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River water level prediction (WLP) plays an important role in flood control, navigation, and water supply. In this study, a WaveNet-based convolutional neural network (WCNN) with a lightweight structure and good parallelism was developed to improve the prediction accuracy and time effectiveness of WLP. It was applied to predict 1/2/3 days ahead the water levels at the Waizhou gauging station of the Ganjiang River (GR) in China, and it was compared with two recurrent neural networks (long short-term memory (LSTM) and gated recurrent unit (GRU)). The results showed that the WCNN model achieved the best prediction performance with the fewest training parameters and time. Compared with the LSTM and GRU models in the 1-day ahead prediction, the training parameters were reduced from 73,851 and 55,851 to 32,937, respectively. The root mean square error (RMSE) was reduced from 0.071 and 0.076 to 0.057, respectively. The mean absolute error (MAE) was reduced from 0.052 and 0.059 to 0.038, respectively. The Nash–Sutcliffe efficiency (NSE) and coefficient of determination (R2) both increased to 0.998. This result indicated that the improved model was more efficient for WLP. HIGHLIGHTS A WaveNet-based convolutional neural network was proposed for water level prediction.; WCNN with a lightweight structure and good parallelism achieved better prediction performance.; WCNN obtained higher accuracy results with the fewest parameters and training time than RNN.; Influence of different inputs and hyperparameters of models on prediction results was revealed.;

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The response of blue and green water to climate and land-use change in the Ganjiang River Basin (GRB) is evaluated via the SWAT model that combines three scenarios (the land-use/land-cover (LULC), climate change, and integrated climate and LULC change scenarios) in the 2040s (2031–2050) and 2060s (2051–2070). The results indicate that, for the GRB, cropland, woodland, and grassland show a decreasing trend, while build-up and water areas show an increasing trend in terms of future land-use change. The climatic conditions projected using NORESM1-M model data under the RCP4.5 and RCP8.5 scenarios suggest, respectively, increases in precipitation (31.17 and 27.24 mm), maximum temperature (2.25 and 2.69 °C), and minimum temperature (1.96 and 2.58 °C). Under climate change conditions, blue water is estimated to decrease by up to 16.89 and 21.4 mm under RCP4.5 and RCP8.5, while green water is estimated to increase up to 19.14 and 20.22 mm, respectively. Under the LULC changes, blue water is projected to increase by up to 5.50 and 7.57 mm, while green water shows decreases of 4.05 and 7.80 mm for the LULC2035 and LULC2055 scenarios, respectively. Under the four combined LULC and climate change conditions (RCP4.5_2040s, RCP4.5_2060s, RCP8.5_2040s, and RCP8.5_2060s), blue water tends to decrease by 0.67, 7.47, 7.28, and 9.99 mm, while green water increases by 19.24, 20.8, 13.87, and 22.30 mm. The influence of climate variation on blue and green water resources is comparatively higher than that of the integrated impacts of climate and land-use changes. The results of this study offer a scientific reference for the water resources management and planning department responsible for scheduling water resource management plan in the GRB. HIGHLIGHTS This study investigates the effects of climate changes and land-use changes on blue/green water.; The NORESM1-M model data from the CMIP5 are combined with the SWAT model to analyse the influence of future climate changes on blue/green water.; The CA–Markov model is applied to generate future land-use scenarios.; Multiple climate and land-use scenarios are set to quantitatively analyse the changes of blue/green water.;

There are abundant resources like climate, water, biological and tourism in the middle and upper reaches of the Ganjiang River (MU-GJR), which is an important ecological protection area in hilly areas of South China. The four periods of land use and land cover (LULC) data from 1980 to 2018 and DEM data are the main data support. The LULC change were analyzed with the area proportion, transfers chord diagram and change characteristics map, the response of ecological environment from LULC change was analyzed by using the landscape ecological environment quality (LEEQ) and contribution index. Then the terrain gradient was used to analyze the impact of LULC transfer on ecological environment under different terrain conditions. (1) The LULC characteristics in the study area show that was dominated by forest land and cultivated land (more than 90 %), various types of land transfer significantly from 2010 to 2018, especially the cultivated land, forest land and grassland. The stable type of LULC change was the most widely distributed, followed by the later change type (2010–2018) and mainly distributed in the flat valley, with the largest change range of cultivated land, forest land and grassland. (2) The LEEQ was generally well, but gradually deteriorates. The obvious change of LEEQ was found after 2010. The deterioration type of quality mostly occurs around the city, while the getting better type occurs in the transition area between the city and the mountains. (3) There are more deterioration categories than improvement categories of LULC transfer from 1980 to 2018. The improvement categories were mainly contributed by the transfer to other land to forest land and build-up land to other land. The deterioration categories were mainly contributed by the transfer of forest land to other land. (4) The impact of LULC change on the ecological environment decreases with the increase of elevation, slope and terrain position. There are differences in the impacts of various types of transfer on the ecological environment under the three gradients. In the elevation gradient, the improvement effect were dominant at −105–100 m and 200–500 m, and the deterioration effect were dominant at 100–200 m, 500–1000 m and 1000–2128 m. In the slope gradient, the improvement effect were dominant at 0–2°, 15–25° and 25–69.7°, and the deterioration effect were dominant at 2–6° and 6–15°. In terrain position gradient, improvement effect were dominant at 0–0.32, 0.32–0.51, 0.7–0.9 and 0.9–1.58, and deterioration effect were dominant at 0.51–0.7. Therefore, the specific conditions of different terrain gradients should be considered for land resource development in the middle and upper reaches of Ganjiang River region.

Alleviating flood stress and reducing flood disaster losses are vital issues when operating flood control systems. To address catastrophic floods, this study establishes an optimal flood control operation model for minimizing the excess flood volume of downstream flood control points. A triple-stage operation method (TSOM) is proposed to solve the model by dividing flood control operation processes into three stages. The constructed model is applied to the operation of a flood control system located in the middle and lower reaches of the Ganjiang River, China. The results demonstrate that the TSOM has superiority in solving efficiency, reducing excess flood volume by more than 30–230 million cubic meters compared with the progressive optimality algorithm (POA) for most designed floods with 500-year return periods. Furthermore, the discharge and water level processes created by the TSOM fluctuate less than those created by the POA, which meets the requirements of practical flood control operations. [ABSTRACT FROM AUTHOR]

Egg and larval fish investigation can be deduced the distribution and reproductive characteristics of adult fish. Ganjiang River is the longest river flowing into the Poyang Lake, and one of the important tributaries of the Yangtze River. Due to the construction of cascade water conservancy projects on the mainstream of the river, the fish resources have been affected. In order to correctly design protection measures of fish resources, egg and larval fish species composition and abundance at Fengcheng section in lower reaches of the river were investigated between May and June 2019. The results indicated that: (a) of the 29 species of egg and larval fish collected, and the individuals of Hemiculter bleekeri, Rhinogobius giurinus, Parabramis pekinensis, Squalidus argentatus and Xenocypris argentea were most abundant; (b) egg abundance was higher through May while larval abundance was higher during June; (c) the egg abundance of the four carps further declined and two new spawning grounds were found. Therefore, we suggested that the ecological regulation of the Ganjiang River should be managed to create flood peaks and make the daily increment of water level greater than 0.55 m when water temperature was between 18-24 °C during May to July. [ABSTRACT FROM AUTHOR]

Copyright of Mountain Research (10082786) is the property of Mountain Research Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Ganjiang River, one of eight major tributaries of the Yangtze River, located in the western hinterland of the Cathaysia Block, SE China, has a length of 823 km and a drainage area of 82 809 km2, whose detrital zircons provide a valuable means to trace sediment provenances of the river and explore the crustal growth and evolution of the Cathaysia Block. In the current study, 389 concordia zircon U–Pb age spots and rare earth element (REE) contents, in combination with 201 Lu–Hf isotope analyses, have been determined. Oscillatory zoning, high Th/U ratios and REE distribution patterns indicate that most detrital zircon grains are of magmatic origin. The age can be further divided into seven groups: 130–185 Ma with a peak at 153 Ma (7 %); 217–379 Ma with a peak at 224 Ma (16 %); 390–494 Ma with a peak at 424 Ma (37 %); 500–698 Ma with a peak at 624 Ma (5 %); 716–897 Ma with a peak at 812 Ma (10 %); 902–1191 Ma with a peak at 976 Ma (13 %); and 2232–2614 Ma with a peak at 2471 Ma (5 %). The sources of almost all the zircon age groups can be found from the exposed rocks. In particular, Yanshanian, Hercynian to Indosinian, Pan-African, Grenvillian and Palaeoproterozoic–Archaean zircons can be mainly sourced from the northern Guangdong – southern Jiangxi – western Fujian region, while Caledonian zircons come from southern and central Jiangxi, and Jinningian zircons are from central and northern Jiangxi. Most determined zircon grains exhibit negative ε Hf(t) values and TDM2 ages of 797 to 4016 Ma with a wide peak at 1500–2100 Ma and a keen peak at 1824 Ma, suggesting that most zircons are sourced from the reworked ancient crustal materials or crust–mantle mixing. The zircon Hf model age cumulative probability diagram shows that rapid crustal growth took place at the Palaeo- to Mesoproterozoic and that about 90 % of the crust of the Cathaysia Block was formed before 1.5 Ga. [ABSTRACT FROM AUTHOR]

• Groundwater discharge (GD) in the curved river was identified. • Rn and spatial high-precision data of multiple parameters were used to identify GD. • GD in the large curved river mostly was determined by the heterogeneity of aquifer. Groundwater discharge to rivers is crucial to river quality and aqueous ecosystem, and has increasingly drawn researchers' attention. However, accurately identifying the locations of groundwater discharge in a curved river is still a challenge in hydrology and hydrogeology because the concave and convex banks cause the river-groundwater interaction complicated. This study applied spatial radon isotope (222Rn) continuous-monitoring and spatial high-precision measurements of multiple parameters (temperature, pH, and dissolved oxygen) to identify the groundwater discharge location in a ∼ 10 km curved reach in the lower Ganjiang River (LGJR). The river water influenced by groundwater discharge in the LGJR contained high 222Rn activity, low pH and high temperature. Six sections with groundwater discharge then were identified in the LGJR. Groundwater discharge is more significant on the east bank than on the west. On the concave and convex banks, the groundwater discharge generally occurs in the front neck, which is contrary to the results of most previous studies considering the hyporheic exchange. We inferred that the groundwater discharge in the LGJR is dominated by heterogeneity of regional groundwater flow. This work provides a new insight on the groundwater discharge in the curved river (a common natural morphology of rivers). [ABSTRACT FROM AUTHOR]

Application of the Soil and Water Assessment Tool (SWAT) model is limited in plain polders, where hydrological and nutrient processes are confined by water conservancy facilities such as dikes and pumping stations. Watershed delineation techniques are proposed to enable SWAT to simulate these processes in a plain polder in Jiangxiang Town (Nanchang County, Jiangxi Province, China). Drainage unit division and multiple-outlet modelling approaches are introduced, and the main river network and land features are incorporated into a digital elevation model (DEM), so that drainage unit delineation can agree well with real flow direction and concentration. The impoundments of pumping stations are regarded as functioning like reservoirs, which are set up in the SWAT model to simulate confined hydrological processes. The results show that confined hydrological and nutrient processes in plain polders are simulated well; the retention rates of total nitrogen and total phosphorus are estimated as, respectively, 39% and 29% in both streams and impoundments. [ABSTRACT FROM AUTHOR]

In this work, we traced sources of nitrate in the Ganjiang River, a major tributary of Yangtze River, China, by analysing the water chemistry, nitrogen isotopes and land use. Water samples from 20 sites in the main stream and tributaries were collected in the dry and wet seasons. Theranged from 0.97 to 8.60 ‰, and was significantly higher in the wet season than in the dry season, and significantly higher in tributaries than in the main stream. In the dry season,concentrations andwere significantly negatively correlated with forest and grassland areas, and positively correlated with paddy field and residential area. However, most of the correlations were not significant in the wet season. The results showed that fertilizer was the main source of nitrate in the Ganjiang River, and domestic sewage was important in the dry season, but its contribution was lower than that in other rivers in the Yangtze Basin. In the wet season, the intensified nitrogen cycle caused by high temperature and the mixing effect caused by rainfall made it difficult to trace nitrate sources usingand land use. [ABSTRACT FROM PUBLISHER]

Surface water samples were collected from 20 sampling sites throughout the Ganjiang River during pre-monsoon, monsoon, and post-monsoon seasons, and the concentrations of dissolved trace elements were determined by inductively coupled plasma-mass spectrometry (ICP-MS) for the spatial and seasonal variations, risk assessment, source identification, and categorization for risk area. The result demonstrated that concentrations of the elements exhibited significant seasonality. The high total element concentrations were detected at sites close to the intensive mining and urban activities. The concentrations of the elements were under the permissible limits as prescribed by related standards with a few exceptions. The most of heavy metal pollution index (HPI) values were lower than the critical index limit, indicating the basically clean water used as habitat for aquatic life. As was identified as the priority pollutant of non-carcinogenic and carcinogenic concerns, and the inhabitants ingesting the surface water at particular site might be subjected to the integrated health risks for exposure to the mixed trace elements. Multivariate statistical analyses confirmed that Zn, As, Cd, and Tl were derived from mining and urban activities; V, Cd, and Pb exhibited mixed origin; and Co, Ni, and Cu mainly resulted from natural processes. Three categorized risk areas corresponded to high, moderate, and low risks, respectively. As a whole, the upstream of the Ganjiang River was identified as the high-risk area relatively. [ABSTRACT FROM AUTHOR]

Rainfall information is a prerequisite to and plays a vital role in driving hydrological models. However, limited by the observation methods, the obtained precipitation data, at present, are still too coarse. In this study, a new downscaling method was proposed to obtain high spatial resolution (~1 km/hourly) precipitation estimates based on Integrated Multi-satellitE Retrievals for GPM (IMERG) data at hourly scale. Compared with original IMERG data, the downscaled precipitation results showed the similar spatial patterns with those of original IMERG data, but with finer spatial resolution. In addition, the downscaled precipitation estimates were further analyzed to quantify their improvements using the Coupled Routing and Excess STorage (CREST) model across Ganjiang River basin. Compared with the observed streamflow, the downscaled precipitation results showed satisfying hydrological performance, with Nash-Sutcliffe Coefficient of Efficiency (NSCE), Root Mean Square Error (RMSE), Relative Bias (BIAS), and Correlation Coefficient (CC). The improvement in terms of four statistic metrics in terms of streamflow simulation also indicated great potential of hydrological utility for the downscaled precipitation results.

• Study on land use and land cover change in the hilly watershed in South China. • Evaluation of landscape ecological environment based on LULC change. • Terrain gradient response of ecological environment to LULC change be analyzed. There are abundant resources like climate, water, biological and tourism in the middle and upper reaches of the Ganjiang River (MU-GJR), which is an important ecological protection area in hilly areas of South China. The four periods of land use and land cover (LULC) data from 1980 to 2018 and DEM data are the main data support. The LULC change were analyzed with the area proportion, transfers chord diagram and change characteristics map, the response of ecological environment from LULC change was analyzed by using the landscape ecological environment quality (LEEQ) and contribution index. Then the terrain gradient was used to analyze the impact of LULC transfer on ecological environment under different terrain conditions. (1) The LULC characteristics in the study area show that was dominated by forest land and cultivated land (more than 90 %), various types of land transfer significantly from 2010 to 2018, especially the cultivated land, forest land and grassland. The stable type of LULC change was the most widely distributed, followed by the later change type (2010–2018) and mainly distributed in the flat valley, with the largest change range of cultivated land, forest land and grassland. (2) The LEEQ was generally well, but gradually deteriorates. The obvious change of LEEQ was found after 2010. The deterioration type of quality mostly occurs around the city, while the getting better type occurs in the transition area between the city and the mountains. (3) There are more deterioration categories than improvement categories of LULC transfer from 1980 to 2018. The improvement categories were mainly contributed by the transfer to other land to forest land and build-up land to other land. The deterioration categories were mainly contributed by the transfer of forest land to other land. (4) The impact of LULC change on the ecological environment decreases with the increase of elevation, slope and terrain position. There are differences in the impacts of various types of transfer on the ecological environment under the three gradients. In the elevation gradient, the improvement effect were dominant at −105–100 m and 200–500 m, and the deterioration effect were dominant at 100–200 m, 500–1000 m and 1000–2128 m. In the slope gradient, the improvement effect were dominant at 0–2°, 15–25° and 25–69.7°, and the deterioration effect were dominant at 2–6° and 6–15°. In terrain position gradient, improvement effect were dominant at 0–0.32, 0.32–0.51, 0.7–0.9 and 0.9–1.58, and deterioration effect were dominant at 0.51–0.7. Therefore, the specific conditions of different terrain gradients should be considered for land resource development in the middle and upper reaches of Ganjiang River region. [ABSTRACT FROM AUTHOR]

Bacteria play a critical role in environmental and ecological processes in river ecosystems. We studied the bacterial community in the Ganjiang River, a major tributary of the Yangtze River, as it flowed through Nanchang, the largest city in the Ganjiang River basin. Water was sampled at five sites monthly during the wet season, and the bacterial community was characterized using Illumina high-throughput sequencing. A total of 811 operational taxonomic units (OTUs) were observed for all samples, ranging from 321 to 519 for each sample. The bacterial communities were maintained by a core of OTUs that persisted longitudinally and monthly. Actinobacteria (41.17% of total sequences) and Proteobacteria (31.80%) were the dominant phyla, while Firmicutes (mostly genus Lactococcus ) became most abundant during flooding. Temperature and flow rate, rather than water chemistry, were the main factors influencing the bacterial community in river water. Temperature was the best individual parameter explaining the variations in OTU abundance, while flow rate was the best individual parameter explaining the variations in phylum abundance. Except for Proteobacteria , the relative abundance of bacterial phyla did not differ significantly between sites, and the degrees of influence of urban landscape on the bacterial community were estimated to be 17%–34%. [ABSTRACT FROM AUTHOR]

Ecological flow is an important indicator for reflecting the stability of a watershed ecosystem. The calculation of ecological discharge under hydrological variation has become a research hot-spot. The Ganjiang River south of Poyang Lake in China was taken as an example in this study. Hydrological Alteration Diagnosis System methods were used to detect the change-points. The Distributed Time Variation Gain Model (DTVGM) was used to carry out runoff restoration. The Probability-weighted Flow Duration Curve was applied to calculate the ecological flow. The results showed that: (1) The hydrological alteration of the Waizhou Station occurred in 1991, the annual runoff increased by 10%, and the Gini coefficient (GI) increased by 0.07 after the change-point. The change in precipitation was the main driving factors. (2) The R value and NSE of the DTVGM were greater than 0.84, which represents the feasibility of the model used to restore runoff. (3) Compared to the traditional hydrological method, the proposed method can better reflect the inter-annual difference of ecological flow, flow ranges for high, normal, and low flow years are 398-3771 m 3 /s, 352-2160 m 3 /s, and 277-1657 m 3 /s, respectively. The calculation method of ecological flow in rivers considering hydrological variation can more scientifically reflect the impact of hydrological variation on ecological flow process, ecological flow under different human activities that can be calculated, such as dam control, water intake and water transfer, furthermore, it also provides a scientific basis for water resources planning and allocation under changing environment.

The four species of carp present in China (grass carp, black carp, silver carp and bighead carp) are all commercially important freshwater fish species. However, the construction of large-scale hydraulic projects, such as dams, along with other anthropogenic changes to river systems has resulted in the rapid decline in abundance of all four carp species. Indeed, the effect of dams on the reproduction of the four species has become a highly sensitive issue in China. Historically, the Ganjiang River contained 12 spawning grounds for the four species. After the construction of the Wan'an Dam, however, four of these spawning areas were flooded. Three additional dams are currently under construction below the Wan'an Dam. While it is clear that these dams will further alter the hydrological regime in the river, there is currently little information available for the management and protection of carp in this river. In this study, we review published studies to characterize the patterns of larval abundance of the four species of carp in relation to environmental correlates in the Ganjiang River to provide baseline information that can be used to conserve these species. [ABSTRACT FROM AUTHOR]

River flow reconstruction under the background of long-term climate change is of great significance for understanding the regional response to future drought and flood disasters, and the sustainable development of water resources. Investigating the basic characteristics and changing trends of the streamflow of the Ganjiang River is scientifically important to mitigate drought and flood disasters in the future. This study reconstructed drought and flood grade series of five regional stations of the Ganjiang River based on spatially explicit and well-dated local chronicle materials and used a linear regression model of modern drought/flood grades and precipitation to reconstruct historical precipitation for the past 515 years. The relationships between the modern precipitation of five regional stations and streamflow of Waizhou Station, which is the last hydrological station of the Ganjiang River were analyzed through principal component regression. The adjusted R2 is 0.909, with a low relative bias of −1.82%. The variation of streamflow from AD 1500 to AD 2014 was reconstructed using the proposed model. Result shows that high flows occur in nine periods and low flows occur in 11 periods. Extremely low stream flow in 515 years appears during the middle and late 17th century. Cumulative anomaly and Mann-Kendall mutation test results reveal that a transition point from predominantly low to high flows occur in AD 1720. Redfit power spectrum analysis result shows that the variation periods of streamflow are 2–5, 7–8 years, and approximately 32 years, where the most significant period is 2–3 years. Continuous wavelet transform indicates that the corresponding relation occurs between streamflow and El Niño/Southern Oscillation for eight years. Streamflow is affected by temperature and East Asian monsoon that is controlled by solar activities. The flood may be related to strong solar activity, monsoon failure, and vice versa. Hydrological frequency curve analysis shows that the streamflow of the Ganjiang River once in a hundred years may reach up to 1031 × 108 m3 for flood or 485 × 108 m3 for drought and the standard of once in a millennium runoff may reach up to 1188 × 108 m3 for flood or 450 × 108 m3 for drought. These results may provide basic hydrological data for the sustainable development of society and serve as a reference for mitigating the impact of drought and flood disasters in the future. [ABSTRACT FROM AUTHOR]

Investigating the pollution conditions of trace elements in the Poyang Lake basin, identifying the pollution sources, evaluating the ecological risks play an important part in formulating the effective strategies for protecting the basin ecosystem. To understand the concentration characteristics, pollution levels, and ecological risks of twelve trace elements (Cd, Hg, Pb, As, Cu, Zn, Cr, Ni, Mn, Sb, W, and Sn) in the floodplain sediments of the five main tributaries in Poyang Lake basin in the past twenty years, we used the enrichment factor (EF) and modified pollution index (MPI) to quantify the pollution levels of the trace elements, and analyzed and discussed the pollution sources in the areas with significant pollution level changes. The results indicated that the concentrations of cadmium, zinc, manganese, tungsten and lead in the floodplain sediments of the Poyang Lake basin during the past twenty years have increased by 134%, 26%, 41%, 25%, and 8%, respectively, and mercury, arsenic, chromium, nickel, antimony, and tin have decreased by 35%, 15%, 22%, 10%, 14%, and 13%, respectively, while copper has not changed significantly. The concentrations of cadmium in the Raohe River, Ganjiang River, and Xinjiang River basins have increased by 331%, 151%, and 107%, while mercury decreased in the Fuhe River, Ganjiang River, and Xiushui River basins by 87%, 41%, and 40%, respectively. The classification results based on the EF indicated that the changes in the pollution levels of trace elements in the Poyang Lake basin were characterized by the aggravation of cadmium pollution and the degradation of mercury pollution, the pollution level of cadmium in the Ganjiang River basin was upgraded to moderate and significant, the pollution level of cadmium in the Le'an River was upgraded to very high, and the pollution level of mercury in the Fuhe River basin was reduced to unpolluted or minimal. The MPI classification results established that the increase in the cadmium pollution had intensified the comprehensive pollution in the Poyang Lake basin, causing the proportion of severely and heavily polluted sites to be raised from 17% to 33%. The MRI classification results also demonstrated that the proportion of very high ecological risk sites have increased from 11% to 22%. The element with the highest MRI contribution rate changed from mercury to cadmium, which was caused by the reduction of the ecological risk level from very high to moderate. The results demonstrated that the significant pollution changes in the trace elements in the floodplain sediments of the Poyang Lake basin were primarily caused by human activities, such as mineral exploitation, smelting, and industrial and agricultural production. Our findings can provide scientific evidence for the prevention and control of river pollution and the optimal management of a watershed ecosystem.

Rainfall information is a prerequisite to and plays a vital role in driving hydrological models. However, limited by the observation methods, the obtained precipitation data, at present, are still too coarse. In this study, a new downscaling method was proposed to obtain high spatial resolution (~1 km/hourly) precipitation estimates based on Integrated Multi-satellitE Retrievals for GPM (IMERG) data at hourly scale. Compared with original IMERG data, the downscaled precipitation results showed the similar spatial patterns with those of original IMERG data, but with finer spatial resolution. In addition, the downscaled precipitation estimates were further analyzed to quantify their improvements using the Coupled Routing and Excess STorage (CREST) model across Ganjiang River basin. Compared with the observed streamflow, the downscaled precipitation results showed satisfying hydrological performance, with Nash-Sutcliffe Coefficient of Efficiency (NSCE), Root Mean Square Error (RMSE), Relative Bias (BIAS), and Correlation Coefficient (CC). The improvement in terms of four statistic metrics in terms of streamflow simulation also indicated great potential of hydrological utility for the downscaled precipitation results. [ABSTRACT FROM AUTHOR]