Naryn River Research Articles

Picrodolerite Dikes of the Naryn River: Age, Composition, and Position in the Geological History of Southern Tuva (Central Asian Orogenic Belt)

Picrodolerite Dikes of the Naryn River: Age, Composition, and Position in the Geological History of Southern Tuva (Central Asian Orogenic Belt)

Repeated failures of the giant Beshkiol Landslide and their impact on the long-term Naryn Basin floodings, Kyrgyz Tien Shan

Landslides are major hazards that lead to cataclysmic changes in regional physiography. Their consequences are particularly significant when they affect a river system, forming dammed-lake upstream that represents a high flood threat for the downstream region. The Naryn River is the largest river in the Kyrgyz Tien Shan and is of great economic importance. The Beshkiol Landslide, the largest one in Central Asia but of unknown age, has most likely blocked the Naryn River in the past during the Late Pleistocene, with evidence of thick lacustrine deposits as well as numerous paleo-shorelines preserved upstream. In this study, a detailed geomorphological and sedimentological analysis combined with luminescence and 14C dating provides a strong chronological framework to refine the dynamics between the Beshkiol landslides and dammed-lakes in the Naryn Basin. We propose that the Beshkiol Landslide was first triggered 51.9 ± 4.4 kyrs ago, with a 410 m-high dam that blocked the Naryn River. A first lake with a total volume of 121 ± 50 km3 lasted for >37.0 ± 5.1 kyrs, one of the longest landslide-dammed lake residence time ever documented in the world. Our sedimentological observations highlight a catastrophic lake outburst flood between 15.6 and 14.1 kyrs cal BP, likely related to a landslide dam breach. A short-lived phase of fluvial erosion impacted the whole Naryn Basin followed by a second landslide activation (280 m- high dam) and subsequent flooding by a second lake of 27 ± 10 km3. This second lake had a minimum residence time of 7.7 ± 1.3 kyrs before its final gradual drainage that was followed by a fluvial erosional phase still active today in the Naryn Basin. We also suggest that the distal unconsolidated part of the Beshkiol Landslide could be remobilized in the event of an earthquake and/or extreme rain episode, causing a potentially dam of the Naryn River, which would have strong regional economic impacts.

Surface water quality in the upper reaches of the Naryn River basin: Composition and seasonal changes

Surface water quality in the upper reaches of the Naryn River basin: Composition and seasonal changes

Biogeomorphology from space: Analyzing the dynamic interactions between hydromorphology and vegetation along the Naryn River in Kyrgyzstan based on dense satellite time series

The structure and development of river corridors are controlled by an interplay of hydrological, geomorphological and ecological processes over a range of spatial and temporal scales. The majority of existing studies on fluvial biogeomorphology focus either on conceptual development or on investigations on the scales of single geomorphic units or study reaches. With this study, we extend the view on biogeomorphology beyond the reach scale using satellite time series. We take the Naryn River in Kyrgyzstan as an example for demonstrating our approach to biogeomorphological analysis of river corridors. The Naryn is still in a natural state on an entire flow length of more than 600 km with full longitudinal and lateral connectivity. Along the central part of the catchment, the Naryn is a highly dynamic braided river system. This makes this river ideal to study large scale biogeomorphological dynamics. In our study, we follow the well-established concept of biogeomorphological succession. We mapped the different succession stages in the field and used the results to derive spectral-temporal indices characterizing the different biogeomorphological succession stages. Monthly time series of the modified difference water index as well as the normalized difference vegetation index derived from the Landsat archive have been used to compute statistical trends and changepoints by means of a Bayesian time series decomposition algorithm. The results are then evaluated regarding biogeomorphological succession and disturbance events. The results show that dense satellite time series are well suited to derive indicators of biogeomorphological interactions on large spatial scale. The temporally continuous nature of this kind of observations allows an observation of processes and an interpretation for instance against the background of the theory of adaptive cycles and panarchy. In conclusion, the suggested approach has the potential to give new insights in the structure and functioning of entire river corridors or networks.

Saussurea arctecapitulata Lipsch. – new species for the flora of Russia

Saussurea arctecapitulata, a herbaceous perennial species, belonging to the type section of the genus Saussurea, previously known only from a few localities in the northern Mongolia, has been found in the Naryn River Valley during field trips to the territory of Republic of Tuva. This article presents an updated description accompanied by photos of the species in nature, updated data on the distribution of the species, as well as phylogenetic relationships with morphologically similar species of the section based on the variability of the site ITS1-5.8S-ITS2.

Analysis of parameter uncertainty in SWAT model using a Bayesian Box–Cox transformation three-level factorial analysis method: a case of Naryn River Basin

Abstract Hydrological models are often plagued by substantial uncertainties in model parameters when analyzing water balance, predicting long-time streamflow, and investigating climate-change impact in watershed management. In this study, a Bayesian Box–Cox transformation three-level factorial analysis (BBC-TFA) method is developed for revealing the influence of parameter uncertainty on the runoff in the Naryn River Basin. BBC-TFA cannot only quantify the uncertainty through Bayesian inference but also investigate the individual and interactive effects of multiple parameters on model output. Main findings disclose that: (i) the contribution rate of runoff potential parameter during the non-melting period reaches 88.22%, indicating a flood risk in the rainy season; (ii) the contribution rate of snow temperature lag factor is the highest during the snow-melting period and the entire year (respectively occupying 76.69 and 53.70%), indicating that the glacier melting exists in the Naryn River Basin throughout the year; (iii) the Box–Cox transformation can successfully remove residual variance and enhance the correlation between input and output variables. These findings serve to revealing the presence of glacial resources in the study basin and the significant runoff during the rainy season. Policymakers can consider water storage during the rainy season while developing glacier resources to alleviate water scarcity.

Shifted discharge and drier soils: Hydrological projections for a Central Asian catchment

Study RegionThe Naryn River Basin, KyrgyzstanStudy FocusWe investigate the impacts of climate change in the basin based on two families of General Circulation Models (GCMs) using the hydrological model SWAT. The forcing datasets are the widely used ISIMIP2 (I2) and the newly derived ISIMIP3 (I3) data which refer to the 5th and 6th stage of the Coupled Model Intercomparison Project (CMIP). Due to notable differences in the forcing we evaluate their impacts on various hydrological components of the basin, such as discharge, evapotranspiration (ETA) and soil moisture (SM). Besides, a partial correlation (PC) analysis is used to assess the meteorological controls of the basin with special emphasize on the SM-ETA coupling.New Hydrological Insights for the RegionAgreement in the basin’s projections is found, such as discharge shifts towards an earlier peak flow of one month, significant SM reductions and ETA increases. I3 temperature projections exceed their previous estimates and show an increase in precipitation, which differs from I2. However, the mitigating effects do not lead to an improvement in the region’s susceptibility to soil moisture deficits. The PC study reveals enhanced water-limited conditions expressed as positive SM-ETA feedback under I2 and I3, albeit slightly weaker under I3.

A snow and glacier hydrological model for large catchments – case study for the Naryn River, central Asia

Abstract. In this paper we implement a degree day snowmelt and glacier melt model in the Dynamic fluxEs and ConnectIvity for Predictions of HydRology (DECIPHeR) model. The purpose is to develop a hydrological model that can be applied to large glaciated and snow-fed catchments yet is computationally efficient enough to include model uncertainty in streamflow predictions. The model is evaluated by simulating monthly discharge at six gauging stations in the Naryn River catchment (57 833 km2) in central Asia over the period 1951 to a variable end date between 1980 and 1995 depending on the availability of discharge observations. The spatial distribution of simulated snow cover is validated against MODIS weekly snow extent for the years 2001–2007. Discharge is calibrated by selecting parameter sets using Latin hypercube sampling and assessing the model performance using six evaluation metrics. The model shows good performance in simulating monthly discharge for the calibration period (NSE is 0.74<NSE<0.87) and validation period (0.7<NSE<0.9), where the range of NSE values represents the 5th–95th percentile prediction limits across the gauging stations. The exception is the Uch-Kurgan station, which exhibits a reduction in model performance during the validation period attributed to commissioning of the Toktogul reservoir in 1975 which impacted the observations. The model reproduces the spatial extent in seasonal snow cover well when evaluated against MODIS snow extent; 86 % of the snow extent is captured (mean 2001–2007) for the median ensemble member of the best 0.5 % calibration simulations. We establish the present-day contributions of glacier melt, snowmelt and rainfall to the total annual runoff and the timing of when these components dominate river flow. The model predicts well the observed increase in discharge during the spring (April–May) associated with the onset of snow melting and peak discharge during the summer (June, July and August) associated with glacier melting. Snow melting is the largest component of the annual runoff (89 %), followed by the rainfall (9 %) and the glacier melt component (2 %), where the values refer to the 50th percentile estimates at the catchment outlet gauging station Uch-Kurgan. In August, glacier melting can contribute up to 66 % of the total runoff at the highly glacierized Naryn headwater sub-catchment. The glaciated area predicted by the best 0.5 % calibration simulations overlaps the Landsat observations for the late 1990s and mid-2000s. Despite good predictions for discharge, the model produces a large range of estimates for the glaciated area (680–1196 km2) (5th–95th percentile limits) at the end of the simulation period. To constrain these estimates further, additional observations such as glacier mass balance, snow depth or snow extent should be used directly to constrain model simulations.

Kyrgyz transboundary rivers’ runoff assessment (Syr-darya and Amu-darya river basins) in climate change scenarios

The research was carried out as part of the preparation “Water Resources” section of the 4th National Communication of the Kyrgyz Republic to the UNFCCC. The article presents extensive information on the current state and changes over a long period of observations of water resources, climate and glaciation in Kyrgyzstan (Syr-Darya and Amu-Darya river basins). The representative rivers were selected as the main objects, which are transboundary between Kyrgyzstan, Uzbekistan, Kazakhstan and Tajikistan. The study aims to assess the inter-annual and intra-annual dynamics of the flow of the rivers for the period from 2020 to 2080, based on the climate projections CMIP5 (RCP4.5 and RCP8.5) and CMIP6 (SSP2-4.5 and SSP5-8.5) (IPCC WG II Report, 2022). The hydrological modeling method in the HBV light and HBV EHT models and the inertial mean annual flow change method were used to estimate changes in water resources. On the rivers of the northern part of the Fergana Valley, the average annual runoff is expected to increase by 1-19%, in the Amudarya river basin (Kyzyl-Suu river) – by 27-64% of the values for 2006-2019. In the Naryn river, water discharge for this period will remain within the current values for 2006-2019. The method of inertial change in the average annual runoff showed an increase in runoff for 2030 and 2040 for all the studied catchment areas by 6-19% of the current values for 2006-2020. The results of the study are intended for decision-makers on the rational use and long-term planning of water resources under climate change.

Corrigendum: Glacier runoff variation since 1981 in the upper Naryn river catchments, Central Tien Shan

The original version of this article has been updated.In the published article, there was a mistake in the Funding statement. In the published article, there was an error. [The Acknowledgements section is missing one statement ].A correction has been made to [Acknowledgements], This sentence previously stated: "[We thank the project CICADA (Cryospheric Climate Services for improved Adaptation), with contract no. 81049674 between Swiss Agency for Development and Cooperation and the University of Fribourg. The CAWa (Central Asian Water) project (http://www.cawa-project.net) was supported by the German Federal Foreign Office (contract no. AA7090002) as a part of the "Berlin Process". This work was carried out with the support of the CAWa ("Central Asia Water") project (www. cawaproject .net, contract no. AA7090002) funded by the German Federal Ministry of Foreign Affairs as part of the "Berlin Process". The authors are grateful to Agency of Hydrometeorology under the Ministry of Emergency Situations of the Kyrgyz Republic (KyrgyzHydromet) for the provision of data.]"The corrected paragraph appears below:

Hydrological Forecasting under Climate Variability Using Modeling and Earth Observations in the Naryn River Basin, Kyrgyzstan

The availability of water resources in Central Asia depends greatly on snow accumulation in the mountains of Tien-Shan and Pamir. It is important to precisely forecast water availability as it is shared by several countries and has a transboundary context. The impact of climate change in this region requires improving the quality of hydrological forecasts in the Naryn river basin. This is especially true for the growing season due to the unpredictable climate behavior. A real-time monitoring and forecasting system based on hydrological watershed models is widely used for forecast monitoring. The study’s main objective is to simulate hydrological forecasts for three different hydrological stations (Uch-Terek, Naryn, and Big-Naryn) located in the Naryn river basin, the main water formation area of the Syrdarya River. We used the MODSNOW model to generate statistical forecast models. The model simulates the hydrological cycle using standard meteorological data, discharge data, and remote sensing data based on the MODIS snow cover area. As for the forecast at the monthly scale, the model considers the snow cover conditions at separate elevation zones. The operation of a watershed model includes the effects of climate change on river dynamics, especially snowfall and its melting processes in different altitude zones of the Naryn river basin. The linear regression models were produced for monthly and yearly hydrological forecasts. The linear regression shows R2 values of 0.81, 0.75, and 0.77 (Uch-Terek, Naryn, and Big-Naryn, respectively). The correlation between discharge and snow cover at various elevation zones was used to examine the relationship between snow cover and the elevation of the study. The best correlation was in May, June, and July for the elevation ranging from 1000–1500 m in station Uch-Terek, and 1500–3500 m in stations Naryn and Big-Naryn. The best correlation was in June: 0.87; 0.76; 0.84, and May for the elevation ranging from 1000–3500 m in station Uch-Terek, and 2000–3000 m in stations Naryn and Big-Naryn. Hydrological forecast modeling in this study aims to provide helpful information to improve our under-standing that the snow cover is the central aspect of water accumulation.

In Search for the Optimal Forest Use Behaviour: Riparian Forest Use in Central Asia, Using the Example of Ak-Tal, Naryn, Kyrgyzstan

Riparian forests are rare and valuable ecosystems in Central Asia, both due to their significance for biodiversity and to their provision of vital ecosystem services to local residents. However, the actual forest use behaviour is under-researched, official figures may not be trustworthy, and the question of over-use is up in the air. This paper sets out to shed light on riparian forest use behaviour by local residents using the example of Ak-Tal Village upon the Naryn River in Kyrgyzstan: Which economic use patterns do they practice (focusing on fuel wood and pasture)? Which other ecosystem services do they recognise? Is there forest over-exploitation? To answer these questions, this study builds on local knowledge, by applying the methods of focus group discussions and a household survey. Results show an extreme discrepancy between official wood consumption figures (50–60 m3 p.a.) and figures based on household wood consumption (310–404 m3 p.a.). The forest also serves as an important winter pasture over the seven months between October and April (stocking density 0.61 livestock units/ha), but payments for these ecosystem services are low, with annually 40 KGS/ha. Local residents are aware of additional material and nonmaterial ecosystem services of the riparian forest. Opinions diverge upon the question if there is forest over-exploitation, potentially because different stakeholders have different concepts of an optimal forest status. Consequently, optimal forest use behaviour can only be defined by the local users themselves, e.g., in a future stakeholder dialogue.

Kulanak Hydroelectric Power Station on the Naryn River in the Kyrgyz Republic: Design Features

Kulanak Hydroelectric Power Station on the Naryn River in the Kyrgyz Republic: Design Features

GEOMORPHOLOGICAL STRUCTURES OF THE FLOODPLAIN AREAS OF THE NARYN RIVER (KYRGYZSTAN)

The ecological state of floodplains is estimated by a high number of different structural units. This is important for ensuring the ecological function and increasing the sustainability of river ecosystems. The impact of land use change on fluvial and hydrological changes in the floodplain and its terraced surface is important for understanding current geomorphological processes. The increase in roughness and the accumulation of sediments on the surface of the floodplain is favorable for the uniform distribution of the river flow. To study the dynamics of changes in the riverbed, study sites were selected far and near settlements, using the example of the village of Emgek-Talaa and Ak-Tal in the Naryn region of Kyrgyzstan. To study changes in the landscape, satellite images were used to map the study areas. Assessment of changes is necessary for the further development of the restoration plan for the structure of floodplain rivers. The results of the study will provide information on management options and assist local authorities in the integrated management of natural resources.

Glacier Runoff Variation Since 1981 in the Upper Naryn River Catchments, Central Tien Shan

Water resources in Central Asia strongly depend on glaciers, which in turn adjust their size in response to climate variations. We investigate glacier runoff in the period 1981–2019 in the upper Naryn basin, Kyrgyzstan. The basins contain more than 1,000 glaciers, which cover a total area of 776 km2. We model the mass balance and runoff contribution of all glaciers with a simplified energy balance melt model and distributed accumulation model driven by ERA5 LAND re-analysis data for the time period of 1981–2019. The results are evaluated against discharge records, satellite-derived snow cover, stake readings from individual glaciers, and geodetic mass balances. Modelled glacier volume decreased by approximately 6.7 km3 or 14%, and the majority of the mass loss took place from 1996 until 2019. The decreasing trend is the result of increasingly negative summer mass balances whereas winter mass balances show no substantial trend. Analysis of the discharge data suggests an increasing runoff for the past two decades, which is, however only partly reflected in an increase of glacier melt. Moreover, the strongest increase in discharge is observed in winter, suggesting either a prolonged melting period and/or increased groundwater discharge. The average runoff from the glacierized areas in summer months (June to August) constitutes approximately 23% of the total contributions to the basin’s runoff. The results highlight the strong regional variability in glacier-climate interactions in Central Asia.

Assessing the Impacts on Natural Ecosystems of the Future Kambarata-1 Hydropower Station on the Naryn River, Kyrgyzstan: A GIS-based Approach

In the semi-arid climate of Kyrgyzstan, the rivers have a particular importance in providing water for irrigation in agriculture, and for the production of hydropower. Kyrgyzstan is in general rich in water resources. Nevertheless, there are conflicts surrounding the operation of Toktogul, one of the most important reservoirs in the region. Exploiting the hydropower potential of the currently free-flowing upper Naryn River is therefore an ongoing planning issue. Despite the obvious advantages, the planned construction of Kambarata-1 hydropower station would cause a significant alteration of the natural conditions of the Naryn. However, there are no recent studies on the ecological impact of this hydropower project. The present study contributes to filling this gap, delivering up-to-date information on the potential impact of the reservoir construction on the natural ecosystems in the area. The results show that, due to the geomorphological characteristics of the reservoir site, it is mostly steppe ecosystems that will be affected by the reservoir construction, and only a relatively small area of floodplain forest will be destroyed. In conclusion, the ecological impacts of Kambarata-1 HPS are minimal due to the specific characteristics of the location.

Energy Profiling of a High-Altitude Kyrgyz Community: Challenges and Motivations to Preserve Floodplain Ecosystems Based on Household Survey

The floodplain areas along the Naryn River in Kyrgyzstan are essential as they hold the riparian (local) ecosystems because they provide firewood, pastureland, and areas for recreation and protection against erosion. Due to limited access to adequate, reliable, and sustainable energy services, the rural population usually derived their energy needs from multiple natural energy resources (i.e., firewood, charcoal, agricultural residues, animal dung, and wood branches). This is considered a common and predominant practice in rural Kyrgyzstan. This situation leads to a negative impact on local ecosystem services. In addition to that, the reliance on solid fuels contributes to indoor and outdoor air pollution, which is partially threatening the local ecosystem services. By contrast, the employment of renewable-based energy supply systems would substantially reduce the burden on the environment, which is mainly untapped. To integrate renewable energies, it is important to understand the energy behavior of floodplain communities. In that response, the presented article is the first attempt to capture the energy identity of the floodplain community of Kyrgyzstan based on a quantitative energy-based (on-site) household survey. Furthermore, the present research article synthesizes the driving factors that have a (direct or indirect) impact on the energy and local ecosystem services. In addition, the present article proposes a brief pathway for the sustainable energy transition. The article records the recommendation to integrate renewable energies to preserve the local ecosystems of Kyrgyzstan.

Identifying the runoff variation in the Naryn River Basin under multiple climate and land-use change scenarios

Abstract A multiple scenario-based ensemble prediction (MSEP) method is developed for exploring the impacts of climate and land-use changes on runoff in the Naryn River Basin. MSEP incorporates multiple global climate models, Cellular Automata–Markov and Soil and Water Assessment Tool (SWAT) within a general framework. MSEP can simultaneously analyze the effects of climate and land-use changes on runoff, as well as providing multiple climate and land-use scenarios to reflect the associated uncertainties in runoff simulation and prediction. A total of 96 scenarios are considered to analyze the trend and range of future runoff. Ensemble prediction results reveal that (i) climate change plays a leading role in runoff variation; (ii) compared to the baseline values, peak flow would increase 36.6% and low flow would reduce 36.8% by the 2080s, which would result in flooding and drought risks in the future and (iii) every additional hectare of arable land would increase the water deficit by an average of 10.9 × 103 m3, implying that the arable land should be carefully expanded in the future. Results suggest that, to mitigate the impact of climate change, the rational control of arable land and the active promotion of irrigation efficiency are beneficial for water resources management and ecological environmental recovery.

Recurrence of earthquakes in the area of the Toktogul HPP cascade

A brief statistical analysis of the current seismicity of the Toktogul region of the Kyrgyz Republic is done. The analysis concerns the region where the Toktogul HPP cascade on the Naryn River is located, and covers the period from 1973 to 2021 years. The space-time distributions of earthquakes, accumulation characteristics, probability and recurrence of seismic events of various magnitudes are considered. According to the analysis results, the maximum magnitude of seismic events in the Toktogul region can be ∼ 7.4, and the recurrence period of earthquakes with a magnitude of M ≥ 7 and above T ≥ 10 years is equal.

Geomorphological Characterization of Rivers Using Virtual Globes and Digital Elevation Data: A Case Study from the Naryn River in Kyrgyzstan

In recent years, fluvial geomorphology included a range of new technologies for the characterization of riverine landscapes in the pool of methods. LIDAR, the analysis of drone imagery or satellite remote sensing improved the ability to analyze river systems in manifold ways. However, the high demand for (often expensive) data and processing skills limit the application commonly to smaller study reaches or to regions where data is already available. In contrast, a range of conceptual frameworks for the geomorphological characterization of river systems highlights the relevance of integrating the catchment scale context. Against this background, virtual globes such as Google Earth are cost-efficient alternatives as they make high resolution satellite imagery available almost worldwide. Merging the information mapped from virtual globes with digital elevation data allows the interpretation of riverscape attributes in the context of the longitudinal profile. In our study, we present the geomorphological mapping of the more than 600 km long Naryn River in Kyrgyzstan based on different virtual globes and the SRTM-1 digital elevation model. The experience from this mapping exercise suggests that the combination of virtual globe imagery and elevation data is a powerful and cost-efficient approach for river research and application in the context of data-scarce river corridors.