This study presents developing procedures and verification of a new hybrid model, namely wavelet packet-genetic programming (WPGP) for short-term meteorological drought forecast. To this end, the multi-temporal standardized precipitation evapotranspiration index (SPEI) has been used as quantifying parameter at two stations Ankara province, Turkey. The WPGP model comprises main steps. In first s...

شاخص سطح برگ استخراج‌شده (LAI) از تصاویر سنجش دور پارامتر مهمی، به‌منظور مدل‌سازی مکانی تولید پوشش گیاهی، محسوب می‌شود. معمولاً شاخص‌های گیاهی که با بازتاب طول موج‌های قرمز و مادون نزدیک محاسبه می‌شوند، در برآورد LAI استفاده روش‌های آماری، به‌کار می‌روند اما بسیاری این شاخص‌ها مقادیر متفاوت به اشباع می‌رسند. برای رفع محدودیت، محدودة لبة شده است؛ بنابراین، باید قابلیت داده‌های دور، ذرت علوفه‌ای، ...

Abstract The frequency and intensity of drought events are increasing with warming climate, which has resulted in worldwide forest mortality. Previous studies have reached a general consensus on the size-dependency resistance to drought, but further understanding at local scale remains ambiguous conflicting evidence. In this study, we assessed impact canopy height broadleaf deciduous southweste...

Abstract. In this study we analyze drought features at the European level over period 1901–2019 using three indices: standardized precipitation index (SPI), evapotranspiration (SPEI), and self-calibrated Palmer severity (scPDSI). The results based on SPEI scPDSI point to fact that Central Europe (CEU) Mediterranean region (MED) are becoming dryer due an increase in potential mean air temperatur...

Future changes in drought characteristics Greece were investigated using dynamically downscaled high-resolution simulations of 5 km. The Weather Research and Forecasting model driven by EC-EARTH output for historical future periods, under Representative Concentration Pathways 4.5 8.5. For the analysis, standardized precipitation index (SPI) precipitation-evapotranspiration (SPEI) calculated. Th...

Drought is an extreme phenomenon that will likely increase in frequency and severity the current context of climate change. As such, it must be studied to improve decision-making process affected areas. a semi-arid zone, Guadalquivir River basin, located southern Iberian Peninsula, interesting area perform this study. The relationship between meteorological hydrological droughts using drought i...

Drought prediction is the most effective way to mitigate drought impacts. The current study examined ability of three renowned machine learning models, namely additive regression (AR), random subspace (RSS), and M5P tree, their hybridized versions (AR-RSS, AR-M5P, RSS-M5P, AR-RSS-M5P) in predicting standardized precipitation evapotranspiration index (SPEI) multiple time scales. SPEIs were calcu...