Irrigation Projects Research Articles

From Watershed Moment to Hydrosocial Movement: Patagonia without Dams and The Free-Flowing Rivers Network in Chile

In this article, we examine how social movement activists draw on the hydrosocial dynamics of the watershed unit to build a river protection network in resistance to extractivist development. We apply a critically engaged activist anthropological focus, and drawing on four years of collaborative fieldwork, we describe how activists formed a hydrosocial movement to reconfigure Chile as an interconnected territory of living watersheds. In 2014, the Patagonia Without Dams movement successfully stopped the development of a mega-dam complex in Chilean Patagonia, catalyzing a major upheaval in environmental politics. The Free-Flowing Rivers Network harnessed momentum from Patagonia Without Dams and jumped scales from place-based campaigns that defend singular rivers against dams to translocal actions that protect watersheds from an array of extractive industries. We show how this movement bridged rural and urban conflict zones, seeking to protect watersheds from forms of extractivism beyond dams, including mining and irrigation projects. By focusing on the Free-Flowing River Network’s efforts to translate its political-ecological platform into policy, we show how hydrosocial territories may be established, defended, expanded, and stabilized through strategies that explicitly connect water and society.

A decade-long study on the effect of furrow and subsurface drip irrigation using unconventional water on soil salinity and the growth of pistachio trees

Furrow irrigation is the most common method of irrigating pistachio orchards in Iran. Water use efficiency using this method of irrigation is close to 35%. Ten years ago, a subsurface drip irrigation (SDI) project was initiated with highly saline and alkaline water for the first time in Iran at the Feyzabad pistachio research station, at 34̊ 54ʹ 15ʺ N, 58̊ 45ʹ 37ʺ E, located in the northeast of Iran, at an altitude of 850 meters from the sea. The water salinity and sodium adsorption ratio were 11.5 dS m-1 and 15.5 at the beginning of the project, and they reached 16.25 dS m-1 and 17.7 in 2021. The amount of SDI water consumption in the first year of the project (2012) was 1640 m3 ha-1 yr-1, and as the trees aged, water consumption reached 3000 m3 ha-1 in 2022. The amount of water utilized for furrow irrigation was about 6912 m3 ha-1 in 2022. Salt entering the soil through irrigation water differed by about 41 t ha-1 in 2022 between the two methods. After ten years of project implementation, the root development layer was more than 100 cm and less than 50 cm, respectively, for SDI and furrow. The trend of soil salinity has changed from 2012 to 2022: it went from 34.7 dS m-1 in 2012 to 110 dS m-1 in 2018, and then decreased to 65 dS m-1 in 2022 in the surface layer of the SDI method. In contrast, salinity increased almost twofold within the root development layer (60-140 cm) in the SDI. In the last two years (2021 and 2022), the height, crown width, trunk circumference, and yield of the pistachio trees were not significantly different between the two irrigation methods. However, there was a significant difference in the irrigation treatments during the two last years (2021 and 2022) in the annual growth, the average number of flower buds in the branch, and the average number of flower buds abscised. The branch vegetative growth in 2022 had decreased by almost 50% compared to 2021 in both methods. The results showed that the lowest annual growth was achieved in the SDI in 2022. Overall, the efficiency of water consumption in the SDI and furrow was equal to 0.09 and 0.06 kg m3, respectively. SDI net income was 1284 $ higher after expenses were deducted from 2012 to 2022. Therefore, due to severe climate change and excessive salinity increase in soil and water resources, a well-managed SDI can provide a more sustainable production method for salt-affected soils for pistachio orchards by reducing water consumption and salt entry into the soil.

Effects of Inequality of Access to Irrigation and Water Productivity on Paddy Yield in Nigeria

This study assessed the equity in irrigation water uses and its impacts on paddy yield and water productivity among rice farmers in the Kano River Irrigation Project. Two hundred and twenty-five (225) respondents were used for the data collection from January to June 2021. The data were analyzed using the Kruskal Walli’s test, Tukey kramer post-Hoc test, physical water productivity, and the Logit model. The results indicated that the downstream farmers had the lowest mean yield (1625 kg/acre), lowest access to irrigation water, and lowest irrigation water use (2430 m3/acre). However, they had the highest water productivity (0.66 kg/m3) against 0.44 kg/m3 and 0.58 kg/m3 for middle and upstream farmers, respectively. The logit regression results disclosed that the farm locations, quantity of irrigation water, access to irrigation water, and training on water use were statistically significant determinant of paddy output. Efforts to teach farmers about the actual crop water requirements are needed to promote irrigation water efficiency and conserve scarce resources for other competing users.

A Study on the Dynamic Mechanism of Community Participation in the Construction of Giant Panda National Park -- Taking Longxi Hongkou National Nature Reserve in Dujiangyan Irrigation Project City as an Example

The report of the 20th National Congress of the Communist Party of China clearly proposes to "promote the construction of a natural reserve system with national parks as the main body". Community participation is an important way to achieve ecological protection and coordinated development of national parks, and it is essential to study how to mobilize the enthusiasm of community residents to participate in the construction of national parks. Therefore, this article conducted in-depth investigations in Longxi Hongkou Nature Reserve through methods such as interviews and questionnaires. Based on the research results and using push-pull theory for analysis, a driving framework for residents to participate in the construction of the Giant Panda National Park was constructed. Through analysis, it was found that: (1) the driving force is divided into external and internal driving forces; (2) Through the analysis of push pull theory, it is found that the driving forces for residents' participation include interests, systems, and identification; (3) Only by establishing a complete system, improving participation channels, and meeting the interests and needs of residents can we promote their participation in the construction of the Giant Panda National Park, thereby achieving sustainable development.

Social capital and farmers’ participation in multi-level irrigation governance in Thailand

Irrigation governance in a community often involves multi-level interactions between formal and informal institutions. Collective efforts by multiple actors at the local level, particularly farmers, encourage participation in irrigation governance. The literature has explored that social capital influences irrigation and water management, but it has not looked in detail at how social capital components may differ for different levels of governance. This study fills this gap by looking at how cognitive and structural social capital can be a contributor to farmers' participation in multi-level irrigation governance (constitutional, collective choice, and operational level). The aim of this paper is to investigate the role of social capital on farmers’ participation in multi-level irrigation governance in the Upper Pasak irrigation project, Lomsak district, Phetchabun province of Thailand. A mixed methods approach was adopted. Data were collected by means of a survey of 345 randomly selected farmers along with in-depth interviews with 14 key informants.Our findings show that a high level of trust within the community and between communities resulted in a low level of farmers’ participation in rule-making. The frequency of the interaction between farmers and governmental officials increases their participation in rule-making and decision-making in irrigation management. The study recommends that encouraging activities to enhance experiences, knowledge, and understanding within the community, boosting the communication and public relations about irrigation management, and promoting a greater role of agriculture-related government agencies in cooperating with irrigation projects will combine to provide sustainable irrigation management and reduce conflicts of interest.

Geospatial data and web based tools for managing irrigation infrastructure expansion projects

AbstractImproving irrigation infrastructure is important for sustaining food security in developing countries like India. The irrigation potential of a system is estimated at the planning phase using conventional approaches. A mismatch in the irrigation potential planned to be created and the land suitable for cultivation can lead to a gap in the irrigation potential created and utilized, making the scheme unrealistic and uneconomical. This study aims to use geospatial data and geographic information system (GIS) tools to identify land suitable for cultivation when planning an irrigation system. This study was conducted in Telangana State in India, where the projected irrigation potential creation was 5 million ha (Mha). It was observed that the total land suitable for cultivation in the state, considering the soil's topography, and physical and chemical characteristics, is about 6 Mha. Time series of average monthly Normalised Difference Vegetation Index (NDVI) over a 10‐year period was used to identify the critical blocks. The study illustrates how the geospatial data derived from remote sensing and recent GIS tools can aid managers in planning, implementing, and monitoring irrigation projects. The study also demonstrates how long‐term satellite information can be used for regional prioritizationprioritisation for constructing irrigation infrastructure and postconstruction impact assessment. This study was conducted as part of the Young Water Professions (YWP) Training program, which allowed the participants to develop professional competencies and implement their learning in real‐world situations.

Application of geospatial technique and hydrological modelling in evaluating reservoir sedimentation in Chhattisgarh state of India

ABSTRACT Soil erosion and sediment deposition in the reservoirs are both consequences of the change in precipitation pattern that has been observed over the past decade. For the purpose of storing water in reservoirs built before the 1980s, the Indian state of Chhattisgarh has a few irrigation projects. As the state has grown, agricultural land has increased while the proportion of forest area has decreased. Due to this development, runoff is introducing more sediment into the reservoirs, resulting in a reduction in intended storage. The effects of sediment deposition in the Kodar reservoir, located in the Mahasamund district of Chhattisgarh State, are evaluated in present study. Prior to five years, the reservoir reported a 30% deficit in actual irrigation. To quantify the sediment load, Remote Sensing (RS), Geographic Information System (GIS), and the Hydrologic Engineering Centre – Hydrologic Modelling System (HEC-HMS) were effectively employed. From 2012 to 2014, the reservoir received an average sediment load of 1.11 million tonnes. In order to preserve soil in the watershed’s erosion-prone area, a treatment plan is developed. It includes numerous thematic maps that are overlaid in order to provide preventive measures against reservoir sedimentation and is further proposed in the form of best management practices.

Transdisciplinary approach for planning the expansion of irrigation infrastructure at a regional scale

AbstractThe focus on irrigation infrastructure development in countries like India, including a significant allocation of the government's budget, highlights the importance of achieving a high benefit–cost ratio for these projects. However, past reviews have revealed instances where irrigation projects yielded low benefits. To address this issue and ensure a more effective evaluation of future projects, it is crucial to develop multi‐criteria and transdisciplinary approaches. In the context of Telangana, India, a study was conducted to determine cultivable land using a multi‐criteria and transdisciplinary approach. This approach aimed to provide assistance to managers involved in the planning, implementation, and monitoring of irrigation schemes. The study was undertaken as part of the Indian Young Water Professionals (IYWP) training program in 2022. The project followed a journey outlined within this paper as part of the training program. It utilized the Situation Understanding and Improvement Project (SUIP) as an inquiry‐based learning design program. This initiative facilitated the understanding and implementation of transdisciplinary learning approaches learned during the training program. The SUIP project demonstrated the benefits of incorporating a multi‐criteria framework, known as the [I]NSPECT model, into the decision‐making process. The [I]NSPECT model considers various perspectives, including individual, natural, social, political, economic, cultural, and technical factors. By incorporating these perspectives, the decision‐making process becomes more comprehensive and holistic. Overall, this study highlights the importance of adopting multi‐criteria and transdisciplinary approaches for evaluating irrigation projects. By incorporating diverse perspectives and considering various factors, it becomes possible to enhance the effectiveness of decision‐making processes in the realm of irrigation infrastructure development. The study concluded that the absence of transdisciplinary approaches, the inefficient techno‐managerial performance of governmental workplaces, and the non‐use of technological advancements to the fullest are primary reasons for gaps in the irrigation potential created and utilized in the State.

THE CONTROVERSIAL TOKEN CURRENCY OF MUHAMMAD BIN TUGHLUQ: A HISTORICAL ANALYSIS

In this study, an attempt has been made to explore the historical significance and legacy of the token currency introduced by Muhammad bin Tughluq during his reign as Sultan of Delhi from 1325-1351. An audacious economic reform, the token currency aimed to ease the strain on the state treasury due to expansive military campaigns and territorial expansion. Notwithstanding, the revolutionary system underpinned by copper and brass coins, intended to supplant traditional precious metals, failed due to the lack of public trust and widespread counterfeiting. Despite its failure, this experiment represented an integral part of a broader socio-economic and cultural evolution. Tughluq's reign witnessed numerous reforms and ambitious projects like the shifting of the capital to Daulatabad and extensive irrigation projects, laying the foundation for the development in the Deccan region. Lessons from this experiment, such as the necessity of public trust, a robust infrastructure, and strong security measures, continue to be relevant for contemporary monetary practices and reforms, particularly in light of debates surrounding the digitization of money and the advent of crypto currencies.

Assessment of Barriers to Canal Irrigation Efficiency for Sustainable Harnessing of Irrigation Potential

Currently, irrigation consumes approximately 84 per cent of the total available water in India and is predicted to remain the dominant water user. This study assessed the barriers to canal irrigation efficiency in Jharkhand State of India. Through an extensive review of the literature and expert consultation, the study classified the barriers into five primary categories: Resource System, Legal and Institutional, Financial Barriers, Capacity Building, and External Environment. This study applied an integrated approach using the Analytic Hierarchy Process (AHP), fuzzy Analytic Hierarchy Process, and decision-making trial and evaluation laboratory approach to assess the issues prevailing in canal irrigation efficiency. The experts were selected based on their expertise and knowledge, and they provided their preferences on the weighting of the models for applying the three methods. From the study, it can be inferred that more attention is needed to reduce Financial Barriers to improve the overall performance of irrigation projects. This necessitates adequate government funding and collection of water rates. The lack of government support/funding and low collection of water charges make WUAs financially unviable and unable to bear the Operation and Maintenance costs and incurs high maintenance costs, resulting in capital loss.

Modeling rainfall-runoff estimation and assessing water harvesting zone for irrigation practices in Keleta watershed, Awash river basin, Ethiopia

The world’s water demand is increasing twice as quickly as the world’s population. Contrarily, the greatest problem facing humanity in the twenty-first century is the supply of food. During dry seasons, when water collecting is a crucial survival strategy, the communities in the study area experience water deficit for agricultural production. In this study, socioeconomic and biophysical parameters were considered to evaluate the water harvesting zone for irrigation practices. With the aid of this technology, water harvesting sites can be found in acceptable sites, and water resource management can be improved to address water shortages during the dry season when crops are at key stages of growth and filling. The integrated geographical information system/Remote Sensing (GIS/RS), Soil Water Assessment Tool (SWAT), fuzzy logic, and analytic hierarchy process (AHP) model were used to carry this out. Rainfall, drainage density, surface runoff, percentage of clay content, land use land cover, slope, lithology, lineament, and Euclidian distance to settlement and road were the criteria utilized to choose the Rainwater Harvesting (RWH) sites. The run-off was estimated using the SWAT model, weights for each influential component were determined using AHP, the input factor was standardized using fuzzy membership, and factors were combined using gamma fuzzy (ℽ= 0.9) overlay weighting. The model’s statistical performance was demonstrated by R2 values of 0.79 and NSE values of 0.77 for monthly calibration periods and R2 values of 0.81 and NSE values of 0.75 for monthly validation periods. The study area’s Rainwater Harvesting potential suitability classes covered very highly suitable (16.91%), extremely suitable (27.6%), moderately suitable (20.23%), low suitable (13.1%), and not suitable (6.43%), and restrictions (15.73%). The study’s findings could help decision-makers identify more lucrative and long-lasting irrigation investment options in the Keleta watershed and make better decisions regarding the development of irrigation projects there.

Scheduling of Leaching Requirements to Prevent the Secondary Salinisation in the Root Zone

Leaching scheduling techniques are one of the suggested solutions for water scarcity problems .The aim of the study is to show the possibility of using leaching scheduling, when applying the irrigation scheduling program for a certain irrigation project, which was prepare by Water Resources Engineering –University of Baghdad with some modifications to generalized it and it make applicable to various climatic zone and different soil types.The objectives of this research is to build a system that concerns the prediction of the leaching scheduling (depth and date of leaching water), illustrating the main problems (soil salinity, save the amount of leaching requirement, and to maintain crops growth).The other objective is to compare between the calculated amount of leaching water with the amount of water that is suggested by designers. The program includes, the calculating of predicted daily soil salinity ,the depth of leaching water that should be applied to remove the salt from the soil when it reaches a harmful level, and the total annual volume of leaching water. The results showed, that the use of predicted leaching scheduling with its applicable constrains require high attention when choosing the cropping pattern for each climate zone. Also, it was found that the leaching program is a useful tool for saving irrigation water if cropping pattern has been adapted carefully. This means the leaching water depth should be added only when needed, and may not be necessary with each irrigation event.

The Quantitative Morphometric Analysis of the Biggest Basin in Western Plateau of Iraq

The integrative utilization of the remotely sensed extracted data with geographic information system analyzing capabilities is the optimal approach to determine the shape of rivers and valleys basins realistically and to know their morphological and geomorphological characteristics, so it gives an accurate perception of ways to exploit surface or groundwater resources for these basins.The concerned region is the western plateau which located between (38° 45’ 31˝) and (48° 17’ 12.58) eastern longitudes; (34 ° 30’ 10.77) and (29 0’ 38) northern latitudes. The hydrological analysis based on the geographic information system of the region basins showed that the Houran valley basin is the largest basin in the western plateau that described as a fourth-order drain basin that has dendritically and sometimes paralleled drain network.The quantitative analysis of the morphological features showed that longitudinal drain density was 0.1698 km / km2, which reflects a soil quality with high permeability plus a desert climate of arid to semi-arid weather. The circulation ratio is 0.08566, which indicates that the basin is in an early geomorphological stage and that the linear structures control the pattern of its drainage network. The elongation ratio is 0.112, which means that there are significant differences in the hardness of its geological structure, and this would help the use of groundwater in the process of sustainable development of the region. The adoption of quantitative methods based on spatial analysis in hydrological studies supports the optimal use of water resources (from accurate identification of dam sites to realistic planning of irrigation projects), especially in areas with scarce water.

Effect of climate change on reservoir water balance and irrigation water demand: a case of Gidabo irrigation project, Rift Valley Basin, Ethiopia.

The consequences of climate change on agriculture water demand are among the current and prospective challenges. The amount of water needed by crops is significantly affected by the regional climate. The influence of climate change on irrigation water demand and reservoir water balance components were examined. The results of seven regional climate models were compared, and the top-performing model was chosen for the study area. After model calibration and validation, the HEC-HMS model was used to forecast future water availability in the reservoir. The results show that under the RCP 4.5 and RCP 8.5 emission scenarios, the reservoir's water availability in the 2050s will decline by approximately 7% and 9%, respectively. The CROPWAT results showed that the required irrigation water might rise by 26 to 39% in the future. However, the water supply for irrigation may be drastically reduced due to the drop in reservoir water storage. As a result, the irrigation command area could drop up to 21% (2878.4ha) to 33% (4502ha) in future climatic conditions. Therefore, we recommend alternative watershed management techniques and climate change adaptation measures to endure upcoming water shortages in the area.

Evaluating climate change impact on the hydrology of Kessie Watershed, Upper Blue Nile Basin, Ethiopia

Climate change affects ecosystems, agriculture, human health, forestry, and water resource availability. This study is mainly aimed at assessing the climate change effect on the water resources of the Kessie Watershed in the Upper Blue Nile Basin, Ethiopia. The updated Coupled Model Intercomparison Project Phase 6 (CMIP-6) data outputs were used. The three climate model outputs: ACESS_ESM1-5, FGOALS_g3, and GFDL_ESM4 with two shared socioeconomic pathways (SSP2-4.5 and SSP5-8.5) scenarios, were used. The climate model output rainfall and temperature data were downscaled to the station level through bias correction. The catchment hydrology was represented by the SWAT—Soil and Water Assessment Tool—through calibration and validation. Future temperatures and rainfall change were evaluated by the Mann–Kendall trend test and Sen’s slope estimator. Future climate change trend analysis and streamflow simulation were done on two time horizons: the 2050s (2041–2070) and the 2080s (2071–2100). The baseline streamflow data (1985–2014) were used as a reference. The global climate model projection data indicated mean annual precipitation and temperatures show a slight increase for the future in both scenarios for all climate model outputs. According to the SSP2-4.5 and SSP5-8.5 scenarios, respectively, mean annual precipitation is expected to increase by 5% and 4.89% in the 2050s and 10.13% and 6.8% in the 2080s based on ACCESS_ESM1-5; 4.7% and 3.8% in the 2050s and 4.3% and 4.84% in the 2080s based on FGOALS_g3; and 4.67% and 3.81% in the 2050s and 4.67% and 3.81% based on GFDL_ESM4 models data. Yearly average maximum temperature may increase by 3.62 °C and 1.87 °C in the 2050s and 3.31 °C and 2.99 °C in the 2080s based on ACCESS ESM1-5, 1.76 °C and 1.25 °C in the 2050s and 3.44 °C and 2.61 °C in the 2080s based on FGOALS-g3, and 2.15 °C and 3.83 °C in the 2050s and 1.37 °C and 2.66 °C in the 2080s based on GFDL-ESM4 model data. Similarly, the mean annual minimum temperature is also expected to increase by 2.73 °C and 1.90 °C in the 2050s and 5.63 °C and 4.52 °C in the 2080s based on ACCESS ESM1-5, 3.04 °C and 2.43 °C in the 2050s and 3.55 °C and 4.36 °C in the 2080s based on FGOALS-g3, and 2.31 °C and 3.29 °C in the 2050s, and 3.16 °C and 3.87 °C in the 2080s based on GFDL-ESM4 model data. The streamflow is also expected to increase. In the 2050s, simulated annual streamflow is expected to increase from 12.1 to 21.8% and 9.8 to 15.4% in SSP2-4.5 and SSP5-8.5, respectively, whereas in the 2080s, the change is expected to increase from 15.14 to 24.08% and 13.08 to 41% in SSP2-4.5 and SSP5-8.5, respectively. Future water resource potential of the case study watershed seems able to support irrigation and other projects.

Role of construction of major irrigation projects on emergence of zoonotic diseases

Role of construction of major irrigation projects on emergence of zoonotic diseases

A simulation tool to optimize the management of modernized infrastructures in collective and on-farm irrigation systems

Irrigated areas face new, pressing challenges due to escalating energy costs for pumping, increasing cost of seeds, fertilizers and agrochemicals, volatility of agricultural commodities, pressure of environmental regulations, water scarcity and mounting cost of irrigation infrastructure investments. At the same time, from the technical standpoint, farmers can chose from a wide array of irrigation design and operation alternatives for collective and on-farm systems, with variable effects on crop yield and profitability. These factors are often subjected to quick changes, complicating decision making. Simulation models have proven useful to support decision making in irrigation infrastructure, water / energy use, crop agronomy and soil management. In this research, new capacities of the Ador-Simulation software are reported, targeting comprehensive analyses of irrigation modernization. The model implements additional on-farm irrigation methods (low-pressure solid-set, center-pivot and drip irrigation); crop intensification (double cropping in the same season); and crop response to different on-farm irrigation management options (timing and frequency). Model performance was verified using a set of theoretical case studies. Finally, the model was applied to the optimization of irrigation design and management (water and energy) in the Bardenas XI project of northeastern Spain. Water application in center-pivot and drip irrigation were simulated using a normal distribution characterized by a user-defined Distribution Uniformity. In center-pivot, the application depth was randomized in every irrigation event, reproducing the random nature of wind disturbances. In drip irrigation, the application depth followed the same random distribution in all irrigation events, reproducing the deterministic effect of manufacturing and hydraulic variability. According to the literature, the effect of irrigation timing was treated differently for two key sprinkler irrigated crops: corn and alfalfa. Differences in water application and crop yield between on-farm methods resulted in different gross and net income. In the Bardenas XI project, irrigation performance indicators showed different patterns of inter-annual variability. Deep percolation was strongly affected by the amount of seasonal precipitation and by Distribution Uniformity. Indicators at the plot level were strongly determined by the on-farm irrigation method, the soil type, and the crop. In the conditions of Bardenas XI, the design option without pumping station was the most adequate. Natural pressure proved sufficient for a combination of low-pressure sprinkler irrigation, pivot and drip irrigation methods, distributed throughout the irrigated area. Escalating energy costs emphasize the need for careful assessment of pumping requirements at the design phase of irrigation projects.

Land suitability analysis using a multicriteria decision‐making approach for optimal irrigation in a medium irrigation scheme in West Bengal, India

AbstractThe present study aspires to distinguish suitable irrigation lands using the analytical hierarchy process (AHP) and geographic information system (GIS) of the Shali River basin area, which is a part of the Shali reservoir irrigation project (medium irrigation project) of West Bengal, India. Therefore, 12 factors were identified as criteria, including elevation, slope, rainfall, soil group, sand, silt, clay, nitrogen, pH, organic carbon, land use and land cover (LULC) and river distance. The results show that the Shali Basin has approximately 64% irrigation‐suitable land. The irrigational suitability reveals that the villages near the river have highly irrigation‐suitable lands. Therefore, it can be said that the distance to the river plays a major role as it determines the irrigation water availability. It is therefore advisable to install rainwater catchment structures in villages that are significantly distant from the river. This study may help farmers to select cropping patterns according to irrigation suitability and the concerned readers to understand the irrigation land suitability analysis with appropriate parameters and methods under any medium irrigation project.

Multi-temporal assessment of land surface temperatures as an indicator of land use/cover changes and climate variability in the Develi Basin, Turkey.

Land surface temperature (LST) is an important parameter that reflects land surface processes of water and energy balance and has been used in assessment of land use/cover changes. However, the use of LST in monitoring changes in non-urban areas such as agricultural areas and wetlands is still limited. In this study, we aim to determine the spatial and temporal changes in LST in a semi-arid agricultural basin in Turkey (Develi Basin), where land use/cover and climatic conditions showed considerable variability since 1980s. Irrigated agriculture have expanded in the basin since 1987, after the construction of a large irrigation project. The basin hosts an internationally important wetland, called the Sultan Marshes, affected negatively by irrigation expansion. The study covers a 39-year period from 1984 to 2022. Four Landsat Thematic Mapper (TM) images acquired in 1984, 1987, 2003, and 2007 and two Landsat 8 OLI/TIRS images acquired in 2014 and 2022 were used in the analyses. The land use/cover changes were evaluated based on Normalized Difference Vegetation Index (NDVI). LST was estimated through top-of-atmosphere brightness temperature from thermal bands of Landsat images. Climate variability from 2014 to 2022 was analyzed with statistical methods. The results indicated that Develi Basin faced both spatial and temporal land use/cover changes. The area covered with natural steppe vegetation and water bodies decreased in the basin. In contrast, the sparsely and densely vegetated soil covers, which mostly denote agricultural areas, increased. Changes in LST values were observed from 1984 to 2022 as a result of climatic factors and land use/cover changes. LST changes were variable across different land use/cover types; LST decreased in irrigated areas and increased in lakes that went dry over years. LST changes proved useful for evaluating land use/cover changes and climatic variations in agricultural basins.

Creation of Geospatial Database and Estimation of Irrigation Water Requirement of a Canal Command in Gayathri Irrigation Project, Kerala

The water requirement of crops in the canal command of distributaries of Gayathri Irrigation Project in Palakkad district, Kerala was estimated using GIS and CROPWAT 8 model. The geospatial data base for canal network, land use, soil and climate were prepared using Geographic Information System (GIS) tools. This data base was used as input to CROPWAT model to estimate irrigation water requirement of different distributaries of the canal command. The gross irrigation requirement was estimated for the historical climate data (2004-2018) as well as the predicted climate data for the years 2026 and 2031. The net irrigation water requirement of different crops in the distributary command was found to vary spatially depending on soil, crop and climate. The net irrigation water requirement of paddy (mundakan) in distributaries located at head to tail reaches varied from 1004.5 to 1573.6 mm. The high value of net irrigation requirement in tail reach was due to the influence of soil series with high infiltration rate compared to head reach soil. The net irrigation requirement also varied for the same crop in same soil series in different distributaries depending upon the climatic conditions. The net irrigation water requirement of paddy (mundakan) in distributaries located at head to middle reaches for the same soil series varied from 1056.5 to 1004.5 mm due to the influence of variations in rainfall. The gross estimated irrigation water requirement showed that distributaries at the middle and tail reaches required more water than the distributaries at the head end. The maximum gross irrigation water requirement of 25369.7 m3/ha was observed for Peringhotukavu distributary in tail reach and lowest of 4390.9 m3/ha for Parakkalchalla distributary in head reach. The estimation of irrigation requirement for projected climate data also showed the same trend as that of historical data.