Soil Salinity Research and Mapping using Remote Sensing GIS (original) (raw)
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Mapping of Soil Salinity Using Remote Sensing and GIS
Salinity can develop naturally or from interventions in the water cycle through irrigation or both. In India the extent of salt affected soils is about 6.73 million ha. Soil salinity reduces crop yield and in severe cases causes complete abandonment of agriculture. It is a major form of land degradation in agricultural areas, where information on the extent and magnitude of soil salinity is needed for better planning and implementation of effective soil reclamation programs. Hence study on mapping of soil salinity in irrigated lands of Krishna Central Delta was taken up using digital image processing and GIS techniques. Different salinity indices were prepared from Landsat8 satellite images of Krishna Central Delta (KCD) which covers about 18 mandals of Krishna district. Normalized Difference Salinity Index (NDSI) was found to range from-0.71 to 0.22. Brightness Index (BI=Sqrt (R 2 + NIR 2)), Salinity Index-1 (SI 1 = Sqrt (B × R)), Salinity Index-2 (SI 2 = Sqrt (G × R)), Salinity Index-3 (SI 3 = R / NIR) and Salinity Index-4 (SI 4 =(SWIR1-SWIR2)/ (SWIR1 + SWIR2)) were found to range from 0.7 to 0.13, 0.42 to 0.11, 0.44 to 0.1, 6.0 to 0.64 and 0.43 to-0.42 respectively in KCD region. On comparing the correlation of all the indices with measured EC values of soil samples collected from the study area, NDSI index showed the best correlation of about 89.3%. It was found that the lands along the coast are mostly affected by soil salinity. From the thematic maps, it was clearly identified that the highest salinity patches fall in the mandals of Machilipatnam, Pedana, Koduru and Nagayalanka. Soil salinity was characterized into five different classes and out of entire KCD ayacut of 1,11,307.81 ha, an area of about 68,754.01 ha was found to be affected by moderate salinity conditions.
E3S Web of Conferences
Soil salinity is a serious agricultural concern in Uzbekistan, causing plant growth to be hampered and crop productivity to be diminished. This issue is especially prevalent in semi-desert and desert regions, compounding problems such as soil erosion, land degradation, subsidence, corrosion, and poor groundwater quality. On the other hand, Geographic Information Systems (GIS) and Remote Sensing (RS) technologies provide more efficient, cost-effective, and timely tools and procedures for mapping soil salinity. Different indices and methods can be used to detect and quantify soil salinity levels using the spectral information acquired by the Landsat-8 OLI sensor. Among these are the Normalized Difference Salinity Index (NDSI) and the Normolazed Difference Vegetation Index (NDVI). GIS software integrates satellite imagery with auxiliary data such as soil type and topography, allowing for a thorough assessment of soil salinity distribution over the research area. Compared to traditional...
Assessment of Remotely Sensed Indices to Estimate Soil Salinity
2018
Soil Salinization is one of the oldest environmental problems and one of the mainpaths to desertification. Access to information in the shortest time and at low cost isthe major factor influencing decision making. The satellite imagery providesinformation data on salinity and also offers large amount of data that can be analyzedand processed to understand several indices based on the type of the sensor used. Inthis research, the capability of different indices derived from IRS-P6 data wasevaluated to identify saline soils in Mahabad County. The quality of the satelliteimages was first evaluated and no noticeable radiometric and geometric distortion wasdetected. The Ortho-rectification of the image was performed using the satelliteephemeris data, digital elevation model, and ground control points. The RMS errorwas less than a pixel. In this study, the correlation between the bands and used indices,including Salinity1, Salinity2, Salinity3, PCA1 (B2, B3), PCA1 (B4, B5), PCA1 (B1,B2, B...
Application of remote sensing indices for mapping salt- affected areas by using field data methods
International Journal of ADVANCED AND APPLIED SCIENCES, 2017
Salinity is one of the oldest and most important environmental problems. Salinization is defined as presence of excessive salts on the top layer of the soil, resulting in deterioration of its chemical and physical properties. This is a form of land degradation turning into a major cause of low agricultural productivity in the South Khorasan province, Iran. The criteria defining saltaffected areas are based on electrical conductivity (EC) values. Kaji Playa is an endorheic basin that located in a distance of 190 km from the south of Birjand city in the South Khorasan province, Iran. The salt affected soils of Kaji Playa drainage basin cover approximately 39% of the study area and the EC values change from 4.2 dS.m-1 to 245 dS.m-1 (decisiemens per meter). Salinity Mapping is an expensive process, and a multi-scale strategy is essential to achieve a rapid and effective assessment of its extent and severity. Advantages of using remote sensing technology include saving time, wide coverage are faster than ground methods and facilitate long term monitoring. In this paper, we offered a project, which monitors soil salinity conditions in the study area using fieldwork, soil sample analysis, and a multi-temporal analysis of Landsat ETM+ data. The fieldwork was done to measure the soil salinity and gather ground truth for image classification. The alternative methodology of this study is based on the interpretation and calculation of salinity index from satellite data. The paper main aim included mapping and monitoring of salinity conditions for environmental management at basin level. According to the results, the soil salinity map produced by satellite index of NDSI (Normalized Difference Salinity Index) had an overall accuracy of 84% and Kappa index of 67%, indicating an acceptable accuracy for this classification.
Earth Sciences Pakistan, 2020
Salinity is the most important factor of consideration for the water management policies. The water availability from the rootzone reduced with the increase in the soil salinity due to the increase in the osmatic pressure. In Pakistan, salinity is the major threat to the agriculture land due to the tradition practices of irrigation and extensive utilization of the groundwater to meet the cope the irrigation water requirement of high intensity cropping system. The salinity impact is spatially variable on the canal commands area of the irrigation system. There is dire need to map the spatially distributed soil salinity with the high resolution. Landsat satellite imagery provides an opportunity to have 30m pixel information in seven spectral wavelength ranges. In this study, the soil salinity mapping was performed using pixel information on visible and infrared bands for 2015. These bands were also used to infer Normalized Difference Vegetation Index (NDVI). The raw digital numbers wer...
2015
Soil salinity occurs on over 50% of the irrigated land and is one of the limiting factors for food crop production in the Central Asian region. Identification and mapping of salt-affected areas is a first step to coping with soil salinity. Traditional methods of mapping soil salinity, based on soil sampling and laboratory analyses, are time consuming and costly. Remote sensing-based approach has been developed to track historical changes in occurrences of soil salinity during the period 2000-2011. The method was tested for Syrdarya Province, Uzbekistan, where rapid salinity build-up has been recorded since 1965 when 300,000 ha of virgin land were developed based on canal irrigation. The seasonal Landsat images for the period 2000-2011 were used to calculate the radiance, reflectance and Normalized Difference Vegetation Index (NDVI) raster layers. The seasonal NDVI values were used to estimate the maximum annual NDVI values for three periods: 2000-2003, 2004-2007 and 2008-2011. The m...
DEVELOPMENT AND DEMONSTRATION OF SATELLITE IMAGE SALINITY ANALYZER – A TOOL FOR SALINITY MAPPING
Abstract Soil salinity is caused by natural or human induced process and considered to be a major environmental hazard. Nearly 20% of all irrigated land in India was salt affected and this proportion tends to increase in spite of considerable efforts dedicated to land reclamation. This requires careful monitoring of the soil salinity status and the variation to the curb degradation trends and secure sustainable land use and management. This study area Nagapattinam district was affected by salinity, the situation became worse after tsunami salinity level has increased that makes portable water un-utilizable and change in cropping pattern even at some places saltpans are available for extracting salt by salt industry. The paper attempts to demonstrate a tool for identifying and mapping salt affected areas and also deriving different levels of soil salinity in order to cope with increasing and sustaining the productivity of crops from remote sensing data using various threshold levels.
Evaluation of soil salinity level through NDVI in Syrdarya province, Uzbekistan
E3S Web of Conferences, 2021
Traditional soil salinity assessments have been doing by collecting of soil samples and laboratory analyzing of collected samples for determining TDS and electro conductivity, but, GIS and Remote Sensing technologies provides more efficient, economic and rapid tools and techniques for soil salinity assessment and soil salinity mapping. Main goals of this research are to map soil salinity of Syrdarya province, to show relation of its result with soil quality index (arable land validity point) values of this field. The soil quality index data and map of 2019 year were digitized and transferred to ArcMap software format and investigated the soil quality index score. As a source of satellite images has been used Landsat OLI 8 Earth-observation satellite. Syrdarya province, every arable land validity point of different locations were measured by State Commite of the Republic of Uzbekistan of Land Resources, Geodesy, Cartography and State Cadastre was compared to our research conducted on...
Evaluation of soil salinity level through using Landsat-8 OLI in Central Fergana valley, Uzbekistan
E3S Web of Conferences
Soil salinity is a major concern in the Uzbekistan. Fergana valleys agricultural lands, it negatively affects plant growth, crop yields, whereas in central part of the valley is semi-desert and desert affects agricultural areas due to subsidence, corrosion and ground water quality, leading to further soil erosion and land degradation. Traditional soil salinity assessments have been doing by collecting of soil samples and laboratory analyzing of collected samples for determining totally dissolved soils (TDS) and electro conductivity, but, Geo-informatic systems (GIS) and Remote Sensing (RS) technologies provides more efficient, economic and rapid tools and techniques for soil salinity assessment and soil salinity mapping. Main goals of this research are to map soil salinity of Fergana valley, to show relation of its result with traditional analysing and analysing withGIS technology As a source of satellite images has been used Landsat-8 OLI. Research areas every arable land validity ...
Detection of salt affected soil in rice-wheat area using satellite image
African Journal of Agricultural Research, 2011
Pakistan's agricultural system is predominately irrigated, which consumes 90% of fresh water resources and contributes 80% to the national production. It is ironic that the irrigated areas are the ones that are afflicted most by the twin menaces of waterlogging and salinity. Climate change is likely to exacerbate this soil degradation process by way of heavy rainfalls and by increased evaporation, respectively. Detection of soil salinity is usually done by laborious soil sampling. A study, to delineate surface soil salinity in the prime rice-wheat cropping area of Pakistan, was conducted. The study employed an index-based approach of using optical remote sensing data in combination with geographic information system. The effectiveness of different satellite imagery indicators was examined. Several combinations of the ratio of signals received in different spectral bands were used for development of this index. Near infrared and thermal IR spectral bands proved to be most effective as this combination helped easy detection of salt affected area from the non saline area. Results showed that 19% of the rice-wheat cropping area of Gujranwala district in Rachna Doab of central Punjab province of Pakistan is salt affected. These results are in agreement with the published survey data. Seasonal dependency of salinity was also analyzed so as to obtain correct classification.