scholarly journals A Harmonious Satellite-Unmanned Aerial Vehicle-Ground Measurement Inversion Method for Monitoring Salinity in Coastal Saline Soil

2019 ◽  
Vol 11 (14) ◽  
pp. 1700 ◽  
Author(s):  
Suming Zhang ◽  
Gengxing Zhao
Keyword(s):  
Soil Salinity ◽  
Saline Soil ◽  
Soil Salinization ◽  
Test Area ◽  
Multispectral Imagery ◽  
Spectral Parameters ◽  
The Core ◽  
Ground Measurement ◽  
Aerial Vehicle ◽  
Sentinel 2A

Soil salinization adversely impacts crop growth and production, especially in coastal areas which experience serious soil salinization. Therefore, rapid and accurate monitoring of the salinity and distribution of coastal saline soil is crucial. Representative areas of the Yellow River Delta (YRD)—the Hekou District (the core test area with 140 sampling points) and the Kenli District (the verification area with 69 sampling points)—were investigated. Ground measurement data, unmanned aerial vehicle (UAV) multispectral imagery and Sentinel-2A multispectral imagery were used as the data sources and a satellite-UAV-ground integrated inversion of the coastal soil salinity was performed. Correlation analyses and multiple regression methods were used to construct an accurate model. Then, a UAV-based inversion model was applied to the satellite imagery with reflectance normalization. Finally, the spatial and temporal universality of the UAV-based inversion model was verified and the soil salinity inversion results were obtained. The results showed that the green, red, red-edge and near-infrared bands were significantly correlated with soil salinity and the spectral parameters significantly improved this correlation; hence, the model is more effective upon combining spectral parameters with sensitive bands, with modeling precision and verification precision of the best model being 0.743 and 0.809, respectively. The reflectance normalization yielded good results. These findings proved that applying the UAV-based model to reflectance normalized Sentinel-2A images produces results that are consistent with the actual situation. Moreover, the inversion results effectively reflect the distributions characteristic of the soil salinity in the core test area and the study area. This study integrated the advantages of satellite, UAV and ground methods and then proposed a method for the inversion of the salinity of coastal saline soils at different scales, which is of great value for real-time, rapid and accurate soil salinity monitoring applications.

scholarly journals Estimation of Soil Salinization by Machine Learning Algorithms in Different Arid Regions of Northwest China

2022 ◽  
Vol 14 (2) ◽  
pp. 347
Author(s):  
Xiaofang Jiang ◽  
Hanchen Duan ◽  
Jie Liao ◽  
Pinglin Guo ◽  
Cuihua Huang ◽  
...  
Keyword(s):  
Soil Salinity ◽  
Land Surface ◽  
Saline Soil ◽  
Soil Salinization ◽  
Landsat 8 ◽  
Hyperspectral Reflectance ◽  
Surface Parameters ◽  
Light Gradient ◽  
The Mean ◽  
Land Surface Parameters

Hyperspectral data has attracted considerable attention in recent years due to its high accuracy in monitoring soil salinization. At present, most existing research focuses on the saline soil in a single area without comparative analysis between regions. The regional differences in the hyperspectral characteristics of saline soil are still unclear. Thus, we chose Golmud in the cold–dry Qaidam Basin (QB–G) and Gaotai–Minghua in the relatively warm–dry Hexi Corridor (HC–GM) as the study areas, and used the deep extreme learning machine (DELM) and sine cosine algorithm–Elman (SCA–Elman) to predict soil salinity, and then selected the most suitable algorithm in these two regions. A total of 79 (QB–G) and 86 (HC–GM) soil samples were collected and tested to obtain their electrical conductivity (EC) and corresponding hyperspectral reflectance (R). We utilized the land surface parameters that affect the soil based on Landsat 8 and digital elevation model (DEM) data, selected the variables using the light gradient boosting machine (LightGBM), and built SCA–Elman and DELM from the hyperspectral reflectance data combined with land surface parameters. The results revealed the following: (1) The soil hyperspectral reflectance in QB–G was higher than that in HC–GM. The soils of QB–G are mainly the chloride type and those of HC–GM mainly belong to the sulfate type, having lower reflectance. (2) The accuracies of some of the SCA–Elman and DELM models in QB–G (the highest MAEv, RMSEv, and were 0.09, 0.12 and 0.75, respectively) were higher than those in HC–GM (the highest MAEv, RMSEv, and were 0.10, 0.14 and 0.73, respectively), which has flatter terrain and less obvious surface changes. The surface parameters in QB–G had higher correlation coefficients with EC due to the regular altitude change and cold–dry climate. (3) Most of the SCA–Elman results (the mean in HC-GM and QB-G were 0.62 and 0.60, respectively) in all areas performed better than the DELM results (the mean in HC–GM and QB–G were 0.51 and 0.49, respectively). Therefore, SCA–Elman was more suitable for the soil salinity prediction in HC–GM and QB–G. This can provide a reference for soil salinization monitoring and model selection in the future.

scholarly journals Study on the Farmland Improvement Effect of Drainage Measures under Film Mulch with Drip Irrigation in Saline–Alkali Land in Arid Areas

2021 ◽  
Vol 13 (8) ◽  
pp. 4159
Author(s):  
Li Zhao ◽  
Tong Heng ◽  
Lili Yang ◽  
Xuan Xu ◽  
Yue Feng
Keyword(s):  
Groundwater Level ◽  
Drip Irrigation ◽  
Saline Soil ◽  
Soil Salinization ◽  
Test Area ◽  
Limiting Factors ◽  
Arid Areas ◽  
Secondary Salinization ◽  
Soil Desalination ◽  
Soil Level

Water scarcity and imbalances in irrigation and drainage are the main factors leading to soil salinization in arid areas. There is a recognized need for effective drainage measures to prevent and improve saline−alkali land. The principal objective of this project was to investigate the effects of drainage measures on soil desalination and farmland drainage in the process of improving saline–alkali soils; these measures included subsurface pipe drainage (SPD) and open ditch drainage (ODD). The results of the tests, conducted over two years, revealed that the soil desalination rate in the SPD test area was between 25.8% and 35.2%, the cotton emergence rate was 36.7%, and a 3.8 t hm−2 seed cotton yield could be obtained. The soil electrolytic conductivity (EC) decreased step by step over time, and the average annual decrease reached 10 dS m−1. The degree of soil salinization was reduced from a moderately saline soil level (8−15 dS m−1) to a weakly saline soil level (4–8 dS m−1). Thus, the phased goal of improving saline–alkali land was achieved. The soil desalination rate in the ODD test area was only 1/10 of the SPD area; high soil EC (9−12 dS m−1) and groundwater level (2–3 m) were the most limiting factors affecting cotton growth in the ODD test area. The current results show that the critical depth of groundwater level affecting farmland secondary salinization is 4 m. In order to improve the salt discharge standard, SPD technology should be used on the basis of ODD. For salt that has accumulated in the soil for a long time, the technical mode of drip irrigation and leaching, followed by SPD drainage, in combination with the current irrigation system can achieve the goal of sustainable agriculture development.

scholarly journals Linking Long-Term Changes in Soil Salinity to Paddy Land Abandonment in Jaffna Peninsula, Sri Lanka

Agriculture ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 211
Author(s):  
Tharani Gopalakrishnan ◽  
Lalit Kumar
Keyword(s):  
Sri Lanka ◽  
Soil Salinity ◽  
Agricultural Land ◽  
Sea Water ◽  
Land Use Changes ◽  
Soil Salinization ◽  
Landsat Images ◽  
Paddy Land ◽  
Semi Arid Region

Soil salinity is a serious threat to coastal agriculture and has resulted in a significant reduction in agricultural output in many regions. Jaffna Peninsula, a semi-arid region located in the northern-most part of Sri Lanka, is also a victim of the adverse effects of coastal salinity. This study investigated long-term soil salinity changes and their link with agricultural land use changes, especially paddy land. Two Landsat images from 1988 and 2019 were used to map soil salinity distribution and changes. Another set of images was analyzed at four temporal periods to map abandoned paddy lands. A comparison of changes in soil salinity with abandoned paddy lands showed that abandoned paddy lands had significantly higher salinity than active paddy lands, confirming that increasing salts owing to the high levels of sea water intrusion in the soils, as well as higher water salinity in wells used for irrigation, could be the major drivers of degradation of paddy lands. The results also showed that there was a dramatic increase in soil salinity (1.4-fold) in the coastal lowlands of Jaffna Peninsula. 64.6% of the salinity-affected land was identified as being in the extreme saline category. In addition to reducing net arable lands, soil salinization has serious implications for food security and the livelihoods of farmers, potentially impacting the regional and national economy.

scholarly journals Screening of Salt Tolerant CIP Potato Germplasm for Saline Areas

2013 ◽  
Vol 11 (1) ◽  
pp. 95-102 ◽  
Author(s):  
MH Rahman ◽  
MM Alam Patwary ◽  
H Barua ◽  
M Hossain ◽  
MM Hasan
Keyword(s):  
Soil Salinity ◽  
Agricultural Research ◽  
Saline Soil ◽  
The Other ◽  
Salt Tolerant ◽  
Agricultural Research Institute ◽  
International Potato ◽  
Local Variety ◽  
Potato Germplasm ◽  
High Level

Fifteen salt tolerant CIP (International Potato Centre) Potato genotypes along with BARI (Bangladesh Agricultural Research Institute) Alu 7 (Diamant) and one local variety viz., Dohazari Sada were evaluated at Bashkhali, Chittagong during 2011-12 to screen the suitable genotypes for cultivation in saline areas of Bangladesh. Diamant and Dohazari Sada and all of the CIP genotypes were found to grow well up to 60 DAP (Days After Planting) at saline areas having healthy plants and no senescence was noticed but after that 61-100% plants died due to high level of soil salinity (6.41dS/m) depending on genotypes. Genotype CIP 112 gave the highest yield (21.07 t/ha) and CIP 102 was comparatively less affected by soil salinity than the other genotypes. However, all the salt tolerant CIP genotypes were found to be promising in the saline soil. DOI: http://dx.doi.org/10.3329/agric.v11i1.15249 The Agriculturists 2013; 11(1) 95-102

scholarly journals The soil-adjusted vegetation index for soil salinity assessment in Uzbekistan

2020 ◽  
Vol 26 (3) ◽  
pp. 324-333
Author(s):  
Nozimjon Teshaev ◽  
Bunyod Mamadaliyev ◽  
Azamjon Ibragimov ◽  
Sayidjakhon Khasanov
Keyword(s):  
Soil Salinity ◽  
Information Technologies ◽  
Vegetation Index ◽  
Arable Land ◽  
Salt Content ◽  
Secondary Data ◽  
Soil Surface ◽  
Soil Salinization ◽  
Arid Zones ◽  
Agronomic Practices

Soil salinization, as one of the threats of land degradation, is the main environmental issue in Uzbekistan due to its aridic climate. One of the most vulnerable areas to soil salinization is Sirdarya province in Uzbekistan. The main human-induced causes of soil salinization are the insufficient operation of drainage and irrigation systems, irregular observations of the agronomic practices, and non-efficient on-farm water use. All of these causes considerably interact with the level of the groundwater, leading to an increase in the level of soil salinity. The availability of historical data on actual soil salinity in agricultural lands helps in formulating validated generic state-of-the-art approaches to control and monitor soil salinization by remote sensing and geo-information technologies. In this paper, we hypothesized that the Soil-Adjusted Vegetation Index-based results in soil salinity assessment give statistically valid illustrations and salinity patterns. As a study area, the Mirzaabad district was taken to monitor soil salinization processes since it is the most susceptible territory of Sirdarya province to soil salinization and provides considerably less agricultural products. We mainly formulated this paper based on the secondary data, as we downloaded satellite images and conducted an experiment against the in-situ method of soil salinity assessment using the Soil-Adjusted Vegetation Index. As a result, highly saline areas decreased by a factor of two during the studied period (2005–2014), while non-saline areas increased remarkably from a negligible value to over 10 000 ha. Our study showed that arable land suitability for agricultural purposes has been improving year by year, and our research held on this district also proved that there was a gradual decrease in high salt contents on the soil surface and land quality has been improved. The methodology has proven to be statistically valid and significant to be applied to other arid zones for the assessment of soil salinity. We assume that our methodology is surely considered as a possible vegetation index to evaluate salt content in arable land of either Uzbekistan or other aridic zones and our hypothesis is not rejected by this research.

scholarly journals Long-Term Amelioration Practices Reshape the Soil Microbiome in a Coastal Saline Soil and Alter the Richness and Vertical Distribution Differently Among Bacterial, Archaeal, and Fungal Communities

2022 ◽  
Vol 12 ◽  
Author(s):  
Ruibo Sun ◽  
Xiaogai Wang ◽  
Yinping Tian ◽  
Kai Guo ◽  
Xiaohui Feng ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Soil Salinity ◽  
Saline Soil ◽  
Saline Water ◽  
Soil Microbial Communities ◽  
Soil Microbiome ◽  
Economic Losses ◽  
Saline Water Irrigation ◽  
Coastal Saline Soil ◽  
Plastic Mulching

Globally soil salinity is one of the most devastating environmental stresses affecting agricultural systems and causes huge economic losses each year. High soil salinity causes osmotic stress, nutritional imbalance and ion toxicity to plants and severely affects crop productivity in farming systems. Freezing saline water irrigation and plastic mulching techniques were successfully developed in our previous study to desalinize costal saline soil. Understanding how microbial communities respond during saline soil amelioration is crucial, given the key roles soil microbes play in ecosystem succession. In the present study, the community composition, diversity, assembly and potential ecological functions of archaea, bacteria and fungi in coastal saline soil under amelioration practices of freezing saline water irrigation, plastic mulching and the combination of freezing saline water irrigation and plastic mulching were assessed through high-throughput sequencing. These amelioration practices decreased archaeal and increased bacterial richness while leaving fungal richness little changed in the surface soil. Functional prediction revealed that the amelioration practices, especially winter irrigation with saline water and film mulched in spring, promoted a community harboring heterotrophic features. β-null deviation analysis illustrated that amelioration practices weakened the deterministic processes in structuring coastal saline soil microbial communities. These results advanced our understanding of the responses of the soil microbiome to amelioration practices and provided useful information for developing microbe-based remediation approaches in coastal saline soils.

scholarly journals Soil salinization under different climate change scenarios: A global scale analysis

2021 ◽  
Author(s):  
Nima Shokri ◽  
Amirhossein Hassani ◽  
Adisa Azapagic
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
Soil Salinity ◽  
Global Scale ◽  
Soil Salinization ◽  
Water Evaporation ◽  
Climate Change Scenarios ◽  
Spatio Temporal ◽  
Salt Affected Soils

<p>Population growth and climate change is projected to increase the pressure on land and water resources, especially in arid and semi-arid regions. This pressure is expected to affect all driving mechanisms of soil salinization comprising alteration in soil hydrological balance, sea salt intrusion, wet/dry deposition of wind-born saline aerosols — leading to an increase in soil salinity. Soil salinity influences soil stability, bio-diversity, ecosystem functioning and soil water evaporation (1). It can be a long-term threat to agricultural activities and food security. To devise sustainable action plan investments and policy interventions, it is crucial to know when and where salt-affected soils occur. However, current estimates on spatio-temporal variability of salt-affected soils are majorly localized and future projections in response to climate change are rare. Using Machine Learning (ML) algorithms, we related the available measured soil salinity values (represented by electrical conductivity of the saturated paste soil extract, EC<sub>e</sub>) to some environmental information (or predictors including outputs of Global Circulation Models, soil, crop, topographic, climatic, vegetative, and landscape properties of the sampling locations) to develop a set of data-driven predictive tools to enable the spatio-temporal predictions of soil salinity. The outputs of these tools helped us to estimate the extent and severity of the soil salinity under current and future climatic patterns at different geographical levels and identify the salinization hotspots by the end of the 21<sup>st</sup> century in response to climate change. Our analysis suggests that a soil area of 11.73 Mkm<sup>2</sup> located in non-frigid zones has been salt-affected in at least three-fourths of the 1980 - 2018 period (2). At the country level, Brazil, Peru, Sudan, Colombia, and Namibia were estimated to have the highest rates of annual increase in the total area of soils with an EC<sub>e</sub> ≥ 4 dS m<sup>-1</sup>. Additionally, the results indicate that by the end of the 21<sup>st</sup> century, drylands of South America, southern and Western Australia, Mexico, southwest United States, and South Africa will be the salinization hotspots (compared to the 1961 - 1990 period). The results of this study could inform decision-making and contribute to attaining the United Nation’s Sustainable Development Goals for land and water resources management.</p><p>1. Shokri-Kuehni, S.M.S., Raaijmakers, B., Kurz, T., Or, D., Helmig, R., Shokri, N. (2020). Water Table Depth and Soil Salinization: From Pore-Scale Processes to Field-Scale Responses. Water Resour. Res., 56, e2019WR026707. https://doi.org/ 10.1029/2019WR026707</p><p>2. Hassani, A., Azapagic, A., Shokri, N. (2020). Predicting Long-term Dynamics of Soil Salinity and Sodicity on a Global Scale, Proc. Nat. Acad. Sci., 117, 52, 33017–33027. https://doi.org/10.1073/pnas.2013771117</p>

scholarly journals On the issue of chemical mechanism and soil salinity degree determination: Russian and foreign practices

2021 ◽  
Author(s):  
S. A. Manzhina ◽  
Keyword(s):  
Retrospective Analysis ◽  
Soil Salinity ◽  
Soil Degradation ◽  
Soil Salinization ◽  
Individual Characteristics ◽  
Chemical Mechanism ◽  
International Level ◽  
Salt Composition ◽  
Soil Salt

Purpose: analysis of the currently available approaches to determining the chemical mechanism and degree of soil salinity. In the course of research, the researches of Russian and foreign scientists, Russian and foreign methodological documents in the field of determining the degree and type of land salinization were studied. The methods of data analysis, processing and generalization were used. Discussion. The retrospective analysis of the Russian and foreign practices of assessing the degree and types of soil salt degradation was made by the author. The main indicators, assessed in the process of determining the degree and chemistry of soil salinization, as well as the methods for their determination, generally accepted in Russia and abroad, are given. Identification of these characteristics is of great importance in planning and carrying out reclamation activities aimed at increasing soil fertility, preventing soil degradation and loss of agricultural and commercial value. Conclusions. Based on a retrospective analysis of various possibilities for determining and classification of soil salt degradation, it was concluded that there are various methods oriented both to individual characteristics of soils in order to identify their unfavorable salt composition, and to different approaches to the procedures and methods of diagnosis. The main purpose of identifying the salt imbalance in agricultural lands composition is the possibility of preserving and improving their fertility, which, undoubtedly is carried out through reclamation measures in the case of their degradation. In order to develop uniformity in assessment and interpretation of data on the salt composition of soils, the degree of their salinity and the need for one or another type of reclamation work, it is necessary to develop a system of indicators based on the experience of Russian and foreign scientists with international practices. The development of the specified regulatory and methodological documentation should be focused on the international level, take into account all possible indicators affecting the accuracy of determination, excluding unnecessary details.

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