Potential of sediment reuse for soil fertilization and water conservation in drylands

2020 ◽  
Author(s):  
Pedro Medeiros ◽  
Brennda Braga ◽  
Camila Lira ◽  
Arlena Brosinsky ◽  
Saskia Foerster ◽  
...  
Keyword(s):  
Water Quality ◽  
Water Conservation ◽  
Crop Production ◽  
Fine Particles ◽  
Small Scale ◽  
Soil Fertilization ◽  
Study Region ◽  
Water Quality Simulation ◽  
Nutritional Deficit ◽  
Maize Cultivation

<p>In dry environments, society has long implemented infrastructure to adapt to water scarcity, but unanticipated feedbacks have threatened the supply-demand balance. For instance, construction of dams increases the water residence time in highly impounded basins, causing sediment and nutrient accumulation in water supply reservoirs. Reuse of reservoirs’ sediment as fertilizer sustainably benefits agricultural and water systems by: replacing fine particles and nutrients to soils, previously lost by erosion; recovering water quantity and quality by the removal of nutrient-enriched sediments from reservoirs. In the last 5 years we have assessed the potential of the sediment reuse technique for soil fertilization and water conservation in the semiarid Ceará State (149 000 km²), Brazil, where there is a dense network of more than 20 000 dams with considerable silting and eutrophication. Our previous studies demonstrated that:</p><ul><li>Local features contribute to the adoption of the proposed technique: (i) small reservoirs fall dry frequently, exposing the sediments for excavation without the need for dredging; (ii) in general, soils present nutritional deficit and, under natural conditions, crop production is limited to patches of fertile soils; (iii) small scale agriculture plays a major role for livelihood of the rural population;</li> <li>Recycling of nutrients from sediments is technically feasible: an experiment with a mixture of soil and sediment as substrate produced statistically higher growth and enzymes’ activity of sunflower plants, compared to the cultivation directly in the soil or with addition of synthetic fertilizers;</li> <li>Sediment reuse is economically feasible: soil fertilization through sediments for maize cultivation may reduce costs by up to 29 % compared to traditional fertilization;</li> <li>Removal of sediment from reservoirs may improve the water quality: simulation of annual removal of sediments when a reservoir of the study region is completely empty indicates a change on the trophic level, from eutrophic or higher to mesotrophic or lower, in 10 % of the time.</li> </ul><p>In spite of the recent advances, sediment recycling must go through some phases in order to be included in the public policy agenda. Our ongoing and planned studies focus on the generation of basic data, real-scale testing, simulations under diverse environmental contexts, elaboration of guidelines and disclosure. Spectroscopy has been successfully applied to characterize sediment and soil properties and reduce the costly laboratory analysis. Additionally, data acquisition will be supported by remote sensing approaches based on hyperspectral satellite images that will become available in the near future (Prisma, EnMAP). Such data will be used to estimate nutrient availability in sediments and deficit in the soils to generate a map of the sediment reuse potential in Ceará. Field scale growth experiments are to be conducted for the main crops cultivated in the study region, in contrast to the indoor controlled conditions of our previous assessment. Furthermore, we are developing a modelling tool to quantify the impacts of the sediment reuse practice on water quality, enabling us to expand our previous study to other reservoirs and to test its effectiveness to water conservation.</p>

Comparative evaluation of runoff and water quality using HSPF and SWMM

2010 ◽  
Vol 62 (6) ◽  
pp. 1401-1409 ◽  
Author(s):  
Sae-Bom Lee ◽  
Chun-Gyeong Yoon ◽  
Kwang Wook Jung ◽  
Ha Sun Hwang
Keyword(s):  
Water Quality ◽  
Simulation Models ◽  
Urban Runoff ◽  
Monitoring Data ◽  
Accurate Estimation ◽  
Small Scale ◽  
Water Quality Simulation ◽  
Hspf Model ◽  
Small Watersheds ◽  
Bodies Of Water

Stormwater pollution is the untreated contaminated water that drains into natural waterways from land uses within an urban catchment. Several studies have demonstrated the deterioration of water quality in receiving bodies of water caused by stormwater runoff. The data have reported that urban runoff play primary roles in degrading water quality in adjacent aquatic systems. The accurate estimation of non-pollutant loads from urban runoff and the prediction of water quality in receiving waters are important. The objective of this paper is to assess the applicability of the watershed scale hydrologic and water quality simulation models SWMM and HSPF to simulate the hydrology of a small watershed in the Han River Basin. Monitoring was performed in small scale watersheds, which is homogeneous land use. The applicability of SWMM and HSPF model was examined for small watersheds using hourly monitoring data. The results of SWMM were reasonably reflected with observed data in small scale urban area. HSPF model was effective at specifying parameters related to runoff and water quality when using hourly monitoring data. The watershed models used in this study adequately simulated watershed characteristics and are recommended to support watershed management.

Landscape variables affecting livestock impacts on water quality in the humid temperate zone

1998 ◽  
Vol 78 (2) ◽  
pp. 181-190 ◽  
Author(s):  
E. Ann Clark
Keyword(s):  
Water Quality ◽  
Water Conservation ◽  
Large Scale ◽  
Management Practices ◽  
Cost Effective ◽  
Small Scale ◽  
Riparian Ecosystem ◽  
Sources Of Pollution ◽  
A Site ◽  
Grazing Livestock

The potential for impact by grazing livestock on unprotected watercourses may vary with climate, with landscape level factors including the landform within which the pasture is located, with the biophysical characteristics of the watercourse itself, and with pasture and grazing management practices. Policies seeking to implement cost-effective measures to protect downstream water quality need to acknowledge large-scale as well as small-scale processes which can moderate or exacerbate potential sources of pollution. Applied and scholarly evidence suggest that unrestricted livestock access accounts for a relatively modest share of watercourse pollution in humid temperate regions, as compared with such watershed-specific factors as leaking septic tanks and confinement feeding systems. A wide variety of evidence suggests that the degree of compatibility of grazing livestock with a healthy riparian ecosystem should be viewed as a hypothesis that is testable on a site-specific basis. Greater understanding of the factors causal to livestock behavior in, and impact on, watercourses may help to better focus preventative and remediation efforts by both producers and policymakers. Key words: Riparian ecosystem; beef cattle; pasture fertility; soil and water conservation

The implications of climate change on residential water use: a micro-scale analysis of Portland (OR), USA

2012 ◽  
Vol 3 (3) ◽  
pp. 225-238 ◽  
Author(s):  
Vivek Shandas ◽  
Meenakshi Rao ◽  
Moriah McSharry McGrath
Keyword(s):  
Climate Change ◽  
Water Use ◽  
Environmental Sustainability ◽  
Water Conservation ◽  
Urban Areas ◽  
Future Climate ◽  
Metropolitan Region ◽  
Study Region ◽  
Residential Water Use ◽  
Residential Water

Social and behavioral research is crucial for securing environmental sustainability and improving human living environments. Although the majority of people now live in urban areas, we have limited empirical evidence of the anticipated behavioral response to climate change. Using empirical data on daily household residential water use and temperature, our research examines the implications of future climate conditions on water conservation behavior in 501 households within the Portland (OR) metropolitan region. We ask whether and how much change in ambient temperatures impact residential household water use, while controlling for taxlot characteristics. Based on our results, we develop a spatially explicit description about the changes in future water use for the study region using a downscaled future climate scenario. The results suggest that behavioral responses are mediated by an interaction of household structural attributes, and magnitude and temporal variability of weather parameters. These findings have implications for the way natural resource managers and planning bureaus prepare for and adapt to future consequences of climate change.

Performance Analysis of the Rotating Biological Contactor Process Based on Particle Fraction and Improvement of Final Effluent Quality

1991 ◽  
Vol 23 (7-9) ◽  
pp. 1457-1466 ◽  
Author(s):  
Kazuhiro Tanaka ◽  
Minoru Tada ◽  
Mitsuo Ito ◽  
Noritugu Shimizu
Keyword(s):  
Suspended Solids ◽  
Fine Particles ◽  
Wastewater Treatment Plants ◽  
Small Scale ◽  
Particle Fraction ◽  
Effluent Quality ◽  
Rotating Biological Contactors ◽  
Activated Sludge Processes ◽  
Fraction Method ◽  
Final Effluent

Biofilm processes are, in general, suitable for small-scale wastewater treatment plants. However, final effluent qualities of biofilm processes are not as good as those of activated sludge processes due to fine particles remaining in the effluents. To improve the effluent qualities of the Rotating Biological Contactors (RBC) process, the behavior of fine particles through the process and the removal of fine particles with solids-liquid separation methods, rapid filtration and coagulation-filtration, were investigated using the particle fraction method. The results are as follows:–An increase of the hydraulic retention time (HRT) in the RBC reactor reduced the amount of fine particles and increased the amount of coarse suspended solids of 44 µm or more in diameter, which are easily removed by clarification. Thus, the final effluent qualities were improved by the increase of HRT.–Suspended solids in effluent from the RBC process at the standard loading are so fine that improvement of the quality is not expected by only lowering the overflow rate of a final clarifier. In contrast, rapid filtration or a coagulation-filtration process is effective. The supended solid concentration and transparency of the effluent from the final clarifier was improved by a factor of two to four, and then BOD of the final effluent was removed by 40-85%.

scholarly journals Agricultural Technical Efficiency of Smallholder Farmers in Ethiopia: A Stochastic Frontier Approach

Land ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 246
Author(s):  
Markose Chekol Zewdie ◽  
Michele Moretti ◽  
Daregot Berihun Tenessa ◽  
Zemen Ayalew Ayele ◽  
Jan Nyssen ◽  
...  
Keyword(s):  
Technical Efficiency ◽  
Crop Production ◽  
Large Scale ◽  
Positive Impact ◽  
Smallholder Farmers ◽  
Stochastic Frontier ◽  
Crop Productivity ◽  
Small Scale ◽  
Stochastic Frontier Approach ◽  
Small Scale Irrigation

In the past decade, to improve crop production and productivity, Ethiopia has embarked on an ambitious irrigation farming expansion program and has introduced new large- and small-scale irrigation initiatives. However, in Ethiopia, poverty remains a challenge, and crop productivity per unit area of land is very low. Literature on the technical efficiency (TE) of large-scale and small-scale irrigation user farmers as compared to the non-user farmers in Ethiopia is also limited. Investigating smallholder farmers’ TE level and its principal determinants is very important to increase crop production and productivity and to improve smallholder farmers’ livelihood and food security. Using 1026 household-level cross-section data, this study adopts a technology flexible stochastic frontier approach to examine agricultural TE of large-scale irrigation users, small-scale irrigation users and non-user farmers in Ethiopia. The results indicate that, due to poor extension services and old-style agronomic practices, the mean TE of farmers is very low (44.33%), implying that there is a wider room for increasing crop production in the study areas through increasing the TE of smallholder farmers without additional investment in novel agricultural technologies. Results also show that large-scale irrigation user farmers (21.05%) are less technically efficient than small-scale irrigation user farmers (60.29%). However, improving irrigation infrastructure shifts the frontier up and has a positive impact on smallholder farmers’ output.

scholarly journals Predicting Shifts in Land Suitability for Maize Cultivation Worldwide Due to Climate Change: A Modeling Approach

Land ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 295
Author(s):  
Yuan Gao ◽  
Anyu Zhang ◽  
Yaojie Yue ◽  
Jing’ai Wang ◽  
Peng Su
Keyword(s):  
Climate Change ◽  
Crop Production ◽  
Large Scale ◽  
Land Suitability ◽  
Large Scale Assessment ◽  
Scale Assessment ◽  
Maize Cultivation ◽  
Large Scale Screening ◽  
Selection Of

Suitable land is an important prerequisite for crop cultivation and, given the prospect of climate change, it is essential to assess such suitability to minimize crop production risks and to ensure food security. Although a variety of methods to assess the suitability are available, a comprehensive, objective, and large-scale screening of environmental variables that influence the results—and therefore their accuracy—of these methods has rarely been explored. An approach to the selection of such variables is proposed and the criteria established for large-scale assessment of land, based on big data, for its suitability to maize (Zea mays L.) cultivation as a case study. The predicted suitability matched the past distribution of maize with an overall accuracy of 79% and a Kappa coefficient of 0.72. The land suitability for maize is likely to decrease markedly at low latitudes and even at mid latitudes. The total area suitable for maize globally and in most major maize-producing countries will decrease, the decrease being particularly steep in those regions optimally suited for maize at present. Compared with earlier research, the method proposed in the present paper is simple yet objective, comprehensive, and reliable for large-scale assessment. The findings of the study highlight the necessity of adopting relevant strategies to cope with the adverse impacts of climate change.

scholarly journals Climate Variability Since 1970 and Farmers’ Observations in Northern Ghana

2016 ◽  
Vol 5 (2) ◽  
pp. 41 ◽  
Author(s):  
Emmanuel Nyadzi
Keyword(s):  
Climate Change ◽  
Climate Variability ◽  
Water Conservation ◽  
Crop Production ◽  
Meteorological Data ◽  
Northern Region ◽  
Northern Ghana ◽  
Climate Variability And Change ◽  
Urban Centers ◽  
Access To Credit

<p>The study examines how farmers’ observations of climate variability and change correspond with 42 years (1970-2011) meteorological data of temperature and rainfall. It shows how farmers in the Northern Region of Ghana adjust to the changing climate and explore the various obstacles that hinder the implementation of their adaptation strategies. With the help of an extension officer, 200 farmers from 20 communities were randomly selected based on their farming records. Temperatures over the last four decades (1970-2009) increased at a rate of 0.04 (± 0.41) ˚C and 0.3(± 0.13)˚C from 2010-2011 which is consistent to the farmers (82.5%) observations. Rainfall within the districts are characterised by inter-annual and monthly variability. It experienced an increased rate of 0.66 (± 8.30) mm from 1970-2009, which was inconsistent with the farmers (81.5%) observation. It however decreased from 2010-2011 at a huge rate of -22.49 (±15.90) mm which probably was the reason majority of the respondents claim rainfall was decreasing. Only 64.5% of the respondents had adjusted their farming activities because of climate variability and change. They apply fertilizers and pesticides, practice soil and water conservation, and irrigation for communities close to dams. Respondents desire to continue their current adaptation methods but may in the future consider changing crop variety, water-harvesting techniques, change crop production to livestock keeping, and possibly migrate to urban centers. Lack of climate change education, low access to credit and agricultural inputs are some militating factors crippling the farmers’ effort to adapt to climate change.</p>

scholarly journals Assessment and distribution of water quality of Pandoh river basin (PRB), Himachal Pradesh, North India

2021 ◽  
Vol 11 (8) ◽  
Author(s):  
C. Prakasam ◽  
R. Saravanan ◽  
M. K. Sharma ◽  
Varinder S. Kanwar
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
River Basin ◽  
Geographical Information ◽  
North India ◽  
Total Hardness ◽  
Drainage Pattern ◽  
Study Region ◽  
Northern India

AbstractAs the surface water in northern India is the main water resource for regional economic and also supply for drinking and irrigation purposes. However, deficiency of water quality leads to serious water pollution in the Pandoh river basin (PRB). Therefore, the main objective of the present study is to evaluate the quality of surface water. With this objective, surface water samples were collected from the PRB of northern India, and analyzed for pH, EC, turbidity, alkalinity, total dissolved solids, and total hardness. Moreover, geographical information system (GIS) tools were used to prepare the geology, drainage pattern, and location maps of the study region. Surface water quality observed from the PRB has an alkaline nature with a moderately hard type. Further studies are encouraged to better understand the water quality in northern India.

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