scholarly journals Participatory Modelling of Surface and Groundwater to Support Strategic Planning in the Ganga Basin in India

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2443 ◽  
Author(s):  
Marnix van der Vat ◽  
Pascal Boderie ◽  
Kees Bons ◽  
Mark Hegnauer ◽  
Gerrit Hendriksen ◽  
...  

The Ganga Basin in India experiences problems related to water availability, water quality and ecological degradation because of over-abstraction of surface and groundwater, the presence of various hydraulic infrastructure, discharge of untreated sewage water, and other point and non-point source pollution. The basin is experiencing rapid socio-economic development that will increase both the demand for water and pollution load. Climate change adds to the uncertainty and future variability of water availability. To support strategic planning for the Ganga Basin by the Indian Ministry of Water Resources, River Development and Ganga Rejuvenation and the governments of the concerned Indian states, a river basin model was developed that integrates hydrology, geohydrology, water resources management, water quality and ecology. The model was developed with the involvement of key basin stakeholders across central and state governments. No previous models of the Ganga Basin integrate all these aspects, and this is the first time that a participatory approach was applied for the development of a Ganga Basin model. The model was applied to assess the impact of future socio-economic and climate change scenarios and management strategies. The results suggest that the impact of socio-economic development will far exceed the impacts of climate change. To balance the use of surface and groundwater to support sustained economic growth and an ecologically healthy river, it is necessary to combine investments in wastewater treatment and reservoir capacity with interventions that reduce water demand, especially for irrigation, and that increase dry season river flow. An important option for further investigation is the greater use of alluvial aquifers for temporary water storage.

Water ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 115 ◽  
Author(s):  
Roxelane Cakir ◽  
Mélanie Raimonet ◽  
Sabine Sauvage ◽  
Javier Paredes-Arquiola ◽  
Youen Grusson ◽  
...  

Modeling is a useful way to understand human and climate change impacts on the water resources of agricultural watersheds. Calibration and validation methodologies are crucial in forecasting assessments. This study explores the best calibration methodology depending on the level of hydrological alteration due to human-derived stressors. The Soil and Water Assessment Tool (SWAT) model is used to evaluate hydrology in South-West Europe in a context of intensive agriculture and water scarcity. The Index of Hydrological Alteration (IHA) is calculated using discharge observation data. A comparison of two SWAT calibration methodologies are done; a conventional calibration (CC) based on recorded in-stream water quality and quantity and an additional calibration (AC) adding crop managements practices. Even if the water quality and quantity trends are similar between CC and AC, water balance, irrigation and crop yields are different. In the context of rainfall decrease, water yield decreases in both CC and AC, while crop productions present opposite trends (+33% in CC and −31% in AC). Hydrological performance between CC and AC is correlated to IHA: When the level of IHA is under 80%, AC methodology is necessary. The combination of both calibrations appears essential to better constrain the model and to forecast the impact of climate change or anthropogenic influences on water resources.


2018 ◽  
Author(s):  
René R. Wijngaard ◽  
Hester Biemans ◽  
Arthur F. Lutz ◽  
Arun B. Shrestha ◽  
Philippus Wester ◽  
...  

Abstract. The Indus, Ganges, and Brahmaputra (IGB) river basins provide about 900 million people with water resources used for agricultural, domestic, and industrial purposes. These river basins are marked as climate change hotspot, where climate change is expected to affect monsoon dynamics and the amount of meltwater from snow and ice, and thus the amount of water available. Simultaneously, rapid and continuous population growth, and strong economic development will likely result in a rapid increase in water demand. Since quantification of these future trends is missing, it is rather uncertain how the future South Asian water gap will develop. To this end, we assess the combined impacts of climate change and socio-economic development on future blue water scarcity for the IGB until the end of the 21st century. We apply a coupled modelling approach consisting of the distributed cryospheric-hydrological model SPHY, which simulates current and future upstream water supply, and the hydrology and crop production model LPJmL, which simulates current and future downstream water supply and demand. We force the models with an ensemble of eight representative downscaled General Circulation Models (GCMs) that are selected from the RCP4.5 and RCP8.5 scenarios, and a set of land use and socio-economic scenarios that are consistent with the Shared Socio-economic Pathway (SSP) marker scenarios 1 and 3. The simulation outputs are used to analyse changes in water availability, supply, demand, and scarcity. The outcomes show an increase in surface water availability towards the end of the 21st century, which can mainly be attributed to increases in monsoon precipitation. However, despite the increase surface water availability, the strong socio-economic development and associated increase in water demand will likely lead to an increase in the water gap during the 21st century. This indicates that socio-economic development is the key driver in the evolution of the future South Asian water gap.


2018 ◽  
Vol 22 (12) ◽  
pp. 6297-6321 ◽  
Author(s):  
René Reijer Wijngaard ◽  
Hester Biemans ◽  
Arthur Friedrich Lutz ◽  
Arun Bhakta Shrestha ◽  
Philippus Wester ◽  
...  

Abstract. The Indus, Ganges, and Brahmaputra (IGB) river basins provide about 900 million people with water resources used for agricultural, domestic, and industrial purposes. These river basins are marked as “climate change hotspots”, where climate change is expected to affect monsoon dynamics and the amount of meltwater from snow and ice, and thus the amount of water available. Simultaneously, rapid and continuous population growth as well as strong economic development will likely result in a rapid increase in water demand. Since quantification of these future trends is missing, it is rather uncertain how the future South Asian water gap will develop. To this end, we assess the combined impacts of climate change and socio-economic development on the future “blue” water gap in the IGB until the end of the 21st century. We apply a coupled modelling approach consisting of the distributed cryospheric–hydrological model SPHY, which simulates current and future upstream water supply, and the hydrology and crop production model LPJmL, which simulates current and future downstream water supply and demand. We force the coupled models with an ensemble of eight representative downscaled general circulation models (GCMs) that are selected from the RCP4.5 and RCP8.5 scenarios, and a set of land use and socio-economic scenarios that are consistent with the shared socio-economic pathway (SSP) marker scenarios 1 and 3. The simulation outputs are used to analyse changes in the water availability, supply, demand, and gap. The outcomes show an increase in surface water availability towards the end of the 21st century, which can mainly be attributed to increases in monsoon precipitation. However, despite the increase in surface water availability, the strong socio-economic development and associated increase in water demand will likely lead to an increase in the water gap during the 21st century. This indicates that socio-economic development is the key driver in the evolution of the future South Asian water gap. The transgression of future environmental flows will likely be limited, with sustained environmental flow requirements during the monsoon season and unmet environmental flow requirements during the low-flow season in the Indus and Ganges river basins.


2020 ◽  
Author(s):  
Athina Angeli ◽  
Eleni Karkani ◽  
Angelos Alamanos ◽  
Stefanos Xenarios ◽  
Nikitas Mylopoulos

<p>Water security poses one of the biggest challenges of the century. It is a versatile problem, going beyond the traditional concepts of hydrology and water quality. It is difficult to give a single definition, since water security signifies a "safe operating subspace" within a multi-dimensional space that maps physical resource availability, water quality, demand, infrastructure and economic choices. The main idea of water security, as addressed in the present study, is the need to balance human and environmental water needs.</p><p>In arid and semi-arid areas, including Greece, intensification of agriculture accompanied with poor management is a common phenomenon. These attempts to meet economic and productive objectives, combined with the physical characteristics of these areas, has led to quantitative and qualitative water degradation, questioning the sustainability of water resources. In Greece, the Ministry of Environment Management Plans found that only 1 or 2 cases in the country are in “a good status”. This study aims to propose a way towards integrated and sustainable management, through hydro-economic tools: water balance, profits from agricultural activities, water value, and water quality. Water security is examined based on these terms in several Greek rural watersheds.</p><p>The methodology consists of the estimation of water availability, water demand, and thus water balance in surface and groundwater resources. The profits from the agricultural activities are estimated from a straightforward economic model, based on the gross profits and production costs. Water quality is based on measurements on concentrations of fertilizers, chemical parameters and pesticides, and its improvement is examined through the quantitative replenishment due to several strategies exploiting dilution processes in surface and groundwater. The analysis used data from the period 2005-2015, and a set of management scenarios were examined, suggesting technical measures (e.g. reducing losses, improving irrigation methods) and crop replacement scenarios, taking into account factors affecting these decisions, and also the Ministry’s recommendations. The water value was calculated using the “change of the net-income” method. All the above factors’ results indicate the degradation of the examined areas.</p><p>More specifically, the watersheds of Lake Karla, Almyros, Koronia, and Loudia were selected as the most representative cases. These watersheds seem to have limited water availability, intensified agriculture, poor water quality and management issues. The Lake Karla watershed is characterized from overexploited surface and groundwater resources, Loudia and Koronia watersheds face the same issues plus a strong qualitative degradation, Almyros watershed main issue is the salinization of its coastal aquifer. In conclusion, the first steps that are introduced in this study can be a starting point for more integrated water security management, helping local water managers understand and address the above issues.</p><p>Overall, it is a novel attempt to integrate all the above parameters in one framework, for a ten-year horizon, and comparing rural Greek case studies. Non-comparable factors also exist among different case studies, which are discussed, however the evidences support the finding of the general degradation and unsustainable management in the country.</p><p><strong>KEYWORDS:</strong> Water Security, agricultural watersheds, Greece, Water Resources Management, Hydro-economic modeling, water quality, scenario analysis.</p>


2016 ◽  
Author(s):  
Mark Honti ◽  
Nele Schuwirth ◽  
Jörg Rieckermann ◽  
Christian Stamm

Abstract. Catchments are complex systems where water quantity, quality and the provided ecological services are determined by interacting physical, chemical, biological, economic, and social factors. The awareness of these interactions led to the prevailing catchment management paradigm of Integrated Water Resources Management. The design and evaluation of solutions for integrated water resources management requires to predict changes of local or regional water quality, which requires integrated approach for modeling too. On one hand, integrated models have to be comprehensive enough to cover the aspects relevant for management decisions, allow for mapping of global change processes – as climate change, population growth, migration, and socio-economic development – to the regional and local contexts. On the other hand, models have to be sufficiently simple and fast enough to apply proper methods of uncertainty analysis, which can consider model structure deficits and propagate errors through the chain of submodels. Here, we present an integrated catchment model satisfying both objectives. The conceptual "iWaQa" model was developed to support the integrated management of small streams. It can predict both traditional water quality parameters like nutrients and a wide set of organic micropollutants originating from plant and material protection products. Due to the model's simplicity, it allows for a full, propagative analysis of predictive uncertainty, including certain structural and input errors. The usefulness of the model is demonstrated by predicting future water quality in a small catchment with mixed land use in the Swiss Plateau. The focus of our study is the change of water quality over the next decades driven by climate change, population growth or decline, socio-economic development and the implementation of management strategies for improving water quality. Our results indicate that input and model structure uncertainties are the most influential factors on certain water quality parameters and in these cases the uncertainty of modeling is already very high for the present conditions. Nevertheless, a proper quantification of today's uncertainty can make the management fairly robust for the foreseen range of possible evolution into the next decades. With a time-horizon of 2050, it seems that human land use and management decisions have a larger influence on water quality than climate change. However, the analysis of single climate model chains indicates that the importance of climate grows when a certain climate prediction is considered instead of the ensemble forecast.


2019 ◽  
Vol 2 (2) ◽  
pp. 125-131
Author(s):  
Loi Thi Pham ◽  
Khoi Nguyen Dao

Assessing water resources under the influence of environmental change have gained attentions of scientists. The objective of this study was to analyze the impacts of land use change and climate change on water resources in terms quantity and quality in the 3S basin in the period 1981–2008 by using hydrological modeling (SWAT model). The results showed that streamflow and water quality (TSS, T-N, and T-P) tend to increase under individual and combined effects of climate change and land use change. In addition, the impact of land use change on the flow was smaller than the climate change impact. However, water balance components and water quality were equally affected by two factors of climate change and land use change. In general, the results of this study could serve as a reference for water resource management and planning in the river basin.


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