MODEL PENDUGAAN DIAMETER POHON BERBASIS CITRA UNMANNED AERIAL VEHICLE (UAV) PADA HUTAN HUJAN TROPIS PAPUA: STUDI DI PULAU MANSINAM PAPUA BARAT (Model of Tree Diameter Estimation Based on Unmanned Aerial Vehicle (UAV) Image in Papua Tropical Rain Forest: a Study in Mansinam Island Papua Barat)

Abstract

Unmanned aerial vehicles (UAV) have often been used for various purposes, not only for photography but also have been used for science in various scientific fields, including forestry. UAV has the ability to move freely in the air and record objects on the ground with high spatial resolution and wide area coverage. This study aimed to estimate the diameter at breast height (DBH) based on the image generated from the UAV. UAV was used to obtain aerial photographs taken at an altitude of 150 m above the land surface in four sample areas of 27 ha at the study site. Aerial photos were processed using agisoft photoscan software to produce a Digital Elevation Model (DEM) and orthophoto. Tree crowns were delineated from orthophoto and analyzed to obtain crown area and diameter. DBH measurements in the field were carried out on 206 sample trees used to build a DBH estimator model. The correlation test results showed that the crown diameter has a high correlation with DBH so that this variable was used as an independent variable. The best DBH estimator model was the polynomial model with the equation y = 0.0118744 x² + 1.08835 x + 22.8125, where y is DBH and x is the canopy diameter of the aerial photo interpretation results. Estimating DBH using UAV has several benefits, such as reducing time, cost and labour. Abstrak Unmanned aerial vehicle (UAV) sudah sering digunakan untuk berbagai tujuan, bukan hanya untuk fotografi, namun telah dimanfaatkan untuk sains di berbagai bidang keilmuan, termasuk bidang kehutanan. UAV memiliki kemampuan bergerak dengan bebas di udara dan merekam objek di darat dengan resolusi spasial tinggi, dan cakupan areal yang luas. Penelitian ini bertujuan untuk melakukan pendugaan diameter setinggi dada (DBH) berdasarkan citra yang dihasilkan dari UAV. UAV digunakan untuk memperoleh foto udara yang diambil pada ketinggian 150 m di atas permukaan darat pada empat areal sampel seluas 27 ha di lokasi penelitian. Foto udara diproses dengan menggunakan perangkat lunak agisoft photoscan untuk menghasilkan Digital Elevation Model (DEM) dan ortofoto. Tajuk pohon dideliniasi dari ortofoto dan dianalisis untuk memperoleh luas dan diameter tajuk. Pengukuran DBH di lapangan dilakukan terhadap 206 pohon sampel yang selanjutnya digunakan untuk membangun model penduga DBH. Hasil uji korelasi menunjukkan bahwa diameter tajuk mempunyai korelasi yang tinggi dengan DBH sehingga variable ini digunakan sebagai variable bebas. Model terbaik penduga DBH adalah model polinomial dengan persamaan y = 0,0118744 x² + 1,08835 x + 22,8125, dengan y adalah DBH dan x adalah diameter tajuk hasil interpretasi foto udara. Pendugaan DBH menggunakan UAV memiliki beberapa manfaat seperti mampu mengurangi waktu, biaya dan tenaga kerja.

Floristic richness and diversity of Bintuni mangrove, Bird's Head Peninsula, West Papua, Indonesia

“…For that reason, regular monitoring of vegetation richness is important since the Bintuni mangrove does not have a significant threat like massive conversion of mangrove (Richards and Friess 2016;Sarker et al 2019;Hagger et al 2022;Sasmito et al 2023). The monitoring can be done through recent technology, such as online and unmanned-aerial vehicles, as done by some publications applying NDVI and other vegetation indexes (Hematang et al 2021(Hematang et al , 2022Manuputty 2022). We proposed that future research not only focus on vegetation but also species richness and diversity of wildlife since the mangrove forest, especially the Bintuni mangrove, functions as the habitat of other organisms and is part of the food chain in the ecotone ecosystem.…”