Wetland inventories especially on their spatial extent are a prerequisite for management and conservation of any wetland. The advancement in geospatial techniques has offered a wide range of methodological applications to prepare the inventories and to understand the dynamics of wetlands. The freely available Landsat imagery has been widely used in extracting spatial and temporal information about wetlands. The literature suggests that wetland has declined all over the globe over the past few decades. This study aims to prepare land use/land cover information of three wetlands of Punjab (Harike, Ropar, and Nangal) through direct on screen digitization and through digital processing using automatic digital indices as well. Evaluation of the performance of two band indices, normalized difference water index (NDWI) and modified normalized difference water index (MNDWI) is also taken up in the present study. Landsat data of two periods-1990/91 and of 2018 are used for the study to perform two band indices. The result indicates that the NDWI and MNDWI are less time consuming and serve the purpose of mapping and monitoring wetlands with higher accuracy.

中文翻译：

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使用地理空间技术绘制和监测印度旁遮普的选定湿地

湿地清查，特别是其空间范围，是管理和保护任何湿地的先决条件。地理空间技术的进步为编制清单和了解湿地动态提供了广泛的方法学应用。免费提供的 Landsat 影像已广泛用于提取有关湿地的时空信息。文献表明，在过去的几十年里，湿地在全球范围内都在减少。本研究旨在通过直接在屏幕上数字化和使用自动数字索引的数字处理来准备旁遮普省三个湿地（Harike、Ropar 和 Nangal）的土地利用/土地覆盖信息。评估两个波段指标的性能，本研究还采用归一化差异水指数（NDWI）和修正归一化差异水指数（MNDWI）。本研究使用 1990/91 年和 2018 年两个时期的 Landsat 数据执行两个波段指数。结果表明，NDWI 和 MNDWI 耗时较少，可以更准确地绘制和监测湿地。