Papers by Alexey Terekhov
Cogent Engineering
The purpose of this article is the development and application of discrete differential geometry ... more The purpose of this article is the development and application of discrete differential geometry methods for digital image analysis within the framework of Topological Data Analysis (TDA). The proposed approach consists of two stages. First of all, topological invariants, Betti numbers, are extracted from the digital image using TDA algorithms. They contain information about the appearance and disappearance of topological properties: the connected components and holes when filtering the image along with the height of the photometric topography. The interval of heights measuring the lifetime of a property is called the persistence of the property. The most common information about Betti's persistent numbers is presented in the form of a cloud of points on the birth-death diagram, the so-called persistence diagram (PD). The vectorization of PD with the help of a diffuse kernel makes it possible to estimate its pdf. At the second stage, we use the representation of the received pdf on the Riemannian sphere. Here, the Fischer-Rao metric reduces to the Hilbert scalar product of semi-density on the tangent bundle of a sphere. This approach allows you to analyze images of complex, multicomponent natural systems that do not have clear spectral boundaries of the transition between texture classes. Space images of natural landscapes were used as digital images. We
E3S Web of Conferences
This paper considers the possibilities of assimilation of FEWS NET (Famine early Warning System N... more This paper considers the possibilities of assimilation of FEWS NET (Famine early Warning System Network) products in natural resource monitoring of the territory of Kazakhstan in the cold period. With an area of 2.7 million km2, Kazakhstan is located in the center of Eurasia in the arid zone, and snow is one of the most important water sources in the first half of the vegetation season. The products “Snow Depth”, “Temperature” and “Precipitation” developed for Central Asia are based on model meteorological data, including short-term weather forecasts. This information, presented in the form of regular matrices, has several advantages in efficiency and spatial detailing over direct ground (remote) measurements of meteorological parameters. The use of FEWS NET products for the environmental monitoring of the entire territory of Kazakhstan or its separate parts is of benefit for assessing the current situation on snow reserves, weather regimes and prospects for spring snowmelt.
E3S Web of Conferences
On the basis of long-term dynamics of the July’s vegetation data (NDVI and VCI indices) for 31 ra... more On the basis of long-term dynamics of the July’s vegetation data (NDVI and VCI indices) for 31 ranges of the Tien Shan and Jungarian Alatau arid mountains located in the Eurasia center are found the atmosphere stratification change. The variability of Atlantic Ocean water vapor transport ability over Northern Tien Shan ranges to the Inner Tien Shan was detected. This phenomenon not related to the overall seasonal humidity but is obviously associated with atmosphere stratification regimes. The analyzed period consists of two eras from 2002–2008 and 2008–2019 years, which differ in the regime of accessibility of the Inner Tien Shan ranges for water vapor from Atlantic Ocean. The overall tendency of the changes in 2002–2019 is the increase in the availability ocean water vapor to the Inner Tien Shan ranges. Recorded changes may be due to global air temperature increases and atmospheric processes intensification.
Estimation of weed infestation in spring crops using MODIS data
IGARSS 2003. 2003 IEEE International Geoscience and Remote Sensing Symposium. Proceedings (IEEE Cat. No.03CH37477), 2003
Spring crops are a monoculture in Northern Kazakhstan. Mid-resolution satellite data of red and n... more Spring crops are a monoculture in Northern Kazakhstan. Mid-resolution satellite data of red and near infrared spectral bands from Terra's MODIS satellite can be used for assessment of regional land use. The objective of this research was the analysis of weed infestation in spring grain crops. Weed infestation was classified into three categories, namely: minimum, average and maximum. The analysis
Frontiers of Earth Science, 2012
Sigificant dependence from climate and anthropogenic influences characterize ecological systems o... more Sigificant dependence from climate and anthropogenic influences characterize ecological systems of Kazakhstan. As result of the geographical location of the republic and ecological situation vegetative degradation sites exist throughout the territory of Kazakhstan. The major process of desertification takes place in the arid and semi-arid areas. To allocate spots of stable degradation of vegetation, the transition zone was first identified. Productivity of vegetation in transfer zone is slightly dependent on climate conditions. Multi-year digital maps of vegetation index were generated with NOAA satellite images. According to the result, the territory of the republic was zoned by means of vegetation productivity criterion. All the arable lands in Kazakhstan are in the risky agriculture zone. Estimation of the productivity of agricultural lands is highly important in the context of risky agriculture, where natural factors, such as wind and water erosion, can significantly change land quality in a relatively short time period. We used an integrated vegetation index to indicate land degradation measures to assess the inter-annual features in the response of vegetation to variations in climate conditions from lowresolution satellite data for all of Kazakhstan. This analysis allowed a better understanding of the spatial and temporal variations of land degradation in the country.
Agriculture land use recognition by multi-temporary middle resolution satellite data in Northern Kazakhstan
IEEE International Geoscience and Remote Sensing Symposium, 2002
Spring crops are a monoculture in Northern Kazakhstan. Mid-resolution satellite data of red and n... more Spring crops are a monoculture in Northern Kazakhstan. Mid-resolution satellite data of red and near infrared spectral bands from the Russian satellite, Resource MSU-SK and Terra's MODIS satellite can be used for assessment of regional landuse and land cover. The objective of this research is to improve the classification of spring crops, range and fallow land from mid-resolution satellites. The
Spring wheat quality estimation in Northern Kazakhstan using MODIS
Proceedings. 2005 IEEE International Geoscience and Remote Sensing Symposium, 2005. IGARSS '05., 2005
Yield forecast and grain quality is very important questions for republic economics and grain mar... more Yield forecast and grain quality is very important questions for republic economics and grain market. The method of crop state estimation and grain quality forecast using TERRA/MODIS data was developed. The most significant factors controllable by the satellite and determining grain quality are the crop rotation, planting date and weed infestation. On the base of ground surveys in 2004 correlation
Estimation of spring crops sowing calendar dates using MODIS in Northern Kazakhstan
Geoscience and Remote Sensing IEEE International Symposium, 2004
Sowing period for spring crop lasts usually more than 40 days in Northern Kazakhstan. Calendar da... more Sowing period for spring crop lasts usually more than 40 days in Northern Kazakhstan. Calendar dates of sowing are important for final crop productivity, which can be varied about 30% in relation to this factor. IMODIS data and ground survey in 2003 were used as the base for developing of cropland sowing date estimation procedure. Spectral characteristics of crop fields
E3S Web of Conferences
The aim of this research was the analysis of long-term and seasonal dynamics of Irrigation Coolin... more The aim of this research was the analysis of long-term and seasonal dynamics of Irrigation Cooling Effect (ICE) of irrigated arable lands in test sites of Kazakhstan and Uzbekistan in agriculture province “Golodnaya stepp”, located in transboundary River Syrdarya basin. The Land Surface Temperature (LST) FEWS NET (Famine early Warning System Network) product was used for calculation and monitoring (2002- 2019) ICE values. The amount and efficiency of irrigation water usage significantly affects the ICE values. Therefore, long-term (2002-2019) ICE monitoring on arable land Kazakhstan and Uzbekistan in “Golodnaya stepp” is important as an objective characteristic of irrigation parameters and their changes during the observation period. Analysis of data from 2002-2019 showed that in the key period (May-June) Uzbekistan's arable land is in a better position. Review of two eras 2003-2010 and 2011-2019 it showed that changes in ICE values are directed at: an increase in May, approxima...
Global Change Biology, 2015
A new 1 km global IIASA-IFPRI cropland percentage map for the baseline year 2005 has been develop... more A new 1 km global IIASA-IFPRI cropland percentage map for the baseline year 2005 has been developed which integrates a number of individual cropland maps at global to regional to national scales. The individual map products include existing global land cover maps such as GlobCover 2005 and MODIS v.5, regional maps such as AFRICOVER and national maps from mapping agencies and other organizations. The different products are ranked at the national level using crowdsourced data from Geo-Wiki to create a map that reflects the likelihood of cropland. Calibration with national and subnational crop statistics was then undertaken to distribute the cropland within each country and subnational unit. The new IIASA-IFPRI cropland product has been validated using very high-resolution satellite imagery via Geo-Wiki and has an overall accuracy of 82.4%. It has also been compared with the EarthStat cropland product and shows a lower root mean square error on an independent data set collected from Geo-Wiki. The first ever global field size map was produced at the same resolution as the IIASA-IFPRI cropland map based on interpolation of field size data collected via a Geo-Wiki crowdsourcing campaign. A validation exercise of the global field size map revealed satisfactory agreement with control data, particularly given the relatively modest size of the field size data set used to create the map. Both are critical inputs to global agricultural monitoring in the frame of GEOGLAM and will serve the global land modelling and integrated assessment community, in particular for improving land use models that require baseline cropland information. These products are freely available for downloading from the http://cropland.geo-wiki.org website.
During the Soviet Virgin Lands Campaign, approximately 23 million hectares (Mha) of Eurasian step... more During the Soviet Virgin Lands Campaign, approximately 23 million hectares (Mha) of Eurasian steppe grassland were converted into cropland in Northern Kazakhstan from 1954 to 1963. As a result Kazakhstan became an important breadbasket of the former Soviet Union. However, the collapse of the Soviet Union in 1991 triggered widespread agricultural abandonment, and much cropland reverted to grasslands. Our goal in this study was to reconstruct and analyze agricultural land-cover change since the eve of the Virgin Lands Campaign, from 1953 to 2010 in Kostanay Province, a region that is representative of Northern Kazakhstan. Further, we assessed the potential of currently idle cropland for re-cultivation. We reconstructed the cropland extent before and after the Virgin Lands Campaign using archival maps, and we mapped the agricultural land cover in the late Soviet and post-Soviet period using multi-seasonal Landsat TM/ETM+ images from circa 1990, 2000 and 2010. Cropland extent peaked at approximately 3.
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Papers by Alexey Terekhov