Omer Yetemen

• PhD
• Istanbul Technical University

We investigate the influence of hillslope aspect on landscape morphology in central New Mexico, where differences in soils, vegetation, and landforms are observed between mesic north-facing and xeric south-facing slopes. Slope-area and curvature-area relations, derived from a Digital Elevation Model (DEM), are used to characterize the opposing hill...

Solar radiation has a clear signature on the spatial organization of ecohydrologic fluxes, vegetation patterns and dynamics, and landscape morphology in semiarid ecosystems. Existing landscape evolution models (LEMs) do not explicitly consider spatially-explicit solar radiation as model forcing. Here, we improve an existing LEM to represent coupled...

Observations at the field, catchment, and continental scales across a range of arid and semiarid climates and latitudes reveal aspect-controlled patterns in soil properties, vegetation types, ecohydrologic fluxes, and hillslope morphology. Although the global distribution of solar radiation on earth's surface and its implications on vegetation dyna...

Erosion rate data worldwide show complex and contrasting dependencies to climate. Laboratory and numerical model experiments on abiotic landscapes suggest a positive response: Wetter (drier) shift in climate leads to an increase (decrease) in erosion rates with longer relaxation times under a drier climate. We performed eco‐geomorphic landscape evo...

Plain Language Summary Sunny (equatorial‐facing) slopes receive more solar radiation than shady (polar‐facing) slopes. A common assumption in water‐limited semiarid ecosystems is that this difference in solar radiation results in shady slopes being greener than sunny slopes, because they lose less water to the atmosphere due to evapotranspiration....

Groundwater-dependent vegetation (GDV) provides vital ecological functions across arid and semiarid areas. The unsustainable depletion of groundwater, however, has led GDVs to face severe degradation, creating an urgent need for accurate identification and targeted management of these critical species. Although many methods have been applied for id...

Solar farms play an integral role in the global energy transition and climate change mitigation. However, criticism has emerged, arguing that mitigating climate change cannot come at the expense of ecosystem degradation due to an ambiguous understanding of solar farms’ environmental impacts. Here we developed a harmonic regression model to conduct...

The hypersaline Urmia Lake in NW Iran offers unique sedimentary environments sensitive to climate and environmental shifts, fostering coated grain formation and serving as a vital indicator of paleoenvironmental conditions. This study characterizes coated grains within a 25‐m sediment core dating back to ~50 cal ka bp , assessing their significance...

ABSTRACT Soil water potential (SWP) strongly influences plant productivity and ecosystem functioning, particularly in arid regions characterized by sporadic and pulsed rainfall. This work aims to improve understanding of the response of SWP to varied rainfall pulses, and of the water-use strategies of a widespread C 4 shrub (Haloxylon ammodendron,...

Güneş enerji santralleri (GES), yenilenebilir enerji kaynakları arasında önemli bir yer tutmakta ve enerji üretim kapasitesinin artırılması için sürekli olarak iyileştirme çalışmaları yapılmaktadır. Bu bağlamda, İnsansız Hava Araçları (İHA) ve fotogrametrik tekniklerin kullanımı, santrallerin verimlilik analizinde yeni bir boyut kazandırmaktadır. İ...

The large wildfire sequence took place in July and August 2023 in Çanakkale, recorded as the largest wildfire incident in NW, Türkiye. The total affected area in two successive wildfires is 79.1 km². This study presents an observation-based instance and statistical model findings of how topography as a major determinant controls wildfire propagatio...

The unmanned aerial vehicles (UAVs) can be used to monitor photovoltaic (PV) systems, specifically focusing on their integration with thermal imaging technology. The process involves equipping UAVs with integrated thermal cameras to capture aerial photographs, which are then used to generate thermal orthomosaic. These thermal data play a crucial ro...

An intricate association between weathering and erosional processes is largely controlled by climate disparities. Weathering as a predisposing process for natural hazards, landform evolution, and sediment mobility, hosts key uncertainties in our understanding of how climate controls differential weathering types and rates. Here, we investigate how...

Landscapes evolve through nonlinear interactions between soil, vegetation, and climate. In semi-arid ecosystems, soil moisture variability (SMV) and vegetation variability (VV) can be strongly related to landscape organisation induced by differences in insolation on opposing north-facing slopes (NFS) and south-facing slopes (SFS). Due to its comple...

At the current juncture with climate change, centennial projections of species distributions in biodiversity hotspots, using dynamic vegetation models may provide vital insight into conservation efforts. This study aims to answer: (1) if climate change progresses under a business-as-usual scenario of anthropogenic emissions for this century, how ma...

Solar energy is a rapidly growing industry, and the performance analysis and maintenance of solar farms are crucial for ensuring their photovoltaics efficiency and longevity. In this context, many solar farms are established and it is crucial for energy producers to operate these farms efficiently. However, control of solar degradation panels local...

Drought risk threatens pastoralism in rangelands, which are already under strain from climatic and socioeconomic changes. We examine the future drought risk (2031–2060 and 2071–2100) to rangeland productivity across Eurasia (West, Central, and East Asia) using a well-tested process-based ecosystem model and projections of five climate models under...

Soil water potential (SWP) strongly influences plant productivity and ecosystem functioning, particularly in arid regions characterized by sporadic and pulsed rainfall. This work aims to improve understanding of the response of SWP to varied rainfall pulses, and of the water-use strategies of a typical desert plant ( Haloxylon ammodendron , HA) in...

As a typical vulnerable ecosystem, alpine steppes can be subject to nonlinear accelerations in degradation, once tipping points are reached or exceeded, and thus far more effort and investment will be needed, to reverse the degraded status of such ecosystems, if effective preventive measures or interventions are not adopted sufficiently early. Thus...

Hydrological connectivity (HC) is a useful framework for understanding hydrological responses to landscape changes. We present herein a novel model (SOFAR) for utility‐scale solar farms (USFs), combining modules of soil moisture dynamics, roof effects of photovoltaic panels (PVs), vegetation growth and landform evolution. By augmenting the model wi...

Soil water potential (SWP) is vital for plant productivity and ecosystem functioning. This is especially true in arid regions, where rainfall typically falls in brief pulses of variable size. This work aims to improve understanding of the response of SWP to varied rainfall pulses, and of the water-use strategies of a typical desert plant ( Haloxylo...

The importance of easy wayfinding in complex urban settings has been recognized in spatial planning. Empirical measurement and explicit representation of wayfinding, however, have been limited in deciding spatial configurations. Our study proposed and tested an approach to improving wayfinding by incorporating spatial analysis of urban forms in the...

While the land use‐street network nexus is well acknowledged, evidence for the one‐way impacts of land‐use patterns on street accessibility is still inadequate. The measurements of land‐use patterns and street accessibility lack systematic knowledge. Their empirical correlations also lack geographical variability, constraining site‐specific land‐us...

Solar farms are critical to tackling climate change and achieving carbon neutrality. Besides producing renewable energy, a solar farm modifies microclimates and changes water distribution, consequently affecting local carbon sequestration capacity (CSC). Yet, how the CSC of an ecosystem responds to these changes after solar farm construction remain...

Teleconnection patterns are one of the key features to understanding high‐frequency natural climate variability. The North Sea‐Caspian Pattern (NCP) was identified as a middle tropospheric dipole and its hydroclimatological implications have been substantially restricted to the Eastern Mediterranean region. Thus, the hydroclimatological influences...

Compared to the growing number of utility-scale solar farms (USFs) sitting in hilly regions, knowledge of the hydrological behaviors in responding to the installation of USFs in these environments remains limited. We present herein a novel model (the Solar-Farm model) to understand the hydrological behaviors following the construction of a USF in t...

This study considers the potential shift of biomes due to simulated changes in climatic drivers up until the end of this century, and how these changes effect the frequency of disturbances which in turn may affect the ranges of vegetation life zones. The study area is mainly the Anatolian Peninsula and its immediate surroundings, a unique location...

Post-wildfire management actions mainly targeting the removal of salvage logs and burned trees is a common but controversial practice. Although it aims to regain some of the natural and economic value of a forest, it also requires disturbing burned areas, which may have some negative consequences affecting, for instance, the carbon cycle, soil eros...

A soil moisture data-driven method through inversely solving the Richards’ equation was tested, and proved to be a reliable alternative estimator of actual evapotranspiration (ETa) for relatively homogeneous soils in an arid region. Few studies have examined the feasibility of the method using soil moisture for soils with more heterogeneities, whic...

Soil water potential (SWP) is vital for controlling the various biological and non-biological processes occurring through and across the soil-plant-atmosphere continuum (SPAC). Although the dynamics and mechanisms of SWP have been investigated for several decades, they are not as widely explored in ecohydrology research as soil moisture, due at lea...

Temperature and population growth are key drivers of energy consumption. However, the relative importance of climatic and socioeconomic factors driving energy consumption at different temporal scales is not well-understood. Therefore, we developed a time-series decomposition method to attribute the relative importance of climatic (heat index and mo...

The central aim of this study is to estimate the current potential distribution of Turkey’s forests and their composition in absence of anthropogenic landcover change, and in this manner to contribute to past studies on the distribution of European forest taxa by filling an important spatial gap. For our simulations, we used high resolution climate...

In this study, we present pollen records together with a multiproxy analysis from a sediment core collected from the Güllük Bay (Bargilya Cove, Muğla, SW Turkey), covering the last 400 years. Pistachio shrubland was occupying around the Güllük Bay between 1613 and 1741 AD. However, after 1741 AD, the vegetation canopy suddenly changed and Turkish p...

Badlands are extremely rugged, outstanding landscapes that can be seen in all ice-free climate regions over erosion-susceptible unconsolidated materials, and they have drawn attention with their spectacular and iconic forms. Unlike nearly all badlands researches conducted at the experimental site and watershed scale, so far, the broader-scale evalu...

Vegetation ecosystems are sensitive to large-scale climate variability in climate transition zones. As a representative transitional climate zone in Northwest China, Gansu is characterized by a sharp climate and vegetation gradient. In this study, the spatiotemporal variations of vegetation over Gansu are characterized using the satellite-based Nor...

Land use planning regulates surface hydrological processes by adjusting land properties with varied evapotranspiration ratios. However, a dearth of empirical spatial information hampers the regulation of place-specific hydrological processes. Therefore, this study proposed a Local Land Use Planning framework for EvapoTranspiration Ratio regulations...

Investigating Quaternary glaciations by terrestrial cosmogenic nuclide dating provides unique insights into glacial landscapes. However, postglacial processes may reshape these topographies via weathering, erosion and deposition, especially after the glaciers have entirely disappeared. Understanding the timing of Quaternary glaciations in the areas...

Emerging drought stress on vegetation over western Eurasia is linked to varying teleconnection patterns. The North-Sea Caspian pattern (NCP) is a relatively less studied Eurasian teleconnection pattern which has a role on drought conditions and the consequence of changing conditions on vegetation. Between 1981 and 2015, we found that the Standardiz...

Topography affects the intensity and spatial distribution of precipitation due to orographic lifting mechanisms and, in turn, influences the prevailing climate and vegetation distribution. Previous modelling studies on the impact of orographic precipitation on landform evolution have considered bare‐soil conditions. However, research on the effect...

The formation of badlands is commonly linked to the presence of dispersive deposits. Meanwhile, the sediments having more resistance to disintegration might also cause badlands formation given the time and adequate climate conditions. Although the notable influences of climate conditions have been highlighted on badlands morphologies so far, only a...

The study aims to predict the potential future forest cover for Anatolia, a peninsula situated in the Eastern Mediterranean Basin, a historic land bridge between Southeast Europe and Southwest Asia with diverse terrestrial ecosystems hosting uniquely adapted species due to topographic heterogeneity and climatic variability. To forecast the potentia...

Unprecedented wildfires swept Mediterranean Europe in the summer of 2021 wreaking havoc economically and socially while clearing large swaths of forest land. Those that scorched the southern coastal highlands in Turkey came on the heels of a heat wave and at the peak of the arid season. Nearly two thirds of the Anatolian Peninsula are under the inf...

The planning of green-blue spaces (GBSs) requires considering the pedestrian needs in their walking routes for improving the walking experience. Incorporating the quantitative spatial characteristics of pedestrian movement is essential for pedestrian-friendly urban planning, which however received insufficient attention. Based on the space syntax t...

One-size-fits-all approach is common in climate-sensitive urban design due to neglecting spatial heterogeneities in urban form and urban climate. This study explores a spatially-varied climate-sensitive urban design based on the Guangdong-Hong Kong-Macau Greater Bay Area (GBA). Three thermal indices, the Wet Bulb Globe Temperature (WBGT), the Appar...

Soil-vegetation-topography interactions play a central role in the hydrologic cycle, as well as in the ecological and biogeochemical functioning of a catchment, particularly in semi-arid areas, which constitute approximately 40% of the world's land surface. These interactions control numerous processes for terrestrial water resources e.g., evapotra...

Spatially-invariant land use and cover changes (LUCC) are not suitable for managing non-stationary drought conditions. Therefore, developing a spatially varying framework for managing land resources is necessary. In this study, the Dongjiang River Basin in South China is used to exemplify the significance of spatial heterogeneity in land planning o...

Ocean-atmosphere modes of climate variability in the Pacific and Indian oceans, as well as monsoons, regulate the regional wet and dry episodes in tropical regions. However, how those modes of climate variability, and their interactions, lead to spatial differences in drought patterns over tropical Asia at seasonal- to interannual time scales remai...

Photovoltaic technology plays an important role in the sustainable development of clean energy, and arid areas are particularly ideal locations to build large-scale solar farms, all over the world. Modifications to the energy balance and water availability through the installation of large-scale solar farms, however, fundamentally affect the energy...

Groundwater-dependent ecosystems (GDEs) exist all over the world, especially in water-limited regions. To achieve better water management, it is necessary to map and identify GDEs. Central Asia (CA) is one of the most arid regions in the mid-latitudes and one of the major regions with shallow groundwater tables. However, the role of groundwater in...

Drought conditions of Southeast China are associated with the sea surface temperature warm pool in the tropical Western Pacific, which is related to low-frequency hydroclimatic patterns and their teleconnections. Empirically, the moisture influx to the region is linked to the interannual and decadal teleconnections, including the Pacific Decadal Os...

Disentangling the effects of climate and land use changes on regional hydrological conditions is critical for local water and food security. The water variability over climate transition regions at the midlatitudes is sensitive to changes in regional climate and land use. Gansu, located in northwest China, is a midlatitude climate transition region...

Atmospheric transmissivity (τ) is a critical factor in climatology, which affects surface energy balance, measured at a limited number of meteorological stations worldwide. With the limited availability of meteorological datasets in remote areas across different climatic regions, estimation of τ is becoming a challenging task for adequate hydrologi...

Badland areas are present in all continents, excluding Antarctica, and play a critical role in establishing local erosion and sedimentation rates. The presence of unconsolidated rocks (e.g., marls, sandstone, mudstone etc.) is a major driver controlling the distribution of badlands, which together with other environmental components, such as climat...

Turkey, aka Asia Minor, is situated in a distinct spot, surrounded by marine basins on three sides and an inner sea, coastlines on the northern and southern parts of the country cut off from the inner plateau by high mountain ranges showcasing different micro-climatic settings. The area, a natural corridor between two continents, also harbors a hea...

Previous studies on semi-arid ecosystems have shown high values of soil moisture variability (SMV) primarily induced by the combined effects of non-uniform precipitation, incoming solar radiation, and soil and vegetation properties. However, the relative impact of these various factors on SMV has been difficult to evaluate due to limited availabili...

29 Kasım 2018 tarihinde 10:00 UTC’de Bodrum (Muğla) Yarımadası’nın güneyinde başlayan gök gürültülü sağanak yağış, devam eden saatler içinde şiddetini artırmış ve yarımada geneline yayılmıştır. 15:00 UTC’ye kadar aralıksız şekilde devam eden yağış sonucunda, Bodrum Kaymakamlığı’ndan alınan resmi rapora göre 175 konut, 140 işyeri ve 60 araç hasar gö...

Aspect-controlled vegetation over opposing hillslopes are driven by non-uniform distribution of incoming solar radiation in semi-arid ecosystems. This leads to variation in soil and vegetation characteristics. In mid-to high-latitudes where available soil moisture is a limiting factor for vegetation growth, poleward-facing slopes develop denser veg...

Topography plays an important role in controlling the amount and the spatial distribution of precipitation due to orographic lift mechanisms. Thus, it affects the existing climate and vegetation distribution. Recent landscape modelling efforts show how the orographic effects on precipitation result in the development of asymmetric topography. Howev...

Badlands are unique landscapes that are extensively developed on unconsolidated sediments or poorly consolidated bedrocks that are covered by little or no vegetation. They are widely observed landscapes in Turkey similar to arid and semi-arid regions of the world. Turkish badlands are commonly formed on Miocene and Plio-Quaternary deposits, especia...

The widespread presence of spatial and temporal variability in rainfall is well known. However, this variability can not be captured by point gauge measurements alone. An accurate representation of this variability is crucial for hydrological and meteorological applications. Precipitation information is an essential input for all hydrological model...

Contrasts in insolation lead to the development of aspect-controlled ecosystems characterized by heterogeneity in vegetation type and density in semi-arid ecosystems. The aspect-controlled solar radiation creates variation in the type and amount of vegetation across the two opposite facings of the hillslopes. In the Southern Hemisphere (SH), the no...

Soil moisture in semi-arid areas plays a critical role as it regulates numerous ecohydrologic processes in land surface hydrology, subsurface hydrology, and vegetation dynamics. Studies on soil moisture distribution and dynamics currently rely on data obtained using three types of approaches: in situ (generally point-scale) measurements, remotely s...

29 Kasım 2018 tarihinde 10:00 UTC'de Bodrum (Muğla) yarımadasının güneyinde başlayan yağış, devam eden saatler içinde şiddetini artırmış ve yarımada geneline yayılmıştır. 15:00 UTC'ye kadar aralıksız şekilde devam eden yağış sonucunda, Bodrum Kaymakamlığı'ndan alınan resmi rapora göre 175 konut, 140 işyeri ve 60 araç hasar görmüş, ilçenin altyapısı...

The State of Queensland is located in the northeast of Australia. The precipitation, which began on January 19, 2019, in the northeast of Queensland, has been effective over the region until 12 February 2019 by increasing its severity from time to time. The region is under the influence of the low-pressure center and the monsoon trough which occasi...

15 Şubat 2015 00:00 Universal Coordinated Time (UTC)’de 60°N enlemi üzerinde enlemlere paralel uzanan karasal arktik soğuk cephe; 030°E boylamı boyunca güneye doğru hızlı bir şekilde ilerlemiştir. Batı Karadeniz ve İstanbul üzerinden geçerek 17 Şubat 2015 00:00 UTC’de Marmara Denizi üzerine ulaşmıştır. Soğuk cephenin tamamen Batı Karadeniz üzerinde...

On August 31, 2017, a hail storm occurred in rural area in Yomra District of Trabzon Province. The hail storm occurred during the harvest season, and it did not cause big losses on hazelnut production because hazelnuts had been fully grown. The hail storm was recorded, and some of hail accumulations had been photographed by a mobile phone. Diameter...

High levels of atmospheric pollutants have been frequently measured in Turkey during the last decade. Specifically, the occurrence of these high particulate matter concentrations is often related to either local-scale conditions or regional-scale transport. In order to better understand the atmospheric factors that trigger poor air quality, further...

Wind storms and heavy rain are important meteorological parameters that negatively affect aviation. In this study, we investigated high-wind and heavy-rain event days based on a 20-year record of daily maximum gust and total precipitation measurements for 1997-2017 at Williamtown Airport, Newcastle, NSW, Australia. Gust speeds equal or faster than...

Contrasts in insolation lead to the development of aspect-controlled ecosystems characterized by heterogeneity in vegetation type and density in semi-arid ecosystems. Vegetation dynamics are strongly influenced by the availability of soil moisture on opposing hillslopes in semi-arid landscapes. Aspect controls on vegetation type and density have lo...

Water-limited ecosystems are characterized by considerable soil moisture variability (SMV) induced by the presence of a non-uniform vegetation distribution and climatic conditions, as well as the combined effects of aspect, topography, and incoming solar radiation. Partitioning of solar radiation and topographic influence is of utmost importance to...

Water-limited ecosystems are characterized by considerable soil moisture variability (SMV) induced by the presence of a non-uniform vegetation distribution and climatic conditions, as well as the combined effects of aspect, topography, and incoming solar radiation. Partitioning of solar radiation and topographic influence is of utmost importance to...

Water-limited ecosystems are characterized by considerable soil moisture variability (SMV) induced by the presence of a non-uniform vegetation distribution and extreme climatic conditions, as well as the combined effects of aspect, topography, and soil texture controls. Understanding this variability is important for the optimal management of water...

The non-uniformity in insolation leads to the development of aspect-controlled ecosystems characterised by heterogeneity in vegetation. Vegetation dynamics is strongly influenced by the availability of soil moisture in opposing hillslopes in semi-arid landscapes; which in turn is responsible for the water balance, soil moisture dynamics as well as...

EP11C-2078  Due to solar insolation, semiarid landscapes experience differentiation in vegetation type and density on opposing hillslopes.  Xeric and sparse vegetation on equator-facing slopes (EFS).  Mesic and denser canopy exists at polar-facing slopes (PFS).  EFS are more prone to erosion due to less vegetation cover leading to gentler slope...

In Part 1 of this two-part manuscript series, we presented an effective assessment method for mapping inundation of geographically isolated wetlands (GIWs) and quantifying their cumulative landscape-scale hydrological connectivity with downstream waters using time series remotely sensed data (Yeo et al., 2018). This study suggested strong hydrologi...

Headwater wetlands affect ecosystem integrity of downstream waters; however, many wetlands – particularly geographically isolated wetlands (GIWs) – continue to be at risk. A significant portion of US federal policy is based on the jurisdictional status of wetlands, which is partly determined by the relationship between wetlands and downstream water...

Anthropogenic activities and climate change are imposing an unprecedented pressure on drylands, increasing their vulnerability to desertification. The spatial organization of the sparse vegetation cover is fundamental for the healthy function of the system, and disturbances can trigger cascading feedbacks leading to catastrophic system collapse. He...

Landscape evolution models (LEMs) are essential tools for the estimation of rehabilitation designs in order to carry out post-mining landscapes. There exist an important question which requires accurate quantification of sediment loss for a post-mining landscape. Geomorphic features are the most important factors which affect the sediment loss and...

Soil moisture variability (SMV) in semiarid landscapes is affected by vegetation, soil texture, climate, aspect, and topography. The heterogeneity in vegetation cover that results from the effects of microclimate, terrain attributes (slope gradient, aspect, drainage area etc.), soil properties, and spatial variability in precipitation have been rep...

Aspect-controlled vegetation patterns emerge as a result of solar insolation in semi-arid ecosystems which leads to a differentiation in soil properties and vegetation characteristics. Denser vegetation cover on poleward-facing aspects provides more erosion protection than on the equatorward-facing aspects. The variation of the protective vegetatio...

Despite the well-documented ecologic and morphologic differences in opposing north- and south-facing slopes in most landscapes, little is known about how the eco-hydro-geomorphic feedbacks controlled by slope form, aspect, and local insolation influence the erosion rates and resulting catchment form. Our ability to predict the long-term controls of...

This study examines the role of climate change during the late Pleistocene-Holocene transition on landscape morphology in a semi-arid basin in central New Mexico through a modeling experiment, corroborated with field observations. In central New Mexico transition from a wetter and cooler climate to recent drier and warmer climate have led to change...

This paper examines the relationship between land surface properties (e.g. soil, vegetation, and lithology) and landscape morphology quantified by the catchment descriptors: the slope–area (S–A) relation, curvature–area (C–A) relation, and the cumulative area distribution (CAD), in two semi-arid basins in central New Mexico. The first site is compo...

The urban heat island (UHI) is a result of urbanization, causing local microclimatologic changes such as increase in ambient temperature. Factors causing the UHI effect are anthropogenic energy release, energy absorption by concrete, tarmac structures and traffic, although the main factor is the replacement of vegetation with man-made structures. T...

Afyon geothermal district heating system (AFJET) provides heating to 4519 residences, covering an area of 513,683m2. Due to limitations in reinjection capacity, geothermal waters are released to the Akarcay Stream, detrimentally affecting the environment. Optimum heating load of the system was determined for a given ambient conditions with respect...