1,721,288 research outputs found
Spatiotemporal trends of forest cover change in Southeast Asia
No full text© 2010, Springer-Verlag Berlin Heidelberg. The current state of tropical forest cover and its change have been identified as key variables in modelling and measuring the consequences of human action on ecosystems. The conversion of tropical forest cover to any other land cover (deforestation) directly contributes to the two main environmental threats of the recent past: 1) the alteration of the global climate by the emission of carbon to the atmosphere and 2) the decline in tropical biodiversity by land use intensification and habitat conversion. The sub-continent of Southeast Asia exhibits one of the highest rates of forest loss and comprises one of the regions with the highest amount and diversity of flora and fauna species, worldwide. The knowledge of the spatial and temporal trends in the variation of forest cover in tropical regions is a prerequisite for the development and establishment of mitigation strategies from the global to the regional level. However, there is considerable disagreement in recent estimates of tropical forest cover change ranging from continuing and intensified decline in forest loss to a distinct decrease in deforestation rates and up to stagnation in other cases. Against this background, the present study aims at a review and comparison of recently available global forest cover estimates for the region of Southeast Asia. In a case study, the results at the national level will be compared to an analysis at the regional level for the island of Sulawesi, Indonesia. The outcome of the study provides recommendations for future remote sensing based forest assessments in tropical regions
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Pengembangan sistem informasi prediksi laju erosi Berbasis web
Full text linkErosion is one of the parameters for the assessment of degraded land and the information of erosion in an area can be used as guidelines for land rehabilitation. The erosion can be predicted within Web-GIS which is integrated in the internet. The objectives of this study are to develop a Web-GIS based information system for predicting the rate of erosion, and to validate the system to calculate the rate of erosion in selected region. The system is built using open source software Mapserver and PostreSQL /PostGIS as Database Management System Software (DBMS) to store the spatial database. The programming language used in the development of the system includes PHP (PHP Hypertext Preprocessor), HTML (HyperText Markup Language) and Javascript. Framework ExtJS, OpenLayers, GeoExt and Mapfish is used to help creating the common functions and web interface
Identifikasi Kekeringan Padi Sawah dengan Indeks NDDI dan Indeks VHI dari Citra Landsat 8 di Kabupaten Indramayu
No full textKejadian El Nino menyebabkan kekeringan yang luar biasa di Indonesia.
Kekeringan merupakan kondisi kekurangan air pada suatu wilayah dalam periode
waktu yang cukup panjang akibat kurangnya curah hujan. Indeks kekeringan
merupakan salah satu sistem monitoring kekeringan yang dapat menghasilkan
peringatan dini akan terjadinya atau berakhirnya suatu fenomena kekeringan.
Penelitian ini bertujuan untuk mengidentifikasi kekeringan padi sawah dan untuk
menduga luas sawah yang terdampak kekeringan dengan menggunakan citra
Landsat 8. Citra Landsat 8 akuisisi Mei – September 2015 dilakukan koreksi
radiometrik, stacking dan transformasi indeks kekeringan untuk menentukan
tingkat kekeringan. Hasil penelitian menunjukan bahwa sawah yang terdampak
kekeringan memiliki pola fase tumbuh dan indeks kekeringan yang berbeda dengan
sawah sehat. Luas wilayah yang terdampak kekeringan pada September 2015 di
Kabupaten Indramayu dengan menggunakan indeks NDDI diduga mencapai 33.876
Ha, sedangkan dengan indeks VHI diduga mencapai 32.650 Ha
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
2019
No full textIndonesia merupakan salah satu negara yang sering terdampak kekeringan,
terutama pada penggunaan lahan sawah. Berdasarkan data dari Balai Besar
Penelitian Tanaman Padi (BBPTP), pada tahun 2015 terdapat lebih dari 10.000 ha
sawah yang terdampak kekeringan di Provinsi Jawa Barat, dimana Kabupaten
Subang yang menjadi salah satu penghasil produksi terbesar, juga terdampak
kekeringan sawah. Penelitian ini bertujuan mengidentifikasi dan mengetahui
dugaan luas kekeringan sawah menggunakan citra Landsat 8 di Kabupaten Subang.
Penelitian difokuskan pada analisis indeks kekeringan sawah menggunakan data
penginderaan jauh. Metode yang digunakan yaitu Normalized Difference Drought
Index (NDDI) yang dihitung berdasarkan indeks vegetasi NDVI dan indeks
kebasahan vegetasi NDWI, serta metode Vegetation Health Index (VHI) yang
mengacu pada indeks vegetasi EVI dan suhu permukaan lahan LST. Hasil dari
penelitian ini berupa peta sebaran kekeringan dan luas dugaan kekeringan sawah di
Kabupaten Subang. Berdasarkan transformasi, pada bulan Agustus didapatkan luas
dugaan kekeringan sawah 7.855 ha menggunakan indeks NDDI dan 7.939 ha
menggunakan indeks VHI
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Deteksi Perubahan Penggunaan Lahan Di Kabupaten Lampung Barat
No full textPerubahan penggunaan lahan merupakan suatu proses perubahan dari penggunaan lahan sebelumnya ke penggunaan lahan lain yang bersifat permanen maupun sementara dan dapat berdampak positif maupun negatif. Tujuan dari penelitian ini adalah mengetahui pola penggunaan lahan dan perubahannya pada periode 2000-2010 dan prediksi penggunaan lahan Kabupaten Lampung Barat tahun 2030 dengan metode Artificial Neural Network (ANN) serta melihat ketidakselarasan alokasi pemanfaatan lahan RTRWK terhadap penggunaan lahan. Perubahan penggunaan lahan pada periode 2000-2010 menunjukkan bahwa hutan lahan kering primer berkurang drastis seluas 15.578 ha, sementara pertanian lahan kering campur semak bertambah seluas 25.943 ha. Prediksi penggunaan lahan tahun 2030 menggunakan ANN mengindikasikan bahwa terjadi penurunan luas penggunaan lahan hutan lahan kering primer (26.118 ha), belukar (17.624 ha), hutan lahan kering sekunder (798 ha), belukar rawa (294 ha), rumput (87 ha ) dan tanah kosong (85 ha), sedangkan pertambahan luas terjadi pada penggunaan lahan pertanian lahan kering campur semak (42.966 ha), pertanian lahan kering (1.296 ha), pemukiman (582 ha) dan sawah (162 ha). Analisis ketidakselarasan penggunaan lahan menghasilkan bahwa terdapat 197.709 ha (39,42%) penggunaan lahan di tahun 2030 tidak selaras terhadap peruntukan lahan dalam RTRWK. Ketidakselarasan pemanfaatan lahan terbesar terjadi di peruntukan Taman Nasional Bukit Barisan Selatan (TNBBS) sebesar 94.796 ha (18,90%)
From global to regional scale: Remote sensing-based concepts and methods for mapping land-cover and land-cover change in tropical regions
No full textA great number of studies have been dealing with land-cover mapping of tropical regions using earth remote sensing technology recently. This is partly due to a growing number of operational sensor systems for both scientific and commercial use and also because of an increasing demand for land-cover information relevant to global environmental issues and international policy instruments (e.g. the Kyoto protocol). Within this context, the present article discusses the state of the art of data processing and analysis for the assessment of broad scale land-cover and land-cover change in tropical regions. Current global scale land-cover maps are compared with regional satellite mapping products (Landsat/ETM+) for a test region in the humid tropics of Central Sulawesi, Indonesia. The paper suggests the land cover classification system (LCCS) to be used as the conceptual basis for future land-cover analysis in Sulawesi because it delivers a consistent and comparable scale-independent class structure for satellite image-based land-cover mapping and monitoring. The results of the comparative analysis of land-cover and land-cover change document the inhomogeneity, inconsistency and hence high uncertainty of existing estimates. The outcome of the harmonized and generalized land-cover products for two base years (1992 and 2000) indicates considerable disagreements in area estimates and spatial distributions of land-cover classes for a single date that in some cases exceed the detectable changes between years. Future work aiming at a long-scale operational land-cover mapping of tropical environments has to account for (a) a further harmonization of existing and planned land-cover definitions and products, (b) the regional validation of products and (c) the implementation of a multi-level standardized technical and conceptual classification workflow for ecosystem mapping and monitoring in tropical regions
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