Below is a full list of publications by City Water Center’s students, faculty and affiliated researchers arranged by publication date.
Can improved agricultural water use efficiency save India’s groundwater?
The potential impact of technology adoption on aquifers in India is investigated. We find substantial technical potential for reversing water table declines. However, we show that these impacts are highly sensitive to assumptions about farmers’ water use decisions. The analysis provides quantitative input to the debate of incentives versus technology based water policies in India. This article is published in Environmental Research Letters.
Citation: Fishman, R., Devineni, N., & Raman, S. (2015). Can improved agricultural water use efficiency save India’s groundwater? Environmental Research Letters, 10(8), 084022. doi:10.1088/1748-9326/10/8/084022
An empirical, nonparametric simulator for multivariate random variables with differing marginal densities and nonlinear dependence with hydroclimatic applications
A new nonparametric simulation approach is developed that reproduces the dependence structure in the data set. It can be applied to multiple variables or to spatial fields with arbitrary dependence structure and marginal densities. The risk of potentially correlated factors can be evaluated. An example that simulates the livestock mortality rate for Mongolia to assess the spatial risk is presented. This article is published in Risk Analysis.
Citation: Lall, U., Devineni, N., & Kaheil, Y. (2015). An Empirical, Nonparametric Simulator for Multivariate Random Variables with Differing Marginal Densities and Nonlinear Dependence with Hydroclimatic Applications. Risk Analysis, n/a–n/a. doi:10.1111/risa.12432
Scaling of extreme rainfall areas at a planetary scale
A global analysis of the scaling characteristics of extreme rainfall areas for durations ranging from 1 to 30 days is presented. We find that the power law scaling may also apply to planetary scale phenomenon, such as frontal and monsoonal systems, and their interaction with local moisture recycling. This article is published in Chaos.
Citation: Devineni, N., Lall, U., Xi, C., & Ward, P. (2015). Scaling of extreme rainfall areas at a planetary scale. Chaos: An Interdisciplinary Journal of Nonlinear Science, 25(7), 075407. doi:10.1063/1.4921719
America’s water risk, current demand and climate variability
A new indicator of drought induced water stress is introduced and applied at the county level in the USA. Potential water stress for each county is estimated using current daily water demand and daily renewable water supply. The indicator directly informs the county’s dependence on exogenous water transfers to meet demands and to buffer multi-year and within year climate variability. This article is published in Geophysical Research Letters. The article also received coverage on Bloomberg News.
Citation: Devineni, N., Lall, U., Etienne, E., Shi, D., & Xi, C. (2015). America’s water risk: Current demand and climate variability. Geophysical Research Letters, 1–9. doi:10.1002/2015GL063487.
A climate informed model for nonstationary flood risk prediction: Application to Negro river at Manaus, Amazonia
A flood risk model that is based on the knowledge of the operating climate regime (e.g. El Niño Southern Oscillation) is presented to predict the probability of flood each year. For the Negro River at Manaus, Amazonia, the annual peak flood (occurring in summer) can be predicted using the river stage at the beginning of the year and the previous December’s sea surface temperature in the tropical Pacific. The model provides an early flood alert system for the city of Manaus by quantifying the changing flood hazard several months in advance. This article is published in Journal of Hydrology.
Citation: Lima, C. H. R., Lall, U., Troy, T. J., & Devineni, N. (2015). A climate informed model for nonstationary flood risk prediction: Application to Negro River at Manaus, Amazonia. Journal of Hydrology, 522, 594–602. doi:10.1016/j.jhydrol.2015.01.009
Up-to-date probabilistic temperature climatologies
Climatologies based on average past temperatures are increasingly recognized as imperfect guides for current conditions. We present several alternatives to derive updated climatologies as probability distributions for monthly temperatures. The exponentially weighted moving average with a time scale of 15 years has good overall performance in hindcasting temperature over the last 30 years. This article is published in Environmental Research Letters.
Citation: Krakauer, N. Y., & Devineni, N. (2015). Up-to-date probabilistic temperature climatologies. Environmental Research Letters, 10(2), 024014. doi:10.1088/1748-9326/10/2/024014
China’s water sustainability in the 21st century: A climate informed water risk assessment covering multi-sector water demands
China is facing a water resources crisis with growing concerns of reliable supply of water for agricultural, industrial and domestic needs. In this article, we modeled the differences in water demand and supply to quantify the dimensions of the water risk. The work provides a detailed quantitative assessment of water risk as measured by the cumulated deficits for China. The risk measures highlight North China Plain counties as highly water stressed. These regions now have depleted groundwater aquifers. This article is published in Hydrology and Earth System Sciences.
Citation: Chen, X., Naresh, D., Upmanu, L., Hao, Z., Dong, L., Ju, Q., Wang, J., Wang, S. (2014). China’s water sustainability in the 21st century: a climate-informed water risk assessment covering multi-sector water demands. Hydrology and Earth System Sciences, 18(5), 1653–1662. doi:10.5194/hess-18-1653-2014
Climate information based streamflow and rainfall forecasts for Huai River basin using hierarchical Bayesian modeling
In this work, we developed a statistical model that will forecast the amount of total summer rainfall for the Huai River Basin, China. The probable rainfall for the months of June, July and August every year is predicted at the beginning of May. This one month lead time will enable water managers to make decisions on whether to release more water during the season (if there is a forecast of good rainfall) or to store more water in the dams (if there is a forecast of drought). Farmers can use this forecast information and the lead time to make choices on what type of crop to grow and secure the sources of irrigation. We used a Hierarchical Bayesian Model to explicitly quantify the parameter uncertainty through each estimation stage using appropriate conditional and prior distributions. This article is published in Hydrology and Earth System Sciences.
Citation: Chen, X., Hao, Z., Devineni, N., & Lall, U. (2014). Climate information based streamflow and rainfall forecasts for Huai River basin using hierarchical Bayesian modeling. Hydrology and Earth System Sciences, 18(4), 1539–1548. doi:10.5194/hess-18-1539-2014
India’s water: A reflection of a nation’s soul?
A short description of the current water issues in India is presented. This article is published as an opinion piece in Center for International Project’s Trust newsletter (CIPT Sandesh).
Citation: Lall, Upmanu ; Devineni, N. (2014). India’s water: A reflection of a nation’s soul? CIPT Sandesh, 1–12.
Climate change impacts on New York City’s water supply system: case study –Allaben watershed and the impact of climate change on erosion rate at Liberty, Sullivan County, NY
This thesis presents climate change impacts on the hydrometeorology of the Allaben watershed and climate change impact on erosion rates at Liberty, Sullivan County, NY were investigated. For climate change impacts on the Allaben watershed the WatBal hydrological model, three General Circulation Models (GCMs) (Canadian Climate Center, Hadley Center and Goddard Institute for Space Studies) and the Palmer Drought Severity Index (PDSI) were used to provide a detailed, comprehensive climate change impacts assessment on the Allaben watershed. The Water Erosion Prediction Project (WEPP) model was used to assess the possible future erosion rates on Liberty.
Citation: Kirub, S. (2002) Climate Change Impacts on New York City’s Water Supply System: Case Study–Allaben Watershed and the Impact of Climate Change on Erosion Rate at Liberty, Sullivan County, NY. CCNY Libraries.
Modeling flow through natural wetlands with a modified dynamic wave equation
This dissertation presents a mathematical model that simulates the hydrodynamics of natural wetlands. The model represents the first attempt to describe wetland flow dynamically with variables and coefficients that can be measured easily in the field.
Citation: Stern, D. (2001). Modeling Flow Through Natural Wetlands with a Modified Dynamic Wave Equation. CCNY Libraries.
Numerical simulation of pressure variation in a variably saturated multi-layered porous medium
This dissertation presents the mathematical and numerical formulation for variably saturated flow in a heterogeneous medium were developed. The complexities arise due to discontinuity in a strongly heterogeneous medium with sharp interfaces. In particular, layered landfill covers and intermediate barrier layers are of concerns for appropriate simulation by avoiding difficulty in representing discontinuities at the interfaces. In the present study, special formulations comprising criteria based on continuity and compatibility were employed to overcome the difficulty in solving multi-layered domain with discontinuities. To define an appropriate boundary condition, evapotranspiration and runoff were computed to determine inflow/outflow.
Citation: Ghias, Z. (1999) Numerical Simulation of Pressure Variation in A Variably Saturated Multi-Layered Porous Medium. CCNY Libraries.
Feasibility of the utilization of sludge ash based on laboratory experiments
This dissertation tests for physical and chemical properties of incinerator sludge ash from Bergen Point Wastewater Treatment Plant are done. Also the tests for physical and chemical properties of cement and asphalt concrete containing different percentages of ash are done in order to compare the results with controlled specimens containing no ash. The EP-Toxicity and TCLP tests results on ash-cement and ash-asphalt concrete are also compared with ground water effluent standard, Class-GA ground water standard and Class-AA surface water standard. Sludge ash from Bergen Point Wastewater Treatment Plant is non-hazardous according to chemical analysis. This ash may be used in cement concrete to replace up to thirty percent (by weight) of its requirement of fine aggregate to get the targeted strength by preparing a properly designed and controlled mix. For asphalt concrete the ash amount is found about 15 percent of its fine aggregate portion. This ash possesses a disposal problem which could be drastically reduced if it is economically used in construction as a substitute material for aggregate.
Citation: Rahman, M. (1993) Feasibility of the Utilization of Sludge Ash Based on Laboratory Experiments. CCNY Libraries.