This study is focused on the comparison of streamflow composition simulated with three well-known rainfall–runoff (RR) models (ECOMAG, HBV, SWAT) against hydrograph decomposition evaluated with End-Member Mixing Analysis (EMMA). In situ observations at two small mountain testbed catchments located in the south of Pacific Russia are used. All applied RR models and EMMA analysis demonstrate that two neighboring catchments disagree significantly on the mutual dynamics of the runoff sources. The RR models' benchmark test is based on proximity to EMMA hydrograph composition. Different aggregation intervals (season, month, and pentad) were applied to find a reasonable generalization period ensuring the clarity of results. ECOMAG is most conformable to EMMA outcome; HBV reflects flood events well enough; SWAT exhibits distinctive behavior compared to the other models. It is shown that, along with standard efficiency criteria of simulated and observed runoff proximity, EMMA analysis might provide useful auxiliary information for the validation of modelling results.

The open-source low-parametric conceptual hydrological model GR4J was used for runoff simulations of 17 nested catchments of the Upper Ussuri River basin w

There is little information about moisture changes in different altitudinal belts in mountainous regions of the southern Russian Far East. We present ecological and taxonomic compositions of the diatom flora and identify the botanical composition of peat in small mountain lake/mire complexes located in the Central Sikhote-Alin Mountains, within large landslides on the paleovolcanic slopes. Frequent changes in diatom assemblages and peat-forming plants indicate unstable hydroclimatic conditions with varying degrees of wet and dry conditions up to the overgrowth of the lakes. Frequent change in sphagnum mosses with different trophic preferences was identified. The chronology is based on 11 radiocarbon dates. Accumulation rates reached 1.7–1.9 mm/year, and the temporal resolution for the reconstructions was up to 30–40 yr. The tendencies of lake evolution depended on different scale hydroclimatic changes over the last 4400 yr. The most detailed data for the last 2600 yr were obtained from the Nizhnee Lake sequence, which is more sensitive to climatic changes. The main reason for the change in the hydrological regime of the lakes was variations in precipitation during short-term climatic changes. The sediment record of moisture fluctuations is relatively well correlated with regional patterns reflecting summer monsoon intensity and cyclogenesis activity.

Определение реакции речных систем на климатические изменения является одной из ключевых проблем современной гидрологии. Тем более это касается Дальнего Востока России, режим увлажнения которого известен своей неустойчивостью. В настоящей статье представлены результаты оценки изменения характеристик паводкового стока рек бассейна Уссури при ожидаемых изменениях климата, связанных с глобальным потеплением. Оценки выполнены на основе схемы динамикостохастического моделирования, при которой на вход в гидрологическую модель подаются многочисленные ряды синтетических осадков, для перебора всевозможных условий увлажнения на водосборе. Для расчетов стока использовалась региональная гидрологическая модель паводочного цикла малого речного бассейна, ориентированная на описание процессов формирования стока летне осеннего паводкового периода. Для задания климатического сценария использовалось объединение регионализированной стохастической модели осадков и данных расчетов по глобальным моделям климата (GCM) на последнюю треть XXI века (2071 2100 гг.). Показано, что увеличение осадков приводит к непропорциональному отклику в исследуемых характеристиках максимального стока теплого периода года. При этом относительный рост норм максимальных расходов за сезон достигает 4 5 раз, а норм суммарного слоя стока 2 3 раз в зависимости от варианта расчета с совмещением различных климатических моделей и сценариев. Полученные результаты согласуются с анализом данных наблюдений на основе использования так называемого коэффициента эластичности , а также с проведенными ранее исследованиями. Таким образом, при климатических изменениях можно предполагать рост паводковой опасности в исследуемом регионе. Виноградов Ю.Б. Математическое моде-лирование процессов формирования сто-ка. Л.: Гидрометеоиздат, 1988. 311 с. Гарцман Б.И. Дождевые наводнения на реках юга Дальнего Востока: методы рас-четов, прогнозов, оценок риска. Влади-восток: Дальнаука, 2008. 421 с. Гарцман Б.И. Губарева Т.С. Прогноз гид-рографа дождевых паводков на реках Дальнего Востока // Метеорология и гид-рология. 2007. № 5. с. 70-80. Гарцман И.Н. Лыло В.М. Черненко В.Г. Паводочный сток рек Дальнего Востока. Л.: Гидрометеоиздат, 1971. 264 с. Гельфан А.Н. Динамико-стохастическое моделирование формирования талого стока. М.: ИВП РАН, 2007. 294 с. Гельфан А.Н. Морейдо В.М. Описание макромасштабной структуры поля снеж-ного покрова равнинной территории с помощью динамико-стохастической мо-дели его формирования // Лёд и Снег. 2015. Т.55. № 4. c. 61-72. Bales R., Molotch N., Painter Th., Dettinger M., Rice R., Dozier J. Mountain hydrology of the western United States // Water Resources Research. 2006. V. 42. Iss. 8. W08432. DOI: 10.1029/2005WR004387 Belyakova P.A. Gartsman B.I. Possibilities of Flood Forecasting in the West Caucasian Rivers Based on FCM Model // Water Re-sources. 2018. V. 45 (Suppl. 1). P. 50-58 DOI: 10.1134/S0097807818050317 Bentsen M. et al. The Norwegian Earth sys-tem model, NorESM1-M – Part 1: Descrip-tion and basic evaluation of the physical cli-mate // Geoscientific Model Development. 2013. Vol. 6. P. 687-720. DOI: 10.5194/gmdd-5-2843-2012 Chen N.Ch. Lee K.T. Gartsman B.I. Applica-tion of Flood Cycle Model for daily flow simulating in different climate area // Taiwan Water Conservancy. 2008. Vol. 56. No. 2. P. 1-13. Dufresne J.-L. et al. Climate change projec-tions using the IPSL-CM5 Earth System Model: from CMIP3 to CMIP5 // Climate Dynamics. 2013. V. 40. Iss. 9-10. P. 2123-2165. DOI: 10.1007/s00382-012-1636-1 Dunne J. et al. GFDL’s ESM2 Global Cou-pled Climate-Carbon Earth System Models. Part I: Physical Formulation and Baseline Simulation Characteristics // Journal of Cli-mate. 2012. Vol. 25. No. 19. P. 6646-6665. DOI: 10.1175/JCLI-D-11-00560.1 Gartsman B.I. Lupakov S.Yu. Effect of cli-mate changes on the maximal runoff in the Amur Basin: Estimation based on dynamic-stochastic simulation // Water Resources. 2017. Vol. 44. Iss. 5. P....

The efficiency of runoff simulation, the values of parameters, and the dynamics of the estimated runoff components were analyzed for two conceptual hydrological models GR4J and HBV for 17 watersheds in the Upper Ussuri River (Primorsky Krai, Russia) with areas from 138 to 24 400 km². Both models demonstrate an increase in the simulation efficiency (based on NSE criterion) with an increase in the catchment area up to 1–2 thousand km², after which they stabilize within the interval of 0.75–0.85 for the calibration period and 0.70–0.80 for the verification period. The estimates obtained for the HBV model were 5–10% higher than those for the GR4J model. Analysis of the measured and calculated annual runoff maximums over the warm season suggests the conclusion that GR4J model is on the average 5–6% more efficient than the HBV model in calculating the maximal values of rain flood discharges. At the same time, the obtained values of the relative error BIAS demonstrate a more accurate reproduction of the annual average runoff by the HBV model. The main distinctions determining the efficiency of simulation in the study region are as follows: the method of considering the precipitation height increments within altitude belts, the specific features of the calculation of model evapotranspiration, the method for calculating the outflow from conceptual runoff-forming storages in the GR4J and HBV models.

There is little information about moisture changes in different altitudinal belts in mountainous regions of the Southern Russian Far East. We present ecological-taxonomic composition of the diatom flora, the botanical composition of peat of small mountain lake/mire complexes located in the Central Sikhote-Alin within large landslides on the paleovolcano slopes are identified. Frequent changes in diatom assemblages and peat-forming plants indicate unstable hydroclimatic conditions with varying degrees of watering and dry condition up to complete overgrowth of the lakes. Frequent change of sphagnum mosses with different trophic preferences was established. The chronology is based on 11 radiocarbon dates. Accumulation rates reached up to 1.9 mm/year, the temporal resolution for the reconstructions is up to 30–40 years. The tendencies of lake evolution depended on different-scale hydroclimatic changes for the last 4400 yr. The most detailed data for the last 2600 yr were obtained from the Nizhnee Lake sequence, more sensitive to climatic changes. The main reason for the change in the hydrological regime of the lakes was variations in precipitation during short-term climatic changes. The sediment record moisture fluctuations are relatively well correlated with regional patterns reflecting summer monsoon intensity and cyclogenesis activity.