Search Results (1,179)

Actual evapotranspiration is one of the major components of the soil water balance equation. Several methods have been presented for estimating actual evapotranspiration, but the older methods are not practical because of their spatial and temporal dependence. Recently, the Food and Agriculture Organization of the United Nations (FAO) created the WaPOR open-access system on water productivity with the aim of covering countries experiencing water crises in Africa and the Middle East, and the estimation of actual evapotranspiration (ETa) is one of its main products. This portal makes it possible to determine water consumption and water productivity on a large scale with minimal time and cost, so it can be used to manage the agricultural sector. The Google Earth Engine System (GEE), introduced by Google in 2010, is an effective remote sensing instrument for gathering important data from satellite imagery. In this study, the actual evapotranspiration maps of the Maroon-Jarahi basin for 2017 were extracted using the methodology introduced by the FAO and provided in the WaPOR database, and the coding was performed in the GEE system. The results showed that the actual evapotranspiration during this period was highest in July and decreased with the onset of the fall season. Limited water resources are a major obstacle to ensuring food security. Considering that the agricultural sector consumes most of the water in Iran and worldwide, water management in the agricultural sector is of great importance. Water productivity is a key indicator in studying and improving agricultural water management as well as one of the Sustainable Development Goals. In this study, the actual evapotranspiration (AET), net primary production (NPP), and water productivity (WP) for the basin were estimated using the WaPOR portal and Google Earth Engine over a 10-day period with a spatial resolution of 250 m (decadal data). Based on the obtained results, areas with low water productivity were identified. By studying the existing cropping patterns, the type of irrigation system used, and the water and soil conditions in these areas, it was possible to investigate the reason for the low water productivity and propose solutions to improve it. Full article

Precipitation changes caused by climate change are a phenomenon that may have far more serious consequences in urban areas than previously thought. Preventing the flood extent in rural and urban areas is crucial for the protection of human well-being and private and public land, and for the prevention of human casualties. Modeling potential floods and studying historic ones are key parameters to prevent damages from this natural disaster. European Union Directive 2007/60/EK obligated Member States to compile flood risk maps, showing the potential flood’s extent and depth. Using Cyprus river flood risk maps of the region of Larnaca, Corine land cover data, and open-access cadaster data, this study attempts to assess the economic damage. Cadaster data of buildings such as floor number and basement existence are incorporated in the damage functions used for flood recurrence intervals of 20, 100, and 500 years return periods. The study found that in the 500 year return flood period, 562 buildings would be potentially affected. The flood risk areas in the region of Larnaca consist of mainly urban (48%) and cultivation zones (50%), both economically important. The results suggest that economic damage assessment based on the applied data, combined with flood risk maps, can provide valuable information to disaster responders. Full article

The microalgae-microbial fuel cell (mMFC) enables us to perform secondary and tertiary treatment of domestic wastewater while simultaneously producing green electricity. In this work, the treatment of wastewater and producing electricity using a dual-chambered mMFC were demonstrated. Furthermore, the electricity produced by the mMFC was utilized to drive microbial electrolysis cell (MEC) for hydrogen synthesis. Primary domestic wastewater was treated in the anodic compartment of mMFC. Chemical oxygen demand (COD) removal of 67.2 and 54% was achieved in the anodic compartment of batch and continuous mode, respectively. Wetland-treated water was filled in the cathodic compartment, and Scenedesmus sp. was used as a catholyte. The overall voltage of 1.85 V was used to run a 1-L MEC. Industrial wastewater was treated with a COD removal of 73% in the MEC and biohydrogen was produced at a rate of 9.8 ± 0.2 mL L⁻¹ d⁻¹. Full article

Floods hit Jakarta and several areas in the Ciliwung–Cisadane Watershed. The rain that occurred on 31 December 2019 stopped briefly and continued until 1 January 2020. As a result, several areas were flooded for several days. It is said that the rain that occurred was the largest in history. At least, the rainfall station at Halim Perdanakusuma Airport recorded rainfall with an intensity of 377 mm/day. That prompts a question about how much discharge was generated by the rainfall. This study was conducted to assess the flood discharge and the inundated area caused by the rain on 2020 New Year’s Eve. The rainfall–runoff–inundation (RRI) model was utilized to simulate the flood discharge and inundation using the 1D–2D hydraulic–hydrology model. This model also calculated infiltration and subsurface flow with the Green–Ampt equation. In addition, the rainfall data used rain data recorded by the ground station, and the topography used SRTM data from the United States Geological Survey (USGS). Then, the flood discharge obtained from the model was compared with the flood return period. The return periods of the flood that were compared were at 2, 5, 10, 25, 50 and 100 years. The results showed that the flood that occurred on 1 January 2020 was larger than the flood with a return period of 100 years. This means that rainfall had the biggest effect on the flood, rather than other factors. Full article

Banned pesticides are continuously preferred by the planters of the Idukki District irrespective of their toxicity. Among the banned pesticides, acephate is preferred because of its high solubility in water and persistent character. Unfortunately, it detriments the biota, leading to neurogenic, carcinogenic, and physiological disorders in fish. The plantation near the Periyar River basin is contaminated with residues of pesticides, which eventually drain into the river. There is an urgent need for the removal of acephate. Therefore, we have focused on the removal of acephate into the lab scale. Batch adsorption studies were carried out for the removal of acephate. We selected a material Fe-MMT (Fe₃O₄-montmorillonite), which is benign and possesses a high adsorption capacity towards acephate. Adsorbent properties were examined by various analytical tools XRD, SEM, FTIR, and a Surface area analyzer. Adsorption followed Langmuir with first-order kinetic. Kinetic plots exhibited multistage adsorption, indicating film diffusion and pore diffusion during the adsorption or the mechanism of adsorption is chemisorption, physisorption, and Lewis’s acid-base interaction. Response surface methodology involving CCD (central composite design) was extracted to maximize the adsorption of acephate onto Fe-MMT. Dosage and concentration seem to be the major parameters that influenced the adsorption. Adsorption achieved a peak (83.18%) at optimum conditions corresponding to pH 6, initial acephate concentration of 2 mg/L, and adsorbent dosage corresponding to 0.5 g/L. Full article

Given the complex climate of the Brazilian Northeast, its variable rainfall regime in spatial and temporal scales due to multiple geographic factors and the action of various atmospheric systems, as well as intense precipitation events becoming increasingly present and strong, are incipient the initiatives to analyze extreme rainfall on a sub-daily scale. Thus, characterizing the spatial and temporal distribution of IPESS on the NEB, analyzing the seasonality of the number of events for each location, and the influence of interannual variability in the occurrence of these events became the objective of that work. For this, hourly precipitation observations were collected from 119 automatic surface weather stations spread across the NEB between 2009 and 2018. The night period presented the highest amounts of IPESS. The meteorological stations Ibimirim/PE and Ilhéus/BA had the highest and lowest number of occurrences, respectively. The amplitude of the values of Q presented the thresholds of the stations with the values of 3.4 mm as a minimum, and 28.6 mm as a maximum, referring to the stations of Petrolina/PE and São Luís/MA, respectively. Among the capitals, Teresina/PI had the highest number of EPIES, as well as João Pessoa/PB had the lowest, not only among the capitals but also the second with the lowest number in general. It was observed that during 2009 the events were more frequent, while 2012 presented the smallest amounts. Full article

Lima Puluh Kota Regency in West Sumatera Province is one of the regencies in Indonesia that has had a flood problem every year in the last decade. In the case of such large-scale flooding, it is important to classify the hazard zone for efficiency of the flood mitigation. In this paper, the Rainfall-Runoff-Inundation (RRI) model is applied to the Batang Sinamar River Basin in order to predict the widespread inundation, where both rainfall-runoff from surrounding mountain and rainfall on flood plain contributes to the flood event. Flood simulation was conducted by using a nationally available dataset, high resolution digital surface model, and rainfall ground station data. The simulation was calibrated with discharge observation data in Batang Sinamar, and provides a good result with the Nash–Sutcliffe Efficiency index and correlation value of 0.768 and 0.908, respectively. The result of the simulation using 10-year and 25-year return, showed the increasing discharge by 15.72% from 406.77 m³/s to 470.74 m³/s. Furthermore, the average peak of inundation water level increased from less than 1.5 m to more than 1.5 m. Based on these results, it can be concluded that the model can predict the potential inundation area in the Batang Sinamar River Basin in Lima Puluh Kota Regency. Full article

In rural areas, water treatment plants use rudimentary techniques to evaluate turbidity. However, the incorrect measurement of turbidity can result in poor water quality and, as a result, health issues for its users because it is a crucial indicator to determine the application of adequate treatment to the water. Aquarisc was a project financed with royalties that sought to strengthen the mechanisms and tools for decision-making of the authorities and territorial institutions related to water supply for human consumption. This project installed sensors to assess turbidity in some plants in rural areas of the department of Cauca, Colombia. However, when the project ended, these sensors were removed. Therefore, it became necessary to create machine learning models to predict turbidity values without sensors, considering only pH, temperature, vapor pressure, and precipitation data captured manually by plant operators. In this study, the Linear Regression, Random Forest Regressor, k-Neighbors Regressor, and Extra Trees Regressor algorithms were trained with data provided by the Aquarisc project and the Institute of Hydrology, Meteorology, and Environment Studies of Colombia (IDEAM). As a result, we selected the Random Forest Regressor since it had the best RMSE among all the models and was also the one that best matched the situation of the studied treatment plants. Furthermore, this model did not consider outliers, resulting in an RMSE of 20.98 and 3.49 for the training and test dataset, respectively. Finally, we determined that this algorithm was able to estimate the water’s turbidity acceptably and supports the operators in making decisions for the application of adequate treatment to drinking water. Full article

Both ecosystems and human societies acknowledge the importance of water. The impact of human activities on both land and water has become more apparent due to various global changes. These include climate change, urbanization, socioeconomic development, and population growth. Although it is widely believed that water security is the key to sustainable development, studies on its evolution and various environmental factors are still in the early stages of development. This study aims to provide an overview of the concept. This concept aims to provide all people with safe water. It goes beyond merely providing adequate supplies to every person in the world, and it also aims to ensure healthy and productive lives. Despite the technological advancements being made in the water resource management industry, the lackadaisical approach to addressing the various challenges associated with water security continues to be a major issue globally. This study will provide an overview of the various facets of the water security concept and its evolution in developing countries due to the environmental changes that have occurred. It also explores the multiple sustainable methods that can be used to address these issues. Full article

Flash floods are considered one of the most devastating and frequent extreme climatological natural hazards in the world. El Minya is one of the most vulnerable areas in Egypt for flash flood problems. It was affected by several hazardous historical flash flood events. These events could lead to both catastrophic losses of life and severe damage to the infrastructures of the study area. The study area is located in the middle of Egypt, about 240 km south of Cairo. It is situated along the Limestone Plateau facing El Minia governorate. The main objective of this study is to assess the risk of flash flood hazard on the human activities in the study area. Integration of remote sensing; geographic information systems, analytical hierarchy process, and the multi-criteria decision analysis (MCDA) techniques were applied in this study. Eight different significant effective factors collected from multisource geospatial data, including lithology, hydrology, topography, soil type, land cover, and rainfall data, were selected to evaluate the flood risk map. Remote sensing imagery was used for land use/cover mapping to detect the vulnerable human activities. ArcGIS-based weighted overlay modeling was used to combine the criteria to calculate the final decision map. Full article

A smart, flexible, fuzzy-based regression is proposed in order to describe non-constant behavior of runoff as a function of precipitation. Hence, for high precipitation, beyond a fuzzy threshold, a conventional linear (precise) relation between precipitation and runoff is established, while for low precipitation, a curve with different behavior is activated. Between these curves and for a runoff range, each curve holds to some degree. Hence, a simplified Sugeno architecture scheme is established on few logical rules. Alternatively, the model can be enhanced by using a combination between the fuzzy linear regression of Tanaka and the aforementioned simplified Sugeno architecture. The training process is achieved based on the Particle Swarm Optimization (PSO) method. Full article

The aim of this research is to find out the effects of different degrees of drought stress on the growth index and yield of semi-late rice. In this experiment, a pot experiment was conducted with hybrid Tian-you-hua-zhan rice as material. Intermittent irrigation was used as control (CK) at the tillering stage, booting stage, heading stage, and milk stage. Three water stress gradients of light drought (70% saturated moisture content), medium drought (60% saturated moisture content), and severe drought (50% saturated moisture content) were set to monitor the soil moisture content. The plant height, number of tillers, leaf area, and chlorophyll content under different water gradients at different growth stages were measured, and the effects of different water stress treatments at different growth stages on rice growth index, yield, and its components were analyzed. The results showed that the inhibition of the plant height at the jointing and booting stages was the most significant; moreover, the number of tillers and leaf area decreased most significantly at the tillering stage, and the heading and flowering stages had the greatest effect on chlorophyll synthesis. As far as yield is concerned, the most sensitive stages are the heading and flowering stages. Different stress treatments reduced the effective panicle number, 1000-grain weight, and seed setting rate of rice, and reduced the yield by 27.57%, 44.23%, and 46.32% respectively, compared with the normal control. The correlation analysis showed that the correlation degree of affecting yield from large to small was 1000-grain weight, seed setting rate, and effective panicle. Therefore, ensuring water supply at the heading and flowering stage can effectively improve the 1000-grain weight, effective panicle, and seed setting rate, and increase the rice yield and water use efficiency. Full article

Energy consumption in wastewater treatment plants (WWTP) is a critical part of their operation and maintenance costs, with tertiary treatments being one of the most energy demanding stages, although as they are not required by law, they are not usually included in the wastewater treatment line. In this research, a photochemical–photovoltaic hybrid system was developed and studied: Open SolWat, which allows solar disinfection of the water while cooling the temperatures on the front surface of the photovoltaic module by means of a thin layer of water flowing from the top, thanks to a pumping system. In comparison to the SolWat technologies studied so far, the improved system allowed better quality reclaimed water (RD1620/2007, R(EU)2020/741) to be obtained from the secondary effluent of a WWTP, with the simultaneous generation of energy. However, this time it also productively improved its energy efficiency (15–21%). The tests were carried out under a 4 h SODIS treatment with real sunlight. Therefore, the possible implementation of the system as a tertiary treatment of a WWTP is considered, as it could improve environmental sustainability and reduce energy consumption. Full article