Large-scale Irrigation Schemes Research Articles

Economic productivity of irrigation water in large-scale irrigation schemes with different typologies: the case of Fincha’a and Koga irrigation schemes in the Abbay River Basin, Ethiopia

Economic productivity of irrigation water in large-scale irrigation schemes with different typologies: the case of Fincha’a and Koga irrigation schemes in the Abbay River Basin, Ethiopia

Comparison of actual evapotranspiration by the google earth engine evapotranspiration flux (EEFlux) to the METRIC model using remote sensing data and in-situ climate observations

Actual evapotranspiration (ETa) is essential data in developing water budgets and calculating irrigation water requirements in large-scale irrigation schemes. Nowadays, remote sensing (RS)-based surface energy balance models help us estimate ETa with high resolution when compared to direct methods that focus only on a single point in a field. This study aimed both at estimating ETa by Mapping EvapoTranspiration at high Resolution with Internal Calibration (METRIC) and Google Earth Engine Evapotranspiration Flux (EEFlux) platform and comparing reference evapotranspiration based on the Penman-Monteith equation (ETo) with ETa by the METRIC and EEFlux in a sub-catchment (A=9495 ha) under irrigation, located in the Lower Seyhan Plain (LSP), Turkiye in the 2020 hydrological year. For this purpose, 16 Landsat 7 and Landsat 8 images, local climatic data acquired from two meteorological stations in the catchment, and CFSv2 gridded global data were used. Results showed a good agreement between ETa-EEFlux with ETa-METRIC. Moreover, a strong correlation was found between ETo and ETa-METRIC (r=0.93 and slope close to 1 and RMSE value of 0.74 mm day-1) if compared to the relationship between ETo with ETa-EEFlux. The results show the potential of applying the METRIC model and EEFlux for mapping ETa over a large-scale irrigation scheme.

Comparing actual evapotranspiration estimations by METRIC to in-situ water balance measurements over an irrigated field in Turkey

ABSTRACT Estimating actual evapotranspiration (ETa) rates in large-scale irrigation schemes is of great importance to improve water use efficiency. Crop types can be determined by employing remote sensing techniques coupled with ground truth data. This study aimed to: (a) conduct a water balance study by making in-situ water balance measurements, (b) derive cropping pattern maps, (c) acquire crop evapotranspiration (ETc), (d) generate fully distributed ETa maps, and (e) compare ETa estimations with ETc and in-situ water balance. Landsat 7 and 8 satellite data, and meteorological data were used to estimate ETa in the Eastern Mediterranean Region of Turkey in the 2021 hydrological year. Crop types were classified using Sentinel 2A–2B satellite images. The change in catchment storage was +67.08 mm with a 3.34% water balance closure error. The correlation between ETa and ETc for irrigated wheat, potato, lettuce, corn-1, peanut-1, soybean-2, and citrus was significant in the growing season.

Cropping pattern classification using artificial neural networks and evapotranspiration estimation in the Eastern Mediterranean region of Turkey

Determination of cropping pattern is a very important factor in quantifying irrigation water requirements at a catchment scale. In this regard, remote sensing is a robust tool for generating spatial-temporal variation of crops. This study focuses on crop classification by using remotely sensed data coupled with ground truth data. Therefore, this study aimed at both classifying each crop type and calculating crop evapotranspiration (ETc) based on reference evapotranspiration (ETo) by using the Penman-Monteith evapotranspiration model and crop coefficient (Kc). ETo was estimated by using data from two meteorological stations located in the study area. To this end, this study was conducted in Akarsu Irrigation District (≈95 km2), a sub-catchment in the Lower Seyhan Plain (LSP), in the 2021 hydrological year. Ground truth data were collected in the two growing seasons. The ENVI program was used to classify crop types from Sentinel 2A-2B satellite images with 10-m by 10-m spatial resolution. Image analysis results demonstrated that bare soil and citrus made up more than half of the area in the winter season, while corn and citrus were preponderant in summer. In addition, the total reference evapotranspiration and crop evapotranspiration were about 1308 mm and 890 mm, respectively in the 2021 water year. ETc values for second crop soybean, first crop corn, wheat, and citrus showed agreement with previous studies of direct methods of evapotranspiration in the Cukurova region. Furthermore, research findings led us to conclude that using remotely sensed satellite data in cropping pattern determination is promising in identifying the crops grown in large agricultural lands. Moreover, remote sensing images can be used to classify accurately crops in the winter and summer seasons, and this study has expanded the application value of remotely sensed data in large-scale irrigation schemes.

Introducing the Importance of Mass Balance Works for Soil Salinity in a Large Scale Irrigation Scheme in the Eastern Mediterranean Region of Turkey

Introducing the Importance of Mass Balance Works for Soil Salinity in a Large Scale Irrigation Scheme in the Eastern Mediterranean Region of Turkey

Performance evaluation of furrow irrigation water management practice under Wonji Shoa Sugar Estate condition, in Central Ethiopia

Wonji Shoa Sugar Estate (WSSE) is one of the large-scale irrigation schemes in Ethiopia which was established in 1951. The aim of this study was to evaluate the performance of current furrow irrigation water management practices of WSSE. Performance evaluation of the current furrow irrigation was evaluated based on field experiment and the WinSRFR model. For this purpose, ten fields were selected from commonly used furrow lengths (32, 48, and 64 m). Application efficiency, distribution uniformity, and deep percolation performance indicators were used for evaluation. The performance of furrow irrigation showed poor performance, and as an improvement option, inflow rate and cutoff time were altered keeping furrow geometry constant. Advance and recession times for all furrow lengths were recorded and simulated using the WinSRFR model to obtain an accurate cutoff time of irrigation. The result obtained showed that the time allocated for all furrow lengths was not accurately determined. As an improvement option, both inflow rate and cutoff time changed and the performance of furrow irrigation significantly improved. By changing those decision variables, application efficacy and deep percolation performance indicators were significantly improved but distribution uniformity was not changed. In almost all statistical indices used, predicted performances by model were better than computed values in the existing situation. From the current result, it can be concluded that the inflow rate and cutoff time should be changed to attain good performance and increase furrow irrigation efficiency.

Editorial Volume 8 Issue 1 (January 2022)

Editorial Volume 8 Issue 1 (January 2022)

Application of HEC-RAS model for adaptive water allocation in a Large-Scale Rice Irrigation Scheme

Application of HEC-RAS model for adaptive water allocation in a Large-Scale Rice Irrigation Scheme

Making small-dams work: everyday politics around irrigation cooperatives in Turkey.

Much research on environmental issues in Turkey has focused on conflictual state-led projects, for example on the large-scale GAP irrigation schemes or hydroelectric plants. This article shows that, in a complementary way, it is also necessary to study less contested projects, since power struggles for control over natural resources tend to occur in the implementation and everyday management of these as well. It analyses the everyday dynamics of negotiations and the arrangements found locally during the implementation of the national programme ‘1000 gölet in 1000 days’. Gölet, hillside reservoirs built for irrigation, enabled the government to demonstrate its involvement at a very local level in numerous villages in Turkey. However, the complex implementation of these numerous and relatively small projects compelled agents of the hydraulic administration to negotiate the transfer of their management to local actors. Taking irrigation cooperatives in the Izmir region as a starting point, this article highlights how the shaping of social arrangements for managing the new water resource depends both on local and supralocal power relations. It challenges the idea of a monolithic state disconnected from homogenous communities of irrigators, and reveals the flexibility of these relations. It focuses on the way actors – not only irrigators but also state officials at the local level – adapt norms, bend rules and find arrangements in order to shape new water institutions and infrastructure.

Remote sensing techniques in mapping spatial variability of salinity in Kano River Irrigation Project (KRIP), Nigeria


 
 
 Salinity has become a major issue in most large scale irrigation schemes, assessing the extent of the spread has become daunting and laborious. Remote sensing techniques were used to map salinity and develop models for extracting and identifying salinity in soils. Sentinel-2B optical imaging satellite with 13 spectral bands and 10 m spatial resolution was used. SNAP Desktop, ERDAS Imagine, and ArcGIS 10.6 software were used as the main GIS packages for building models and running functions such as input, output, analysis, and processing. Stepwise Multiple Linear Regression (MLR) techniques were carried out for the assessment of the spatial distribution of ECe and to predict salinity level at different locations of the Kano River Irrigation Project (KRIP). Four models were developed, however, due to the lower Variance Inflation Factor (VIF), model 2 which is a combination of salinity Index and band 3 (Green band) was used in delineating the spatial extent of the salinity. Close monitoring of the salt development and application of reversal measures were recommended.
 
 

Water Resource Management and Crop Production in General and in Ethiopian Scenario

Water was considered a free commodity in the past, which meant that its quality was unregulated and it was available whenever it was needed. However, as a result of increased population and urbanization, diversification, and a rapid increase in resource demands, water resources are becoming limited and of lower quality. Only 13-18% of the water used by irrigated crops worldwide is used in the form of transpiration, which is correlated with yield and production. Small-scale irrigation development would result from a lack of quality and quantity of water supply for growing crops, as well as increased social, economic, and environmental costs associated with developing large-scale irrigation schemes. This type of development has an impact on the use of rain-fed water for irrigation efficiency. Whereas rain-fed agriculture produces more irrigation products in developing countries' semi-arid regions, accounting for up to 90% in some cases. The primary option would be to increase crop production in these areas by increasing rain-fed agriculture, which ensures that freshwater supply is not stressed in irrigated agriculture. Ethiopia also has a significant amount of available water resources. Despite the country's remarkable water resource potential, river basin development is rarely carried out. Water is critical to the development of the country. Furthermore, Ethiopia's abundant natural water resource endowment, rapidly growing economy, and ambitious government agenda present significant opportunities. It is critical to recognize and capitalize on these opportunities. Water resource management in Ethiopia is hampered by a lack of knowledge about resource conditions, patterns of use, and change drivers, as well as a lack of capacity and capacity within organizations to manage water distribution, determine impacts and trade-offs, and ensure 'climate-smart' planning. Keywords: Crop, Ethiopia, Rain-fed, Water resource management DOI: 10.7176/CER/13-6-02 Publication date: October 31 st 2021

Climate change impacts on rice yield of a large-scale irrigation scheme in Malaysia

The yield of lowland rice is prone to climatic factors and farming practices, among which water management and weed control are crucial. Crop simulation models can help evaluating the impacts of these factors and practices on yield growth. This study assessed the impacts of climate, irrigation practices, and weed control measures on the yield of lowland rice by using FAO-AquaCrop model. Necessary data were generated by well-planned field experiments during two consecutive rice-growing seasons (off-/dry season: January–April and main-/wet season: July–October) in 2017. Ensemble climate data was downscaled from eighteen General Circulation Models (GCMs) under three Representative Concentration Pathway (RCP) scenarios (RCP4.5, RCP6.0 and RCP8.5) both for baseline (1976–2005) and future (2010–2099) periods. AquaCrop model was calibrated and validated with observed data with regard to Normalized Root-Mean-Square Error (NRMSE), Prediction Error (Pe), Mean Absolute Error (MAE), and Index of Agreement (d). The model simulated biomass, yield and productivity of rice satisfactorily. It predicted 13.6%, 14.1% and 15.3% increase in yield under RCP4.5, RCP6.0 and RCP8.5 emission scenario, respectively for the off-season in the future compared to the baseline period. The corresponding increase in yield is 13.9%, 14.5% and 15.2% for the main-season. The model simulated reduced yield under water stress and poor weed control, with yield reduction mounting to 65% under worse weed control. However, proper weed control and water management practices will likely augment yield under changing climate. The stress exerted by rising temperature on yield will likely be compensated by the ensuing increase in CO2 fertilization. The predicted susceptibility of rice yield to weed infestation and water stress under changing climate will help devising proper management practices for sustainable rice productivity in the future.

Soil and Irrigation Water Management: Farmer’s Practice, Insight, and Major Constraints in Upper Blue Nile Basin, Ethiopia

This study assessed farmers’ soil and irrigation water management practices, perceptions, and major constraints at Koga, a large-scale irrigation scheme in Ethiopia. Key informant interviews, structured and semi-structured questionnaires, focus group discussions, and field visits were used for data collection. Soil samples were collected for the assessment of soil properties and a comparison with the respondents’ perception of soil-related constraints. A total of 385 respondents were involved in the questionnaire. All of the respondents had a good perception of soil acidity and its management strategies. Respondents’ perception was in line with the mean soil pH, soil texture, infiltration rate, exchangeable acidity, and soil organic carbon obtained from lab analysis and field tests. Soil acidity, unwise use of water, water scarcity, and lack of market linkages hampered the performance of the Koga irrigation scheme. Yet, respondents had a low awareness of irrigation water management. Farmers never used irrigation scheduling, but apply the same amount of water regardless of the crop type. As a result, low yield and water use efficiency were reported. To reduce soil acidity, an adequate lime supply for farmers with hands-on training on how to apply it would be desirable. Farmers should be aware of how to design effective irrigation scheduling and adopt water-saving management strategies.

GIS-Based Susceptibility Mapping of the Fentale–Metehara Blisters and Blister Caves in the Main Ethiopian Rift: Implications for Their Conservation

The biggest and most spectacular blister caves in the world are found in the Fentale–Metehara area, in the Main Ethiopian Rift, where we inventoried 639 blisters and blister caves in an area of 80 sq. km straddling between the southern foot of Fentale volcano and the northern shore of Lake Beseka. The blisters were formed by a unique geological process involving up-doming of fluid-rich pyroclastic flows due to pressure of gases entrapped in the progressing flow, and subsequent breaching of some of the hollow domes. These unique geological heritages have been threatened, in some cases already destroyed, by various man-made and natural factors such as the unprecedented expansion of Lake Beseka, extensive infrastructure development (roads, railways, settlements and urbanization, and large-scale irrigation schemes), and younger fissural lava flows. In order to systematically determine the degree of threat quantitatively and qualitatively and evaluate the probability of destruction of any of the blisters and blister caves, we applied GIS-based frequency ratio model and non-hierarchical cluster analysis techniques and produced a susceptibility map of the area. The susceptibility map, validated using the degree of fitness technique, indicates that most of the blister field falls within very high to high susceptibility of destruction, implying that the destruction of most of these spectacular features is imminent particularly due to expansion of Lake Beseka and the Metehara town. This calls for concerted effort by the local authorities to devise mechanisms to protect the threatened blisters and blister caves along with mitigating the impacts of the expanding Lake Beseka. The susceptibility map will be helpful to guide and prioritize conservation efforts.

Comparative assessment of technical efficiencies of irrigated crop production farms: A case study of the large-scale Kampe-Omi irrigation scheme, Nigeria

The technical inefficiencies of crop production system in terms of large-scale irrigation schemes are major problems attributed to the underperformance of crop farms. Therefore, the aim of this study was to estimate and compare farm-level technical efficiencies of four major crop productions system including, pepper, okra, garden egg, and tomato under the large-scale Kampe-Omi irrigation scheme, Nigeria. The data development analysis (DEA) approach was used to study the hypothesized determinants affecting the efficiencies of crop farms using an ordinary least squares regression model. The results showed that the selected pepper, okra, garden egg, and tomato crop farms were fully efficient at 20, 10, 16.92, and 40% under constant return to scale (CRS), and at 13.33, 30, 10.77, and 25.71% under variable return to scale (VRS), respectively. DEA revealed a considerable variation in technical inefficiency among the selected crop farms under the irrigation scheme. The significant determinants of technical efficiencies of the four crop farms include farmers’ age, family size, experience, alternative income, education, credit accessibility, and contact with extension agents. The outcomes of this study are useful for improving production efficiencies while serving as a convenient guide for both farmers and irrigation scheme managers of selected crops.

Challenges and Opportunities of Irrigation Practices in Ethiopia: A Review

Ethiopia has been started traditional irrigation practice since ancient time for the aim of subsistence food production. Since 1950’s modern irrigation system was introduced in Awash and Rift Valley basins for production of industrial crops. Government, donors and non-governmental organizations are investing to the development of irrigation systems from small to large scale irrigation schemes. As a result, irrigation is developing rapidly. However, its contribution to the national economy is insignificant when compared to rain-fed agriculture. This review was conducted to investigate the irrigation practice challenges and opportunities in Ethiopia. The extension service was inadequate and not packaged. Credit service bureaucracy like group collateral was constrained to improve irrigated crop production. Water governance was done by water users but interference by the government bodies aggravated water use conflicts. Streams drying, percolation and seepage of water are the most challenges. Irrigation created employment opportunity for household members and the rural community and also improved their income. Therefore, policy makers and development practitioners should improve policies and strategies based on the agro-ecology and socio-economic settings of irrigation areas to overcome the challenges and strengthen the opportunities.

Effect of land use-land cover change on the regimes of surface runoff-the case of Lake Basaka catchment (Ethiopia).

In this study, the effect of land use-land cover change (LULCC) on surface (direct) runoff was estimated for Lake Basaka catchment using the soil conservation services-curve number model in the geospatial information system (ArcInfo), assisted by remote sensing. The result indicated that Lake Basaka catchment experienced a significant LULCC. About 86% of forest coverage and 46% of grasslands were lost over the study period (1973-2015), which were shifted to open bushy woodlands, farms, lake water and wetlands. The runoff responses were observed to be increasing since 1970s, especially after the inception of large-scale irrigation schemes to the region. The highest increase of surface runoff was observed to occur after mid-1980s, which is in line with the significant LULCC and the corresponding increment of lake level in that period. The reduction in vegetation cover has resulted in an increase of runoff coefficient (rc) from 0.07 in the 1960s to about 0.23 in 2000s. The sensitivity analysis result indicated that about 70% of the increase runoff rate in the lake catchment is attributed to LULCC, and the remaining proportion is due to rainfall. However, the effect of extreme rainfall on runoff process could not be underemphasized since it has significant impact especially during extreme events (observed rc of 0.33 in 2008). Overall, when predicting the runoff response of the lake catchment, it is importance to take into account possible future LULCC and evolution.

A comparative analysis of two paddy irrigation schemes under contrasting water management of participatory and top-down systems in Uganda

This research focused on two large-scale paddy irrigation schemes of Doho (1000 ha) and Lwoba (700 ha) in Uganda for a comparative analysis of major factors affecting the effectiveness of water management. The schemes have almost the same irrigation and farming conditions, while they adopt contrasting water management methods of participatory and top-down in Doho and Lwoba, respectively. A questionnaire survey targeting the farmers in both schemes on their farming, yields and evaluation of water management was conducted, and the results were analyzed by paying attention to the locations of their farms. The survey reveals that the average yield is higher in Lwoba than in Doho. A tendency of lower evaluation on water distribution by farmers in Doho is found especially in the downstream part at the terminal canal level. Doho has the government’s operation in the main facilities with farmer operation in the on-farm systems. In contrast, the water management in Lwoba is totally controlled by a single landlord of the whole scheme, appointing block leaders, water guards and supervisor who watch the block leaders and his children as farmer to spy on the block leaders. The landlord has strong incentives for higher and stable rent income, thus requiring this strong monitoring and feedback system to achieve equitable water management. It is concluded that for the successful achievement of higher water productivity within the framework of PIM, one of the main problems is to install a practically effective system to secure the equitable water distribution in a democratic manner.

Modeling climate-smart decision support system (CSDSS) for analyzing water demand of a large-scale rice irrigation scheme

Climate projection at local scale is one of the crucial challenges that affects the development of water management-related mitigation plans. Moreover, the currently available climate models do not directly simulate some of the hydro-climatic parameters (e.g., effective rainfall, reference evapotranspiration, irrigation requirements), which are of interest in irrigation sector. Modeling crop-water demands under changing climate involves several step-by-step approaches that are tedious and time-consuming for many water users. This study developed a water management tool, hereafter called Climate-Smart Decision-Support System (CSDSS), for modeling water demand of rice irrigation schemes under climate change impacts. The CSDSS is a user-friendly interactive program consisting of three main modules integrated in MATLAB and a graphical user interface development environment (GUIDE). The model runs with ten Global Climate Models (GCMs) and three emission scenarios (RCP 4.5, 6.0 and 8.5). It can generate several hydro-climatic parameters based on a daily water balance model, with input data from GCMs projections, crop, soil and field conditions. The model allows water managers to make fast decision for paddy water management. The generated outputs can be obtained through individual GCMs as well as through multi-models (ensemble) projection and can be converted into excel format for further analysis. The model was applied to evaluate the impacts of climate change on irrigation water demand and other key hydro-climatic parameters in Tanjung Karang Rice Irrigation Scheme in Malaysia for the period 2010–2099 with reference to the baseline period of 1976–2005. The results show that irrigation water demand will increase during the off-season (January–June) but decrease during the main season (July–December) due to significant contribution from effective rainfall in the latter season. The CSDSS tool can be used for managing water resources under changing climate and would, therefore, be helpful in promoting appropriate adaptation and mitigation strategies that can lead to more sustainable water use at farm level. Some future improvements of the tool, due to methodological limitations of the study, will however improve its performance.

Investigating the invisible roots of a prevailing narrative of farmers’ failed collective action in Morocco

ABSTRACTIn rural areas in developing countries, the origin and persistence of prevailing narratives of failed collective action have often been explained by the existence of relations of domination. This article focuses on a case in which power relations alone cannot explain the persistence of a prevailing narrative. In a large-scale irrigation scheme in Morocco, farmers and staff from the regional agricultural development authority share the view that farmers lack the capacity to undertake successful collective action. This narrative influences public policies as well as the farmers’ self-esteem. It prevails despite rare communication between the farmers and the staff of the development authority and despite several successful examples of informal collective action at local scale. An analysis of the different actors’ discourses and of the farmers’ practices revealed the different underlying root causes of the narrative: (i) farmers and development authority staff overlook contextual factors, (ii) they confuse collective action with formal farmers’ organisations, (iii) the resistance of words where the actors describe a changed situation using the same words, and (iv) the nostalgia of the older generation for a strong state-managed scheme. As a consequence, actors consider that the failure of past collective action is the farmers’ fault, irrespective of the unfavourable context and the legacy of the past. Studies of prevailing narratives that are not simply linked to power relationships, should go beyond discourse analysis and focus on actors’ practices and on the origin of the narratives. Understanding the roots of prevailing narratives can also help challenging them.