Perubahan Muara Bodri Periode 1972-2017 Diinterpretasi pada Citra Landsat, dan Pengaruhnya Terhadap Pantai Kendal

Dataran Kendal mempunyai peran sangat penting dalam transportasi di pantai utara Jawa Tengah, sehingga infrastruktur dan populasi daerah ini berkembang dengan cepat. Lima sungai utama mengalir di Dataran Kendal, yaitu Sungai Bodri, Sungai Cangkring, Sungai Blukar, Sungai Damar, dan Sungai Koto. Sungai Bodri mempunyai daerah aliran sungai (DAS) paling luas, dengan perkembangan sangat dinamis. Data penginderan jauh sangat efektif digunakan untuk monitoring permukaan bumi, baik lokal maupun regional. Untuk mengetahui perubahan Delta Bodri digunakan Citra Landsat, yang meliputi citra landsat Multispectral Scanner (MSS) tahun 1972, citra landsat Thematic Mapper (TM) tahun 1992, citra Landsat Enhance Thematic Mapper+ (ETM+) tahun 2001, dan citra Landsat Data Continuity Mission (LDCM) tahun 2017. Citra MSS dan TM dilakukan koreksi geometri, sedangkan citra lainnya sudah mempunyai titik kontrol secara otomatis. Pantai dan sungai diinterpretasi pada setiap citra di layar komputer, hasilnya ditumpang-tindihkan dan perbedaannya dianalisis secara ilmiah. Pada citra Landsat MSS, tampak Muara Bodri bercabang dua, yaitu Sungai Badri dan Sungai Kenceng, yang masing-masing membentuk delta cuspate. Penampakan citra Landsat TM menunjukkan Sungai Bodri sudah bermeander, dan muara sungai agak menjorok ke laut. Sementara itu, muara Sungai Bodri pada citra Landsat ETM+ menjorok ke baratlaut dan membentuk delta kerucut, sedangkan pada citra LDCM sungai ini berbelok ke utara, dan muara sungai menghadap relatif ke utara. Muara Sungai Badri warnanya makin pekat, yang ditunjukkan oleh warna putih pekat, mengidentifikasikan suplai material sungai bertambah. Sebaran pengendapan suspended material makin meluas, menunjukkan energi di laut makin besar. Perubahan Muara Bodri dipengaruhi oleh kondisi DAS Badri Hulu (batuannya mudah tererosi, dipicu oleh tutupan lahan terbuka dan curah hujan tinggi); dan energi laut berupa gelombang barat, yang dipengaruhi oleh pemanasan global.Katakunci: Muara Bodri, citra landsat, periode 1972-2017,perkembangan Pantai Kendal.

Shoreline Changes Along the Coast of Mainland China—Time to Pause and Reflect?

Shoreline changes are of great importance for evaluating the interaction between humans and ecosystems in coastal areas. They serve as a useful metric for assessing the ecological costs of socioeconomic developmental activities along the coast. In this paper, we present an assessment of shoreline changes along the eastern coast of mainland China from ~1990 to 2019 by applying a novel method recently developed by us. This method which we call the Nearest Distance Method (NDM) is used to make a detailed assessment of shorelines delineated from Landsat Thematic Mapper (TM) and Operational Land Imager (OLI) images. The results indicate a dramatic decline in natural shorelines that correspond to the rapid increase in the construction of artificial shorelines, driven by China’s economic growth. Of the entire coast of mainland China, the biggest change occurred along the Bohai Sea, where artificial shorelines expanded from 42.4% in ~1990 to 81.5% in 2019. Over this period, this study indicates that China lost > 60% of its biological shorelines, a trend that is especially worrisome because these include areas that were once biologically diverse and extremely rich. As anticipated, shoreline losses were greatest where regions of low economic value had been transformed to areas of higher economic value. Overall, this influence of human activities on shorelines in China is unprecedented. The repercussions of these changes on ecosystems, and the susceptibility of new shoreline developments to population growth and sea-level rise, need to be assessed urgently before additional changes are effected.

Multisource classification for land-use mapping based on spectral, textural, and terrain information using landsat thematic mapper imagery: A Case Study of Semarang-Ungaran Area, Central Java

Automatic classification of remotely sensed digital data is recognised as a robust and efficient method for mapping various land-cover types over a large area. However when more abstract concept such as land-use is required the automatic classification methods cannot be fully useful. This is due to the fact that land-use is related to various landscape factors, and cannot be mapped merely based on its spectral reflectance. This study tried to develop a knowledge-based technique that incorporates textural and terrain information of the image scene into a spectral-based decision making process for land-use labelling. To do so. six reflective hands of Landsat Thematic Mapper (TM) covering Semarang-Ungaran area. Central Java, were used. In addition, all bands were then be filtered using the so-called textural filter, which can accentuate several statistical parameters within a given window. .1 variance parameter was chosen in order to extract heterogeneity within every 7x7 pixels. and the l'ariance values of the whole image dalaset were then stored as a set of texture-filtered bands. Three bands with the lowest 'between-band correlations' were chosen and added to the reflective bands. Based on the nine-layer image dataset, a standard multispectral classification using maximum likelihood algorithm was run. Parallel to this process, a visual interpretation using heads-up digitisation was carried out in order to generate a terrain unit map containing land characteristics relevant to spatial distribution of the land-use in the study area. Finally. the terrain unit map was superimposed with the tentative land-corer map derived from the multispectral classification process. A final land-use map was generated from the nnthisource data integration, controlled by a formalised knowledge about ecological relationship between land-cover. land-use, and land characteristics exist in the field. It was found that the overall accuracy level of the final land-use map is higher as compared to the result generated from six-band classification. However, the use of textural filter also created an 'edge-effect', which shows misclassified pixels alongside the borders of particular land-use categories. The edge-effect also leads to lower accuracy levels for the corresponding land-use categories. In addition, based on the research findings, further research agenda was also set up.

Spatio-temporal environmental characterization of the Pontal River Basin in the State of Pernambuco

As zonas rurais e urbanas estão passando por transformações do uso do solo de forma significativa. Estas mudanças têm afetado o uso da terra, principalmente nas áreas marginas às urbanas. É ao longo destas áreas onde o processo de expansão urbana entra em conflito com o uso da terra para fins agrícolas. Um recurso inestimável neste contexto é o sensoriamento remoto, que aparece como uma ferramenta de avaliação dos processos de transformação territórial. Técnicas de observação de dados adquiridos por satélites em variação temporal e espacial possuem potencial de detectar, identificar e mapear as mudanças no uso da terra. O objetivo do trabalho foi realizar uma caracterização atual do uso da terra e análise espaço-temporal das modificações ao longo dos períodos de 2000 a 2010, 2010 a 2015 e 2000 a 2015, na Bacia do Rio Pontal, usando dados Landsat Thematic Mapper (TM). De acordo com os resultados obtidos, pode-se concluir que na região estudada houve um crescimento considerável de área destinada à agricultura irrigada, redução das áreas de caatinga densa ou substituição da mesma por caatinga aberta e solo exposto e por fim se observou a redução dos corpos hídricos da região.

Inversion of Lake Bathymetry through Integrating Multi-Temporal Landsat and ICESat Imagery

Lake bathymetry provides valuable information for lake basin planning and treatment, lake watershed erosion and siltation management, water resource planning, and environmental protection. Lake bathymetry has been surveyed with sounding techniques, including single-beam and multi-beam sonar sounding, and unmanned ship sounding. Although these techniques have high accuracy, most of them require long survey cycles and entail a high degree of difficulty. On the contrary, optical remote sensing inversion methods are easy to implement, but tend to provide less accurate bathymetry measures, especially when applied to turbid waters. The present study, therefore, aims to improve the accuracy of bathymetry measurements through integrating Landsat Thematic Mapper imagery, the Ice, Cloud, and Land Elevation Satellite’s Geoscience Laser Altimeter System (ICESat/GLAS) data, and water level data measured at hydrological stations. First, the boundaries of a lake at multiple dates were derived using water extraction, initial boundary extraction, and Landsat Thematic Mapper/Enhanced Thematic Mapper (TM/ETM+) strip removal processing techniques. Second, ICESat/GLAS data were introduced to obtain additional topographic information of a lake. The striped topography of a lake’s area was then obtained through eliminating and correcting erroneous points and interpolating the values of unknown points. Third, the entire bathymetry of the lake was obtained through interpolating water level values of lake boundary points in various dates. Experiments show that accurate bathymetry (±1 m) can be successfully derived.

Caracterização ambiental espaço-temporal da Bacia Hidrográfica do Rio Pontal no Estado de Pernambuco

As zonas rurais e urbanas estão passando por transformações do uso do solo de forma significativa. Estas mudanças têm afetado o uso da terra, principalmente nas áreas marginas às urbanas. É ao longo destas áreas onde o processo de expansão urbana entra em conflito com o uso da terra para fins agrícolas. Um recurso inestimável neste contexto é o sensoriamento remoto, que aparece como uma ferramenta de avaliação dos processos de transformação territórial. Técnicas de observação de dados adquiridos por satélites em variação temporal e espacial possuem potencial de detectar, identificar e mapear as mudanças no uso da terra. O objetivo do trabalho foi realizar uma caracterização atual do uso da terra e análise espaço-temporal das modificações ao longo dos períodos de 2000 a 2010, 2010 a 2015 e 2000 a 2015, na Bacia do Rio Pontal, usando dados Landsat Thematic Mapper (TM). De acordo com os resultados obtidos, pode-se concluir que na região estudada houve um crescimento considerável de área destinada à agricultura irrigada, redução das áreas de caatinga densa ou substituição da mesma por caatinga aberta e solo exposto e por fim se observou a redução dos corpos hídricos da região.

THE USE OF ARCHIVAL LAND SURVEY DATA AT STUDY THE STATUS OF AGRICULTURAL LAND ACCORDING TO REMOTE SENSING

The state data funds have a huge database of various land management information on the entire territory of the Russian Federation. This database requires constant updating and is now significantly outdated. In most regions, not inventory of agricultural land, there are no actual data about their qualitative, quantitative condition is not carried out soil, and geobotanical surveys, are not updated thematic maps of the status and use of lands. The article shows the possibility of joint application of the results of soil, geobotanical surveys and planning and cartographic materials with archival data of Landsat satellites. The features of identifying the processes of overgrowth of agricultural land according to the sensor Landsat Thematic Mapper are analyzed. The technology of accounting for the vegetation period in the recognition of agricultural land on satellite images is demonstrated.

Glacier changes between 1971 and 2016 in the Jankar Chhu Watershed, Lahaul Himalaya, India

ABSTRACTGlacier changes in the Jankar Chhu Watershed (JCW) of Chandrabhaga (Chenab) basin, Lahaul Himalaya were worked out based on Corona and Sentinel 2A images between 1971 and 2016. The JCW consists of 153 glaciers (>0.02 km2) with a total area of 185.6 ± 3.8 km2that include 82 glaciers with debris-covered ablation zone, comprising 10.9% of the total glacierized area as in 2016. Change analysis based on Corona (1971), Landsat (2000) and Sentinel 2A (2016) was restricted to 127 glaciers owing to the presence of cloud cover on 26 glaciers in 1971. A subset of glaciers was also mapped using Landsat Thematic Mapper (TM; 1989) image. The total glacier area decreased by 14.7 ± 4.3 km2(0.3 ± 0.1 km2a−¹). The number of glaciers in the JCW increased by four between 1971 and 2016 due to fragmentation. More recently (2000–16), recession rate has increased. Clean-ice area decreased by 21.8 ± 3.8 km2(0.5 ± 0.1 km2a−¹) while debris-covered ice increased by 7.2 ± 0.4 km2(0.2 ± 0.01 km2a−¹). Field observations of select glaciers also support derived recession trend in the JCW. Retreat rates in the JCW have been observed to be much lower than previously reported.

SUBTYPE COASTLINE DETERMINATION IN URBAN COAST BASED ON MULTISCALE FEATURES: A CASE STUDY IN TIANJIN, CHINA

In urban coast, coastline is a direct factor to reflect human activities. It is of crucial importance to the understanding of urban growth, resource development and ecological environment. Due to complexity and uncertainty in this type of coast, it is difficult to detect accurate coastline position and determine the subtypes of the coastline. In this paper, we present a multiscale feature-based subtype coastline determination (MFBSCD) method to extract coastline and determine the subtypes. In this method, uncertainty-considering coastline detection (UCCD) method is proposed to separate water and land for more accurate coastline position. The MFBSCD method can well integrate scale-invariant features of coastline in geometry and spatial structure to determine coastline in subtype scale, and can make subtypes verify with each other during processing to ensure the accuracy of final results. It was applied to Landsat Thematic Mapper (TM) and Operational Land Imager (OLI) images of Tianjin, China, and the accuracy of the extracted coastlines was assessed with the manually delineated coastline. The mean ME (misclassification error) and mean LM (Line Matching) are 0.0012 and 24.54 m respectively. The method provides an inexpensive and automated means of coastline mapping with subtype scale in coastal city sectors with intense human interference, which can be significant for coast resource management and evaluation of urban development.