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Water and water-related disasters, e.g. flooding, landslide and droughts, are affecting the world and it is important for decision makers and experts to build the capacity of forecasting hydrodynamic disasters and safeguarding people’s life and property. This study focuses on building capacity of decision makers and analysts with an aim to create and support a robust framework for decision makers in integrated water resource management. Capacity building training workshops has been conducted using Coupled Routing and Excess Storage (CREST) and Ensemble Framework for Flash Flood Forecasting (EF5) distributed hydrological modeling jointly developed by University of Oklahoma (OU) and National Aeronautics and Space Administration (NASA), involving Regional Center for Mapping of Resources for Development (RCMRD), ICPAC and Kenyan Meteorological department (KMD). The OU_Applied Science Team (AST) in collaboration with RCMRD provided an EF5 hydrologic model website to KMD to visualize and forecast streamflow. Further, an advanced EF5 training was conducted in East Africa and a system to collect citizen reports to gather observations of flooding was developed. This effort will improve awareness of and access to available services through providing user-tailored services to inform development of decision-making processes and build the capacity of SERVIR hubs and their partners to provide high quality services, creating a stronger network at the regional and international level. The study will guide users/forecasters on how to use EF5 operationally and enhances development of an impact-based flood early warning system with users, linking hydrologic forecasts with vulnerability assessment and risk analysis to mitigate the potential negative impact to the public and properties. Key words: Capacity building, drought, flood, hydrologic model, landslide, streamflow.

Estimation of crop water requirement (CWR) is key to the rational water use and agricultural water conservation in arid regions. Using remote sensing data to obtain long-term CWR over large areas helps water resources management in water-scarce areas. This study, taking the Kaidu-Kongqi River basin in arid northwest China as the study area, investigated the feasibility of synergistically using phenological characteristics, Savitzky-Golay filter, harmonic analysis and decision tree to extract crop planting structures (CPS) from MODIS EVI, and meanwhile analyzed the spatiotemporal variation in the estimated CWR. The results show that the integrated method for CPS identification and extraction is feasible and reliable with the classification accuracy over 80%. The mid-season stage requires the most water and cash crops need more water than cereal crops. Summer accounts for 69% the total growing season water use. The significant increase in the area of high water demand crops such as cotton raised the total CWR of the basin surging from 14.91× 108m3 in 2000 to 34.92×108m3 in 2017. The spatial distribution of CWR was more related to crop types and area than to climatic conditions. Controlling the expansion of arable land and optimizing the agricultural planting structure remain important tasks for the sustainable management of water resources in the basin.

High fluoride concentrations in groundwater pose a health risk to people living in the Rift valley of Ethiopia and beyond. The Nalgonda and electrolytic defluoridation (EDF) fluoride treatment systems were developed and adapted in India for fluoride removal. A recent study evaluated twenty Nalgonda techniques that were implemented in the Rift valley of Ethiopia. A number of these systems were found to be non-functional or had never been utilized. The purpose of this study is to evaluate the performance of the Nalgonda technique and seek ways to enhance the fluoride uptake capacities. Further, pilot testing of the EDF system was conducted in the Rift Valley of Ethiopia to evaluate its effectiveness at fluoride removal using natural groundwater in this setting. This study has shown that the performance of the Nalgonda system was significantly enhanced by adding aluminum hydro(oxide) (AO) and cow bone char powder into the existing Nalgonda systems; the initial fluoride concentration of 9.3 mg/L was lowered to 2.5 mg/L on average. In addition to the increased effectiveness at fluoride removal, the addition of AO and cow bone char powder produced significantly less sludge compared to the existing Nalgonda system. The EDF system proved to be effective at removing the excess fluoride concentration in drinking water in the Rift Valley of Ethiopia; the initial fluoride concentration of 7.9 mg/L was lowered to 2.8 mg/L meeting the USEPA standard fluoride level of 4 mg/L. The pilot study showed Aluminum leaching into the treated water. Thus, further optimization of the electrode size, electrolysis time, and voltage/current used during the electrolysis process is needed to meet the WHO target treatment goal of 1.5 mg/L fluoride level and eliminate aluminum leaching as well. Key words: Electrolytic defluoridation, fluoride, Nalgonda, pilot-testing, sustainability.

More than half of all streams globally are non-perennial, and thus dynamic due to their expanding and retracting nature. Field mapping in conjunction with observational data from gauges and/or in-situ loggers is a typical approach for studying non-perennial stream dynamics, but these approaches underrepresent their spatiotemporal variability. High-resolution distributed hydrological modeling promises to bridge this gap, thanks to advances in model physics, remote sensing, and computational power. As the first step towards this goal, we investigate the capability of distributed hydrologic modeling to capture stream dynamics in Upper Blue River Basin, OK. Coupled Routing and Excess STorage (CREST), a distributed hydrological model, is used to simulate spatiotemporally varied streamflow at 10-meter spatial resolution and daily time steps. USGS stream gauge data and in-situ state logger data are used to calibrate and validate the simulation at the watershed outlet and small headwater tributaries, respectively. Dynamic Surface Water Estimate (DSWE), a LANDSAT product is also compared with simulated water presence in high-order streams. Results show that the CREST model can capture low-moderate streamflow values at the watershed outlet with a log-NSE value over 0.7 in the validation period, while underestimating high flow values due to the daily time step. Also, the calibrated model can accurately estimate wet/dry status as monitored by in-situ state loggers in nine headwater catchments. The dynamic stream networks are mapped over 2510 stream segments using the CREST simulation. Non-perennial streams are the most dynamic in small headwater tributaries (contributing area

Under the impacts of hydrologic extremes, there is a growing need for integrated frameworks for flood inundation mapping. In this study, we introduce a framework: the Coupled Routing and Excess Storage for inundation MApping and Prediction (CREST-iMAP). It utilizes a highly parallelized and fully integrated hydrologic-hydraulic model and aims to improve flood prediction. To highlight the advantages, a synthetic rainfall event and the 500-year Hurricane Harvey event were investigated using the CREST-iMAP, compared with a hydrologic model, a hydraulic model, and a simplified hydrologic-hydraulic model. The results indicate the CREST-iMAP achieves good performances in both hydrologic simulation and floodplain inundation mapping. Moreover, the antecedent soil moisture is the most sensitive parameter to model accuracy, followed by the land surface characteristics; the infiltration process to a flood forecasting model is significant. Overall, the CREST-iMAP delivers accurate and timely flood information, making it one of the latest developments of an integrated hydrologic-hydraulic expert system.

This paper addresses how business models inform viability of different fluoride treatment technologies for developing countries as well as the pursuit of financial and operational sustainability. Excess fluoride concentrations in drinking water supplies negatively impact the health of communities living in fluoride affected regions of the world by causing dental and skeletal fluorosis and other severe socio-economic problems. Given that fluoride mitigation solutions have proven elusive, we apply business model logic to compare fluoride removal technologies to examine the financial sustainability of water service provisions. We analyze the investment cost of producing fluoride safe water, the annual revenues generated, and the net benefits obtained from different technologies. Furthermore, the reduced medical costs and productivity losses averted due to access to fluoride safe water can lead to an average annual cost saving of $67 per person. Our results validate the use of business models to help evaluate different technologies as a means of pursuing sustainable applications for safe drinking water.

Precipitation is an essential climate and forcing variable for modeling the global water cycle. Particularly, the recent Integrated Multi-satellite Retrievals for GPM (IMERG) product retrospectively provides an unprecedented two decades of high-resolution satellite precipitation estimates. The primary goal of this study is to examine the similarities and differences between the two latest and also arguably the most popular, GPM IMERG Early and Final Run (ER and FR) products across the globe. The results reveal that: (1) ER systematically estimates 12.0% higher annual rainfall than FR, particularly over land (16.7%); (2) ER and FR show significant differences in instantaneous rates (Root Mean Squared Difference: RMSD = 2.38 mm h−1 and normalized RMSD: RMSD_norm = 1.09), especially in Africa (RMSD = 2.40 mm h−1) and hot, arid regions (RMSD_norm = 1.11), but less so in Europe (RMSD = 2.16 mm h−1) and cold areas (RMSD_norm = 0.87); and (3) ER measures 33.0% higher extreme rainfall rates than FR over the globe. The exploration of their similarities and differences provides a first-order global assessment of various hydrological utilities: FR is designed to be more suitable for retrospective hydroclimatology and water resource applications, while the earliest available ER product, though not bias-corrected by rain gauges, still shows potential utility for operational modeling of rainfall-triggered hazards. The findings of this study can provide an assessment to product developers and broader data users and practitioners to address the inherent issues in hardware limitations, retrieval algorithms, and uncertainty quantification for research and applications.

Thermally activated cow bone is widely utilized for treating fluoride impacted drinking water to meet the World Health Organization guideline value of 1.5 mg/L. However, the fluoride removal capacity of bone char is low, leaving room for further improvement. This study, therefore, strives to improve the fluoride adsorption capacity of cow bone by using chemical activation in place of thermal activation. Chemically activated cow bones (CABs) had, on average, a four-fold higher fluoride adsorption capacity than bone char. Characterization of the most effective CAB were made to explore potential reasons for the increased fluoride adsorption capacity. The X-ray diffraction pattern of the CAB showed formation of bassanite and monetite minerals which may be responsible for the higher fluoride adsorption capacity. Chemical activation is also a lower-cost production process than the thermal activation of cow bone. Further, a higher mass of media was recovered per unit mass of starting material during chemical activation. Therefore, this research shows that increased fluoride removal capacity can be achieved with chemical activation of cow bone while reducing activation costs and greatly increasing product yield per unit mass of starting material, all of which support further evaluation and field testing of this material.

In an effort to further understand the fourfold higher fluoride removal capacity of chemically activated cow bone (CAB) previously reported compared to bone char, fundamental properties of ...

Various fluoride adsorbents have been studied for removal of excess fluoride from drinking water to meet the World Health Organization (WHO) Guideline value of 1.5 mg/L. Production of these adsorbents emits contaminants that can affect human health and the environment, but the extent of these impacts is currently unknown. This study evaluates the environmental impacts of four low-cost and easy to use adsorbents: activated alumina, aluminum oxide amended wood char, bone char, and treated alum waste. The environmental impacts of these adsorbents were evaluated using life cycle assessment (LCA). The life cycle stages considered were raw material acquisition, adsorbent manufacturing, and waste management. The functional unit was defined as the quantity of adsorbent necessary to reduce the fluoride concentration of 100,000 L of water from 10 mg/L to the World Health Organization recommended drinking water level of 1.5 mg/L. Eco-indicator and the Tool for Reduction and Assessment of Chemicals and other Environmental Impacts (TRACI) were used to interpret the environmental impacts. The results indicate that the environmental impacts of these adsorbents vary greatly using a common functional unit of treating 100,000 L (100 m3) of fluoride-impacted water. A key determining factor for the impacts is the fluoride adsorption capacity of the adsorbent material because this affects how much material is required to produce safe water. Aluminum oxide amended wood char had the highest overall negative environmental impact in all impact categories, and the lowest adsorption capacity. The two adsorbents that performed the best (lowest environmental impact) were the bone char and the treated alum waste. The environmental impacts of the adsorbents can be reduced by increasing their fluoride adsorption capacity and/or carefully selecting key process components, such as the distance and means of transportation, particularly for activated alumina. Regeneration and reuse of spent adsorbents has the potential to minimize impacts to ecosystem quality.

In this study, a novel material, chemically activated cow bone (CAB), was further evaluated for fluoride removal via laboratory batch and field column studies using fluoride-impacted groundwaters in the Rift Valley of Ethiopia. Regeneration of the exhausted CAB was evaluated using 0.05 M NaOH and 0.01 M Ca(OH)2 solutions. Water-quality parameters were analyzed to ensure that the CAB-treated water is safe for human consumption. The study indicated that the CAB produced in the laboratory and field showed fourfold improvement in fluoride removal capacity as compared to thermally activated cow bone (commonly known as bone char). The study also showed that more than 92% adsorption capacity of the exhausted CAB media can be regained using 0.05 M NaOH and 0.01 M Ca(OH)2 solutions. The water-quality analysis conducted on the highly fluoride-impacted drinking waters treated using CAB media were found to be safe for public consumption. Therefore, these results further reinforce that CAB media can be used to...