Improving Water Supply Systems for Domestic Uses in Urban Togo: The Case of a Suburb in Lomé

The rapid urbanization facing developing countries is increasing pressure on public institutions to provide adequate supplies of clean water to populations. In most developing countries, the general public is not involved in strategies and policies regarding enhancement, conservation, and management of water supply systems. To assist governments and decision makers in providing potable water to meet the increasing demand due to the rapid urbanization, this study sought to characterize existing water supply systems and obtain public opinion for identifying a community water supply system model for households in a residential neighborhood in Lomé, Togo. Existing water supply systems in the study area consist of bucket-drawn water wells, mini water tower systems, rainwater harvesting, and public piped water. Daily domestic water consumption in the study area compared well with findings on water uses per capita from Sub-Saharan Africa, but was well below daily water usage in developed nations. Based on the surveys, participants thought highly of a large scale community water tower and expressed interest in maintaining it. Even though people rely on water sources deemed convenient for drinking, they also reported limited confidence in the quality of these sources

Regression Modeling of Baseflow and Baseflow Index for Michigan USA

Baseflow plays an important role in maintaining streamflow. Seventeen gauged watersheds and their characteristics were used to develop regression models for annual baseflow and baseflow index (BFI) estimation in Michigan. Baseflow was estimated from daily streamflow records using the two-parameter recursive digital filter method for baseflow separation of the Web-based Hydrograph Analysis Tool (WHAT) program. Three equations (two for annual baseflow and one for BFI estimation) were developed and validated. Results indicated that observed average annual baseflow ranged from 162 to 345 mm, and BFI varied from 0.45 to 0.80 during 1967–2011. The average BFI value during the study period was 0.71, suggesting that about 70% of long-term streamflow in the studied watersheds were likely supported by baseflow. The regression models estimated baseflow and BFI with relative errors (RE) varying from −29% to 48% and from −14% to 19%, respectively. In absence of reliable information to determine groundwater discharge in streams and rivers, these equations can be used to estimate BFI and annual baseflow in Michigan

Annual baseflow variations as influenced by climate variability and agricultural land use change in the Missouri River Basin

The Missouri River system has a large water storage capacity, where baseflow plays an important role. Understanding historical baseflow characteristics with respect to climate and land use impacts is essential for effective planning and management of water resources in the Missouri River Basin (MORB). This study evaluated statistical trends in baseflow and precipitation for 99 MORB minimally disturbed watersheds during 1950–2014. Elasticity of baseflow to climate variability and agricultural land use change were quantified for the 99 studied watersheds. Baseflow was derived from daily streamflow records with a recursive digital filter method. The results showed that baseflow varied between 38 and 80% (0 and 331 mm/year) of total streamflow with an average of 60%, indicating that more than half of streamflow in the MORB is derived from baseflow. The trend analysis revealed that precipitation increased during the study period in 78 out of 99 watersheds, leading to 1–3.9% noticeable increase in baseflow for 68 of 99 watersheds. Although the changes in baseflow obtained in this study were a result of the combined effects of climate and land use change across the basin, upward trends in baseflow generally coincide with increased precipitation and agricultural land use trends in the basin. Agricultural land use increase mostly led to a 0–5.7% decrease in annual baseflow in the basin, except toward east of the basin where baseflow mostly increased with agricultural land use increase (0.1–2.0%). In general, a 1% increase in precipitation and a 1% increase in agricultural land use resulted in 1.5% increase and 0.2% decrease in baseflow, respectively, during the study period. These results are entirely dependent on the quality of data used; however, they provide useful insight into the relative influence of climate and land use change on baseflow conditions in the Great Plains region of the USA

Effective Post-Construction Best Management Practices (BMPs) to Infiltrate and Retain Stormwater Run-off

Performance analyses of newly constructed linear BMPs in retaining stormwater run-off from 1 in. precipitation in post-construction highway applications and urban areas were conducted using numerical simulations and field observation. A series of simulations were conducted using an idealized catchment on a four-lane highway located on sites with soil types ranging from clayey to sandy material across state of Illinois. The use of turfgrasses and prairie grass vegetative surface covers in pre-BMP scenarios in promoting infiltration and reducing stormwater run-off were investigated. Three types of BMPs—bioswale, infiltration trench, and vegetated filter strips—as well as combinations thereof, were studied for determining their ability to control stormwater run-off in an idealized catchment. This report also documents the maintenance cost, construction cost, and life-cycle analyses of those BMPs to identify cost-effective solutions. The effects of erosion and a sediment accumulation rate of 1 t/ac/y on BMPs during the 2- year and 10-year lifespans of bioswales and infiltration trenches were studied using full-scale field tests. The simulation and field test results provide insight for developing guidelines for cost-effective BMPs to control stormwater run-off in linear projects.IDOT-R27-141Ope

Comparative Analysis of METRIC Model and Atmometer Methods for Estimating Actual Evapotranspiration

Accurate estimation of crop evapotranspiration (ET) is a key factor in agricultural water management including irrigated agriculture. The objective of this study was to compare ET estimated from the satellite-based remote sensing METRIC model to in situ atmometer readings. Atmometer readings were recorded from three sites in eastern South Dakota every morning between 8:15 and 8:30 AM for the duration of the 2016 growing season. Seven corresponding clear sky images from Landsat 7 and Landsat 8 (Path 29, Row 29) were processed and used for comparison. Three corn fields in three sites were used to compare actual evapotranspiration (ETa). The results showed a good relationship between ETa estimated by the METRIC model (ETa-METRIC) and ETa estimated with atmometer (ETa-atm) (r2 = 0.87, index of agreement of 0.84, and RMSE = 0.65 mm day−1). However, ETa-atm values were consistently lower than ETa-METRIC values. The differences in daily ETa between the two methods increase with high wind speed values (>4 m s−1). Results from this study are useful for improving irrigation water management at local and field scales

Drainage Water Storage for Improved Resiliency and Environmental Performance of Agricultural Landscapes

Drained lands, which include some of the most productive lands in the world, can experience both water excess and water deficit within a year. Storing drained water within the landscape could increase the sustainability of water for agriculture, particularly as intense rainfall and prolonged summer drought continue to increase under future climate change. A team of researchers and extension specialists from nine states are currently working towards a vision of transforming the process of designing and implementing agricultural drainage to include storage through the use of controlled drainage, saturated buffers, and drainage water recycling (i.e. capture, storage, and reuse). Field research data from experimental drainage sites from across the U.S. Corn Belt have been brought together in a database to support synthesis and modeling to determine economic and environmental impacts of drainage water storage. Results from this effort will extend the strategies and tools to agricultural producers, the drainage industry, watershed managers, agencies, and policy makers, and educate the next generation of engineers and scientists to design drainage systems that include water storage in the landscape

Regionalization of land-use impacts on streamflow using a network of paired catchments

Quantifying the impact of land use and cover (LUC) change on catchment hydrological response is essential for land-use planning and management. Yet hydrologists are often not able to present consistent and reliable evidence to support such decision-making. The issue tends to be twofold: a scarcity of relevant observations, and the difficulty of regionalizing any existing observations. This study explores the potential of a paired catchment monitoring network to provide statistically robust, regionalized predictions of LUC change impact in an environment of high hydrological variability. We test the importance of LUC variables to explain hydrological responses and to improve regionalized predictions using 24 catchments distributed along the Tropical Andes. For this, we calculate first 50 physical catchment properties, and then select a subset based on correlation analysis. The reduced set is subsequently used to regionalize a selection of hydrological indices using multiple linear regression. Contrary to earlier studies, we find that incorporating LUC variables in the regional model structures increases significantly regression performance and predictive capacity for 66% of the indices. For the runoff ratio, baseflow index, and slope of the flow duration curve, the mean absolute error reduces by 53% and the variance of the residuals by 79%, on average. We attribute the explanatory capacity of LUC in the regional model to the pairwise monitoring setup, which increases the contrast of the land-use signal in the data set. As such, it may be a useful strategy to optimize data collection to support watershed management practices and improve decision-making in data-scarce regions

A participatory system dynamics model to investigate sustainable urban water management in Ebbsfleet Garden City

This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this recordGrowing urban populations, changes in rainfall patterns and ageing infrastructure represent significant challenges for urban water management (UWM). There is a critical need for research into how cities should adapt to become resilient to these impacts under uncertain futures. UWM challenges in the Ebbsfleet Garden City (UK) were investigated via a participatory process and potential sustainable solutions were explored using a System Dynamics Model (SDM). Collaborative development of the SDM by the Ebbsfleet Learning and Action Alliance developed stakeholders’ understanding of future UWM options and enabled a structured exploration of interdependencies within the current UWM system. Discussion by stakeholders resulted in a focus on potable water use and the development of the 2 SDM to investigate how residential potable water consumption in the Ebbsfleet Garden City might be reduced through a range of interventions, e.g., socio-environmental and economic policy incentives. The SDM approach supports decision-making at a strategic, system-wide level, and facilitates exploration of the long-term consequences of alternative strategies, particularly those that are difficult to include in quantitative models. While an SDM can be developed by experts alone, building it collaboratively allows the process to benefit from local knowledge, resulting in a collective learning process and increased potential for adoption.Engineering and Physical Sciences Research Council (EPSRC