Department of Watershed Management Engineering, Faculty of Natural Resources, Member of Agrohydrology Group, Tarbiat Modares University, Noor 4641776489, Mazandaran Province, Iran.
Watershed Management Sciences and Engineering, Department of Watershed Management Engineering, Faculty of Natural Resources, Tarbiat Modares University, Iran.
Sci Total Environ. 2019 Jan 15;648:880-893. doi: 10.1016/j.scitotenv.2018.08.004. Epub 2018 Aug 8.
The current study aimed to comprehensively assess the potential watershed health (WH) using an adapted reliability, resilience and vulnerability (RRV) framework for the 24 sub-watersheds of Shazand, Markazi Province, Iran. Towards this goal, the appropriate criteria and acceptable corresponding thresholds were adapted to calculate the main WH indictors of reliability (R), resilience (R) and vulnerability (V). Accordingly, the RRV framework was conceptualized and customized for five criteria of standardized precipitation index (SPI), normalized difference vegetation index (NDVI), soil erosion, and low and high flow discharges. The effect sizes of used criteria and indicators on the Shazand WH status were also determined. Consequently, the status of R, R and V indicators and integrated WH status were mapped for four years of 1986, 1998, 2008 and 2014 and for the whole watershed by developing an integrated watershed health index (IWHI). Finally, the change detection approach was applied to determine the trend of changes in IWHI during last three decades. The results approved the high variability in effectability of R, R and V indicators and integrated health status of the Shazand Watershed from the selected criteria in study four years. The results revealed that in the all study years, the R indicator almost had the higher contribution rate (≥34%) in the Shazand WH. None of sub-watersheds in the study years were assessed in a healthy status in terms of IWHI based on the RRV framework. In terms of WH change detection over the study periods, WH was found to declining by some 4% in the periods of 1986-1998 and 1986-2008 due to impact of industrialization and urban development. Whilst, the health status was non-significantly improved in other study periods. The present procedure can be supposed as a screening tool for a directive and efficient management of the watersheds.
本研究旨在综合评估伊朗马赞德兰省沙赞德的 24 个次流域的潜在流域健康状况（WH），采用了适应性可靠性、弹性和脆弱性（RRV）框架。为此，适应了适当的标准和可接受的相应阈值，以计算可靠性（R）、弹性（R）和脆弱性（V）的主要 WH 指标。相应地，为标准化降水指数（SPI）、归一化差异植被指数（NDVI）、土壤侵蚀以及低流量和高流量排放等五个标准概念化和定制了 RRV 框架。还确定了所使用标准和指标对沙赞德 WH 状况的影响大小。因此，为四年（1986 年、1998 年、2008 年和 2014 年）和整个流域绘制了 R、R 和 V 指标以及综合 WH 状况的地图，通过开发综合流域健康指数（IWHI）来绘制。最后，应用变化检测方法来确定过去三十年中 IWHI 变化的趋势。结果表明，在所选择的四年研究中，R、R 和 V 指标以及流域综合健康状况的有效性在各年之间具有高度的可变性。在所研究的所有年份中，R 指标在 Shazand 流域的 WH 中几乎具有更高的贡献率（≥34%）。根据 RRV 框架，在所研究的年份中，没有一个次流域被评估为处于健康状态。就研究期间的 WH 变化检测而言，由于工业化和城市发展的影响，在 1986-1998 年和 1986-2008 年期间，WH 下降了约 4%。而在其他研究期间，健康状况则没有明显改善。本程序可被视为流域定向和有效管理的筛选工具。
