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1. Study on the streamflow compensation characteristics of reservoirs in Luanhe River Basin based on Copula function.

Author

Fang Wan, Lingfeng Xiao, Qihui Chai, and Li Li

Subjects
COPULA functions, WATERSHEDS, STREAMFLOW, WATER supply, WATER security
Abstract

With the rapid development of economy and society, the contradiction between supply and demand of water resources is increasing. Efficient utilization and allocation of limited water resources are one of the main means to solve the above contradictions. In this paper, the multidimensional joint distribution of natural streamflow series in reservoirs is constructed by introducing the mixed Copula function, and the probability of wet and dry encounters between natural streamflow is analyzed. Luan River is located in the northeastern part of Hebei Province, China, taking the group of Panjiakou Reservoir, Douhe Reservoir and Yuqiao Reservoir in the downstream of Luan River Basin as an example, the probabilities of synchronous and asynchronous abundance and depletion of inflow from the reservoirs are calculated. The results show that the probability of natural streamflow series between reservoirs is 61.14% for asynchronous wetness and dryness, which has certain mutual compensation ability. Therefore, it is necessary to minimize the risk of water supply security in Tianjin, Tangshan and other cities, and strengthen the optimal joint water supply scheduling of reservoirs. The research results are reasonable and reliable, which can provide reference for water supply operation of other basins. [ABSTRACT FROM AUTHOR]

Published
2022
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2. São Paulo drought: trends in streamflow and their relationship to climate and human-induced change in Cantareira watershed, Southeast Brazil.

Author

Nicoleti de Freitas, Gabriela

Subjects
*CLIMATE change, *REFORESTATION, *DROUGHTS, *WATER supply, *STREAMFLOW, *LAND use mapping
Abstract

The 2013-2015 drought in the Metropolitan Region of São Paulo exposed the lack of resilience of the regional water supply system, highly dependent on the Cantareira reservoirs. In this paper, inflows to each of the four main Cantareira reservoirs are tested for systematic change. Persistent trends in streamflow, rainfall, temperature and evapotranspiration are first evaluated. Streamflow was also tested for step change. Double-mass curves were employed to assess modification in the precipitation-runoff relationship. Subsequently, we used the climate elasticity method and the ABCD model to quantify the relative contribution of climate and human activities into the detected trends. Only Cachoeira and Atibainha sub-basins showed a significant downward trend in streamflow. The results for step change were also significant, and the year of occurrence coincided with breakpoints in precipitation-runoff relationship. For both Cachoeira and Atibainha, human activities had a more significant impact on streamflow reduction than climate variability. Land use and cover maps suggest that the reduction of pasture/abandoned land parallel to an increase in reforestation/silviculture is behind streamflow reduction. The results highlight the importance of coordinating land-use patterns and water management, as an important contributor beyond any considerations of a changing climate. Implications for better managing regional water resources are discussed. [ABSTRACT FROM AUTHOR]

Published
2020
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3. Baseflow estimation in typical catchments in the Yellow River Basin, China.

Author

Caihong Hu, Dong Zhao, and Shengqi Jian

Subjects
RIVER conservation, STREAMFLOW, WATER supply, ENVIRONMENTAL protection, STANDARD deviations
Abstract

Baseflow is crucial to maintaining river flow during low-rainfall periods. The baseflow estimation is important to water supply and ecological environmental protection in the Yellow River Basin (YRB), China. This paper comprehensively assessed the applicability of four single-parameter digital filtering, recursive digital filtering, and HYSEP (streamflow hydrograph separation) methods across four typical catchments in the Yellow River Basin: the Zuli River Basin, the Kuye River Basin, the Tuwei River Basin, and the Jingle sub-basin. We also investigated annual and monthly variations in baseflow. We found the standard deviation and coefficient of variation of baseflow index through recursive digital filter were relatively small. And the baseflow process line was smoother and more reasonable in typical year and typical storm-flood events, which conformed to the damping and hysteresis effect of the underlying surface. Thus the recursive digital filter method had the best performance, which was recommended for baseflow separation in the YRB. The estimated baseflow index of typical basins were between 0.354 and 0.502. In addition, inter-annual baseflow showed a decreasing trend and intra-annual baseflow was characterized by uneven distribution, which was subject to the characteristics of each basin. [ABSTRACT FROM AUTHOR]

Published
2021
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4. Hydrological alteration of the upper Yangtze River and its possible links with large-scale climate indices.

Author

Qianjin Dong, Debin Fang, Jian Zuo, and Yongqiang Wang

Subjects
*CLIMATOLOGY, *WATER supply, *RIVERS, *WATER management, *RESOURCE management, *STREAMFLOW, SAN Xia Dam (China)
Abstract

The relationship between hydrological alteration and climate variability in the upper Yangtze River is not fully understood. In this paper, the periodicity features and the intercorrelation of annual and seasonal eco-flow metrics at the Yichang gauge station are analyzed for the period 1882 to 2013. Analysis is carried out to explore the formation of the eco-flow metrics and the possible linkages between eco-flow metrics and selected climate indices, using the cross-wavelet and wavelet coherence methods on data from 1948 to 2013. The results show that the variation of eco-flow metrics correlates well with some selected climate indices, but changes in different eco-flow metrics are complex. Most annual and seasonal eco-flow metrics correlate well with the Northern Hemisphere (N.H) and Indian Ocean Dipole (IOD) and have a significant common power in the two to four years band. In addition, most annual eco-flow metrics have an obvious phase relationship with the selected climate indices. However, the seasonal eco-flow metrics have no significant phase relationship with the selected climate indices. These findings provide a better understanding of how hydrological alterations of the streamflow and better water resource management can ensure ecosystem sustainability for the Yangtze River. [ABSTRACT FROM AUTHOR]

Published
2019
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5. A distributed hydrological model in the Heihe River basin and its potential for estimating the required irrigation water.

Author

Lei Li, Zongxue Xu, Jie Zhao, and Longqiang Su

Subjects
*HYDROLOGIC models, *IRRIGATION water, *HYDRAULICS, *STREAMFLOW, *WATER supply
Abstract

A Grid-based Integrated Surface-Groundwater Model (GISMOD) was developed to estimate the required irrigation water using a control-site method. The entire catchment is divided into multiple grid cells of equal size, and several grid cells can be chosen as the control sites by users in this model. The grid cells from the upper stream of each control site, which have a land-use type of farmland, are automatically identified as a controlled grid cell. The crop information around each controlled grid cell is set to be the same as its corresponding control site. Next, the irrigation water requirement for each controlled grid cell is calculated using a crop coefficient method that is integrated into the human water-use module of the GISMOD. After runoff is generated, the actual discharge of each control site is computed by comparing the available water sources with the irrigation water requirement based on the water-supply operation rules of the model. This paper subsequently presents a case study in the upper-middle reaches of the Heihe River to evaluate the performance of the GISMOD. The results demonstrate that the actual water consumption for irrigation in the Heihe River basin could be generally estimated by the GISMOD on a monthly basis. [ABSTRACT FROM AUTHOR]

Published
2017
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6. Climate change and reliability of urban water supply.

Author

S. Maheepala and C. Perera

Subjects
*CLIMATE change, *MUNICIPAL water supply, *WATER supply, *STREAMFLOW
Abstract

This paper describes a probability-based method for assessing the potential impact of climate change on urban water supply systems. Specifically, the assessment method uses probability distributions to place a confidence level on the plausible values of response variables. The Benalla water supply system has been used to demonstrate applicability of the proposed assessment method. For the application, the impact of the 2030 climate change scenarios on streamflows and system yield has been examined. The preliminary results have demonstrated that the proposed assessment method can provide valuable insights into the impact of climate change on water supply systems, allowing it to be incorporated into planning decisions. [ABSTRACT FROM AUTHOR]

Published
2003
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7. Hydroinformatics advances for operational river forecasting: using graphs for drainage network descriptions.

Author

Cui, Zhengtao, Koren, Victor, Cajina, Neftali, Voellmy, Andreas, and Moreda, Fekadu

Subjects
*INFORMATION technology, *WATER supply, *PREDICTION models, *GRAPH theory, *DRAINAGE, *GEOLOGICAL basins, *STREAMFLOW, *PARALLEL algorithms
Abstract

Distributed hydrologic models provide accurate river streamflow forecasts and a multitude of spatially varied products on basin scales. The distributed elements of the basins are pieced together using drainage networks. An efficient representation of drainage networks in computer code is necessary. Graph theory has long been applied in many engineering areas to solve network problems. In this paper we demonstrate that adjacent list graph is the most ef?cient way of presenting the drainage network in terms of development and execution. The authors have implemented drainage networks using the adjacency-list structure in both the research and operational versions of the US National Weather Service (NWS) distributed model. A parallel routing algorithm based on Dijsktra's shortest path algorithm was also developed using the MPI library, which was tested on a cluster using the Oklahoma Illinois River basin dataset. Theoretical analysis and test results show that inter-processor communication and unbalanced workload among the processors limit the scalability of the parallel algorithm. The parallel algorithm is more applicable to computers with high inter-processor bandwidth, and to basins where the number of grid cells is large and the maximum distance of the grid cells to the outlet is short. [ABSTRACT FROM AUTHOR]

Published
2011
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8. Implications of Climate Change for Water Resources Development in the Ganges Basin

Author

Jorge Jose Escurra, N. Harshadeep, Don Blackmore, Marc Jeuland, and Claudia Sadoff

Subjects
STREAMFLOW, GENERAL CIRCULATION MODEL, RIVERS, WATER CONSUMPTION, COASTS, FLOW, CANALS, EMISSIONS TRENDS, Geography, Planning and Development, RIVER BASINS, EMISSIONS SCENARIOS, GASES, GROUNDWATER RESOURCES, WATER MANAGEMENT SYSTEMS, LARGE DAMS, CONVERGENCE, WATER, Water cycle, RAINFALL, LAND USE, MONSOONS, EMISSIONS, Water Science and Technology, MUNICIPAL WATER, EVAPOTRANSPIRATION, EMISSIONS SCENARIO, SEAWATER, ANNUAL RAINFALL, WATER AVAILABILITY, WATER RESOURCE, TEMPERATURE CHANGE, CATCHMENTS, EVAPORATION, WATER DEMAND, WATER POLICY, SURFACE RUNOFF, AVAILABLE WATER, CRU, Downscaling, FLOW AUGMENTATION, GROUNDWATER IRRIGATION, HYDROPOWER POTENTIAL, WATER USES, CRYOSPHERE, POWER PLANTS, WATER MANAGEMENT, HYDROLOGIC REGIME, AQUIFER, Management, Monitoring, Policy and Law, COVERING, IRRIGATION SYSTEMS, WATERS, HYDROPOWER PRODUCTION, Water scarcity, CAPACITY, WATER USE PATTERNS, REMOTE SENSING, LEAD, HYDROLOGY, CATCHMENT, GLACIERS, SURFACE WATER, SALINE INTRUSION, GLOBAL WARMING, WATER CYCLE, WATER SHORTAGE, METERS, WATER RESOURCES DEVELOPMENT, RAIN, AQUIFERS, ATMOSPHERE, GCM, WATER ALLOCATION, CLIMATIC VARIABILITY, ENVIRONMENTAL ISSUES, SNOW, CLIMATE DATA, Water resource management, GREENHOUSE, HYDROLOGICAL RESPONSE, HYDROLOGICAL DATA, HYDROLOGICAL MODEL, DOMESTIC WATER, GROUNDWATER, CLIMATE RESEARCH UNIT, CLIMATE CHANGE, ENERGY PRODUCTION, FLOODING, ENGINEERING, WATER STORAGE, RIVER BASIN, WATER MANAGERS, HYDRODYNAMICS, ENERGY, Water balance, WATER TOWERS, CLIMATE VARIABILITY, FORESTS, SURFACE WATER IRRIGATION, IRRIGATION, LESS, RUNOFF, INDIRECT RECHARGE, TEMPERATURE, DROUGHT, IPCC, ALTERNATIVE ENERGY, STORAGE CAPACITY, PRECIPITATION, GROUNDWATER RECHARGE, WATER SYSTEMS, IRRIGATORS, SEDIMENT LOAD, CLIMATOLOGY, GREENHOUSE GASES, CLEAN ENERGY, WATER YIELD, Climate change, WATER REQUIREMENTS, HYDROLOGIC CYCLE, FLOOD DAMAGE, BASINS, BENEFITS, RIVER DELTAS, SNOW MELT, DAMS, Hydrology, WATER ALLOCATIONS, FLOODS, Global warming, WATER SUPPLY, WATER USE, NATURAL RESOURCES, Water resources, CLIMATE, CLEAN ENERGY TECHNOLOGY, COASTAL AREAS, INTERNATIONAL WATERS, WATER RESOURCES, Environmental science, ECOSYSTEM, Climate model, RESERVOIRS, EMISSION
Abstract

This paper presents the first basin-wide assessment of the potential impact of climate change on the hydrology and production of the Ganges system, undertaken as part of the World Bank’s Ganges Strategic Basin Assessment. A series of modeling efforts, downscaling of climate projections, water balance calculations, hydrological simulation and economic optimization, inform the assessment. The authors find that projections of precipitation across the basin, obtained from 16 Intergovernmental Panel on Climate Change-recognized General Circulation Models are highly variable, and lead to considerable differences in predictions of mean flows in the main stem of the Ganges and its tributaries. Despite uncertainties in predicted future flows, they are not, however, outside the range of natural variability in this basin, except perhaps at the tributary or sub-catchment levels. The authors also find that the hydropower potential associated with a set of 23 large dams in Nepal remains high across climate models, largely because annual flow in the tributary rivers greatly exceeds the storage capacities of these projects even in dry scenarios. The additional storage and smoothing of flows provided by these infrastructures translates into enhanced water availability in the dry season, but the relative value of this water for the purposes of irrigation in the Gangetic plain, and for low flow augmentation to Bangladesh under climate change, is unclear.

Published
2013