Seyhan River Basin Research Articles

Spatial characterization of drought through CHIRPS and a station-based dataset in the Eastern Mediterranean

Abstract. Drought is a natural hazard which occurs in all climatic zones and affects different sectors, such as irrigation, energy, water supply, and ecology. Monitoring and predicting drought are pressing challenges, as drought is becoming more common and severe owing to the impacts of climate change and increased climatic variability. However, in many areas of the globe, the temporal and spatial characterization of droughts and drought severities are hindered by a lack of reliable, locally-measured long-term data and unevenly distributed, erratic meteorological stations. In this situation, remote sensing datasets such as Climate Hazards Group InfraRed Precipitation with Station Data (CHIRPS) can offer valuable insights into long-term developments and the spatial characteristics of droughts. Nonetheless, it is often uncertain to which extent data such as CHIRPS succeeds in representing local dynamics and how this varies between geographical regions and climate zones. In this analysis, we aim to evaluate spatial drought conditions over the Seyhan River basin in Turkey in the Eastern Mediterranean. Using the Standardized Precipitation Index (SPI) as a drought index, the applicability of CHIRPS as a long-term satellite precipitation product for drought monitoring is investigated. We compare two spatial representations of the SPI: one derived on a per-pixel basis from CHIRPS data since 1981, the other based on data from 19 meteorological stations scattered across the basin, which was spatialized using inverse distance weighted interpolation (IDW). Our results offer insights into the relative accuracy of CHIRPS data and avenues towards optimizing the quality of spatial drought characterization.

Assessment of the impact of land cover changes on sediment yield: a case study

Abstract Land use is one of the most important variables impacting river basin water and land resource planning and management. Sediment transport in streams is an important issue in the assessment of sediment deposition in dam reservoirs and its impact on operational activities. Evaluation of sediment yield contributes to decision-makers for effective water management and protection of the dam body and its elements. In this study, land use cover changes, in particular in forest areas, agricultural areas, arable lands, permanent crops, heterogeneous agricultural areas, and pastures in the Çakıt and Körkün sub-basins of the Seyhan River basin were examined between 1990 and 2018 using CORINE land use cover (CLC) data. The effect of land use/land cover (LULC) modifications on sediment yield was studied using suspended sediment observation data and CLC data. It was determined that the forest area in the Çakıt sub-basin drainage area increased between 1990 and 2018, and decreased in the Körkün sub-basin. It was determined that the increase in forest area in the Çakıt sub-basin drainage region until 2018 helped to reduce sediment movement. The regression values between forest area and suspended sediment concentration in Çakıt and Körkün sub-basins were found to be 0.9521 and 0.4431, respectively.

Distribution and Some Diagnostic Properties of Capoeta damascina (Valenciennes, 1842) in Streams of the Ceyhan and Seyhan River Basins, Türkiye

This study determined the distribution and some diagnostic characteristics of Capoeta damascina, which belongs to the Cyprinidae family, in the Ceyhan and Seyhan River basins. C. damascina individuals were detected in 21 of 25 Ceyhan River Basin stations and 12 out of 15 in the Seyhan River basin stations. C. damascina show a wide distribution in the Ceyhan and Seyhan River basins. It has been determined that C. damascina lives at altitudes between 125 m (Hemite Stream) and 1620 m (Söğütlü Stream) in the Ceyhan River basins, and in streams at altitudes ranging from 165 m (Çakıt stream) to 1758 m (Sarız Stream) in the Seyhan River basins. The average total length of C. damascina individuals (n: 218) caught in the Ceyhan River Basin is 14.72 cm, and their average weight is 40.12 g. In the Seyhan River basin, the average total length of C. damascina individuals (n: 74) was found to be 17.31 cm, and their average weight was 72.24 g. The mean number of line lateral scales was 71, the number of gill rakers was 23, and the number of pharyngeal teeth was 4:3:2-2:3:4.

Revisiting Major Dry Periods by Rolling Time Series Analysis for Human-Water Relevance in Drought

Drought is increasingly gaining importance for society, humans, and the environment. It is analyzed commonly by the use of available hydroclimatic or hydrologic data with little in-depth consideration of specific major dry periods experienced over a region. Also, it is not a common practice to assess the probability of drought categories with a rolling time series and hence the changing knowledge for operational drought monitoring. A combination of such quantitative analysis with a comprehensive qualitative assessment of drought as a human-water relation aimed to fill this gap performing a case study in the Seyhan River Basin, Turkey. Six major dry periods were identified from the precipitation time series of 19 meteorological stations. Major dry periods were analyzed by rolling time series and full time series, and they were also analyzed individually. A major dry period could be important in terms of its duration while another in terms of its severity or intensity, and each with its own impact on the human-water relations that can be influential on the drought mitigation, management and governance. Significantly higher probabilities were calculated for extreme droughts with the use of individual major dry periods. An important outcome from the study is that drought is underestimated in practice with the sole use of the whole data record.

Design of Small Earthen Dam Reservoirs Lying in Drought-Prone Areas: An Application to the Seyhan River Basin

Gölet hazne tasarımlarında, olasılıklı havza su verimleri kullanılmaktadır. Araştırma kapsamında, kuraklığa eğilimli havzalarda gölet hazne tasarımlarında kullanılacak uygun olasılık düzeyinin belirlenmesi amaçlanmıştır. Meteoroloji gözlem istasyonlarının yıllık toplam yağış serilerine, frekans analizi uygulanmıştır. İstasyonların %50, %80 ve %90 olasılıklı beklenen yağışları ve Normalin Yüzdesi İndeksi kuraklık sınıflarına karşılık gelen eşik yağış değerleri hesaplanmıştır. Bu değerler, CBS ortamında Ordinary Cokriging yöntemi ile haritalanarak M. Turc yöntemine göre yüzey akış haritaları oluşturulmuştur. Yüzey akışların, hipsometrik eğrileri çizilmiştir. %80 ve %90 olasılıkla beklenen akımların hipsometrik eğrileri “Hafif“ ve “Orta Şiddette” kuraklık sınıfına karşılık gelen eşik yağış akımlarını, %50 olasılıklı akımlar ise “Normal ve Üzeri-Risk Yok” kuraklık sınıfı eşik üstü akımları temsil etmiştir. Kuraklığa eğilimli Seyhan Havzasında gölet hazne tasarımlarında, %50 olasılıklı havza su verimlerinin kullanılması uygun bulunmamıştır. Maliyetleri azaltmak için, %80 veya %90 olasılıklı yüzey akışların kullanılması önerilmiştir.

Determination of drought intensity in Seyhan and Ceyhan River Basins, Turkey, by hydrological drought analysis

This paper studied hydrological drought identified by the Streamflow Drought Index (SDI) at eight river-gauging stations in the Eastern Mediterranean part of Turkey for a roughly 43-year period covering from 1972 to 2014 (4 stations), from 1973 to 2015 (2 stations), and from 1969 to 2011 (2 stations). Results of SDI analyses indicate that the number of drought years was highest during the 3-month October–December period. A considerable part of the drought years was determined to be mild drought. Although moderate drought conditions were observed in all stations, moderate drought conditions were determined especially at Goksu-H in the Seyhan River Basin and Sogutlu and Savrun in the Ceyhan River Basin. Short-term fluctuations of dry and wet conditions are the dominant pattern for most of the stations; however, long-term persistent drought conditions are also prominent, especially at Tacin and Korkun in Seyhan Basin and Goksun in Ceyhan Basin. The starting point for the negative trend in the 12-month series was the years 1996, 1999, and 2000.

Spatial Drought Characterization for Seyhan River Basin in the Mediterranean Region of Turkey

Drought is a natural phenomenon that has great impacts on the economy, society and environment. Therefore, the determination, monitoring and characterization of droughts are of great significance in water resources planning and management. The purpose of this study is to investigate the spatial drought characterizations of Seyhan River basin in the Eastern Mediterranean region of Turkey. The standardized precipitation index (SPI) was calculated from monthly precipitation data at 12-month time scale for 19 meteorological stations scattered over the river basin. Drought with the largest severity in each year is defined as the critical drought of the year. Frequency analysis was applied on the critical drought to determine the best-fit probability distribution function by utilizing the total probability theorem. The sole frequency analysis is insufficient in drought studies unless it is numerically related to other factors such as the severity, duration and intensity. Also, SPI is a technical tool and thus difficult to understand at first glance by end-users and decision-makers. Precipitation deficit defined as the difference between precipitation threshold at SPI = 0 and critical precipitation is therefore more preferable due to its usefulness and for being physically more meaningful to the users. Precipitation deficit is calculated and mapped for 1-, 3-, 6- and 12-month drought durations and 2-, 5-, 10-, 25-, 50- and 100-year return periods at 12-month time scale from the frequency analysis of the critical drought severity. The inverse distance weighted (IDW) interpolation technique is used for the spatial distribution of precipitation deficit over the Seyhan River basin. The spatial and temporal characteristics of drought suggest that the Seyhan River Basin in the Eastern Mediterranean region of Turkey experiences quite mild and severe droughts in terms of precipitation deficit. The spatial distribution would alter greatly with increasing return period and drought duration. While the coastal part of the basin is vulnerable to droughts at all return periods and drought durations, the northern part of the basin would be expected to be less affected by the drought. Another result reached in this study is that it could be common for one point in the basin to suffer dry conditions, whilst surrounding points in the same basin experience normal or even humid conditions. This reinforces the importance of spatial analysis over the basin under investigation instead of the point-scale temporal analysis made in each of the meteorological stations. With the use of spatial mapping of drought, it is expected that the destructive and irreversible effects of hydrological droughts can be realized in a more physical sense.

New Record of the Big-Scale Sand Smelt Atherina boyeri Risso, 1810 (Atherinidae) in the Seyhan Dam Reservoir (Seyhan River basin, Turkey)

Fifteen specimens of the big-scale sand smelt, Atherina boyeri were caught by a single trawl haul with a net mesh size of 3 mm on February 2017 from the Seyhan Dam Reservoir (South Anatolia, Adana/Turkey). In this study the big-scale sand smelt, A. boyeri, was recorded for the first time in the Seyhan Dam Reservoir. In addition, some morphometric and meristic measurements of A. boyeri were given and these values were compared to populations in two different lakes. Furthermore, the possible ecological effects of A. boyeri on Seyhan Dam Reservoir were briefly discussed.

Forecasting Daily Streamflow for Basins with Different Physical Characteristics through Data-Driven Methods

Modelling streamflow is essential for activities, such as flood control, drought mitigation, and water resources utilization and management. Artificial neural network (ANN), adaptive neuro-fuzzy inference system (ANFIS), and support vector machines (SVM) are techniques that are frequently used in hydrology to specifically model streamflow. This study compares the accuracy of ANN, ANFIS, and SVM in forecasting the daily streamflow with the traditional approach known as autoregressive (AR) model for basins with different physical characteristics. The accuracies of the models are compared for three basins, that is, 1801, 1805, and 1822, at the Seyhan River Basin in Turkey. The comparison was performed by using coefficient of efficiency, index of agreement, and root-mean-square error. Results indicate that ANN and ANFIS are more accurate than AR and SVM for all the basins. ANN and ANFIS perform similarly, while ANN outperformed ANFIS. Among the models used, the ANN demonstrates the highest performance in forecasting the peak flood values. This study also finds that physical characteristics, such as small area, high slope, and high elevation variation, and streamflow variance deteriorate the accuracy of the methods.

Planning of Sectoral Water Allocation: A case study of Seyhan River Basin

In this study water allocation plan for Seyhan Basin that is the second largest after the Nile basin located in the eastern Mediterranean was prepared. The purpose of the study is that a plan for water allocation among groups of water use, or sector is developed by considering environmental and socio-economic conditions as well as the potential of surface and groundwater resources. Current (the year 2016) and future conditions (2017, 2022, 2027 and 2037) have been analyzed in terms of economic and environmental aspects. Scenarios on water allocation were created to determine the most suitable water use pattern. The major finding is that water potential is expected to drop to 6.6 billion m 3 in mild drought conditions and 6.3 billion m 3 in severe drought conditions due to the impacts of climate change. Consequently, agricultural water needs are met in the range of 90% level (the year 2037) to 94% level (the year 2017), and environmental flow need s are met in C level of environmental management class in the context of applied method (GEFC) .

Planning of Sectoral Water Allocation: A Case Study of Seyhan River Basin

Planning of Sectoral Water Allocation: A Case Study of Seyhan River Basin

Soil organic carbon losses by water erosion in a Mediterranean watershed

Soil organic carbon (SOC) is one of the primary elements required in the functioning of ecosystems. Soil erosion, a major mechanism of land degradation, removes SOC and transfers it to the hydrosphere or the atmosphere, thereby affecting key ecosystem functions and services. The Mediterranean region is highly susceptible to land degradation because of erosion due to heavy rains following long, dry, hot summers. Although the Mediterranean landscape typically has a high altitude and incline, the soil is brittle and soft and is easily washed away by rain. Thus, vast regions in Turkey have been afflicted by this type of soil degradation. This study aimed to (1) estimate the temporal distribution of water erosion in the Seyhan River Basin, (2) assess the spatial distribution of SOC and (3) estimate the depletion of SOC through soil erosion using the Pan-European Soil Erosion Risk Assessment model, a physically based, regionally scaled soil erosion model. The annual amount of soil eroded from the Seyhan River Basin is estimated to be 7.8million tonnes per hectare (tha–1year–1). The amount of fertile soil loss from agricultural areas is ~1.2million tonnes per year. The maximum amount of soil erosion occurs in maintenance scrubland and degraded forest areas, contributing to 68% of erosion, followed by that in agricultural land, contributing to 27% of erosion, with the remaining in forests and urban areas.

Drought planning and management: experience in the Seyhan River Basin, Turkey

The focus of this study was to integrate drought planning and management into local and regional decision-making processes in the Seyhan River Basin, which is the second-largest basin after the Nile in the Eastern Mediterranean and agriculturally one of the most productive regions in Turkey and Europe. The methodological approach consisted of two steps: Step 1 – review and analyse historical data sets to evaluate and characterize water resources and drought-driven elements; Step 2 – evaluate drought indices to characterize drought conditions through use of the Standardized Precipitation Index and Standardized Precipitation Evapotranspiration Index. Historical and future expected drought periods were identified in the context of hydrologic, meteorologic and agricultural drought conditions.

Assessment of ınverse distance weighting (ıdw) ınterpolation on spatial variability of selected soil properties in the Cukurova plain

This study attempts to evaluate interpolation technique for mapping spatial distribution of some soil characteristics at the Lower Seyhan River Basin in Cukurova (Turkey). These soil characteristics may help to improve agricultural land management practices. In the study area, 7 parallel transects each having 150 m of length were selected at 5 m intervals, and 104 soil samples were collected. In these samples, calcium carbonate, organic matter, cation exchange capacity and clay content (from particle size distribution) were determined. Inverse distance weighting (IDW) interpolation and employing of GIS technology were applied on the results. Calcium carbonate, organic matter, cation exchange capacity and clay content values derived from IDW interpolation were consistent with the results of the soil analysis. The verity of the interpolation technique was tested by employing cross validation. Interpolation of organic matter values showed a high mean error in 30-60 cm depth (2.82%) while this high deviation was not the case with the other parameters studied.

Length-weight relationships for six freshwater fish species from the Seyhan Reservoir (south-eastern Anatolia, Turkey)

Length–weight relationships (LWRs) were evaluated for six freshwater species from the Seyhan Reservoir (south-eastern Anatolia, Turkey): Alburnus orontis, Capoeta angorae, Capoeta erhani, Garra rufa, Luciobarbus pectoralis and Salaria fluviatilis. A total of 525 specimens were captured from five locations using gill nets, scoop nets, and trammel nets of various mesh sizes in November 2012, March 2013 and September 2013. Regressions of all species were found to be significant. These are the first LWR reports for these species from the Seyhan River basin, and the first LWR reports for three of these species (Alburnus orontis, Garra rufa, Luciobarbus pectoralis) from inland waters of Turkey.

Erosion Modelling In A Mediterranean Subcatchment Under Climate Change Scenarios Using Pan-European Soil Erosion Risk Assessment (PESERA)

Abstract. The Mediterranean region is particularly prone to erosion. This is because it is subject to long dry periods followed by heavy bursts of erosive rainfall, falling on steep slopes with fragile soils, resulting in considerable amounts of erosion. In parts of the Mediterranean region, erosion has reached a stage of irreversibility and in some places erosion has practically ceased because there is no more soil left. With a very slow rate of soil formation, any soil loss of more than 1 t ha−1 yr−1 can be considered as irreversible within a time span of 50-100 years. The objectives of this study were i) to estimate the temporal and spatial distribution of soil erosion under climate change scenarios in study area ii) to assess the hydrological runoff processes. In this study, climate data, land use, topographic and physiographic properties were assembled for Egribuk Subcatchment at Seyhan River Basin in Turkey and used in a process-based Geographical Information System (GIS) to determine the hydrological sediment potential and quantify reservoir sedimentation. The estimated amount of sediment transported downstream is potentially large based on hydrological runoff processes using the Pan-European Soil Erosion Risk Assessment (PESERA) model. The detailed model inputs included 128 variables derived mainly from, soil, climate, land use/cover, topography data sets. The outcomes of this research were spatial and temporal distribution of erosion amount in t ha−1 yr−1 or month−1.

3D Agro-ecological Land Use Planning Using Surfer Tool for Sustainable Land Management in Sumani Watershed, West Sumatra Indonesia

3D Agro-ecological Land Use Planning Using Surfer Tool for Sustainable Land Management in Sumani Watershed, West Sumatra Indonesia

Soil Erosion Estimation in Lower Asi River Catchment Using GIS

Different methods are used to calculate the amount of erosion. Assessment of erosion factors through the use of spatial data integration is the most common method. Generally, RUSLE (3D) erosion model is preferred in the implementation of this method. Current study identified the erosion risk levels and distribution along with annual soil loss according to RUSLE (3D) erosion model in Lower Asi River Basin sample. Geographical Information Systems (GIS) and Remote Sensing (RS) methods and techniques were used in implementing the RUSLE model. Results of analysis show that the basin area experiences low (< - 5 t ha-1 y-1) levels of erosion the most (1787.40 km2 - 41.40%) and very severe (150 - > t ha-1 y-1) levels of erosion the least (154.75 km2 - 3.58%). Areas with high levels of erosion are the slope areas with high declivity. Total annual soil loss in the basin area was calculated to be 50.66 t ha-1 y-1 and average annual soil loss in the basin area was calculated to be 10.74 t ha-1 y-1. These values are lower than those of neighboring (Seyhan River) basin.

Evaluating the impact of land use uncertainty on the simulated streamflow and sediment yield of the Seyhan River basin using the SWAT model

As a result of the increased availability of spatial information in watershed modeling, several easy to use and widely accessible spatial datasets have been developed. Yet, it is not easy to decide which source of data is better and how data from different sources affect model outcomes. In this study, the results of simulating the stream flow and sediment yield from the Seyhan River basin in Turkey using 3 different types of land cover datasets through the soil and water assessment tool (SWAT) model are discussed and compared to the observed data. The 3 land cover datasets used include the coordination of information on the environment dataset (CORINE; CLC2006), the global land cover characterization (GLCC) dataset, and the GlobCover dataset. Streamflow and sediment calibration was done at monthly intervals for the period of 2001-2007 at gauge number 1818 (30 km upstream of the Catalan dam). The model simulation of monthly streamflow resulted in good Nash-Sutcliffe efficiency (NSE) values of 0.73, 0.71, and 0.68 for the GLCC, GlobCover, and CORINE datasets, respectively, for the calibration period. Furthermore, the model simulated the monthly sediment yield with satisfactory NSE values of 0.48, 0.51, and 0.46 for the GLCC, GlobCover, and CORINE land cover datasets, respectively. The results suggest that the sensitivity of the SWAT model to the land cover datasets with different spatial resolutions and from different time periods was very low in the monthly streamflow and sediment simulations from the Seyhan River basin. The study concluded that these datasets can be used successfully in the prediction of streamflow and sediment yield.

Effects of climate change on surface water management of Seyhan basin, Turkey

The goal of this study was to set-up the basis for climate change adaptation of water resources management policies in Seyhan River basin. The first priority was to identify the balances between water resources and water users with respect to existing and planned projects. In this respect various aspects of Seyhan basin were evaluated, including evaluation of existing water resources, determination of water demand of existing and planned projects, and water resources supply-demand characteristics. The global climate change model was downscaled to the basin scale, the results were associated with hydrometeorological monitoring network and finally the impact of climate change on surface water resources and demands were determined for specific projection years. Water resources management scenarios were developed to evaluate adaptation alternatives to climate change scenarios at the basin level. It was determined that even though there was no water stress in Seyhan basin in 2010, many parts of the basin were expected to suffer significant shortages over the coming years.