scholarly journals Avaliação de metodologias de transferência de vazões de referência em bacias hidrográficas: sua aplicação na bacia do rio Japaratuba - Sergipe - Brasil

2021 ◽  
Vol 14 (3) ◽  
pp. 1571
Author(s):  
Marcus Aurélio Soares Cruz ◽  
José Carlos De Anunciação Cardoso Junior ◽  
Amanda De Azevedo Gonçalves ◽  
Júlio Roberto Araújo de Amorim ◽  
Ricardo De Aragao
Keyword(s):  
River Basin ◽  
Water Resource Management ◽  
Climatic Variables ◽  
Annual Rainfall ◽  
Mean Annual Rainfall ◽  
Statistical Hydrology ◽  
Maximum Flows ◽  
Gap Data ◽  
Area X ◽  
Flow Transfer

Para avaliar a disponibilidade de água e definir as áreas de inundação nas bacias hidrográficas, é necessário considerar a vazão mínima, média e máxima, denominadas de vazões de referência, e isto requer dados observados de vazão, que são bem escassos em bacias brasileiras, principalmente as pequenas e médias bacias. Para superar esta falta, utiliza-se dados de bacias contribuintes com comportamento hidrológico similar, que são transferidos por meio de operações matemáticas, utilizando variáveis físicas e climáticas. Tais procedimentos, geralmente, são mal avaliados quanto à sua precisão. Assim, objetivou avaliar a acurácia da estimação de cinco vazões de referência em quatro estações de medição dos dois principais afluentes do rio Japaratuba (Sergipe, Brasil), os rios Japaratuba-Mirim e Siriri. Os resultados mostraram diferentes comportamentos para as duas sub-bacia, quer seja pelas variáveis influentes, quer seja pelos efeitos antrópicos como a mudança no uso do solo que precisam ser melhor avaliados. Para a bacia do rio Japaratuba-Mirim a transferência de vazões mínimas e médias deve ser realizada considerando-se o produto área x precipitação média anual e para as vazões máximas deve-se considerar o comprimento do rio até a seção. Para a bacia do Siriri, os melhores resultados de transferência de vazões médias e máximas foram obtidos com o produto "área x precipitação média anual” e a variável "precipitação média anual" gerou um erro menor para as vazões mínimas. Assessing the reference flow transfer methodologies in watersheds: their application at Japaratuba River Basin – Sergipe State – BrazilA B S T R A C TIn order to evaluate the water availability and define the flood areas in the river basins, it is necessary to consider minimum, medium and maximum discharge, called reference flows requiring records on flow data, quite scarce in Brazilian river basin, mainly those of small and medium scale. To overcome this gap, data from nearby basins with similar hydrological behavior are used, based on mathematical operations involving physical and climatic variables of the contributing basins. However, these procedures are poorly evaluated for their accuracy. Thus, this study aimed to evaluate the accuracy of the estimation of five reference flows through the transfer of information, using physical and climatic variables in four gage stations of the main tributaries of the Japaratuba river basin (Japaratuba-Mirim and Siriri river) - Sergipe State, Brazil. The results showed different behaviors for the two sub-basins as for either by influential variables or by anthropic effects such as land use and land cover changes that need to be better evaluated. The flow transfer to the subbasin of the Japaratuba-Mirim river should be performed considering the product "Area x Mean annual rainfall" for minimum and medium flows. For maximum flows the "Length" of the basin should be considered. For the Siriri river basin, the "Mean annual rainfall" variable generated a smaller error in the minimum flows and the product "Area x Mean annual rainfall” led to better results for medium and maximum flows.Keywords: Water resource management; statistical hydrology; geographic information systems.

scholarly journals DETERMINATION OF THE RUNOFF CHARACTERISTICS OF THE YESIL RIVER BASIN BASED ON GIS TECHNOLOGIES

2021 ◽  
Vol 2 (446) ◽  
pp. 74-81
Author(s):  
K. K. Duskayev ◽  
A.K. Mussina ◽  
M.S. Ospanova ◽  
A.T. Bazarbek ◽  
M.G. Macklin
Keyword(s):  
River Basin ◽  
Water Resource Management ◽  
Policy Decision ◽  
Runoff Coefficient ◽  
Gis Technologies ◽  
Information Gap ◽  
Lakes And Reservoirs ◽  
Policy Decision Making ◽  
Gap Data

The article examines the effectiveness of GIS-technologies in Kazakhstan for determining and clarifying hydrographic characteristics (e.g. catchment area, river length, location, lakes and reservoirs), the analysis of hydrological processes and phenomena, as well as the creation of a cartographic and attributive database of water bodies. Yesil River, the main waterway of the central and northern part of Kazakhstan, is one of the least hydro- logically studied catchments in the region. To address this research and information gap data was obtained from remote sensing and runoff depth based on the Kazhydromet network for the period 1945 to 2016. A topographic and river network map (1:1,000,000) of the Yesil River basin, including locations of gauging stations as well as depth and runoff coefficient maps were created using ArcGIS software. These maps provide a very useful tool for water resource management and economic policy decision making.

scholarly journals Long-Term Hydro–Climatic Trends in the Mountainous Kofarnihon River Basin in Central Asia

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2140
Author(s):  
Aminjon Gulakhmadov ◽  
Xi Chen ◽  
Nekruz Gulahmadov ◽  
Tie Liu ◽  
Rashid Davlyatov ◽  
...  
Keyword(s):  
High Altitude ◽  
Central Asia ◽  
River Basin ◽  
Water Resource Management ◽  
Climatic Variables ◽  
Mountainous Regions ◽  
Temperature And Precipitation ◽  
Temperature Trends ◽  
Monthly Streamflow

Hydro–climatic variables play an essential role in assessing the long-term changes in streamflow in the snow-fed and glacier-fed rivers that are extremely vulnerable to climatic variations in the alpine mountainous regions. The trend and magnitudinal changes of hydro–climatic variables, such as temperature, precipitation, and streamflow, were determined by applying the non-parametric Mann–Kendall, modified Mann–Kendall, and Sen’s slope tests in the Kofarnihon River Basin in Central Asia. We also used Pettitt’s test to analyze the changes during the 1951–2012 and 1979–2012 time periods. This study revealed that the variations of climate variables have their significant spatial patterns and are strongly regulated by the altitude. From mountainous regions down to plain regions, the decadal temperature trends varied from −0.18 to 0.36 °C/decade and the variation of precipitation from −4.76 to −14.63 mm yr−1 per decade. Considering the temporal variation, the temperature trends decreased in winter and significantly increased in spring, and the precipitation trends significantly decreased in spring but significantly increased in winter in the high-altitude areas. As consequence, total streamflow in headwater regions shows the obvious increase and clear seasonal variations. The mean monthly streamflow decreased in fall and winter and significantly increased in the spring and summer seasons which can be attributed to the influence of global warming on the rapid melting of snow and ice. Although the abrupt change points in air temperature and precipitation occurred around the 1970s and 1990s in the low-altitude areas and 2000s in the high-altitude areas during the 1951–2012 and 1979–2012 periods, the general trends of hydro–climatic variables keep consistent. This study benefits water resource management, socio–economic development, and sustainable agricultural planning in Tajikistan and its downstream countries.

scholarly journals Spatiotemporal Rainfall Distribution of Soan River Basin, Pothwar Region, Pakistan

2021 ◽  
Vol 2021 ◽  
pp. 1-24
Author(s):  
Fiaz Hussain ◽  
Ghulam Nabi ◽  
Ray-Shyan Wu
Keyword(s):  
River Basin ◽  
Water Resource Management ◽  
Monsoon Season ◽  
Rainfall Variability ◽  
Annual Rainfall ◽  
Mountainous Areas ◽  
Distribution Maps ◽  
Annual Basis ◽  
Rational Management ◽  
Rainfall Patterns

This study evaluates the spatiotemporal rainfall variability over the semimountainous Soan River Basin (SRB) of sub-Himalayan Pothwar region, Pakistan. The temporal rainfall trend analysis of sixteen rain gauges was performed on annual basis with long-term (1981–2016) data. The results depicted that there is substantial year-to-year and season-to-season variability in rainfall patterns, and rainfall patterns are generally erratic in nature. The results highlight that most of the highland rainfall stations showed decreasing trends on annual basis. The central and lowland stations of the study area recorded an increasing trend of rainfall except for Talagang station. The average annual rainfall of the study area ranges between 492 mm and 1710 mm in lowland and high-altitude areas, respectively. Of the whole year’s rainfall, about 70 to 75% fall during the monsoon season. The rainfall spatial distribution maps obtained using the inverse distance weighting (IDW) method, through the GIS software, revealed the major rainfall range within the study area. There is a lack of water during postmonsoon months (November–February) and great differences in rainfall amounts between the mountainous areas and the lowlands. There is a need for the rational management of mountainous areas using mini and check dams to increase water production and stream regulation for lowland areas water availability. The spatiotemporal rainfall variability is crucial for better water resource management schemes in the study area of Pothwar region, Pakistan.

scholarly journals Rainfall Variability and Trends over the African Continent Using TAMSAT Data (1983–2020): Towards Climate Change Resilience and Adaptation

2021 ◽  
Vol 14 (1) ◽  
pp. 96
Author(s):  
Niranga Alahacoon ◽  
Mahesh Edirisinghe ◽  
Matamyo Simwanda ◽  
ENC Perera ◽  
Vincent R. Nyirenda ◽  
...  
Keyword(s):  
Climate Change ◽  
River Basin ◽  
Water Resource Management ◽  
Rainfall Variability ◽  
Decision Makers ◽  
Annual Rainfall ◽  
African Continent ◽  
Climate Zones ◽  
Mk Test ◽  
Rainfall Trends

This study reveals rainfall variability and trends in the African continent using TAMSAT data from 1983 to 2020. In the study, a Mann–Kendall (MK) test and Sen’s slope estimator were used to analyze rainfall trends and their magnitude, respectively, under monthly, seasonal, and annual timeframes as an indication of climate change using different natural and geographical contexts (i.e., sub-regions, climate zones, major river basins, and countries). The study finds that the highest annual rainfall trends were recorded in Rwanda (11.97 mm/year), the Gulf of Guinea (river basin 8.71 mm/year), the tropical rainforest climate zone (8.21 mm/year), and the Central African region (6.84 mm/year), while Mozambique (−0.437 mm/year), the subtropical northern desert (0.80 mm/year), the west coast river basin of South Africa (−0.360 mm/year), and the Northern Africa region (1.07 mm/year) show the lowest annual rainfall trends. There is a statistically significant increase in the rainfall in the countries of Africa’s northern and central regions, while there is no statistically significant change in the countries of the southern and eastern regions. In terms of climate zones, in the tropical northern desert climates, tropical northern peninsulas, and tropical grasslands, there is a significant increase in rainfall over the entire timeframe of the month, season, and year. This implies that increased rainfall will have a positive effect on the food security of the countries in those climatic zones. Since a large percentage of Africa’s agriculture is based only on rainfall (i.e., rain-fed agriculture), increasing trends in rainfall can assist climate resilience and adaptation, while declining rainfall trends can badly affect it. This information can be crucial for decision-makers concerned with effective crop planning and water resource management. The rainfall variability and trend analysis of this study provide important information to decision-makers that need to effectively mitigate drought and flood risk.

Identification of Synchronicity in Deterministic Chaotic Attractors for the Downscaling Process in the Bogotá River Basin

2021 ◽  
Author(s):  
Santiago Duarte ◽  
Gerald Corzo ◽  
Germán Santos
Keyword(s):  
Time Series ◽  
Time Delay ◽  
River Basin ◽  
Spatial Scales ◽  
Climatic Variables ◽  
Chaotic Attractors ◽  
Multiple Attractors ◽  
Nearest Neighbours ◽  
Basin Scale ◽  
Non Linear

<p>Bogotá’s River Basin, it’s an important basin in Cundinamarca, Colombia’s central region. Due to the complexity of the dynamical climatic system in tropical regions, can be difficult to predict and use the information of GCMs at the basin scale. This region is especially influenced by ENSO and non-linear climatic oscillation phenomena. Furthermore, considering that climatic processes are essentially non-linear and possibly chaotic, it may reduce the effectiveness of downscaling techniques in this region. </p><p>In this study, we try to apply chaotic downscaling to see if we could identify synchronicity that will allow us to better predict. It was possible to identify clearly the best time aggregation that can capture at the best the maximum relations between the variables at different spatial scales. Aside this research proposes a new combination of multiple attractors. Few analyses have been made to evaluate the existence of synchronicity between two or more attractors. And less analysis has considered the chaotic behaviour in attractors derived from climatic time series at different spatial scales. </p><p>Thus, we evaluate general synchronization between multiple attractors of various climate time series. The Mutual False Nearest Neighbours parameter (MFNN) is used to test the “Synchronicity Level” (existence of any type of synchronization) between two different attractors. Two climatic variables were selected for the analysis: Precipitation and Temperature. Likewise, two information sources are used: At the basin scale, local climatic-gauge stations with daily data and at global scale, the output of the MPI-ESM-MR model with a spatial resolution of 1.875°x1.875° for both climatic variables (1850-2005). In the downscaling process, two RCP (Representative Concentration Pathways)  scenarios are used, RCP 4.5 and RCP 8.5.</p><p>For the attractor’s reconstruction, the time-delay is obtained through the  Autocorrelation and the Mutual Information functions. The False Nearest Neighbors method (FNN) allowed finding the embedding dimension to unfold the attractor. This information was used to identify deterministic chaos at different times (e.g. 1, 2, 3 and 5 days) and spatial scales using the Lyapunov exponents. These results were used to test the synchronicity between the various chaotic attractor’s sets using the MFNN method and time-delay relations. An optimization function was used to find the attractor’s distance relation that increases the synchronicity between the attractors.  These results provided the potential of synchronicity in chaotic attractors to improve rainfall and temperature downscaling results at aggregated daily-time steps. Knowledge of loss information related to multiple reconstructed attractors can provide a better construction of downscaling models. This is new information for the downscaling process. Furthermore, synchronicity can improve the selection of neighbours for nearest-neighbours methods looking at the behaviour of synchronized attractors. This analysis can also allow the classification of unique patterns and relationships between climatic variables at different temporal and spatial scales.</p>

scholarly journals Quantification of southwest China rainfall during the 8.2 ka BP event with response to North Atlantic cooling

2016 ◽  
Vol 12 (7) ◽  
pp. 1583-1590 ◽  
Author(s):  
Yuhui Liu ◽  
Chaoyong Hu
Keyword(s):  
High Resolution ◽  
Southwest China ◽  
East Asian Monsoon ◽  
Moving Average ◽  
Ice Core ◽  
Scale Model ◽  
Annual Rainfall ◽  
Transport Pathway ◽  
Mean Annual Rainfall ◽  
Monsoon Area

Abstract. The 8.2 ka BP event could provide important information for predicting abrupt climate change in the future. Although published records show that the East Asian monsoon area responded to the 8.2 ka BP event, there is no high-resolution quantitative reconstructed climate record in this area. In this study, a reconstructed 10-year moving average annual rainfall record in southwest China during the 8.2 ka BP event is presented by comparing two high-resolution stalagmite δ18O records from Dongge cave and Heshang cave. This decade-scale rainfall reconstruction is based on a central-scale model and is confirmed by inter-annual monitoring records, which show a significant positive correlation between the regional mean annual rainfall and the drip water annual average δ18O difference from two caves along the same monsoon moisture transport pathway from May 2011 to April 2014. Similar trends between the reconstructed rainfall and the stalagmite Mg ∕ Ca record, another proxy of rainfall, during the 8.2 ka BP period further increase the confidence of the quantification of the rainfall record. The reconstructed record shows that the mean annual rainfall in southwest China during the central 8.2 ka BP event is less than that of present (1950–1990) by  ∼  200 mm and decreased by  ∼  350 mm in  ∼  70 years experiencing an extreme drying period lasting for  ∼  50 years. Comparison of the reconstructed rainfall record in southwest China with Greenland ice core δ18O and δ15N records suggests that the reduced rainfall in southwest China during the 8.2 ka BP period was coupled with Greenland cooling with a possible response rate of 110 ± 30 mm °C−1.

scholarly journals Modelling monthly runoff generation processes following land use changes: groundwater–surface runoff interactions

2004 ◽  
Vol 8 (5) ◽  
pp. 903-922 ◽  
Author(s):  
M. Bari ◽  
K. R. J. Smettem
Keyword(s):  
Land Use ◽  
Water Balance ◽  
Surface Runoff ◽  
Land Use Changes ◽  
Annual Rainfall ◽  
Rainfall Runoff ◽  
Runoff Generation ◽  
Mean Annual Rainfall ◽  
Monthly Runoff ◽  
Stream Bed

Abstract. A conceptual water balance model is presented to represent changes in monthly water balance following land use changes. Monthly rainfall–runoff, groundwater and soil moisture data from four experimental catchments in Western Australia have been analysed. Two of these catchments, "Ernies" (control, fully forested) and "Lemon" (54% cleared) are in a zone of mean annual rainfall of 725 mm, while "Salmon" (control, fully forested) and "Wights" (100% cleared) are in a zone with mean annual rainfall of 1125 mm. At the Salmon forested control catchment, streamflow comprises surface runoff, base flow and interflow components. In the Wights catchment, cleared of native forest for pasture development, all three components increased, groundwater levels rose significantly and stream zone saturated area increased from 1% to 15% of the catchment area. It took seven years after clearing for the rainfall–runoff generation process to stabilise in 1984. At the Ernies forested control catchment, the permanent groundwater system is 20 m below the stream bed and so does not contribute to streamflow. Following partial clearing of forest in the Lemon catchment, groundwater rose steadily and reached the stream bed by 1987. The streamflow increased in two phases: (i) immediately after clearing due to reduced evapotranspiration, and (ii) through an increase in the groundwater-induced stream zone saturated area after 1987. After analysing all the data available, a conceptual monthly model was created, comprising four inter-connecting stores: (i) an upper zone unsaturated store, (ii) a transient stream zone store, (ii) a lower zone unsaturated store and (iv) a saturated groundwater store. Data such as rooting depth, Leaf Area Index, soil porosity, profile thickness, depth to groundwater, stream length and surface slope were incorporated into the model as a priori defined attributes. The catchment average values for different stores were determined through matching observed and predicted monthly hydrographs. The observed and predicted monthly runoff for all catchments matched well with coefficients of determination (R2) ranging from 0.68 to 0.87. Predictions were relatively poor for: (i) the Ernies catchment (lowest rainfall, forested), and (ii) months with very high flows. Overall, the predicted mean annual streamflow was within ±8% of the observed values. Keywords: monthly streamflow, land use change, conceptual model, data-based approach, groundwater

scholarly journals Study on Variations in Climatic Variables and Their Influence on Runoff in the Manas River Basin, China

Water ◽  
2017 ◽  
Vol 9 (4) ◽  
pp. 258 ◽  
Author(s):  
Lei Ren ◽  
Lian-qing Xue ◽  
Yuan-hong Liu ◽  
Jia Shi ◽  
Qiang Han ◽  
...  
Keyword(s):  
River Basin ◽  
Climatic Variables ◽  
Manas River Basin
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