt special management practices and to use irrigation in order to reach high agricultural productivity in West Paulista.

Climate fluctuation impacts in Astronium urundeuva (M. Allemão) Engl. silvicultural characters in the Brazilian Cerrado

Currently, mankind is responsible for changing our planet’s conditions. These changes are usually catastrophic, and yet, mankind does not develop preventative strategies to reduce their impacts. However, a species present in the Brazilian Cerrado, Astronium urundeuva, can be very economically logged and has a known landscape distribution, but lacks information regarding the impacts of climate change on its silviculture. This research aimed to verify A. urundeuva’s silvicultural behavior under current environmental conditions. Progenies from three populations (Cerrado and Atlantic Forest/Cerrado transition) were measured for silvicultural characters: height (HT) and diameter at breast height (DBH), in 2019. Climatic data (temperature, precipitation, evapotranspiration and soil available water, averages and accumulated) were also measured between 1996 and 2018. Descriptive and sequential water balance analysis, descriptive statistics, collinearity tests and a multiple linear regression were performed. There was water deficit in all years (−12.7 mm) researched, which showed an irregular rainfall distribution in Selvíria-MS, concentrated mostly in summer. Average HT ranged from 8.02 m to 10.69 m, while average DBH ranged from 0.10 m to 0.12 m, with high variability (CVs between 21.99% and 34.77%). There was significant correlation between HT, DBH, , and and between , and , which highlighted the importance of water availability . Multiple linear regression showed has a direct and negative relationship with silvicultural characters, implying productivity losses while evapotranspiration increases. Even though it is not a typical Cerrado species, A. urundeuva may have adapted to phytogeographic domain conditions, with slow growth due to water deficit for its survival, considering that, in Brazil, climate change has resulted from annual variations.

Comparisons of sequential water balances between 1920-2018 in the municipality of Serra Talhada and São Bento do Una – Pe, Brazil

A sequential water balance was performed using the Thorn Thwaite and Mather method in order to verify the contribution of water storage and damming in the municipality of São Bento do Una in relation to the water crisis. The monthly average climatological precipitation data were grouped into 95 years, characterizing a period of climatological normal, where the software was used in electronic spreadsheets to extract the values ​​of the monthly, annual averages of precipitation for the period from 1920 to 2018. Were estimated by the multiple regression line methods applied to the T-estima software, taking into account the geographic coordinates. Climatic impacts have caused changes in the region's water balance in the last decade. Environmental degradation, the local effect of human action, has by itself accelerated the process of modifying the regional climate, thus directly affecting the conditions of the rainfall regime and the availability of water in the soil. It is extremely necessary to use rainwater harvesting and other storage sources for human, animal and plant survival, thus contributing to the agricultural and poultry sector in the region. Climatic impacts may cause changes in the region's water balance, as heavy and short-lived rains are expected, leading to a drop in poultry and agricultural production.

Water balance for determination of excess water in soybean cultivated in lowland soils

The aim of this study was to derive a methodology for calculating a sequential water balance that accurately estimates the occurrence of excess water in soybeans cultivated in lowlands. We tested four calculation strategies of water balance associated with the simulation of soybean development, which differed on the calculation of rainfall and time of water drainage from the soil macropores. Data of volumetric moisture monitored in three soil layers throughout the soybean cycle in the 2014/15 agricultural year were used as a reference. Microporosity was used as a lower limit for the occurrence of excess water in the area. Excess water was considered to be whenever the daily volumetric soil moisture in the 0-100 mm layer was greater than 0.39 mm3 mm-3. Over the 111 days of measurement, soil moisture indicated the presence of excess water in 38 days. The traditional calculation strategy of water balance underestimated the occurrence of excess water, as well as the other strategies that considered effective precipitation in their formulas. The calculation strategy that considers that all the rainfall infiltrates in the soil and that the water from macropores is removed only by crop evapotranspiration exhibited good performance and indicated 35 days of excess water, being the most appropriate and recommended for determining excess water in lowland soybeans.

Balanço hídrico sequencial para Lagoa Seca – Paraíba – Brasil

As principais atividades socioeconômicas no município de lagoa seca estão relacionadas a agricultura familiar e ao setor hortigranjeiro, que é beneficiada pelas características do solo e clima da região. Desta forma, o estudo teve como objetivo a realização do cálculo do balanço hídrico sequencial, visando constatar as oscilações dos elementos climáticas e determinando e disponibilizando contribuições para elaborações de planejamento rural, urbano e agropecuário. Os dados pluviais médios mensais foram caracterizados como um período de normal climatológica, onde, empregou-se do software em planilhas eletrônicas, para extrair os valores das médias mensais e anuais da precipitação do período de 1981 a 2019. Os dados de temperatura média foram estimadas pelo software Estima. Visto que o referido município não tem equipamentos para se realizar tal observação. A metodologia aplicada foi a de Thornthwaite & Mather para o computo do balanço hídrico sequencial. O BHS proveem conhecimentos detalhados dos elementos climáticos do período estudado gerando informações extraordinárias aos tomadores de decisões governamentais e aos elaboradores de projetos pecuários, agrícolas, agronegócios, aos hortifrutigranjeiros entre visando um desenvolvimento sustentável das produções na área estudada. O balanço hídrico sequencial muniu contribuições para a análise de valores extremos dos elementos estudadas para o período de 1981 a 2019. Os valores da evapotranspiração mensais para o município em estudo apresentam vinculação das coordenadas geográfica, principalmente, da orografia. A compactação de solo (urbano e rural), o crescimento vertical e a falta de arborização próxima aos lençóis d’água vêm aumentando o poder evapotranspirativo.

Evaluation of groundwater recharge estimation methods in a watershed in the Brazilian Savannah

The Brazilian Savannah Biome is strategic for Brazilian agriculture and for maintaining Brazil's hydrological balance, contributing to river flows from eight of the twelve Brazilian hydrographic regions. In recent years, there has been a continuous growth of irrigated agriculture, the main activity that uses the water resource, and the emergence of conflicts over water use. Thus, to improve water resource management in the Brazilian Savannah, it is important to better understand groundwater recharge rates to determine the magnitude of the sustainable groundwater resource in the region. The study aimed to evaluate groundwater recharge estimation methods in a watershed located in the Brazilian Savannah region. For this, recharge rates were calculated for the period from October 2009 to September 2011 using the methods of baseflow separation, water table fluctuation, and a sequential water balance (BALSEQ). The recharge rates estimated by the baseflow separation, and water table fluctuation methods were, respectively, 23.7% and 26.6% of the total rainfall of 1753.8 mm in the watershed. Using the BALSEQ water balance method, the potential recharge for the period was estimated to be 31.5% of annual average precipitation. The recharge estimates calculated by the methods were consistent with those observed in other agricultural watersheds in the Brazilian Savannah Biome. Also, the evaluated methods can be used as a tool by water resource managers for the rational use of groundwater.

Evaluating Precipitation Estimates from Eta, TRMM and CHRIPS Data in the South-Southeast Region of Minas Gerais State—Brazil

Precipitation estimates derived from the Eta model and from TRMM (Tropical Rainfall Measuring Mission) and CHIRPS (Climate Hazards Group InfraRed Precipitation with Station data) remotely sensed data were compared to the precipitation data of the INMET (National Institute of Meteorology) meteorological stations in the south-southeast region of Minas Gerais state, Brazil, in the period between July 2009 and June 2015. Then, information about evapotranspiration (ETR), water deficit (DEF), and water surplus (EXC) was obtained from the precipitation data, using the sequential water balance (SWB) separately for each type of precipitation data (INMET, TRMM, Eta, and CHIRPS). Subsequently, the components of the SWB were comparatively analyzed. The results indicate that all three products overestimate rainfall. The strongest relationships between the INMET data and the estimated data were observed for the TRMM, in terms of precipitation estimates, as well as DEF, EXC, and ETR components. The Eta precipitation estimates are overestimated relative to those from INMET, resulting in underestimation of the water deficit (DEFETA) and overestimation of evapotranspiration (ETRETA). In general, the CHIRPS data presented a pattern similar to the station data, though statistical analyses were lower than those of the TRMM data.

Water availability to soybean crop as a function of the least limiting water range and evapotranspiration1

ABSTRACT Irrigation management aimed at optimal production has been based only on the water factor. However, in addition to the water potential of the soil, factors such as soil penetration resistance and soil O2 diffusion rate also affect plant growth and interfere with water absorption, even if moisture is within the available water range. This study aimed at quantifying the least limiting water range and demonstrating its potential in soil and water management in irrigated agriculture. In order to determine the least limiting water range, soil water retention curves and soil resistance to penetration were determined from undisturbed soil samples. The sequential water balance and the reference, crop and real evapotranspiration were determined for a soybean crop season. Soil aeration was the least limiting water range upper limit for soils with bulk density greater than 1.33 Mg m-3, whereas soil resistance to penetration was the lower limit for bulk density higher than 1.43 Mg m-3. The bulk density of the soil studied was 1.35 Mg m-3, indicating 0.37 m3 m-3 of water availability, based on the least limiting water range, which is sufficient to supply the crop evapotranspiration. Irrigation management based on the least limiting water range is more efficient and complete than that based only on available water.

POT IRRIGATION CONTROL THROUGH THE CLIMATOLOGIC SEQUENTIAL WATER BALANCE

Ratings of crop behavior under different soil water conditions are very important to improve agricultural management, a difficult task to be carried out in greenhouses due to the lack of simple methodologies of low cost and of easy implementation. This article evaluates the efficiency of using a computational program of Sequential Water Balance, to study the response of the Jatropha curcas crop under different irrigation levels. Pots of large size (1.0 m high and 0.3 m in diameter), difficult to be weighed, were used in a greenhouse, from June to December 2009, in Piracicaba, SP, Brazil, with plants grown in a substrate of 50% sandy soil and 50% cured manure. The experimental design consisted of randomized blocks with treatments corresponding to water depths of 100%, 75% and 50% of the maximum available water capacity (AWC), with 16 replicates. Measuring only air temperature and knowing substrate AWC it was possible to control the soil water conditions over the whole experimental period, which were checked at the end of the experiment. Data indicate that this simple method that avoids weighing heavy containers in large number is very suitable for water control in pots arranged in a greenhouse.

Long-term water balances in La Violada irrigation district (Spain): I. Sequential assessment and minimization of closing errors

Long-term analysis of hydrologic series in irrigated areas allows identifying the main water balance components, minimizing closing errors and assessing changes in the hydrologic regime. The main water inputs [irrigation (I) and precipitation (P)] and outputs [outflow (Q) and potential (ETc) crop evapotranspiration] in the 4000-ha La Violada irrigation district (VID) (Ebro River Basin, Spain) were measured or estimated from 1995 to 2008. A first-step, simplified water balance assuming steady state conditions (with error ɛ = I + P − Q − ETc) showed that inputs were much lower than outputs in all years (average ɛ = −577 mm yr−1 or −33% closing error). A second-step, improved water balance with the inclusion of other inputs (municipal waste waters, canal releases and lateral surface runoff) and the estimation of crop's actual evapotranspiration (ETa) through a daily soil water balance reduced the average closing error to −13%. Since errors were always higher during the irrigated periods, when canals are full of water, a third-step, final water balance considered canal seepage (CS) as an additional input. The change in water storage in the system (ΔW) was also included in this step. CS and ΔW were estimated through a monthly soil–aquifer water balance, showing that CS was a significant component in VID. With the inclusion of CS and ΔW in the water balance equation, the 1998–2008 annual closing errors were within ±10% of total water outputs. This long-term, sequential water balance analysis in VID was an appropriate approach to accurately identify and quantify the most important water balance components while minimizing water balance closing errors.

Época de semeadura da soja para a região de Dourados - MS, com base na deficiência hídrica e no fotoperíodo

O objetivo deste trabalho foi definir a época de semeadura da soja para a região de Dourados - MS, em função da deficiência hídrica e do fotoperíodo. Foram avaliadas três épocas de semeadura (15 de outubro, 15 de novembro e 15 de dezembro), utilizando-se de série de 20 anos de dados. A deficiência hídrica da soja foi estimada por meio de balanço hídrico-climatológico diário sequencial, e o fotoperíodo foi calculado em função da latitude e da data. O atraso da semeadura reduziu o déficit hídrico. Analisando-se conjuntamente os fatores déficit hídrico e fotoperíodo, concluiu-se que semeaduras da soja em novembro são mais indicadas para a região de Dourados.

Modelling the local climate in island environments: water balance applications

In small volcanic islands the local scale climate is influenced by the regional scale climate and by the orography and orientation of air masses movement over the islands. A model was developed in a GIS environment to generate local scale climate variables from those observed at the synoptic scale, from coastal weather stations. An advective submodel, based on the Foehn effect and assuming the conservation of mass and energy, computes local scale air temperature, relative humidity, clouds occurrence and precipitation. A radiative submodel, using information generated by the advective submodel, computes local scale global radiation. A rotational terrain model allows that computations be performed according to the direction of wind. Because the model works within a GIS, results concern the spatial distribution of all climatic variables on the island territory. Results of the validation of temperature, relative humidity, global radiation and rainfall are presented. For agro-meteorological purposes, an application of generated data to perform the sequential water balance is also analysed by comparing results from computations using simulated and observed data at a control weather station located at medium altitude. Results support assumptions utilised in the model and the further use of generated local climate fields for water management and environmental studies in small island environments.

Modelling Irrigation Water Consumptions and Needs. Application to River Ave Basin

The assessment of present and future water consumptions and needs for irrigation is of prime importance for water resources planning and management at basin level. As river Ave basin is being used as a Portuguese case study, a model has been developed for assessing present situation: agrometeorological data and crop systems and yield data provides the estimation of real evapotranspiration which can be used for a sequential water balance inside each homogeneous agricultural sub-region, so giving crop's consumptive use; estimated global irrigation efficiencies allows the calculation of total irrigation requirements; a final aggregation of results gives regional water consumption and needs. For forecasting future conditions another model has been developed: it uses the same agrometeorological and soil data but agricultural inputs are considered according scenarios of crop pattern evolution, development of agricultural technologies, crop yields increases and modernization of irrigation technologies. Results of application of such models are presented and discussed, showing their usefulness for coupling decisions on water and land use.