ORIGINAL RESEARCH ARTICLE
Tayebe Tahmasbi; Khodayar Abdollahi; Mehdi Pajoohesh
Abstract
Curve number is a dimensionless empirical method for predicting direct runoff. Since river discharge and sediment load are highly connected thus the relationship between runoff and bed load could be used to evaluate the continuous sediment load. This study proposes a new curve number that characterizes ...
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Curve number is a dimensionless empirical method for predicting direct runoff. Since river discharge and sediment load are highly connected thus the relationship between runoff and bed load could be used to evaluate the continuous sediment load. This study proposes a new curve number that characterizes this parameter based on redefined lookup tables and a fuzzy approach for calculating sediment load. The developed distributed monthly Fuzzy Curve Number Sediment Simulation(CNS2) in Python was applied to predict runoff and sediment load using the rating curve concept. The model uses the fuzzy curve number and some factors such as the number of rainy days, the management of RUSLE-3D, slope, teta coefficient, and soil texture for simulating sediment load at a monthly time scale. The results of model sensitivity analysis indicated that rainfall, base-flow and runoff were the most critical factors affecting sediment load in the study area of interest. The Nash-Sutcliff index evaluated the effectiveness of the simulated runoff; the calculated metric value was 0.6 and 0.53 during two calibration and validation periods, respectively. The Nash-Sutcliff index for simulated sediment load was 0.54 and 0.43 during the calibration and validation periods, respectively. The distributed structure of the developed model provides the possibility for improving estimating spatial variability of sediment yield over the basins; therefore, it can capture the heterogeneity in affecting factors for sediment production.
ORIGINAL RESEARCH ARTICLE
Mayra Ivelisse Rodriguez Gonzalez; Kevin Gabriel Torres Garrido
Abstract
Water ecosystem services are benefits obtained from natural processes held by terrestrial vegetation in relation to hydrologic systems. These benefits have implications for human wellbeing through the mitigation of flood risk, management of stormwater runoff, and removal of pollutants from water systems ...
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Water ecosystem services are benefits obtained from natural processes held by terrestrial vegetation in relation to hydrologic systems. These benefits have implications for human wellbeing through the mitigation of flood risk, management of stormwater runoff, and removal of pollutants from water systems that ultimately supply drinking and irrigation water. Assessing national and regional stocks of these important ecosystem services is crucial for the sustainable development of the land and for conservation purposes. In this study, we applied three models from the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) tool to map the production of flash-flood risk mitigation, stormwater retention, and nitrogen retention. Our findings were consistent with impact assessments on local communities. Through the three ecosystem services mapped, we demonstrated the role of existing terrestrial vegetation in processing hydrologic systems in the Republic of Ecuador. The results from this modeling also provided insights into potential planning pathways for future management using the InVEST software.
ORIGINAL RESEARCH ARTICLE
Bernard Moeketsi Hlalele
Abstract
Drought is a major environmental problem that affects agriculture, water resources, and communities around the world. In the Lesotho Highlands commercial dams, drought can have a significant impact on agricultural production, water supply, and local livelihoods. Understanding the patterns and severity ...
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Drought is a major environmental problem that affects agriculture, water resources, and communities around the world. In the Lesotho Highlands commercial dams, drought can have a significant impact on agricultural production, water supply, and local livelihoods. Understanding the patterns and severity of drought is crucial for effective water management and agricultural planning. This study aimed to analyse and understand the patterns of agricultural drought in the Lesotho Highlands commercial dams through the use of the Standardized Precipitation Index (SPI) and the theory of runs, as well as various drought parameters. The study used Average Dry Spell Duration, Drought Tendency, Longest Dry Spell Duration, Longest Multi-year Drought, Largest Single Year Drought, Standard Total Accumulative Dry Spell, and Number of Consecutive SPI-values, to provide a comprehensive analysis of the drought situation. The results revealed that the precipitation levels at the four dams were relatively similar, but with a potential increase in precipitation at Muela Dam. The SPI-3 and SPI-6 analyses showed a significant downward trend indicating an increase in dryness in the area. The drought parameters did not show significant differences between the stations/dams, indicating similar levels of drought across the dams. The study recommends regular monitoring of precipitation and drought conditions using the SPI and other water-balance drought indices, development of water conservation and management strategies, use of drought-resistant crops and water-efficient agriculture practices, and increased collaboration among stakeholders for sustainable water management and agricultural resilience.
ORIGINAL RESEARCH ARTICLE
Armela Tafa; Iva Kertusha
Abstract
Organochlorine pesticides (OCPs), also known as DDTs and Chlorinated Cyclodienes, are extensively used in agricultural settings for pest, weed, and ant control, leading to widespread concerns about water, air, and soil pollution. This study focuses on evaluating the concentrations of DDTs and Chlorinated ...
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Organochlorine pesticides (OCPs), also known as DDTs and Chlorinated Cyclodienes, are extensively used in agricultural settings for pest, weed, and ant control, leading to widespread concerns about water, air, and soil pollution. This study focuses on evaluating the concentrations of DDTs and Chlorinated Cyclodienes in nine soil samples collected from agricultural farms in Durres city, Albania. The soil samples were extracted using a Soxhlet apparatus, followed by column chromatography purification, and quantified using Gas Chromatography-Mass Spectrophotometry (GC-MS). The results revealed significant contamination of the soil samples with organochlorine pesticides, underscoring the environmental risks and potential threats to human health. It is important to note that this study solely pertains to Durres city and its agricultural lands, and the findings should not be generalized to all soils in Albania. The identification of pesticide pollution in these specific soil samples highlights the urgent need for mitigation strategies and reduced pesticide usage in the area. This pioneering research provides crucial insights into the levels of DDTs and Chlorinated Cyclodienes in agricultural farms within Durres city, fostering a foundation for sustainable farming practices and environmental preservation.
ORIGINAL RESEARCH ARTICLE
Ummulkhair Sanusi; Caleb Akoji Odiji; Blessing Kakushia Nwadike; Dorcas Dabo Hamza; Sadia Tijani Baba; Salman Khalid Salis
Abstract
Flooding is one of the most frequent and widespread of all environmental hazards and of various types and magnitudes, occurs in most terrestrial portions of the globe. The downstream of Shiroro dam has been experiencing recurrent floods resulting in the destruction of properties and loss of lives. Consequently, ...
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Flooding is one of the most frequent and widespread of all environmental hazards and of various types and magnitudes, occurs in most terrestrial portions of the globe. The downstream of Shiroro dam has been experiencing recurrent floods resulting in the destruction of properties and loss of lives. Consequently, the study aims at mapping flood risk and vulnerability areas downstream of shiroro dam. Topographic maps, soil maps, geology maps, demographic data, and digital elevation models (DEM) were used. These data were analyzed using pair-wise evaluation techniques for decisive weighted-overlay investigation of each factor in flood vulnerability assessment. The result shows that 6.4% of the study area was highly vulnerable, 64.02% was moderate and 29.58% was low. The study highlights the application of GIS in modeling flood risk in the Down Stream of Shiroro Dam and its Environs. Vulnerability assessment critical because it provides an organization with details on any weaknesses in its environment.
ORIGINAL RESEARCH ARTICLE
Bright Chisadza; Simon Peter Musinguzi; Onalenna Gwate; Wayne Malinga
Abstract
Despite the existing literature on climate variability (CV) and land use change (LUC) impact assessments, understanding their effectiveness in semi-arid regions remains challenging. This review aims to assess the effectiveness of CV and LUC impact assessments in guiding adaptation options for smallholder ...
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Despite the existing literature on climate variability (CV) and land use change (LUC) impact assessments, understanding their effectiveness in semi-arid regions remains challenging. This review aims to assess the effectiveness of CV and LUC impact assessments in guiding adaptation options for smallholder farmers in semi-arid ecosystems and associated challenges and opportunities. We conducted a systematic literature review, primarily using Google Scholar, to examine the impact of LUC and CV in African semi-arid ecosystems. We employed VosViewer to analyze the relationships among the identified sources. Our findings reveal that current assessment approaches often fall short in capturing the intricate interactions within semi-arid ecosystems. These assessments frequently emphasize biophysical productivity, employ reductionist modeling methods, and neglect the social, economic, and adaptive aspects of these systems. Our review underscores the importance of integrating CV and LUC impact assessments. While a majority of studies concentrate on CV adaptation (26%), they often overlook the pivotal role of LUC and their interplay with climate impacts. Only a small fraction (2%) integrates CV and LUC in impact assessments. Assessing the benefits of CV and LUC impact assessments presents mixed results, particularly smallholders. While global and regional benefits are discernible, quantifying these advantages at the local smallholder level remains challenging due to diversified land use and small-scale operations. This highlights the need for localized studies addressing the specific challenges confronting smallholder farmers in semi-arid regions. To enhance assessments effectiveness, we recommend for more interdisciplinary research and the application of a complex systems approach, integrating GIS and remote sensing.
