Evaluation of Salinity by Using Wavelet Modeling

Every year, due to the salinity resulting from improper irrigation practices, almost 10 billion ha of agricultural lands across the world cannot be used. Among the main elements (cations) for salinity in regions with dry or semi-dry climate are potassium (K+), sodium (Na+), calcium (Ca+2) and magnesium (Mg+’2). Using proper irrigation methods as well as ensuring the quality of irrigation water are of great importance in terms of the salinity of agricultural soils. In this study, laboratory analyses of ground water resources for salinity parameters were conducted in the province of Yalova (Taşköprü, Çiftlikköy, and Altınova regions). In the explanation of the analysis results, variations and effects based on the level of salinity were taken into account and the role of small, meso and large scale factors were determined through the use of the wavelet model. The study results would be of use in the estimation of salinity contents of soils with respect to groundwater irrigation in agricultural areas.

Hydrochemistry Characteristics of Groundwater with the Influence of Spatial Variability and Water Flow in Hetao Irrigation District, China

Groundwater is an important resource of water in arid and semi-arid agricultural regions. This study considered the spatial differentiation of geographical features and the concentration of groundwater flow. The upstream of the Hetao Irrigation District Shenwu Irrigation Area (SWIA) and the downstream Wulate Irrigation Area (WLTIA) were selected as the study area, and a total of 85 groundwater samples (42 from SW and 43 from WLTIA) were collected. The aims of the study were to analyze the chemical composition and main control mechanisms of groundwater, and to evaluate the suitability of groundwater irrigation in the study area from the perspective of salt and alkali damage. Geological and environmental factors increase the spatial variability of groundwater chemical characteristics in the Hetao Irrigation District. In addition the groundwater of the study area is weakly alkaline, with the flow of groundwater; the solute content of downstream (WLTIA) is higher than that of upstream (SWIA); SWIA is mainly fresh water (47.62%); and WLTIA is mainly brackish water (65.12%). The main water chemistry types are Cl-Na type, Cl·SO-Ca· Mg type, Na+ and Cl− have obvious advantages in WLTIA, and they are the main contribution indicators of groundwater TDS in the study area. Rock weathering, ions exchange and evaporate crystallization are the main controlling factors for groundwater in the Hetao Irrigation District. Na+ mainly originates from the dissolution of evaporate salt rock and silicate rock, and Ca2+ from the dissolution of gypsum and carbonate. The order of contribution of different rocks is evaporation rock > silicate rock > carbonate rock, and the contribution rates of human activities and atmospheric input are small. The groundwater quality of the upstream SW is better than that of the downstream WLTIA. However, due to the high chemical ion concentration of the groundwater, most of the groundwater cannot be directly used for irrigation, which may cause salt and alkali damage. Therefore, when using groundwater irrigation, either drip irrigation or irrigation water aeration pretreatment can be used to avoid damages such as reduced soil permeability and compaction.

A GIS-Based Approach to Estimate Electricity Requirements for Small-Scale Groundwater Irrigation

Access to modern energy services is a precondition to improving livelihoods and building resilience against climate change. Still, electricity reaches only about half of the population in Sub-Saharan Africa (SSA), while about 40% live under the poverty line. Heavily reliant on the agriculture sector and increasingly affected by prolonged droughts, small-scale irrigation could be instrumental for development and climate change adaptation in SSA countries. A bottom-up understanding of the demand for irrigation and associated energy services is essential for designing viable energy supply options in an effective manner. Using Uganda as a case study, the study introduces a GIS-based methodology for the estimation of groundwater irrigation requirements through which energy demand is derived. Results are generated for two scenarios: (a) a reference scenario and (b) a drought scenario. The most critical need is observed in the northern and southern regions of the country. The total annual irrigation demand is estimated to be ca. 90 thousand m3, with the highest demand observed in the months of December through February, with an average irrigation demand of 445 mm per month. The highest energy demand is observed in the northern part of the study area in January, reaching 48 kWh/ha. The average energy demand increases by 67% in the drought scenario. The study contributes to current gaps in the existing literature by providing a replicable methodological framework and data aimed at facilitating energy system planning through the consideration of location-specific characteristics at the nexus of energy–water–agriculture.

PERFORMANCE INDEX MODEL OF GROUNDWATER IRRIGATION SYSTEMS

This research will develop a groundwater irrigation system performance index model with the aim of identifying the groundwater irrigation system performance index; this information can be used by stakeholders to determine management steps. The research location is in Gunungkidul Regency and includes surrounding areas — acknowledging that the karst aquifer has complex characteristics and non-karst aquifer, namely high heterogeneity as a result of the formation of a groundwater flow system through fractures which eventually becomes completely underground runoff. Screening for the variables was carried out using the smart-PLS (Partial Least Square) tool, which was then analyzed using the GRG (Generalized Reduced Gradient) method which is useful for solving non-linear equations. In this research, it examines the physical aspects, social aspects and management aspects as variables. The groundwater irrigation system performance index model examines 3 (three) variables, namely physical aspects, social aspects, and management aspects, then 11 (eleven) dimensions and 42 (forty two) indicators. The analysis using PLS SEM using smart PLS tools determined that the 3 (three) variables, 11 (eleven) dimensions and 30 (thirty) indicators are interrelated and effective. Whereas by using GRG (Generalized Reduced Gradient) analysis with the solver tool in Microsoft Excel, the most influential weights were obtained from the physical aspects, namely physical infrastructure (0.5782), geological conditions (0.2311), water quality (0.1286) and recharge area conditions (0.0475); the social aspects that obtained the most influential weight are socio-cultural (0.7471) and economy (0.2529); the management aspects that obtained the most influential weights are budgeting (0.2534), plant productivity (0.2270), WUA organizational conditions (0.2090), JIAT management organizational conditions (0.1987) and spatial planning directives (0.0674). In general, the weight of the influence of groundwater irrigation performance for these three aspects is 0.6686 physical aspects, 0.0856 social aspects and 0.2458 management aspects which are formulated into a performance index model for groundwater irrigation systems "Kautsar", namely IL = 0.6686 physical IL + 0.0856 social IL + 0.2458 IL management. For development, further research is needed on the performance index model of the groundwater irrigation system using Geography Information System (GIS) and a software application on android, iOS, or windows operation systems. A groundwater irrigation system performance index that consists of these three aspects is unique and has never been assembled in previous studies; it conveniently allow the user to determine survey results immediately.

Human arsenic exposure risk via crop consumption and global trade from groundwater-irrigated areas

While drinking water is known to create significant health risk in arsenic hazard areas, the role of exposure to arsenic through food intake is less well understood, including the impact of food trade. Using the best available datasets on crop production, irrigation, groundwater arsenic hazard, and international crop trade flows, we estimate that globally 17.2% of irrigated harvested area (or 45.2 million hectares) of 42 main crops are grown in arsenic hazard areas, contributing 19.7% of total irrigated crop production, or 418 million metric tons (MMT) per year of these crops by mass. Two-thirds of this area is dedicated to the major staple crops of rice, wheat, and maize (RWM) and produces 158 MMT per year of RWM, which is 8.0% of the total RWM production and 18% of irrigated production. More than 25% of RWM consumed in the South Asian countries of India, Pakistan, and Bangladesh, where both arsenic hazard and degree of groundwater irrigation are high, originate from arsenic hazard areas. Exposure to arsenic risk from crops also comes from international trade, with 10.6% of rice, 2.4% of wheat, and 4.1% of maize trade flows coming from production in hazard areas. Trade plays a critical role in redistributing risk, with the greatest exposure risk borne by countries with a high dependence on food imports, particularly in the Middle East and small island nations for which all arsenic risk in crops is imported. Intensifying climate variability and population growth may increase reliance on groundwater irrigation, including in arsenic hazard areas. Results show that RWM harvested area could increase by 54.1 million hectares (179% increase over current risk area), predominantly in South and Southeast Asia. This calls for the need to better understand the relative risk of arsenic exposure through food intake, considering the influence of growing trade and increased groundwater reliance for crop production.

The Impact of Groundwater Irrigation Development on Cropping Intensity and Crop Productivity in Krishnagiri District

Aims: The study is done with the objective of assessing the impact of groundwater irrigation development on cropping intensity and crop productivity in Krishnagiri, Tamil Nadu, India. Study Design: Purposive random sampling Place and Duration of Study: Krishnagiri district, Tamil Nadu, India during 2019-20. Methodology: The data on irrigation sources and area under various irrigation sources in Krishnagiri, Tamil Nadu and India is subjected to growth analysis using trend studies and CAGR (Compound Annual Growth rate) to study the ground water irrigation development. Whereas, regression analysis was done with the primary data collected from 120 farming households in Krishnagiri on agricultural land use and irrigation to study the impact of groundwater irrigation on cropping intensity and crop productivity. Results: As the net tube wells and other well irrigated area to net sown area (GWA) increases, there has been a corresponding increase in cropping intensity and crop productivity. The rise in percent of net tank and canal irrigated area to net sown area and percent of fertilizer applied area to net sown area have also increased cropping intensity and crop productivity whereas the increase in percent of net rainfed area to net sown area have decreased the cropping intensity and crop productivity. Conclusion: The ground water utilization through tube well construction have increased the cropping intensity and crop productivity.

Evaluating the Spatio-Temporal Distribution of Irrigation Water Components for Water Resources Management using Geo-Informatics Approach

Irrigation water management components evaluation is mandatory for sustainable irrigated agriculture production in the era of water scarcity. In this research spatio-temporal distribution of irrigation water components were evaluated at canal command area in Indus Basin Irrigation System (IBIS) using remote sensing based geo-informatics approach. Satellite derived MODIS product-based Surface Energy Balance Algorithm for Land (SEBAL) was used for the estimation of the Actual Evapotranspiration (ETa). Satellite derived SEBAL based ETa was calibrated and validated using the ground data-based advection aridity method (AA). Statistical analysis of the SEBAL based ETa and AA shows the mean 87.1 mm and 47.9 mm and, 100 mm and 77 mm, Standard deviation of 27.7 mm and 15.9 mm and, 34.9 mm and 16.1 mm, R of 0.93 and 0.94, NSE of 0.72 and 0.85, PBIASE -12.9 and -4.4, RMSE 34.9 and 5.76 for the Kharif and Rabi season, respectively. Rainfall data was acquired from the Tropical Rainfall Measuring Mission (TRMM). TRMM based rainfall was calibrated with the point observatory data of the Pakistan Metrological Department Stations. Canal water data was collected from the Punjab Irrigation department for the assessment of canal water availability. Water The water balance approach was applied in the unsaturated zone for the quantification of the gross and net Groundwater irrigation. Mmonthly variation of ETa with the minimum average value of 63.3 mm in January and the maximum average value of 110.6 mm in August was found. While, the average annual of four cropping years (2011-12 to 2014-15) ETa was found 899 mm. Average of the sum of Net Canal Water Use (NCWU) and Rainfall during the study period of four years was only 548 mm (36% of ETa) and this resulted the 739.6 mm of groundwater extraction. While the annual based variation in groundwater extraction of 632 mm and 780 mm was found. Seasonal analysis revealed 39% and 61% of groundwater extraction proportion during Rabi and Kharif season, respectively. The variation in four cropping year’s monthly groundwater extraction was found 28.7 mm to 120.3 mm. This variation was high in the 2011-12 to 2012-13 cropping year (0 mm to 148.7 mm), dependent upon the occurrence of rainfall and crop phenology. Net groundwater irrigation, estimated after incorporating the efficiencies was 503 mm year-1 on average for the four cropping years.