Bartold Maciej, Wróblewski Konrad, Kluczek Marcin, Dąbrowska-Zielińska Katarzyna, Goliński Piotr
Remote Sensing Centre, Institute of Geodesy and Cartography, Modzelewskiego 27, 02-679 Warsaw, Poland.
Department of Grassland and Natural Landscape Sciences, Poznań University of Life Sciences, Dojazd 11, 60-632 Poznań, Poland.
Plants (Basel). 2024 Aug 20;13(16):2319. doi: 10.3390/plants13162319.
In this study, the emphasis is on assessing how satellite-derived vegetation indices respond to drought stress characterized by meteorological observations. This study aimed to understand the dynamics of grassland vegetation and assess the impact of drought in the Wielkopolskie (PL41) and Podlaskie (PL84) regions of Poland. Spatial and temporal characteristics of grassland dynamics regarding drought occurrences from 2020 to 2023 were examined. Pearson correlation coefficients with standard errors were used to analyze vegetation indices, including NDVI, NDII, NDWI, and NDDI, in response to drought, characterized by the meteorological parameter the Hydrothermal Coefficient of Selyaninov (HTC), along with ground-based soil moisture measurements (SM). Among the vegetation indices studied, NDDI showed the strongest correlations with HTC at r = -0.75, R = 0.56, RMSE = 1.58, and SM at r = -0.82, R = 0.67, and RMSE = 16.33. The results indicated drought severity in 2023 within grassland fields in Wielkopolskie. Spatial-temporal analysis of NDDI revealed that approximately 50% of fields were at risk of drought during the initial decades of the growing season in 2023. Drought conditions intensified, notably in western Poland, while grasslands in northeastern Poland showed resilience to drought. These findings provide valuable insights for individual farmers through web and mobile applications, assisting in the development of strategies to mitigate the adverse effects of drought on grasslands and thereby reduce associated losses.
在本研究中，重点是评估卫星衍生的植被指数如何响应以气象观测为特征的干旱胁迫。本研究旨在了解波兰大波兰省（PL41）和 Podlaskie 省（PL84）草地植被的动态变化，并评估干旱的影响。研究了 2020 年至 2023 年干旱发生期间草地动态的时空特征。使用带有标准误差的皮尔逊相关系数来分析植被指数，包括归一化植被指数（NDVI）、归一化差异红外指数（NDII）、归一化差异水体指数（NDWI）和归一化差异干旱指数（NDDI），以响应以谢良尼诺夫水热系数（HTC）这一气象参数为特征的干旱，同时结合地面土壤湿度测量（SM）。在所研究的植被指数中，NDDI 与 HTC 的相关性最强，r = -0.75，R = 0.56，均方根误差（RMSE） = 1.58；与 SM 的相关性为 r = -0.82，R = 0.67，RMSE = 16.33。结果表明，2023 年大波兰省草地存在干旱严重情况。NDDI 的时空分析表明，在 2023 年生长季的最初几十年里，约 50%的田地面临干旱风险。干旱状况加剧，特别是在波兰西部，而波兰东北部的草地对干旱具有韧性。这些发现通过网络和移动应用程序为个体农民提供了有价值的见解，有助于制定策略减轻干旱对草地的不利影响，从而减少相关损失。
