Faculty of Natural Resources, University of Tehran, Karaj, Iran.
College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran.
Environ Monit Assess. 2021 Apr 24;193(5):299. doi: 10.1007/s10661-021-09078-y.
Soil moisture, vegetation cover, and land surface temperature are vital variables in water-energy balance, eco-hydrological processes, and water resources management, which can be influenced by watershed management activities. This research focused on the spatial and temporal variability of soil moisture, vegetation cover, land surface temperature, and Temperature-Vegetation Dryness Index (TVDI) under a biological watershed management practice in the Taleghan paired watershed, namely, treated (TW) and control watersheds (CW), in Alborz province, Iran. In this research, along with the remote sensing techniques, the soil moisture and vegetation cover data were measured and statistically analyzed in the three aspects of both TW and CW during a growth period from May to October 2017. The results indicated that soil moisture, vegetation cover, and land surface temperature values in the paired watershed were significantly different at the 0.01 level during the study period. The increased vegetation cover in the TW had an inverse effect on the land surface temperature and TVDI, while directly impacted the soil moisture content. The average TVDI in the CW was 0.83, while this index was found to be 0.69 in the TW. Unlike the vegetation cover and soil moisture, the results revealed that the southern aspects had the highest TVDI and land surface temperature compared to the northern and eastern aspects of both watersheds. However, the increased vegetation cover as a biological watershed management activity in the steep terrain and mountainous areas of TW led to an increased soil moisture and a decreased land surface temperature and soil dryness. As a result, decreasing soil dryness in the TW can exert vital controls on the water resources and increasing water availability. In the arid and semiarid countries such as Iran, a proper watershed management activity can effectively increase soil moisture and water availability in the watersheds. In particular, the vegetation cover protection and biological practices can be considered as practical solutions in the rehabilitation of exhausted watersheds in arid and semiarid environments.
土壤湿度、植被覆盖和地表温度是水-能量平衡、生态水文学过程和水资源管理中的重要变量，这些变量可能受到流域管理活动的影响。本研究聚焦于伊朗阿尔博兹省塔勒甘配对流域（即处理流域 TW 和对照流域 CW）中生物流域管理实践下土壤湿度、植被覆盖、地表温度和温度植被干燥指数（TVDI）的时空变化。在这项研究中，除了遥感技术外，还在 2017 年 5 月至 10 月的生长期间，从三个方面对 TW 和 CW 的土壤湿度和植被覆盖数据进行了测量和统计分析。结果表明，在研究期间，配对流域的土壤湿度、植被覆盖和地表温度值在 0.01 水平上有显著差异。TW 中增加的植被覆盖对地表温度和 TVDI 有反作用，而直接影响土壤湿度。CW 的平均 TVDI 为 0.83，而 TW 的这一指数为 0.69。与植被覆盖和土壤湿度不同，结果表明，与两个流域的北部和东部相比，南部地区的 TVDI 和地表温度最高。然而，TW 陡峭地形和山区的生物流域管理活动增加了植被覆盖，导致土壤湿度增加，地表温度和土壤干燥度降低。因此，TW 土壤干燥度的降低可以对水资源和增加水的可用性产生重要控制作用。在伊朗等干旱和半干旱国家，适当的流域管理活动可以有效地增加流域的土壤湿度和水的可用性。特别是在干旱和半干旱环境中，保护植被和生物实践可以被视为枯竭流域恢复的实用解决方案。
