Investigating changes in some soil properties depending on land use and depth layers: A case study for the godrahav creek watershed in Artvin, Turkey

The Eastern Black Sea Region is characterized by mountainous and steep terrain, limiting agricultural activities. This, in turn, has been causing the natural lands of mostly forests and grasslands in the region to be converted to other uses, mostly agriculture as an alternative income for the local people. However, it is well known that such conversions negatively affect all the natural resources including soil properties. Therefore, in this study, changes in some soil parameters in the forest and the neighboring agriculture (converted from the forest) lands within the watershed of the Godrahav Creek Watershed were investigated with respect to current land use type and soil depth. For this purpose, a total of 36 soil samples based on land use types (forestland, agriculture) and soil depth (0-10 cm and 10-20 cm) were taken to be analyzed for texture, permeability, bulk density, organic matter (OM), pH. Differences and relations among these properties were statistically examined using the analysis of variance analyses (ANOVA). It was determined that the most of the soil characteristics analyzed were significantly different between the lands of forest and agriculture in the study area. For example, as expected, the amount of OM was significantly higher in forestlands with 6.71% than the agricultural land with 5.50% while the pH was increased from 5.51 to 6.88 after conversion. In addition, bulk density was also increased from 1.07 gr/cm3 in forests to 1.23 gr/cm3 in agriculture areas whereas better permeability was found for forestlands (302.32 mm/hr) than agricultural lands (110.96 mm/hr)

Subdividing large mountainous watersheds into smaller hydrological units to predict soil loss and sediment yield using the geowepp model

Our research was funded by Artvin Coruh University, Coordinatorship of Scientific Research Projects (project No: 2011.F10.02.13).The number of studies using prediction models on measuring soil loss and/or sediment yield has been continuously increasing since these models are considered timely and cost-effective. Similarly, in this study, we used the GeoWEPP model to determine how much soil is being lost and the amount of sediment being yielded from Godrahav Creek Watershed (GCW) located in northeastern Turkey. Because the watershed is large (5,298.21 ha) and has mountainous and steep terrain, it was subdivided into smaller hydrological units (SHUs) so that the model can run easily and give detailed findings. The results revealed that out of 18,596.8 t of soil loss generated from both hillslopes and channels within the whole GCW, approximately 9,854.8 t y(-1) reached Borcka Dam reservoir as sediment. The model also predicted annual average soil loss and sediment yield as 1.73 t ha(-1)y(-1) and 1,86 t ha(-1)y(-1), respectively. In addition, with a sediment delivery ratio (SDR) of 0.530, the results indicated that almost half of the detached soil particles were carried away as sediment. Despite the dominant vegetation coverage, relatively high SDR and soil loss - particularly in certain SHUs - can be associated with steep terrain and conversion of natural lands in the watershed

Artvin Düz dere havzası’nda toprak erozyonu durumunun tahmini

Aim of study: Main objective of this research was to predict some of the processes (soil loss, runoff and sediment yield) related to soil erosion with the help of WEPP (Water Erosion Prediction Project) model. Area of study: The WEPP model was applied to the Düz Creek Watershed (1059 ha in size). It is a subwatershed flowing into the greater Çoruh River Basin near the district of Borçka, Artvin. Material and methods: As required by the WEPP model, four large-data files of soil, climate, slope and plant cover/management were created for the watershed using the data gathered from in-field samplings (soil), laboratory analyses and GIS (Geographical Information Systems) assessments. For easier run and detailed investigation of soil erosion process of the research area, the studied watershed was divided into eight small hydrological units (SHUs) and the program was run on these SHUs. Main results: At the end of GeoWEPP’s run, the results revealed that a total of about 735 mm annual precipitation was fell within the study area. The model also predicted that there was approximately 207 mm as runoff out of this amount of precipitation, which, in turn, generated an annual total soil loss and sediment amounts as 2815.2 t and 2720.9 t, respectively. In addition, the sediment yield per unit area was estimated to be around 2.57 ton/ha/yr while the sediment delivery ratio (SDR) was found to be as 0.977. Lastly, the model predicted that the particle distribution of eroded sediment were 20%, 25% and 55% of clay, silt and sand, respectively, while the mean organic matter (OM) amount of the lost sediment was about 5% for the studied watershed. Highlights: Soil loss and sediment yield can be calculated for large areas in a short time and with little costÇalışmanın amacı: Havzada oluşan toprak kaybı ve sediment veriminin WEPP modeli ve CBS (Coğrafi Bilgi Sistemleri) tekniklerinin entegre edildiği GeoWEPP arayüzü kullanılarak kısa sürede ve az masrafla hesaplanması amaçlanmıştır. Çalışma alanı: Çoruh nehrine birleşen Düz Dere Havzası araştırma alanı olarak seçilmiştir. Materyal ve yöntem: GeoWEPP ara yüzü için gerekli olan iklim, eğim ve bitki amenajmanı dosyalarına ek olarak toprak dosyası oluşturulmuştur. Araştırma havzası sekiz alt havzaya bölünmüş ve program bu alt havzalarda yürütülerek toprak kaybı, yüzeysel akış ve sediment veriminin ortalama değerleri hesaplanmıştır. Sonuçlar: Çalışma sonucunda, havzaya 735 mm’lik yağış düştüğü ve bunun yaklaşık olarak 207 mm’sinin yüzeysel akışa geçtiği tahmin edilmiştir.1059 ha’lık bir alana sahip olan havzada yıllık toplam toprak kaybı ve sediment miktarı sırası ile 2815.2 ve 2720.9 ton olarak bulunmuştur. Bununla beraber, birim alandan ise 2.57 ton/ha/yıl sediment verimi gerçekleştiği hesaplanmıştır. Ortalama sediment iletim oranı yaklaşık 0.977 olarak bulunmuştur. Ek olarak, taşınan sediment içerisindeki ortalama kil oranının % 20, toz oranının % 25, kum oranının % 55, organik madde miktarının ise % 5 olduğu tahmin edilmiştir. Önemli vurgular: Toprak kaybı ve sediment verimi, büyük alanlar için kısa sürede ve daha az maliyetle hesaplanabili

The effects of land-use changes on soil properties: The conversion of alder coppice to tea plantations in the Humid Northern Blacksea Region

Over the last century, the conversion of natural ecosystems to agricultural production is one of the primary factors in environmental degradation. As in most parts of the world, forest soils in the north- east of Turkey are being seriously degraded and destroyed due to extensive agricultural activities. This study investigated the effects of changes in land-use on some soil properties in Rize, Turkey. Two adjacent sites were studied: One had been converted 60 years previously from alder coppice to tea cultivation (TC); the other remained as alder coppice (AC). The experimental design at each site was a randomized complete block with four replications in the study area. Four disturbed and four undisturbed soil samples were taken randomly at soil depths of 0 -10 cm, 10 - 30 cm and 30 - 50 cm in each plot in the study area. When the alder coppice was converted into tea cultivation, the bulk density (Db) increased from 0.84 g cm-3 to 1.02 g cm-3, soil penetrometer resistance (SPR) increased from 0.94 to 1.27 MPa, the soil organic matter (SOM) decreased from 5.14 to 4.06%, saturated hydraulic conductivity (Ksat) decreased from 40.64 to 16.33 mm h-1 at 0 to 10 cm depth of soil. According to soil depth steps the mean PAW, St, Ksat, SOM and total N content decreased linearly in alder coppice (AC) and tea cultivation (TC). The results indicated that the change in land use and introduction of cultivation had a significant effect on soil properties

Determining land use change and land degradation caused by dam and road projects planned on the coruh river with the help of GIS

Ülkemizin enerjideki dışa bağımlılığını azaltmanın yanında içme-kullanma suyu ve taşkın kontrolü gibi ana amaçları ile son yıllarda daha da artan sayıda başvurulan yatırımların başında gelen büyük barajlar, arazi kullanım değişimleri, tarım alanlarının daralması, sedimantasyon, ekosistemlerin tahribatı ve insanların zorunlu göçleri gibi birçok sorunu da beraberinde getirmektedir. Ayrıca, barajların öncelikle üzerinde yapıldıkları havzayı, akarsu sistemini ve yakın çevresini hem fiziksel açıdan hem de yerine getirdiği doğal işlevleri bakımından ciddi boyutlarda değiştirdiği de bir gerçektir. Benzer değişikliklerin yaşandığı havzalardan biri de DSİ Çoruh Barajlar Projesinin gerçekleştirildiği Çoruh Nehri Havzası’dır. Bu proje kapsamında planlanan toplam 15 büyük barajdan 7’si Çoruh Nehri’nin Artvin sınırları içerisindeki ana ve yan kolları üzerindedir. Bu barajların inşaatı ve bağlantılı olarak yol ağının yenilenmesi ile Çoruh Nehri ve Vadisi üzerinde özellikle arazi kullanımında önemli değişimlerin ve alandaki ekosistem üzerinde de ciddi tahribatların meydana geldiği gözlemlenmektedir. Söz konusu bu değişimlerin ve tahribatların bilimsel olarak irdelenmesi ve sağlıklı verilerin elde edilmesi amacı ile inşaatına başlanılan Artvin Barajı ve HES ile kısa zamanda inşaatına başlanılacak olan Yusufeli Barajı ve HES iki örnek baraj olarak seçilmiştir. Bu barajlar içerisinde yaklaşık 12124 kişi ve 3031 hanenin doğrudan etkileneceği, vadi boyunca yer alan su basar alanlardaki tarım alanlarının nerede ise tamamını kaybedecek olan Yusufeli Barajı büyük önem taşımaktadır. CBS teknikleri kullanılarak öncelikle bu barajların etki alanlarındaki (yaklaşık 1870 km2) mevcut arazi kullanım şekilleri belirlenmiş ve çalışma alanındaki idari sınırlar, havza sınırları, alt havzalar ve Sayısal Arazi Modeli (SAM) olmak üzere çok sayıda katman oluşturulmuştur. Bunların yanında, havzanın akarsu ağı, drenaj ve alt havzalarına ilişkin haritalar oluşturulmuş ve Sayısal Arazi Modeli kullanılarak bazı havza karakteristikleri ortaya konulmuştur. Çalışmanın bundan sonraki aşamaları ise her iki barajın tamamlanacağı ve su tutma sürecinin başlayacağı varsayımı ile rezervuar alanlarının sınırlarının ortaya konulması ile özellikle yeni yol yapım çalışmalarının neden olduğu/olacağı arazi tahribatının alansal büyüklüğünün belirlenmesi olacaktır. Böylece daha önce üretilen katmanlarla çakıştırıldığında çalışma alanında meydana gelecek arazi kullanım değişimi tespit edilmiş olacaktır. Belirlenecek veriler yardımı ile üretilecek olan haritalar ve elde edilecek veriler, Çoruh Nehri boyunca yapılması planlanan diğer büyük barajlar için önemli bir altlık oluşturacaktır.Lately, large dams have been one of the most referenced development projects mainly for the purposes of drinking and potable water, flood control and reducing the Turkey’s energy dependency on foreign resources. However, they also bring along some issues including land use change, reducing arable lands, sedimentation, destruction of ecosystems, and forced migration of people. Moreover, it is a fact that large dams, beside river ecosystems and its close environment, first of all, severely change the watershed they are to be constructed on, both physically and in terms of its natural functions. The Coruh River Watershed where the DSI’s Coruh Dams Project has been carried out is one of many watersheds experiencing similar changes mentioned above. Seven of fifteen large dams planned for this Project are on the Coruh River’s main and tributary channels flowing within the boundary of Artvin. Important negative changes have been observed in the area especially in respect to land use and severe destructions on ecosystems due to the construction of the dam projects and the renewing of road network. In order to make scientific evaluation about these changes and destructions and obtaining reliable data, two dams, one (the Artvin Dam and HPP) is already being constructed and the other (the Yusufeli Dam and HPP) is in the beginning of its construction stage, were chosen as case studies. Out of these two dams, the Yusufeli Dam is considered as more important since about 12124 people and 3031 homes are going to be affected directly by this dam as well as almost all arable lands along the floodplains of the valley are going to be lost. Using GIS techniques, first of all, the present land use types within the area (close to 1870 km2) impacted by the dams were identified and many layers including administrative and watershed boundaries, sub-watersheds, and digital terrain model (DTM) of the study area were created. In addition, the maps showing river network of the watershed and drainage and sub-watersheds were also prepared and using DTM, some characteristics of the watershed were obtained. The next step of this study -with the assumption that construction of both dams are completed and inundation is started- is to find out boundaries of the reservoir areas and determine spatial size of land degradation that have been and/or will be caused especially by building new road system. Then, when previously created maps were overlapped, the projected land use change in the study area will be determined. The data obtained and the maps created from this study will be a very important base for the other large dams planned to be constructed along the Coruh River

Determining physical characteristics of watersheds in Artvin province using SRTM and topographic map data

Su kaynaklarının kullanımı ve korunmasına yönelik çalışmalarda Coğrafi Bilgi Sistemleri (CBS) ve bağlantılı yazılım ve/veya modüllerin uygulanmasının son yıllarda arttığı bir gerçektir. Bu programlar sayesinde yağış havzalarının sınırları, arazi kullanımları, drenaj ağları, eğim ve yükselti gibi bazı fiziksel özellikleri hızlı, detaylı ve güvenilir bir şekilde belirlenebilmektedir. Bu çalışmada da CBS programlarından biri olan ArcGIS 10.3.1 ile entegre halde çalışan ArcHydro modülü kullanılarak Artvin il sınırları içerisinde kalan yağış havzalarının bazı özelliklerinin (sınırlar, drenaj ağı, büyüklük, eğim, vb.) belirlenmesi amaçlanmıştır. Sayısal Yükseklik Modeli (SYM) oluşturmak için hem “Shuttle Radar Topography Mission (SRTM)” hem de 1/25.000 ölçekli “topoğrafik harita” verilerinden yararlanılmış ve böylece elde edilen sonuçların bu iki farklı altlık arasında karşılaştırılması sağlanmıştır. Genel olarak, SRTM ve topoğrafik harita verilerinin havzaların özelliklerinin belirlenmesinde birbirine oldukça yakın sonuçlar verdiği ortaya konulmuştur. Örneğin, araştırma alanında tespit edilen büyük havza (10-100 km2) sayısı SRTM ve topoğrafik harita verilerine göre sırasıyla 315 ve 312 olarak belirlenmiş, çok büyük havzaların (>100 km2) sayısı ise her iki altlıkta da 30 olarak tespit edilmiştir. Ayrıca, topoğrafik haritalardan elde edilen eğim sınıfları gruplamasında ilin %89.27‘sinin çok dik-sarp arazi sınıfında yer aldığı belirlenirken, STRM verilerine göre ise bu oranın %87.13 gibi oldukça benzer bir sonuç verdiği bulunmuştur.It is a fact that applying Geographical Information Systems (GIS) and associated software and/or modules on studies regarding use and protection of water resources have been increased in recent years. With such programs, some physical characteristics of watersheds including borders, land use, drainage system, slope and elevation can be determined in a quick, detailed and reliable way. In this research, the aim was to use ArcHydro module -integrated with ArcGIS 10.3.1 one of the programs of GIS- to assess some features (borders, drainage, size, steepness, etc.) of river basins located within Artvin province. In order to create Digital Elevation Model (DEM), data from both “Shuttle Radar Topography Mission (SRTM)” and “topographical map” was used; thus, providing comparison of the results gathered from these two base maps. In general, it was stated that both SRTM and topographic map data resulted in very close findings in determining watershed characteristics. For example, while the number of large watersheds (10-100 km2) counted as 315 and 312 by SRTM and topographic maps, respectively, the number of very large watersheds (> 100 km2) was 30 according to both base maps. Moreover, in grouping of slope classification, as 89.29% of the province was found to be within the verysteep slope class based on the topographic maps, a very similar result of 87.13% was revealed using SRTM data

Effect of visitor activities on topsoil hydrophysical properties in two protected areas in northern blacksea region

In this study, the effects of visitor acitivities on topsoil hydrophysical properties in two protected areas in northern Bleacksea region were investigated. For this purpose, soil samples taken from study area that was characterized as heavily trafficked site (HTS), moderately trafficked sites (MTS) and control (non-trafficked site). The soil bulk density and soil penetration resistance increased from 1.02 to 1.39 g cm–3 and 0.66 to 1.55 MPa, respectively, saturated hydraulic conductivity decreased from 60.60 to 10.35 mm h–1 in moderately and heavily trafficked sites, respectively, at 0–10 cm soil depth in Ayder protected area. The soil bulk density and soil penetration resistance increased from 0.85 to 1.40 g cm–3 and 0.68 to 1.50 MPa, respectively, saturated hydraulic conductivity decreased from 58.75 to 10.35 mm h–1 in moderately and heavily trafficked sites, respectively, at 0–10 cm soil depth in Kafkasor protected area. The intensity of visitor activities had a negative impact on topsoil hydrophysical properties in the study area in Ayder and Kafkasor. The principles of management in Ayder and Kafkasor protected areas should be revised, and use of this area without a plan should be stopped as soon as possible

Changes on soil properties associated with soil depth in eroded areas: a case study of Pamukcular watershed

This study was carried out to investigate changes on soil properties associated with soil depth in eroded areas under semi-arid climate conditions. Pamukcular Watershed (Yusufeli-Artvin-Turkey), with total annual rain amount of 250- 400 mm and alluvial soils formed especially by sudden floods, was chosen as the study area. Due to poor vegetation cover, continuous surface erosion was observed for most of the year in the research area, leading us to predict that negative changes may have occurred in soil physical and chemical properties. In order to determine these changes, disturbed and undisturbed soil samples were taken at two depths (0-10 ve 10-20 cm) in 12 parcels with about 3% slope. When soil samples were taken, it was observed that vegetation cover rate was low (20%-30%). The results show that clay content, moisture, aggregate stability, pH, bulk density and dispersion rate of soils was significantly different between soil depths. However, silt, sand, lime and organic matter contents along with air and hydraulic conductivity did not show significant differences

Determination of snow water equivalent (SWE) according to elevation and its importance for water resources in semi-humid region of Turkey

The aim of this study was to determine the altitudinal distribution of snow water equivalent (SWE) in the north-east facing aspect of the basin of the Fabrika River in Artvin. Study sites were selected at four different altitudes, where a total of thirty snow samples were collected from each study site from the depth steps of 0–5 cm and 5–10 cm. As a result, the snow sample collected on February 21, 2008 at 1250 m altitude and from 5–10 cm depth was found to produce the highest SWE value while the snow sample collected on February 15, 2008 at 200 m altitude and from 0– 5 cm depth was found to produce the lowest SWE value. A strong relationship was detected between the SWE of the snow sample collected from 0–5 cm depth and the altitude of the sampling site. This relationship was formulated as: [R2= 0.94, SWE = 0.1328* (Altitude 0.687)], while this relationship was formulated as: R2= 0.928, SWE = 0.15 * (Altitude 0.6750)], in depth of 5–10 cm

Ecologic and social problems caused by run-of-river type hydroelectric power plants in Artvin

Son yıllarda ortaya çıkan enerji açığı ve enerjide dışa bağımlılık Türkiye’yi, aslında uygulaması gereken uzun vadeli enerji politikaları yerine, kısa vadede çabuk sonuç almayı hedefleyen yöntemler kullanmaya veya kullanılan mevcut yöntemin üretimdeki payını arttırmaya yönelik çalışmalara zorlamaktadır. Bu kapsamda, 2007 yılı elektrik üretiminde toplam payı %18,7 olan hidroelektrik santrallerin payının arttırılması ülkemizde son dönemde en çok başvurulan seçeneklerden biri olmaktadır. Bu nedenle, enerji açığının kapatılması konusunda son yıllarda hızla artan sayıda baraj ve nehir tipi hidroelektrik santral (HES) projeleri gündeme girmiştir. Bu çerçevede, Çoruh Nehri’nin ana ve yan kolları üzerinde planlanan ve yapımı süren 15 adet büyük baraja ek olarak 116 adet nehir tipi HES tesisinin yapımı gündeme gelmiştir. Ancak, arazi yapısının oldukça sarp ve eğiminin yüksek oluşu, bölgedeki orman, toprak ve su kaynaklarının ciddi şekilde zarar göreceği gerçeğini gözler önüne sermiştir. Nehir tipi HES tesislerinin, öncelikle üzerinde inşa edileceği akarsuyun su miktarında ve akım rejiminde değişimler yaratacağından, bu akarsularda yaşayan sucul canlıların (örn: balıklar, amfibiler, vb.) ve dere kenarı vejetasyonunun önemli derecede etkileneceği açıktır. Ayrıca, bu tesislerle beraber yapılacak olan yeni yol ve tüneller sonucu ortaya çıkan hafriyatın depo edilmesinde veya uzaklaştırılmasında sorunlar yaşandığı ve bunun toprak erozyonu ile beraber akarsu ve göletlerde sedimantasyona neden olduğu günümüzdeki örnekleri ile bilinmektedir. Bunun yanında, her bir HES ve buna bağlı yol ve tünel yapımının, özellikle ormanlık alanların parçalanmasına, böylece bölgede yaşayan yaban hayvanlarının yaşam alanlarının daralmasına yol açacağı da yüksek olasılıkla karşılaşılacağımız önemli bir sorun olacaktır. Yukarıda açıklanan ekolojik etkilere ilave olarak, HES projelerinin, yapıldıkları akarsu havzaları boyunca su kaynaklarına yakın yerlerde kurulan yerleşim alanlarında yaşayan yerel halk ile arazi ve su kullanımı açısından çeşitli sorunlar oluşturacağı da açıktır. Bunun yanında, ildeki kamu kurumları da bu tesislere izin verilmesi konusunda habersiz ve etkisiz kalmaktadırlar. Tüm bu çevresel ve sosyal olumsuz sonuçlara rağmen, çoklu HES tesislerinin yaratacağı etkilerin büyüklüğü, kapsamı ve en aza indirilmesi için gerekli önlemlerin alınması ile bağlantılı herhangi bir çalışma yapılmamaktadır. Buradan yola çıkarak, bu bildiride; sayıları son yıllarda artan çoklu HES projelerinin ekolojik ve sosyal açıdan oluşturduğu ve oluşturacağı sorunlar Artvin’deki örnekleri bağlamında irdelenecektir.Turkey, as one of the countries recently being affected by energy shortage, is in search for various solutions to close this gap. Out of several solution ideas, increasing the proportion of hydroelectric power, which is at %18,7 as of 2007 out of the whole energy production, has become one of the most applied. This, in turn, resulted in ever-increasing projects of building many large dams and run-of-river type hydroelectric power plants. In this regard, besides 15 large dams being planned to be built on the main channel of the Coruh River Watershed, one of many large basins of the Black Sea Region, there are also more than 116 run-of-rivertype hydroelectric power plants lawfully permitted to be constructed on the tributaries of the River. However, because of the steepness and the roughness of the terrain in the region, natural resources (e.g., forest, water and soil) have been damaged during construction works of these projects. Changes and derivations of the water regime of natural river channel, serious damages on riverine habitats (e.g. fish, amphibians) and riparian zone vegetation, accelerated soil erosion and sedimentation problems occurring in rivers and associated large dam reservoirs are some of negative outcomes resulted in by building regulators, roads, water transferring tunnels and energy generating structures. In addition, forest ecosystems are getting fragmented due to roads and tunnels, dividing a united system into many pieces; thus, creating a more fragile situation for forests for damaging effects of insects, snow and wind, runoff, or landslides. The other important result of the constructing so many of these power plants are their social outcomes. Besides the severe damage to nature in the proximity of the power plant construction areas, much of the water will be transferred to water-carrying tunnels from the main channel of the creeks when these plants start to operate. All these changes may cause conflicts between local people living in these watersheds for hundreds of years and the management of these plants especially over water usage. Finally, there is a confusion in respect to laws and regulations regarding these plants as the associated local government administrations (governors, directorates of regional forest and environments, universities, NGOs, etc.) almost do not have any saying on whether these power plants should be built in such unique and fragile ecosystems. Despite all these possible negative outcomes both on the ecological and social aspects, there are not any studies on the size and scope of the adverse effects caused by building so many power plants. In this article, the current and future ecological and social outcomes of the run-of-river type power plants permitted to be built in many rivers and creeks of Artvin were investigated