在流域一级评估干旱参数是规划可持续作物生产的基本过程之一。这项研究旨在评估Vaippar盆地内的短期和长期气象干旱参数,位于印度南部,采用标准化降水指数(SPI)。使用从13个雨量计站开发的网格降雨值来计算SPI值。干旱参数,涵盖事件,强度,持续时间,频率,和趋势,对短期和长期干旱进行了评估。研究结果表明,短期干旱的发生率为51.7%,长期干旱占49.82%。值得注意的是,该盆地在1980年、1998年和2016年经历了极端的短期干旱,在1981年、2013年和2017年经历了长期干旱。利用创新的SPI值趋势识别方法,短期干旱在10月和12月以及长期干旱在12月发现了显着的单调上升趋势。这项研究定义了最小阈值降雨量,这代表了防止短期干旱(设定为390毫米)和长期干旱(设定为635毫米)所需的临界量。本研究得出的干旱严重度复发曲线表明,当SPI值低于-1.0时,短期干旱会影响流域面积的25%,而长期干旱以20年的复发间隔影响流域50%的面积。此外,干旱灾害指数(DHI),结合了干旱强度和严重程度,在西北地区短期干旱和南部地区长期干旱表现出较高的值。这项研究的发现,突出干旱脆弱地区,严重程度,和盆地的复发模式,当干旱开始时,引导注意力及时干预。
Evaluating drought parameters at the basin level is one of the fundamental processes for planning sustainable crop production. This study aimed to evaluate both short-term and long-term meteorological drought parameters within the Vaippar Basin, located in southern India, by employing the standardized precipitation index (
SPI). Gridded rainfall values developed from 13 rain gauge stations were employed to calculate the
SPI values. Drought parameters, encompassing occurrence, intensity, duration, frequency, and trends, were assessed for both short-term and long-term droughts. The study findings indicated that the occurrence of short-term drought was 51.7%, while that of long-term drought was 49.82%. Notably, the basin experienced extreme short-term droughts in 1980, 1998 and 2016 and long-term droughts in 1981, 2013, and 2017. Utilizing an innovative trend identification method for
SPI values, a significant monotonic upwards trend was identified in October and December for short-term drought and in December for long-term drought. This study defined the minimum threshold rainfall, which represents the critical amount required to prevent short-term drought (set at 390 mm) and long-term drought (set at 635 mm). The drought severity recurrence curves developed in this study indicate that when the
SPI values fall below - 1.0, short-term drought affects 25% of the basin area, while long-term drought impacts 50% of the basin area at a 20-year recurrence interval. Additionally, the drought hazard index (DHI), which combines drought intensity and severity, demonstrated higher values in the northwestern regions for short-term drought and in the southern areas for long-term drought. The study\'s findings, highlighting areas of drought vulnerability, severity, and recurrence patterns in the basin, direct the attention for timely intervention when drought initiates.