Tropical forests have been experiencing remarkable rates of transformation over the past century as they are getting degraded or decimated to a great extent by anthropogenic activities. This study aims at investigating the long-term forest cover transformation in Palamau Tiger Reserve (PTR), Jharkhand, India, using Landsat TM, ETM+, and OLI satellite images during 1975–2015. The forest cover was delineated utilizing various keys of visual interpretation techniques. The forest cover was primarily decreased in the north-eastern and north-western parts in PTR. In order to identify the anthropogenic disturbance in the forest reserve, human settlement density was mapped using high-resolution Google Earth imagery. The results showed a positive correlation between human population density and settlement density. Five major affected sites with an outer buffer of 2 km were demarcated in order to deduce the anthropogenic influences in major non-forested sites in PTR. It was observed that the forest change was maximum at site 3 (Ranidah, area 61.06 km2, − 6.47% change) followed by site 2 (Saidup, area 124.38 km2, − 7.65% change), where settlement units were also high (2638 and 2621 settlement units, respectively). At site 1 (Barkheta, area 81.59 km2), − 1.99% change was observed, and at site 4 (Samadh Tola, area 9.15 km2), 1.03% change was observed having moderate settlement units (2422 and 1892 settlement units, respectively). Areas with the low level of human settlements (1038 settlement units) observed the least change, i.e., at site 5 (Netarhat, area 48.52 km2), 0.58% change was observed mainly during the years. The forest cover exhibited an overall decrease of 14.55 km2 (− 1.34% change) with episodic variation during 1975–2015 in PTR, Eastern India. A significant forest disturbance occurred primarily in the north-eastern and north-western parts of PTR along the forest fringe due to the high population and settlement density. The study highlighted the potential use of freely available multi-temporal satellite observations in forest management.

中文翻译：

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遥感方法，评估印度东部帕拉毛老虎保护区森林覆盖的人为影响

在过去的一个世纪中，热带森林正经历着惊人的转化速度，这是由于人类活动在很大程度上使其退化或毁灭。这项研究旨在利用1975-2015年期间的Landsat TM，ETM +和OLI卫星图像，调查印度贾坎德邦帕拉毛老虎保护区（PTR）的长期森林覆盖率变化。利用各种视觉解释技术来描绘森林覆盖物。在PTR的东北和西北部分，森林覆盖率主要下降。为了识别森林保护区中的人为干扰，使用高分辨率的Google Earth影像绘制了人类住区密度图。结果表明，人口密度与定居密度呈正相关。划定了5个外部缓冲区2 km的主要受影响站点，以推断PTR主要非森林站点的人为影响。可以观察到，在站点3（拉尼达，面积61.06 km2，变化-6.47％）处森林变化最大，其次是站点2（Saidup，面积124.38 km2，-7.65％变化），其中定居单元也很高（2638和分别为2621个结算单位）。在站点1（Barkheta，面积81.59 km2），观察到-1.99％的变化，在站点4（Samadh Tola，面积9.15 km2），观察到1.03％的变化，具有中等沉降单元（分别为2422和1892个沉降单元）。人类住区水平低的地区（1038个定居单位）变化最小，即在站点5（内塔尔哈特，面积48.52 km2），主要是这些年来的0.58％变化。在印度东部的PTR，1975年至2015年间，森林覆盖率总体下降了14.55 km2（变化了1.34％）。由于人口和定居密度高，主要在PTR的东北和西北部沿森林边缘发生了严重的森林扰动。该研究强调了可免费获得的多时相卫星观测在森林管理中的潜在用途。