P. P. Mujumdar

Indian Institute of Science | IISC · Department of Civil Engineering

Plain Language Summary Floods are frequent natural disasters in India that affect millions of people and disrupt socioeconomic conditions. Climate change and human interventions further exaggerate flood hazards in many regions of the country. The west and west‐central Indian Himalayas are the worst flood‐affected regions in recent decades. A detail...

In this study, catchments are considered as complex systems, and information-theoretic measures are used to capture temporal streamflow characteristics. Emergence and self-organization are used to quantify information production and order in streamflow time series, respectively. The measure complexity is used to quantify the balance between emergen...

Time irreversibility or temporal asymmetry refers to the steeper ascending and gradual descending parts of a streamflow hydrograph. The primary goal of this study is to bring out the distinction between streamflow indices directly linked with rising limbs and falling limbs and to explore their utility in uncovering processes associated with the ste...

Since the early times Indians have used various ingenious methods to conserve and use water for various purposes like domestic, irrigation, hydropower, navigation and recreation. This chapter traces the history and evolution of water management since the earliest times in India and briefly covers the history from the Indus Valley (Harappa) Civilisa...

Estimating the dependence structure of concurrent extremes is a fundamental issue for accurate assessment of their occurrence probabilities. Identifying the extremal dependence behavior is also crucial for scientific understanding of interactions between the variables of a multidimensional environmental process. This study investigates the suitabil...

The past few decades have witnessed massive shifts in land-use patterns, land management practices and water demand in the river basins of peninsular India. Changes in hydrologic regimes of different components of the water cycle pose immense challenge to water security at the catchment scale. This paper provides a comprehensive overview and a quan...

In this study, catchments are considered as complex systems; and information-theoretic measures are used to capture temporal streamflow characteristics. Emergence and self-organization are used to quantify information production and order in streamflow time series respectively. The measure, complexity is used to quantify the balance between emergen...

The Ganga River is the lifeline for close to half a billion people residing in the northern Indian region. The hydrology of the Ganga River basin has been significantly modified owing to increasing anthropogenic interventions and changing climatic conditions during the 20th century. For example, the increasing high-intensity rainfall events often c...

The past few decades have witnessed massive shifts in land-use patterns, land management practices and water demand in the river basins of peninsular India. Changes in hydrologic regimes of different components of the water cycle pose immense challenge to water security at the catchment scale. This paper provides a comprehensive overview and a quan...

Climate change and anthropogenic activities pose serious threats to river basin hydrology worldwide. The Ganga basin is home to around half a billion people and has been significantly impacted by hydrological alterations in the last few decades. The increasing high-intensity rainfall events often create flash flooding events. Such events are freque...

Global urban population is projected to double by 2050. This rapid urbanization is the driver of economic growth but has environmental challenges. To that end, there is an urgent need to understand, simulate and disseminate information about extreme events, routine city operations and long term planning decisions. This paper describes an effort un...

Recent studies report that the extreme rainfall characteristics in most parts of the globe exhibit temporal non-stationarity. Therefore, modeling the nonstationary behavior of extreme rainfall for different water resources applications is vital. When modeling non-stationarity in extreme rainfall series, previous studies consider a single threshold...

In the recent past, a steep increase in the frequency and intensity of flash floods in urban regions has resulted in significant damage to life and property, necessitating a holistic approach to address the problem. An integrated urban flood model for Bengaluru city, Karnataka, India has been developed with a modular approach, which includes real-t...

This paper presents a comparison of the predictive capability of three hydrological models in a heavily influenced catchment in Peninsula India. In catchments where there is a high dependence on both streamflow and groundwater to meet demands, it is of importance to capture the catchment processes correctly. This study highlights the performance ev...

Hydrologic knowledge in India has a historical footprint extending over several millenniums through the Harappan civilization (∼ 3000-1500 BCE) and the Vedic Period (∼ 1500-500 BCE). As in other ancient civilizations across the world, the need to manage water propelled the growth of hydrologic science in ancient India. Most of the ancient hydrologi...

Urbanization modifies the hydrologic response of a catchment significantly. An understanding of historical patterns and changes in trends of hydrological variables in cities is important to design, maintain and operate the urban infrastructure. The historical trend analysis of various climate variables including temperature and precipitation, and t...

Estimation of morphometric indices can be useful in defining similarity relationships between catchments over a wide range of scales and it facilitates the effective understanding of hydrogeologic processes. This study aims at evaluating morphometric parameters to investigate geomorphologic similarity between the sub-catchments of the Cauvery river...

The heavily industrialised Kanpur region is the most polluted stretch of the Ganga river because of excessive pollutant discharge from the industries. Agricultural runoff along with climate change further adds to the pollution risk in this industrialised stretch of Ganga. In this paper, we analyse the potential impacts of climate change and land us...

Floods are widespread natural disasters having significant socio-economic impacts and require appropriate modelling and management strategies. Flood modelling is an enduring challenge, especially over the data-sparse mountainous regions such as the Himalayas, due to the lack of accurate rainfall measurements. Global datasets are often employed for...

Hydrologic knowledge in India has a historical footprint extending over several millenniums through the Harappan civilization (∼3000–1500 BCE) and the Vedic Period (∼1500–500 BCE). As in other ancient civilizations across the world, the need to manage water propelled the growth of hydrologic science in ancient India. Most of the ancient hydrologic...

Flood modelling is an important first step towards understanding and managing floods, at all spatial scales, from a large catchment of a river to highly developed urban areas and to individual property and infrastructure. Recent advances in modelling techniques along with sophisticated computational tools and data products have facilitated a rapid...

Key Points:  A three-stage algorithm for generating concurrent multisite streamflow is proposed.  Time irreversible dynamics of hydrologic processes at daily scale are accounted for.  The algorithm results in simulated sequences that capture variability beyond that represented in the historical streamflow record. Abstract Synthetic daily streamf...

Understanding response of temporal distribution, timing, frequency and amount of high and low intensity rainfall to warming is important in water resources management. In this paper, Relative Entropy is used to investigate the spatial variability and change in uniformity of rainfall distribution over India. Temporal trends in atmospheric temperatur...

This book is the result of an Indian National Science Academy (INSA) initiative to map the responsiveness of India’s science and technology to an impending water crisis. With contributions from eminent scientists and practitioners, the focus of the book is on scientific tools, methodologies and technologies available in the country today to address...

Extreme rainfall is the most common cause of flooding and likelihood of such events is found to increase in recent studies. Large scale natural variability, human induced global warming and local atmospheric warming are important drivers of extreme rainfall. Understanding the association of these drivers with extreme rainfall and finding out the mo...

Hydrologic persistence plays an important role in natural mechanisms governing hydrologic processes and their interdependence. The spatio-temporal evolution of persistence in rainfall and streamflow and their joint behaviour is examined here through the estimation of Hurst Coefficient using Detrended Fluctuation Analysis (DFA) and Detrended Cross-C...

Addressing spatial variation of extreme precipitation in urban areas is important for urban hydrologic designs. Climatology of urban areas is, in general, different from that of its surroundings and the spatial variation of extreme precipitation within the city exhibits shorter spatial range, especially for short duration events. This work aims at...

Reliable estimates of extreme rainfall events are necessary for an accurate prediction of floods. Most of the global rainfall products are available at a coarse resolution, rendering them less desirable for extreme rainfall analysis. Therefore, regional mesoscale models such as the advanced research version of the Weather Research and Forecasting (...

The impacts of concurrent droughts and heatwaves could be more serious compared to their individual occurrence. Meteorological drought condition is generally characterized by low rainfall, but impact of such an event is amplified with simultaneous occurrence of heatwaves. Positive feedback between these two extremes can worsen the rainfall deficit...

Variations in precipitation extremes over the relatively small spatial scales of urban areas could be significantly different from those over larger regions. An understanding of such variations is critical for urban infrastructure design and operation. Urban climatology and sparse spatial data lead to uncertainties in the estimates of spatial preci...

Hydrologic designs, hazard mitigation, and water resources management rely heavily on frequency analysis and risk assessment of extremes such as floods and droughts. Return periods and corresponding return levels of such extremes have been traditionally derived under the assumption of stationarity that has been challenged by recent studies. The pre...

Assessing the impacts of Land Use (LU) and climate change on future streamflow projections is necessary for efficient management of water resources. However, model projections are burdened with significant uncertainty arising from various sources. Most of the previous studies have considered climate models and scenarios as major sources of uncertai...

Reliable estimates of extreme rainfall events are necessary for an accurate prediction of floods. Most of the global rainfall products are available at a coarse resolution, rendering them less desirable for extreme rainfall analysis. Therefore, regional mesoscale models such as the Advanced Research version of the Weather Research and Forecasting (...

This paper presents the development of fuzzy set-based performance measures for an irrigation reservoir system to answer questions on how likely a system is to fail (fuzzy reliability), how quickly it is likely to recover from failure (fuzzy resiliency), and how severe the consequences of failure are likely to be (fuzzy vulnerability). The failure/...

The book is organized to consist of three parts—Part One: Basics of Systems Techniques; Part Two: Model Development; and Part Three: Applications. The book was published earlier by a professional publishing company. We, the authors (S. Vedula and P .P. Mujumdar) have got back the copy rights from that publisher, which exclusively are owned by us no...

Using recent advancements in the statistical extreme value theory, this study proposes a methodology for detection of change in flood return levels under climate change. Nonstationary scaling of regional projected peak flows with global warming is first tested by a likelihood ratio test. For nonstationary possible future realizations, the authors t...

Article Available online : http://authors.elsevier.com/a/1RnkY52cu6pkR Climate change is expected to influence extreme precipitation which in turn might affect risks of pluvial flooding. Recent studies on extreme rainfall over India vary in their definition of extremes, scales of analyses and conclusions about nature of changes in such extremes....

A short-term real-time operation model with fuzzy state variables is developed for irrigation of multiple crops based on earlier work on long-term steady-state policy. The features of the model that distinguish it from the earlier work are (1) apart from inclusion of fuzziness in reservoir storage and in soil moisture of crops, spatial variations i...

Quantifying the isolated and integrated impacts of land use (LU) and climate change on streamflow is challenging as well as crucial to optimally manage water resources in river basins. This paper presents a simple hydrologic modeling-based approach to segregate the impacts of land use and climate change on the streamflow of a river basin. The upper...

This paper presents the development and application of a stochastic dynamic programming model with fuzzy state variables for irrigation of multiple crops. A fuzzy stochastic dynamic programming (FSDP) model is developed in which the reservoir storage and soil moisture of the crops are considered as fuzzy numbers, and the reservoir inflow is conside...

Quantifying distributional behavior of extreme events is crucial in hydrologic designs. Intensity Duration Frequency (IDF) relationships are used extensively in engineering especially in urban hydrology, to obtain return level of extreme rainfall event for a specified return period and duration. Major sources of uncertainty in the IDF relationships...

Climate change is most likely to introduce an additional stress to already stressed water systems in developing countries. Climate change is inherently linked with the hydrological cycle and is expected to cause significant alterations in regional water resources systems necessitating measures for adaptation and mitigation. Increasing temperatures,...

Streamflow regime is sensitive to changes in land use and climate in a river basin. Quantifying the isolated and integrated impacts of land use and climate change on streamflow is challenging as well as crucial to optimally manage water resources in the river basin. This paper presents a simple hydrologic modelling based approach to segregate the i...

Significant changes are reported in extreme rainfall characteristics over India in recent studies though there are disagreements on the spatial uniformity and causes of trends. Based on recent theoretical advancements in the Extreme Value Theory (EVT), we analyze changes in extreme rainfall characteristics over India using a high-resolution daily g...

Developments in the statistical extreme value theory, which allow non-stationary modeling of changes in the frequency and severity of extremes, are explored to analyze changes in return levels of droughts for the Colorado River. The transient future return levels (conditional quantiles) derived from regional drought projections using appropriate ex...

Global change in climate and consequent large impacts on regional hydrologic systems have, in recent years, motivated significant research efforts in water resources modeling under climate change. In an integrated future hydrologic scenario, it is likely that water availability and demands will change significantly due to modifications in hydro-cli...

Land-use change and related changes in water use are key drivers of changes in the regional water cycle. This is especially the case for large-scale changes from bare and forested land into irrigated agriculture. Over the last decades, the Gangetic plains in northern India have undergone the world's largest and fasted increase in irrigated agricult...

Climate change would significantly affect many hydrologic systems, which in turn would affect the water availability, runoff, and the flow in rivers. This study evaluates the impacts of possible future climate change scenarios on the hydrology of the catchment area of the Tunga–Bhadra River, upstream of the Tungabhadra dam. The Hydrologic Engineeri...

Quantifying how changes in land use affect the hydrological response at the river basin scale is a challenge in hydrological science and especially in the tropics where many regions are considered data sparse. Earlier work by the authors developed and used high-resolution, reconstructed land cover maps for northern India, based on satellite imagery...

Water is the most important medium through which climate change influences human life. Rising temperatures together with regional changes in precipitation patterns are some of the impacts of climate change that have implications on water availability, frequency and intensity of floods and droughts, soil moisture, water quality, water supply and wat...

Detecting and quantifying the presence of human-induced climate change in regional hydrology is important for studying the impacts of such changes on the water resources systems as well as for reliable future projections and policy making for adaptation. In this article a formal fingerprint-based detection and attribution analysis has been attempte...

Water resources systems problem are often characterized by uncertainty due to partial ignorance resulting from missing hydrologic data. Imprecise probability is a branch of advanced probability theory which models partial ignorance. The paper presents mathematical background of the theory of imprecise probability with its application to waste load...

The paper presents an overview of the methodologies developed for assessing hydrologic impacts of climate change with an emphasis on statistical techniques for regional impact assessment and modelling of uncertainty, resulting from the use of multiple climate models. The methodologies are demonstrated with the case study of Orissa meteorological su...

Uncertainty analysis plays a major role in a water quality management problem to establish a proper decision scheme, as most input parameters in any realistic system are inherently uncertain. Modeling of some uncertain parameter in the optimization model is not possible through conventional probabilistic or fuzzy approach, because of inadequacy of...

In this paper, an integrated model is presented that enhances the features of the earlier models to simultaneously address stochastic variations in reservoir inflow and command area rainfall in arriving at reservoir release decisions. The stochastic variation of inflows is addressed through the inflow transition probabilities, and the rainfall vari...

A modeling framework is presented in this paper, integrating hydrologic scenarios projected from a General Circulation Model (GCM) with a water quality simulation model to quantify the future expected risk. Statistical downscaling with a Canonical Correlation Analysis (CCA) is carried out to develop the future scenarios of hydro-climate variables s...

This paper presents an approach to model the expected impacts of climate change on irrigation water demand in a reservoir command area. A statistical downscaling model and an evapotranspiration model are used with a general circulation model (GCM) output to predict the anticipated change in the monthly irrigation water requirement of a crop. Specif...

Various modeling methodologies are available to aid planning and operational decision making: this book synthesises these, with an emphasis on methodologies applicable in data scarce regions, such as developing countries. Problems included in each chapter, and supported by links to available online data sets and modelling tools, engage the reader w...

Many downscaling techniques have been developed in the past few years for projection of station-scale hydrological variables from large-scale atmospheric variables simulated by general circulation models (GCMs) to assess the hydrological impacts of climate change. This article compares the performances of three downscaling methods, viz. conditional...

Analysis of climate change impacts on streamflow by perturbing the climate inputs has been a concern for many authors in the past few years, but there are few analyses for the impacts on water quality. To examine the impact of change in climate variables on the water quality parameters, the water quality input variables have to be perturbed. The pr...

Representation and quantification of uncertainty in climate change impact studies are a difficult task. Several sources of uncertainty arise in studies of hydrologic impacts of climate change, such as those due to choice of general circulation models (GCMs), scenarios and downscaling methods. Recently, much work has focused on uncertainty quantific...

Regional impacts of climate change remain subject to large uncertainties accumulating from various sources, including those due to choice of general circulation models (GCMs), scenarios, and downscaling methods. Objective constraints to reduce the uncertainty in regional predictions have proven elusive. In most studies to date the nature of the dow...

Impacts of climate change on hydrology are assessed by downscaling large scale general circulation model (GCM) outputs of climate variables to local scale hydrologic variables. This modelling approach is characterized by uncertainties resulting from the use of different models, different scenarios, etc. Modelling uncertainty in climate change impac...

Relatively few studies have addressed water management and adaptation measures in the face of changing water balances due to climate change. The current work studies climate change impact on a multipurpose reservoir performance and derives adaptive policies for possible futurescenarios. The method developed in this work is illustrated with a case s...

Fuzzy waste Load Allocation Model (FWLAM), developed in an earlier study, derives the optimal fractional levels, for the base flow conditions, considering the goals of the Pollution Control Agency (PCA) and dischargers. The Modified Fuzzy waste Load Allocation Model (MFWLAM) developed subsequently is a stochastic model and considers the moments (me...

Downscaling to station-scale hydrologic variables from large-scale atmospheric variables simulated by general circulation models (GCMs) is usually necessary to assess the hydrologic impact of climate change. This work presents CRF-downscaling, a new probabilistic downscaling method that represents the daily precipitation sequence as a conditional r...

Hydrologic impacts of climate change are usually assessed by downscaling the General Circulation Model (GCM) output of large-scale climate variables to local-scale hydrologic variables. Such an assessment is characterized by uncertainty resulting from the ensembles of projections generated with multiple GCMs, which is known as intermodel or GCM unc...

Uncertainty plays an important role in water quality management problems. The major sources of uncertainty in a water quality management problem are the random nature of hydrologic variables and imprecision (fuzziness) associated with goals of the dischargers and pollution control agencies (PCA). Many Waste Load Allocation (WLA) problems are solved...

A fuzzy logic based centralized control algorithm for irrigation canals is presented. Purpose of the algorithm is to control downstream discharge and water level of pools in the canal, by adjusting discharge release from the upstream end and gates settings. The algorithm is based on the dynamic wave model (Saint-Venant equations) inversion in space...

A fuzzy dynamic flood routing model (FDFRM) for natural channels is presented, wherein the flood wave can be approximated to a monoclinal wave. This study is based on modification of an earlier published work by the same authors, where the nature of the wave was of gravity type. Momentum equation of the dynamic wave model is replaced by a fuzzy rul...

Hydrological implications of global climate change are usually assessed by downscaling appropriate predictors simulated by General Circulation Models (GCMs). Results from GCM simulations are subject to a number of uncertainties due to incomplete knowledge about the underlying geophysical processes of global change (GCM uncertainties) and uncertain...

This paper presents an overview of the current water resources scenario in India, and recent work carried out in India to assess the climate change impact on hydrology and water resources. Issues that need to be addressed with respect to climate change/variability in sustainable water resources planning and management are discussed.

A fuzzy optimization model, developed earlier to address uncertainty due to imprecision in management goals in river water quality management problems, is applied to a case study in this paper by addressing uncertainty due to randomness implicitly through Monte Carlo simulations. Municipal and industrial effluents, characterized by their Biochemica...

Climate change impact assessment on water resources with downscaled General Circulation Model (GCM) simulation output is characterized by uncertainty due to incomplete knowledge about the underlying geophysical processes of global change (GCM uncertainties) and due to uncertain future scenarios (scenario uncertainties