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PR, IFPRI3; 1 Fostering Climate-Resilient and Sustainable Food Supply; 4 Transforming Agricultural and Rural Economies, Natural Resources and Resilience (NRR); Transformation Strategies, Irrigation, and especially farmer-led irrigation, is considered to be a promising option for enhancing agricultural productivity in Sub-Saharan Africa. However, there is a lack of thorough understanding of the impacts of irrigation development on environment. Past discussions are mainly limited to the water depletion and hydrological regime change effect of irrigation. This paper presents a study to narrow the knowledge gap by assessing nutrient water pollution risk induced by the expansion of farmer-led irrigation in Ethiopia. Using household survey data collected from four woredas in Ethiopia where irrigated crop production currently concentrates, we first evaluate the impact of irrigation on cropping intensity and annual consumption level of fertilizers and then use the findings of the household survey data analysis to support conceptualization of a modeling framework for assessing agricultural nutrient water pollution risk from farmer-led irrigation development in Ethiopia at national scale. We project that overall farmer-led irrigation development in Ethiopia will lead to a gentle increase in national total of agricultural nutrient loadings. This result helps justify the endeavor of promoting farmer-led irrigation in Ethiopia. On the other hand, the projected nutrient flow and nutrient loading growth rate related to the farmer-led irrigation expansion are highly heterogeneous spatially, and risk of local water quality deterioration exists. There is still need to make investment to ensure the environmental sustainability of farmer-led irrigation development.

Ethiopia is experiencing considerable impact of climate change and variability in the last five decades. Analyzing climate trends and variability is essential to develop effective adaptation strategies, particularly for countries vulnerable to climate change. This study analyzed trends and variabilities of climate (rainfall, maximum temperature (Tmax), and minimum temperature (Tmin)) at local and regional scales in Ethiopia. The local analysis was carried out considering each meteorological station, while the regional analyses were based on agro-ecological zones (AEZs). This study used observations from 47 rainfall and 37 temperature stations obtained from the Ethiopian Meteorological Institute (EMI) for the period of 1986 to 2020. The Modified Mann-Kendall (MMK) trend test and Theil Sen's slope estimator were used to analyze the trends and magnitudes of change, respectively, in rainfall as well as temperature. The coefficient of variation (CV) and standardized anomaly index (SAI) were also employed to evaluate rainfall and temperature variabilities. The local level analysis revealed that Bega (dry season), Kiremt (main rainy season), and annual rainfall showed increasing trend, albeit no significant, in most stations, but the rainfall in Belg (small rainy) season showed a non-significant decreasing trend. The regional levels analysis also indicated an increasing trend of Bega, Kiremt, and annual rainfall in most AEZs, while Belg rainfall showed a decreasing trend in the greater number of AEZs. The result of both local and regional levels of analysis discerned a spatially and temporally more homogeneous warming trend. Both Tmax and Tmin revealed an increasing trend in annual and seasonal scales at most meteorological stations. Likewise, an increase was recorded for mean Tmax and Tmin in entire/most AEZs. The observed trends and variabilities of rainfall and temperature have several implications for climate change adaptations. For example, the decrease in Belg rainfa

The availability of water at the regional and river basin scales in the future will be significantly impacted by climate change. Effective water management in the sub-basin is essential for ensuring long-term sustainability in the face of changing climatic conditions. The Maner River basin is a significant contributor to the Godavari River, and agriculture serves as the primary source of income for the majority of individuals residing in the subbasin. Nearly 50–65% of irrigational fields in the Maner basin are cultivated using local Tank Cascade Systems (TCS) and reservoirs that are managed by monsoon precipitation. The regional level climate change impact on the water resources of these tank cascade systems is important for sustainable management of water resources. In this study, The NEX-GDDP RCM models of CCSM4, MPI-ESM-LR and MIROC-ESM-CHEM were utilized to examine climate patterns during historical and future periods under RCP 4.5 and RCP 8.5 scenarios. The Maner sub-basin and KTCS (Katakshapur Tank Cascade System) were modeled using the SWAT hydrological model to simulate runoff and water availability. The average monsoon (July-October) streamflow increase in the Maner basin during the near, mid, and far futures is projected to be 47%, 66%, and 114% under the RCP 4.5 scenario, and 53%, 72%, and 69% under the RCP 8.5 scenario, respectively. Excess flow may overflow from Ramchandrapur, Mallampalli, and Dharmaraopalli tanks to the downstream Katakshapur tank since it can accommodate the up to 18.91 Mm3. To enhance water management in response to climate change, one potential adaptation strategy is to utilize the surplus inflow to refill downstream artificial ponds, which can aid in the replenishment of groundwater and the provision of water supply to tail end tanks.

Climate-induced changes in precipitation and temperature can have a profound impact on watershed hydrological regimes, ultimately affecting agricultural yields and the quantity and quality of surface water systems. In India, the majority of the watersheds are facing water quality and quantity issues due to changes in the precipitation and temperature, which requires assessment and adaptive measures. This study seeks to evaluate the effects of climate change on the water quality and quantity at a regional scale in the Nagavali and Vamsadhara watersheds of eastern India. The impact rainfall variations in the study watersheds were modeled using the Soil and Water Assessment Tool (SWAT) with bias-corrected, statistically downscaled models from Coupled Model Intercomparison Project-6 (CMIP-6) data for historical (1975–2014), near future (2022–2060), and far future (2061–2100) timeframes using three Shared Socioeconomic Pathways (SSP) scenarios. The range of projected changes in percentage of mean annual precipitation and mean temperature varies from 0 to 41.7% and 0.7 °C to 2.7 °C in the future climate, which indicates a warmer and wetter climate in the Nagavali and Vamsadhara watersheds. Under SSP245, the average monthly changes in precipitation range from a decrease of 4.6% to an increase of 25.5%, while the corresponding changes in streamflow and sediment yield range from −11.2% to 41.2% and −15.6% to 44.9%, respectively. Similarly, under SSP370, the average monthly change in precipitation ranges from −3.6% to 36.4%, while the corresponding changes in streamflow and sediment yield range from −21.53% to 77.71% and −28.6% to 129.8%. Under SSP585, the average monthly change in precipitation ranges from −2.5% to 60.5%, while the corresponding changes in streamflow and sediment yield range from −15.8% to 134.4% and −21% to 166.5%. In the Nagavali and Vamsadhara watersheds, historical simulations indi

Crop management involves a series of critical, interdependent decisions or actions in a complex and highly uncertain environment, which exhibit distinct spatial and temporal variations. Managing resource inputs such as fertilizer and irrigation in the face of climate change, dwindling supply, and soaring prices is nothing short of a Herculean task. The ability of machine learning to efficiently interrogate complex, nonlinear, and high-dimensional datasets can revolutionize decision-making in agriculture. In this paper, we introduce a reinforcement learning (RL) environment that leverages the dynamics in the Soil and Water Assessment Tool (SWAT) and enables management practices to be assessed and evaluated on a watershed level. This drastically saves time and resources that would have been otherwise deployed during a full-growing season. We consider crop management as an optimization problem where the objective is to produce higher crop yield while minimizing the use of external farming inputs (specifically, fertilizer and irrigation amounts). The problem is naturally subject to environmental factors such as precipitation, solar radiation, temperature, and soil water content. We demonstrate the utility of our framework by developing and benchmarking various decision-making agents following management strategies informed by standard farming practices and state-of-the-art RL algorithms.

PR, IFPRI3; 1 Fostering Climate-Resilient and Sustainable Food Supply; ISI, Natural Resources and Resilience (NRR); Transformation Strategies, Soil erosion and subsequent land degradation undermine efforts to ensure food security and environmental sustainability in Ethiopia. The government of Ethiopia has implemented extensive soil and water conservation (SWC) programs in severely degraded and food-insecure areas of the country, in some cases integrated with subsequent or parallel irrigation development. However, the effectiveness of these interventions has not been extensively evaluated. This study, therefore, evaluates the performance and impacts of SWC practices in terms of improving vegetation greenness and reducing soil erosion in Feresmay watershed in Ethiopia. Long-term Landsat-based Normalised Difference Vegetation Index (NDVI), Revised Universal Soil Loss Equation (RUSLE), and Soil and Water Assessment Tool (SWAT) were used for change-detection analysis before and after the implementation of various SWC interventions. The results revealed the positive impacts of SWC interventions in improving the vegetation greenness and soil erosion reduction although the outcome varied by intervention. Increased vegetation greenness was observed largely in areas where area closure with catchment treatment (ACCT) and impacts of irrigation (IRR) interventions are dominant, while relatively little impact was observed at the watershed level analysis. Although these interventions helped to reduce soil loss, the results highlighted the need for more SWC interventions to minimise further soil loss.

Non-PR, IFPRI5; 1 Fostering Climate-Resilient and Sustainable Food Supply, Natural Resources and Resilience (NRR); Transformation Strategies, Individual farmer investments have the potential to fill the gap in public investments and be more cost-effective than large-scale irrigation. However, this development primarily occurs outside of formal systems. Water depletion and declining water quality in some areas of Africa and Southeast Asia suggest the need for careful planning and monitoring of small-scale irrigation to support resilience and avoid maladaptation. ILSSI research partners sought to support decision-makers to understand where and how water can be sustainably used by small-scale irrigators, employing and strengthening capacity for tools to manage competing demands and mitigate the risks to water security. Research partnerships also guided organizations and companies to deploy solar irrigation technologies based on biophysical and socio-economic suitability. Working with farmers, water users, and extension services, the project aimed to improve on-farming water management practices and engage communities to help safeguard water resources.

Rainfall forecasting and its spatio-temporal variability is important for many hydrological applications. It is critical to understand the uncertainty and verify the quality of rainfall forecasts provided by Numerical Weather Prediction (NWP) models. In the present study, the National Center for Environmental Prediction (NCEP) Global Forecast System (GFS) model performance is evaluated for day-1 to day-5 forecast with a threshold of 1 mm/day in the Nagavali and Vamsadhara river basins, India. From the results, the model predicted the rainfall with a correlation coefficient of >0.3 and probability of detection >0.6 for day-1 and day-3 forecasts. The bias in rainfall prediction shifted from overestimation to underestimation by 30% as forecast lead time increased. The total mean error is decomposed into hit, false, and missed bias. The main sources of total mean error are hit bias and false bias. However, missed bias influenced total mean error as lead time increased. Bias correction is applied for the rainfall events with a rainfall intensity >12 mm/day. RMSE improved by >18% for day-1 forecast in both the Nagavali and Vamsadhara basins, and the improvement ranged between 3% to 9% for other days. In the Nagavali basin, BIAS and ME improved and ranged from 44% to 65% for day-1 to day-5 forecast, whereas in the Vamsadhara basin, it ranged from 65% to 93%. Our findings are useful for early warning dissemination during the flood events, resource mobilization to protect communities, and sustainable water resources planning and management.

Climate change, population growth, and water scarcity present unprecedented challenges for agriculture. This project aims to forecast soil moisture using domain knowledge and machine learning for crop management decisions that enable sustainable farming. Traditional methods for predicting hydrological response features require significant computational time and expertise. Recent work has implemented machine learning models as a tool for forecasting hydrological response features, but these models neglect a crucial component of traditional hydrological modeling that spatially close units can have vastly different hydrological responses. In traditional hydrological modeling, units with similar hydrological properties are grouped together and share model parameters regardless of their spatial proximity. Inspired by this domain knowledge, we have constructed a novel domain-inspired temporal graph convolution neural network. Our approach involves clustering units based on time-varying hydrological properties, constructing graph topologies for each cluster, and forecasting soil moisture using graph convolutions and a gated recurrent neural network. We have trained, validated, and tested our method on field-scale time series data consisting of approximately 99,000 hydrological response units spanning 40 years in a case study in northeastern United States. Comparison with existing models illustrates the effectiveness of using domain-inspired clustering with time series graph neural networks. The framework is being deployed as part of a pro bono social impact program. The trained models are being deployed on small-holding farms in central Texas.

With increased demand for water and soil in this Anthropocene era, it is necessary to understand the water balance components and critical source areas of land degradation that lead to soil erosion in agricultural dominant river basins. Two medium-sized east-flowing rivers in India, namely Nagavali and Vamsadhara, play a significant role in supporting water supply and agriculture demands in parts of the Odisha districts of Kalahandi, Koraput and Rayagada, as well as the Andhra Pradesh districts of Srikakulam and Vizianagaram. Floods are more likely in these basins as a result of cyclones and low-pressure depressions in the Bay of Bengal. The water balance components and sediment yield of the Nagavali and Vamsadhara river basins were assessed using a semi-distributed soil and water assessment tool (SWAT) model in this study. The calibrated model performance revealed a high degree of consistency between observed and predicted monthly streamflow and sediment load. The water balance analysis of Nagavali and Vamsadhara river basins showed the evapotranspiration accounted for 63% of the average annual rainfall. SWAT simulated evapotranspiration showed a correlation of 0.78 with FLDAS data. The calibrated SWAT model showed that 26.5% and 49% of watershed area falling under high soil erosion class over Nagavali and Vamsadhara river basins, respectively. These sub watersheds require immediate attention to management practices to improve the soil and water conservation measures.

With increased demand for water and soil in this Anthropocene era, it is necessary to understand the water balance components and critical source areas of land degradation that lead to soil erosion in agricultural dominant river basins. Two medium-sized east-flowing rivers in India, namely Nagavali and Vamsadhara, play a significant role in supporting water supply and agriculture demands in parts of the Odisha districts of Kalahandi, Koraput and Rayagada, as well as the Andhra Pradesh districts of Srikakulam and Vizianagaram. Floods are more likely in these basins as a result of cyclones and low-pressure depressions in the Bay of Bengal. The water balance components and sediment yield of the Nagavali and Vamsadhara river basins were assessed using a semi-distributed soil and water assessment tool (SWAT) model in this study. The calibrated model performance revealed a high degree of consistency between observed and predicted monthly streamflow and sediment load. The water balance analysis of Nagavali and Vamsadhara river basins showed the evapotranspiration accounted for 63% of the average annual rainfall. SWAT simulated evapotranspiration showed a correlation of 0.78 with FLDAS data. The calibrated SWAT model showed that 26.5% and 49% of watershed area falling under high soil erosion class over Nagavali and Vamsadhara river basins, respectively. These sub watersheds require immediate attention to management practices to improve the soil and water conservation measures.

In the semi-arid regions of South Asia, tank systems are the major source of irrigation. In India, the Telangana state government has initiated the Mission Kakatiya program to rejuvenate irrigation tank systems. Understanding the hydrological processes that supply water to these systems is critical to the success of these types of programs in India. The current study attempted to comprehend the hydrological processes and flow routing in the Salivagu watershed tank cascade system in Telangana. There are a lot of ungauged tank cascade systems in this region. Soil Water Assessment Tool (SWAT), a physically-based model, was used to simulate flow patterns in the Salivagu watershed with and without tank systems. The geospatially extracted area and volume were used for this study provided by WBIS-Bhuvan-NRSC. Additionally, the Katakshapur Tank Cascade System (KTCS) was chosen to analyze the water availability in each tank using the water balance approach. The Salivagu watershed flow simulation without tanks overestimated streamflow. The volume difference in flow between with and without tank was 606 Mm3, 615.9 Mm3, and 1011 Mm3 in 2017, 2018, and 2019, respectively. The SWAT simulated volumes of the Ramchandrapur and Dharmaraopalle tanks in KTCS were merely satisfied because the tank size was less than 0.7 km2 and the storage capacity was up to 1 Mm3. Due to tank sizes more than 0.8 km2 and capacities greater than 2 Mm3, the Mallampalli and Katakshapur tank simulation findings were in good agreement with WBIS-Bhuvan-NRSC. This research advances our understanding of the hydrological processes in ungauged cascading tank systems in tropical semi-arid regions.

In the semi-arid regions of South Asia, tank systems are the major source of irrigation. In India, the Telangana state government has initiated the Mission Kakatiya program to rejuvenate irrigation tank systems. Understanding the hydrological processes that supply water to these systems is critical to the success of these types of programs in India. The current study attempted to comprehend the hydrological processes and flow routing in the Salivagu watershed tank cascade system in Telangana. There are a lot of ungauged tank cascade systems in this region. Soil Water Assessment Tool (SWAT), a physically-based model, was used to simulate flow patterns in the Salivagu watershed with and without tank systems. The geospatially extracted area and volume were used for this study provided by WBIS-Bhuvan-NRSC. Additionally, the Katakshapur Tank Cascade System (KTCS) was chosen to analyze the water availability in each tank using the water balance approach. The Salivagu watershed flow simulation without tanks overestimated streamflow. The volume difference in flow between with and without tank was 606 Mm3, 615.9 Mm3, and 1011 Mm3 in 2017, 2018, and 2019, respectively. The SWAT simulated volumes of the Ramchandrapur and Dharmaraopalle tanks in KTCS were merely satisfied because the tank size was less than 0.7 km2 and the storage capacity was up to 1 Mm3. Due to tank sizes more than 0.8 km2 and capacities greater than 2 Mm3, the Mallampalli and Katakshapur tank simulation findings were in good agreement with WBIS-Bhuvan-NRSC. This research advances our understanding of the hydrological processes in ungauged cascading tank systems in tropical semi-arid regions.

The quantitative prediction of hydrological components through hydrological models could serve as a basis for developing better land and water management policies. This study provides a comprehensive step by step modelling approach for a small agricultural watershed using the SWAT model. The watershed is situated in Petzenkirchen in the western part of Lower Austria and has total area of 66 hectares. At present, 87% of the catchment area is arable land, 5% is used as pasture, 6% is forested and 2% is paved. The calibration approach involves a sequential calibration of the model starting from surface runoff, and groundwater flow, followed by crop yields and then soil moisture, and finally total streamflow and sediment yields. Calibration and validation are carried out using the r-package SWATplusR. The impact of each calibration step on sediment yields and total streamflow is evaluated. The results of this approach are compared with those of the conventional model calibration approach, where all the parameters governing various hydrological processes are calibrated simultaneously. Results showed that the model was capable of successfully predicting surface runoff, groundwater flow, soil profile water content, total streamflow and sediment yields with Nash-Sutcliffe efficiency (NSE) of greater than 0.75. Crop yields were also well simulated with a percent bias (PBIAS) ranging from −17% to 14%. Surface runoff calibration had the highest impact on streamflow output, improving NSE from 0.39 to 0.77. The step-wise calibration approach performed better for streamflow prediction than the simultaneous calibration approach. The results of this study show that the step-wise calibration approach is more accurate, and provides a better representation of different hydrological components and processes than the simultaneous calibration approach.

Understanding the spatio-temporal distribution of rainfall characteristics has a major role in assessing the availability of water resources over a catchment. Therefore, it is necessary to understand the changes in rainfall characteristics using gridded precipitation data and robust statistical analysis for making decisions. In this study, the trends in rainfall and rainfall extremes over the Nagavali and Vamsadhara river basins are studied at three time steps (long-term-1901-2018, pre-1950, and post-1950) with four different Mann-Kendall (MK) tests using daily gridded rainfall data of 118 years (1901–2018). The spatial patterns of the trends are evaluated with the kriging interpolation method. Magnitude in rainfall and rainfall extremes (CDD, CWD, PRCPTOT, R10MM, R20MM, R40MM, R95PTOT, RX1DAY, and RX5DAY) are analyzed using the Sen’s slope method. Except in the monsoon season, a decreasing trend is observed in all the rainfall extremes in post-1950 compared to pre-1950 period. Whereas, in the monsoon an increasing trend is observed for the extremes in post-1950 period. Overall period (i.e, 1901–2018) an increasing trend is observed for rainfall and rainfall extremes in the pre-monsoon (March–May), monsoon (June–Sep) seasons and a decreasing trend in the winter season (Dec–Feb) for both the basins. No obvious trends are evident in the post-monsoon season (Oct–Nov). At the annual scale, rainfall and rainfall extremes exhibited an increasing trend. Overall, the Nagavali basin experienced more extreme rainfall events indicating the higher vulnerability of floods while the middle and lower portions of the Vamsadhara basin shown increase in extremes. When linked with hydrological analysis, insights gained from this study are useful for flood vulnerability mapping and risk assessment for both the basins.

Understanding the spatio-temporal distribution of rainfall characteristics has a major role in assessing the availability of water resources over a catchment. Therefore, it is necessary to understand the changes in rainfall characteristics using gridded precipitation data and robust statistical analysis for making decisions. In this study, the trends in rainfall and rainfall extremes over the Nagavali and Vamsadhara river basins are studied at three time steps (long-term-1901-2018, pre-1950, and post-1950) with four different Mann-Kendall (MK) tests using daily gridded rainfall data of 118 years (1901–2018). The spatial patterns of the trends are evaluated with the kriging interpolation method. Magnitude in rainfall and rainfall extremes (CDD, CWD, PRCPTOT, R10MM, R20MM, R40MM, R95PTOT, RX1DAY, and RX5DAY) are analyzed using the Sen’s slope method. Except in the monsoon season, a decreasing trend is observed in all the rainfall extremes in post-1950 compared to pre-1950 period. Whereas, in the monsoon an increasing trend is observed for the extremes in post-1950 period. Overall period (i.e, 1901–2018) an increasing trend is observed for rainfall and rainfall extremes in the pre-monsoon (March–May), monsoon (June–Sep) seasons and a decreasing trend in the winter season (Dec–Feb) for both the basins. No obvious trends are evident in the post-monsoon season (Oct–Nov). At the annual scale, rainfall and rainfall extremes exhibited an increasing trend. Overall, the Nagavali basin experienced more extreme rainfall events indicating the higher vulnerability of floods while the middle and lower portions of the Vamsadhara basin shown increase in extremes. When linked with hydrological analysis, insights gained from this study are useful for flood vulnerability mapping and risk assessment for both the basins.

In the face of future climate change, Europe has encouraged the adoption of biofuel crops by its farmers. Such land-use changes can have significant impacts on the water balance and hydrological behavior of a system. While the heavy pesticide use associated with biofuel crops has been extensively studied, the water balance impacts of these crops have been far less studied. We conducted scenario analyses using the Soil and Water Assessment Tool (SWAT) to determine the effects of farm-scale biofuel crop adoption (rapeseed) on a basin’s water balance. We found that rapeseed adoption does not support the goal of developing a sustainable agricultural landscape in the Czech Republic. The adoption of rapeseed also had disproportionate effects on a basin’s water balance depending on its location in the basin. Additionally, discharge (especially surface runoff ratios), evapotranspiration, and available soil water content display significant shifts in the rapeseed adoption scenarios.

Understanding the spatio-temporal distribution of rainfall characteristics has a major role in assessing the availability of water resources over a catchment. Therefore, it is necessary to understand the changes in rainfall characteristics using gridded precipitation data and robust statistical analysis for making decisions. In this study, the trends in rainfall and rainfall extremes over the Nagavali and Vamsadhara river basins are studied at three time steps (long-term-1901-2018, pre-1950, and post-1950) with four different Mann-Kendall (MK) tests using daily gridded rainfall data of 118 years (1901–2018). The spatial patterns of the trends are evaluated with the kriging interpolation method. Magnitude in rainfall and rainfall extremes (CDD, CWD, PRCPTOT, R10MM, R20MM, R40MM, R95PTOT, RX1DAY, and RX5DAY) are analyzed using the Sen’s slope method. Except in the monsoon season, a decreasing trend is observed in all the rainfall extremes in post-1950 compared to pre-1950 period. Whereas, in the monsoon an increasing trend is observed for the extremes in post-1950 period. Overall period (i.e, 1901–2018) an increasing trend is observed for rainfall and rainfall extremes in the pre-monsoon (March–May), monsoon (June–Sep) seasons and a decreasing trend in the winter season (Dec–Feb) for both the basins. No obvious trends are evident in the post-monsoon season (Oct–Nov). At the annual scale, rainfall and rainfall extremes exhibited an increasing trend. Overall, the Nagavali basin experienced more extreme rainfall events indicating the higher vulnerability of floods while the middle and lower portions of the Vamsadhara basin shown increase in extremes. When linked with hydrological analysis, insights gained from this study are useful for flood vulnerability mapping and risk assessment for both the basins.

The Ogallala Aquifer has experienced a continuous decline in water levels due to decades of irrigation pumping with minimal recharge. Corn is one of the major irrigated crops in the semi-arid Northern High Plains (NHP) of Texas. Selection of less water-intensive crops may provide opportunities for groundwater conservation. Modeling the long-term hydrologic impacts of alternative crops can be a time-saving and cost-effective alternative to field-based experiments. A newly developed management allowed depletion (MAD) irrigation scheduling algorithm for Soil and Water Assessment Tool (SWAT) was used in this study. The impacts of irrigated farming, dryland farming, and continuous fallow on water conservation were evaluated. Results indicated that simulated irrigation, evapotranspiration, and crop yield were representative of the measured data. Approximately 19%, 21%, and 32% reductions in annual groundwater uses were associated with irrigated soybean, sunflower, and sorghum, respectively, as compared to irrigated corn. On average, annual soil water depletion was more than 52 mm for dryland farming scenarios. In contrast, only 18 mm of soil water was lost to evaporation annually, for the long-term continuous fallow simulation. The fallow scenario also showed 31 mm of percolation for aquifer recharge.

Climate change and freshwater quality are well-linked. Changes in climate result in changes in streamflow and rising water temperatures, which impact biochemical reaction rates and increase stratification in lakes and reservoirs. Using two water quality modeling systems (the Hydrologic and Water Quality System; HAWQS and US Basins), five climate models, and two greenhouse gas (GHG) mitigation policies, we assess future water quality in the continental U.S. to 2100 considering four water quality parameters: water temperature, dissolved oxygen, total nitrogen, and total phosphorus. Once these parameters are aggregated into a water quality index, we find that, while the water quality models differ under the baseline, there is more agreement between future projections. In addition, we find that the difference in national-scale economic benefits across climate models is generally larger than the difference between the two water quality models. Both water quality models find that water quality will more likely worsen in the East than in the West. Under the business-as-usual emissions scenario, we find that climate change is likely to cause economic impacts ranging from 1.2 to 2.3 (2005 billion USD/year) in 2050 and 2.7 to 4.8 in 2090 across all climate and water quality models., United States. Environmental Protection Agency. Climate Change Division (EP-BPA-12-H-0024), United States. Environmental Protection Agency. Office of Water (EP-G15H-01113)

Water harvesting systems have improved productivity in various regions in sub-Saharan Africa. Similarly, they can help retain water in landscapes, build resilience against droughts and dry spells, and thereby contribute to sustainable agricultural intensification. However, there is no strong empirical evidence that shows the effects of intensification of water harvesting on upstream-downstream social-ecological systems at a landscape scale. In this paper we develop a decision support system (DSS) for locating and sizing water harvesting ponds in a hydrological model, which enables assessments of water harvesting intensification on upstream-downstream ecosystem services in meso-scale watersheds. The DSS was used with the Soil and Water Assessment Tool (SWAT) for a case-study area located in the Lake Tana basin, Ethiopia. We found that supplementary irrigation in combination with nutrient application increased simulated teff (Eragrostis tef, staple crop in Ethiopia) production up to three times, compared to the current practice. Moreover, after supplemental irrigation of teff, the excess water was used for dry season onion production of 7.66 t/ha (median). Water harvesting, therefore, can play an important role in increasing local-to regional-scale food security through increased and more stable food production and generation of extra income from the sale of cash crops. The annual total irrigation water consumption was similar to 4%-30% of the annual water yield from the entire watershed. In general, water harvesting resulted in a reduction in peak flows and an increase in low flows. Water harvesting substantially reduced sediment yield leaving the watershed. The beneficiaries of water harvesting ponds may benefit from increases in agricultural production. The downstream social-ecological systems may benefit from reduced food prices, reduced flooding damages, and reduced sediment influxes, as well as enhancements in low flows and water quality. The benefits of water h

This study tests the applicability of the curve number (CN) method within the Soil and Water Assessment Tool (SWAT) to estimate surface runoff at the watershed scale in tropical regions. To do this, surface runoff simulated using the CN method was compared with observed runoff in numerous rainfall-runoff events in three small tropical watersheds located in the Upper Blue Nile basin, Ethiopia. The CN method generally performed well in simulating surface runoff in the studied watersheds (Nash-Sutcliff efficiency [NSE] > 0.7; percent bias [PBIAS] < 32%). Moreover, there was no difference in the performance of the CN method in simulating surface runoff under low and high antecedent rainfall (PBIAS for both antecedent conditions: similar to 30%; modified NSE: similar to 0.4). It was also found that the method accurately estimated surface runoff at high rainfall intensity (e.g., PBIAS < 15%); however, at low rainfall intensity, the CN method repeatedly underestimated surface runoff (e.g., PBIAS > 60%). This was possibly due to low infiltrability and valley bottom saturated areas typical of many tropical soils, indicating that there is scope for further improvements in the parameterization/representation of tropical soils in the CN method for runoff estimation, to capture low rainfall-intensity events. In this study the retention parameter was linked to the soil moisture content, which seems to be an appropriate approach to account for antecedent wetness conditions in the tropics.

PR, IFPRI4; CRP2; A Ensuring Sustainable food production; D Transforming Agriculture; E Building Resilience; Land Resource Management for Poverty Reduction, EPTD; PIM, CGIAR Research Program on Policies, Institutions, and Markets (PIM)

The Soil and Water Assessment Tool (SWAT) model has been applied widely in many types of environment with different goals. The purpose of this paper is to assess the ability of SWAT to simulate hydrological processes in the Aixola watershed. Electrical conductivity (EC) was used to estimate water contribution from the two main sub-watersheds. Streamflow contribution from the sub-watersheds varies throughout the year; the larger of the two contributes greater flow in wetter seasons, while the smaller one has more regulation capacity and contributes more in summer. The data obtained from EC were used to calibrate the model, simulating this variability satisfactorily and even more-so when the model was forced during calibration. Additionally, EC measured at the outlet of the watershed was used to make a decomposition of the hydrograph (surface runoff – base flow), comparing the data obtained with those simulated by SWAT. The results showed that the model performed well and identified the source of uncertainties in modelling this watershed. When additional data is included in the calibration, this made it possible to obtain a more realistic hydrological simulation of the Aixola watershed.

The United States Air Force has a need to ascend objects in a silent and stealthy manner, without the use of a grappling hook or similar device. To that end they issued a design challenge to a group of universities to have teams of engineering students design and manufacture an alternative design to existing methods. With this goal in mind they outline several objectives; first the design must be able to ascend ninety feet. Second, the design must be inaudible at two hundred feet. Finally, the design must be safe. With these goals (i.e. design obstacles) in mind the design team at Wright State University has come up with two distinct designs. The first design essentially uses a remote control car to climb the wall. The vehicle is held to the wall using a combination of sticky tread (tank tracks) and pressure differentials, i.e. a vacuum. The second method is a buildable pole, which is comprised of three and half foot sections that collapse to twenty-four inches in length. This project is important to the United States Air Force because it will provide extra mobility to units that are in urban environments, as well as rough terrain. This is because the solution will provide a method to overcome the obstacles that exist in these environments. In urban environments the main obstacles will be buildings and in rural settings the main obstacles will be cliffs. The progress of the team has been marked by the completion of the pole, which completed a successful test run at the end of February. The fifth prototype of the robot successfully climbed the wall using a tanktread mode of movement, while the most recent branch of the vehicle utilizing four-wheels also successfully ascended a testing wall. All three designs will be presented at the competition in order to ensure that an optimum score is achieved., The original document contains color images.

Data scarcity has been a huge problem in modeling the water resources of the Upper Blue Nile basin, Ethiopia. Satellite data and different statistical methods have been used to improve the quality of conventional meteorological data. This study assesses the applicability of the National Centers for Environmental Prediction's Climate Forecast System Reanalysis (CFSR) climate data in modeling the hydrology of the region. The Soil and Water Assessment Tool was set up to compare the performance of CFSR weather with that of conventional weather in simulating observed streamflow at four river gauging stations in the Lake Tana basin — the upper part of the Upper Blue Nile basin. The conventional weather simulation performed satisfactorily (e.g., NSE ≥ 0.5) for three gauging stations, while the CFSR weather simulation performed satisfactorily for two. The simulations with CFSR and conventional weather yielded minor differences in the water balance components in all but one watershed, where the CFSR weather simulation gave much higher average annual rainfall, resulting in higher water balance components. Both weather simulations gave similar annual crop yields in the four administrative zones. Overall the simulation with the conventional weather performed better than the CFSR weather. However, in data-scarce regions such as remote parts of the Upper Blue Nile basin, CFSR weather could be a valuable option for hydrological predictions where conventional gauges are not available., Water resources management and social-ecological resilience

Non-PR, IFPRI1; A.2 Sustainable Natural Resource Policies; CRP2; CRP5; Land Resource Management for Poverty Reduction, EPTD; PIM, CGIAR Research Program on Policies, Institutions, and Markets (PIM); CGIAR Research Program on Water, Land and Ecosystems (WLE), This study was conducted with the objective of determining the returns to sustainable land management (SLM) at the national level in Bhutan. The study first uses satellite data on land change (Landsat) to examine land use change in 1990–2010 and its impact on sediment loading in hydroelectric power plants. The study then uses the Soil and Water Assessment Tool (SWAT) model to analyze the impact of land use change and land management on sediment loading. The results from the land use change and SWAT analyses are used to assess the economic benefits of SLM.

The choice of spatial resolution for experimentally-collected 3D microstructural data is often governed by general rules of thumb. For example, serial section experiments often strive to collect at least ten sections through the average feature-of-interest. However, the desire to collect high resolution data in 3D is greatly tempered by the exponential growth in collection times and data storage requirements. This paper explores the use of systematic down-sampling of synthetically-generated grain microstructures to examine the effect of resolution on the calculated distributions of microstructural descriptors such as grain size, number of nearest neighbors, aspect ratio, and the third moment invariant., Preprint to be submitted to International Conference on 3D Materials Science.

Climate change has the potential to reduce water resource availability in the Nile Basin countries in the forthcoming decades. We investigated the sensitivity of water resources to climate change in the Lake Tana Basin, Ethiopia, using outputs from global climate models (GCMs). First, we compiled projected changes in monthly precipitation and temperature in the basin from 15 GCMs. Although the GCMs uniformly suggest increases in temperature, the rainfall projections are not consistent. Second, we investigated how changes in daily temperature and precipitation might translate into changes in streamflow and other hydrological components. For this, we generated daily climate projections by modifying the historical data sets to represent the changes in the GCM climatologies and calculated hydrological changes using the Soil and Water Assessment Tool (SWAT). The SWAT model itself was calibrated and validated using the flows from four tributaries of Lake Tana. For the Special Report on Emissions Scenarios A2 scenario, four of the nine GCMs investigated showed statistically significant declines in annual streamflow for the 2080-2100 period. We interpret our results to mean that anthropogenic climate changes may indeed alter the water balance in the Lake Tana Basin during the next century but that the direction of change cannot be determined with confidence using the current generation of GCMs., QC 20110524 Denna artikel är en förändrad version av manuskriptet "Impact of Changing Climate on Water Resources Variability in the Lake Tana Basin, Ethiopia"som hör till avhandlingen "Modelling Hydrological and Hydrodynamic Processes in Lake Tana Basin, Ethiopia".

This program addresses the basic scientific and engineering issues related to the development of the second-generation high-temperature superconducting (HTS) coated conductor for use in magnet and generator coil windings of power applications relevant to the Air Force (AF). Current work focuses on the development of an ac YBCO-coated conductor and enhancement of the current dc coated conductor. The dc coated conductor development is done as part of an overall AF program that includes industry and academic research facilities. This program is coordinated with the Department of Energy's Coated Conductor Program to ensure integration with no redundancy. Flux pinning in the conductor is a significant focus of the overall coated conductor work to improve in-field critical currents. The ac loss issues as well as stability (and quench protection) ultimately must be considered for study, and work has commenced in this area within the in-house program. In order for the conductor to be ready for projected power generation requirements (for directed energy weapons), the superconductivity group is determining the unique AF requirements of the conductor and investigating ac loss and flux pinning issues.

Titanium alloys offer attractive mechanical and physical property combinations, with make them desirable for a variety of critical applications. Titanium alloys are proved to be reliable materials for important aerospace applications including many engine and airframe components, and the applications are expanding further in the next generation aircraft. The cost of titanium is still a major factor in the selection of titanium. A majority of the cost of titanium is associated with processing which is essential to obtain controlled microstructures. Small additions of boron to conventional titanium alloys have been found to produce significant changes to the microstructures and associated properties. Grain refinement and improved strength and stiffness are first-order effects, which lead to possibilities for developing novel and affordable processing methodologies and to enhance performance over conventional titanium alloys. Ongoing efforts to develop affordable titanium technologies for potential aerospace applications will be discussed in this paper., Work unit no. M02R4000. Pub. in Advanced Materials and process, p1-3, Dec 2006. Prepared in collaboration with Wright State University, Dayton, OH and Ohio State University, Athens, OH.

Described is a process for manufacturing powder metallurgy (P/M) performs which are conditioned for optimum intrinsic workability is described which comprises steps of heating a quantity of P/M material in a can to a first preselected temperature under vacuum to degas the material, compacting the canned material at a second preselected temperature under pressure to provide a compact of the material; or cold compacting the powder to about 75% density and degassing it at suitable temperature and then vacuum hot pressing the powder at about 0.75 melting point; generating flow stress data as a function of strain rate and temperature on samples of the compact at predetermined strain within predetermined ranges of temperature and strain rate and determining powder dissipation efficiency of the compact and entropy rate ratio within those ranges of temperature and strain rate; selecting values of stain rate and extrusion temperature at which dynamic recrystallization is the dominant metallurgical mechanism characterizing the compact: and extruding the compact in an extrusion can at the selected extrusion temperature and at an extrusion rate corresponding to the selected strain rate using a streamlined die. An improved processing map for preselecting optimum processing parameters for the material is described. Keywords: Patents. (kt), Supersedes PAT-APPL-70 276-87.

Water resources management and social-ecological resilience

This TechBrief is a technical summary of the Federal Highway Administration report, "Safety Evaluation of Improved Curve Delineation" (FHWA-HRT-09-045). The objective of this study was to evaluate the safety effectiveness of improved delineation on horizontal curves through signing improvements.

DTFH61-10-D-00022, The Jurisdiction Speed Management Action Plan Development Package includes four separate resources: 1) a Speed Management Action Plan Template, developed to provide a model for State and local agencies to use in developing jurisdiction-specific speed management safety action plans; 2) a Speed Management Toolkit document, which includes a comprehensive speed management bibliography, tables of speed management countermeasures with expected crash or speed effects; and tip sheets for communications programs; 3) the Speed Management Action Plan for Randolph County, an example of a local jurisdiction action plan; and 4) Alabama Speed Management Action Plan, an example of a statewide action plan. The plan template guides the user to develop particular actions, safety goals and a plan for countermeasures implementation through a systematic process, as well as to address larger speed management issues that often limit program effectiveness and durability. The Toolkit provides information on countermeasures effects and other resources. The other documents provide more information and examples to help local agencies develop their own action plans.

(c) 1030652, The objective of this study was to evaluate the change in crash frequency or severity of varying lateral offset distances of high-tension cable median barriers in Minnesota. Crash and traffic data from 2016 to present were conjoined with roadway cross-sectional data and high-tension cable barrier locations to perform cross-sectional analyses for interstate segments equal to or greater than 0.05-miles long. Negative binomial regression models were estimated and used to develop crash modification factors (CMFs) for the following crash types: total crashes, target crashes, and barrier crashes. In addition to evaluating the impact of lateral offset, a naïve before-after evaluation was completed to quantify the impact of installing high-tension cable barrier.

"The objective of this effort is to develop safety performance functions (SPFs) for different types of facilities in North Carolina, and illustrate how they can be used to improve the decision making process. The prediction models in Part C of the Highway, Safety Manual were calibrated using data from North Carolina. SPFs were estimated for 9 crash types for 16 roadway types, using statewide data from North Carolina – these SPFs just include AADT and can be used for network screening. In addition, SPFs for rural two lane roads were developed using AADT and other site characteristics including shoulder width/type and, terrain. Using examples, this report outlines how the different SPFs can be used for network screening, project level analysis, and before-after evaluation using the empirical Bayes method. Finally, there is a discussion of how NCDOT can use the SPFs in, the future by either calibrating the SPFs developed in this effort and/or develop SPFs using negative binomial regression. Along, with the final report are Excel files that can be used by NCDOT to calibrate the SPFs in the future and to implement the HSM, prediction methodology."

55657-03-15, The overall objective of this research was to study work zone accidents in New York State, with particular attention to the, occurrence and mitigation of rear-end vehicle accidents. The specific objectives were to, Recommend changes to the NYSDOT’s accident database system for more efficient management and analysis., Conduct a detailed investigation of rear-end crashes in work zones and recommend measures that can reduce the frequency, of these types of crashes., Report on traffic exposure data and accident patterns / parameters to be incorporated into future NYSDOT accident data, analysis., Task 1 focused on evaluating the current NYSDOT work zone accident reporting system, surveying practices used in other states, and providing recommendations for improvement. The results of this task revealed that the current NYSDOT work zone accident, reporting system is the most comprehensive in the country. Further changes to improve the system were recommended based on a, review of the literature and practices being implemented in other state agencies., The first part of Task 2 was focused on analyzing rear-en accidents in work zones that occurred in New York State between 1994, and 2001. Since data were available only on work zones that had accidents, truncated count data models were estimated to study, the relationship between crash frequency and work zone characteristics. Ordered probit models were developed to study crash, severity., The second part of Task 2 provides some corrective actions to reduce frequency of work zone accidents. These actions are, primarily based on a review of the literature since information on changes made by NYSDOT at the project level was not available, to the research team., The first subtask of Task 3 provided some recommendations to incorporate more project information to the work zone database, either through adding more variables or including project information in a separate database that can be linked through a project, identification number. The second subtask of Task 3 focused on various venues and approaches for obtaining exposure to traffic, for various types of work zones. The final subtask of Task 3 focused on identifying parameters correlated with work zones and the, county level.

The objective of network screening should ideally be to not only identify sites for safety, investigation but also to prioritize those sites efficiently. Using roadway, intersection, and, collision data from California, this study compared the performance of methods based on the EB, procedure, the LOSS method, and the Table C method. Two intersection types (rural four leg, stop controlled and rural four leg signalized) and two roadway types (rural two lane roads and, urban freeways) were included in the evaluation.

BDM10 977-01, This report is a before-after evaluation of shared lane markings on Washington Avenue in Miami Beach, FL, which requested and received permission from the Federal Highway Administration (FHWA) to conduct a pilot study of shared lane markings. The markings were placed in the center of the outside lane to encourage bicyclists to take control of the lane. The experimental design was to collect videotape data of bicyclists interacting with motorists before and after the installation of the markings. After the markings were placed, approximately 20 percent of the bicyclists rode over the shared lane marking, and another 10 percent avoided the marking when they approached. Thus, 30 percent tracked over or very near the shared lane marking. Some 44 percent were positioned near the center of the lane when interacting with a motor vehicle after the markings were placed on the street. From an analysis of the spatial data, there was an increase of about 10.5 inches between bicycles and parked motor vehicles after the introduction of the shared lane markings. In addition, more bicyclists were riding out of the door zone. The spacing increased about 4.5 inches between motor vehicles in the travel lane and parked motor vehicles. All of these findings were statistically significant. Approximately 2 to 3 percent of bicyclists were riding in the wrong direction in the street, and there was no change after the shared lane marking. However, the percentage of bicycles using the sidewalk decreased from about 55 to 45 percent, and this reduction was statistically significant. Whereas about 10 percent of bicyclists weaved between motor vehicles in the traffic lane and parked motor vehicles in the before period, some 14 percent did so in the after period. This maneuver greatly increases the risk of a dooring crash.

New Jersey has made significant investments in transportation over the last 10 years, and numerous additional projects are planned or proposed for the next decade and beyond. These investments have improved and will continue to improve accessibility throughout the State and will increase New Jersey's attractiveness to businesses and individuals. In the past, these investments have been studied on a project basis. Each is designed to solve a problem within its corridor of influence. Collectively, however, these projects may substantially change the relative accessibility of northern New Jersey and affect economic development and land use throughout the region. With so much development proposed or in progress, it becomes vital to understand these effects. The questions that arise include: 1.) How do the planned and progressing infrastructure investments affect the accessibility of Northern New Jersey, and how can the changes be quantified?; 2.) If such changes occur, how and to what extent will they affect land use decisions? How can such decisions be shaped to have maximum positive impact on economic development, jobs and quality of life for the people in New Jersey?; and, 3.) How can the New Jersey Department of Transportation assist in this decision-making through development of appropriate planning and policy analysis tools? This report describes the results of our research on these questions. We begin by reviewing the parallel development of New Jersey's economy and transportation infrastructure. Next, we define accessibility and show how it has changed. At the heart of the report, we present the results of our studies, showing that improvements in accessibility have a significant impact on economic growth, and detailing the relationships between transportation infrastructure improvements and land development. Finally, we provide a set of analytical tools and guidelines to help shape future projects for maximum positive economic impact, and we analyze proposed pr

SPR 000-1(181) 704, The predictive method in the Highway Safety Manual (HSM) includes a safety performance function (SPF), crash modification factors (CMFs), and a local calibration factor (C), if available. Two alternatives exist for, applying the HSM prediction methodology to local conditions. They are either calibration of the SPFs found in, the HSM or the development of jurisdiction-specific SPFs, The objective of this study was to develop a process to evaluate the SPFs contained in the HSM for road, segments and intersections on the Arizona State Highway System and to determine if those SPFs should be, calibrated or if Arizona-specific SPFs should be developed., The recommendations are that ADOT move forward with SPF calibration for all HSM safety performance, functions as for project-level safety analysis in Arizona. A specific calibration function has been calculated for, two-lane rural undivided highways. Safety analysis is progressing at a promising rate and can be used to attain, significant reductions in fatal crashes and crash severity. To achieve this, ADOT will need to make a significant, commitment to developing and maintaining a comprehensive database of roadway characteristics combined, with crash data and average annual daily traffic volume data that are all linked through a common linear, referencing system.

The objective of this study was to evaluate the safety impacts of increasing the speed limit from 55 mph to 60 mph on twolane, two-way state highway road segments in Minnesota. An empirical Bayes (EB) before-after analysis was used to estimate crash modification factors (CMFs) for both segments and intersections. The segment analysis showed an 8 percent reduction in total crashes that was statistically significant, alongside a significant 15 percent increase in combined fatal, serious injury, and minor injury (KAB) injury crashes. The range of most of the segment CMFs hovered close to 1. The intersection analysis was split into two groups (all traffic control types and thru-stop control only). The aggregate CMFs for all intersections within these two groups showed, on average, between a 10% and 20% statistically significant reduction in total and injury crashes. Analysis was also performed on four subgroups (3- and 4-leg, lighting/no lighting) within the two main intersection groups. Disaggregating the intersections into further groups led to smaller sample sizes that led to higher standard errors showing a widespread range of CMFs around 1 for the individual crash types and severities. The aggregate estimated crash safety effects (for total and injury crashes) for combined segments and intersection sites showed a reduction in total crashes but an increase in the KAB injury crashes.