Remote Sensing of Shrubland Drying in the South-East Mediterranean, 1995–2010: Water-Use-Efficiency-Based Mapping of Biomass Change

Remote Sensing

Maxim Shoshany²  Lev Karnibad¹  Arnon Karnieli³ 

[1]Agricultural Engineering, Faculty of Civil & Environmental Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel

[2] E-Mail:

[3]Mapping and Geoinformation Engineering, Faculty of Civil & Environmental Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel

[4]id="af1-remotesensing-07-02283">1Mapping and Geoinformation Engineering, Faculty of Civil & Environmental Engineering, Technion-Israel Institute of Technology, Haifa 32000, Isra

关键词: desert-fringe ecosystems;    climate change;    shrubland biomass;    remote sensing;    water-use efficiency;   

DOI  :  10.3390/rs70302283

来源: mdpi

【 摘 要 】

Recent climate studies of the South-Eastern Mediterranean indicate an increase in drought frequencies and decreasing water resources since the turn of the century. A four-phase methodology was developed for assessing above-ground biomass changes in shrublands caused by these recent trends. Firstly, we generalized the function SB = 0.008MAP^1.54 describing the shrublands above-ground biomass (SB) dependence on mean annual precipitation (MAP) for areas of full shrub cover. Secondly, relationships between MAP and NDVI were formalized, allowing an estimation of precipitation levels from observed NDVI values (MAP_NDVI). Thirdly, relative water-use efficiency (RWUE) was defined as the ratio between MAP_NDVI and MAP. Finally, the function SB_RWUE = 0.008MAP^{0.54 + RWUE} was formalized, utilizing RWUE in estimating shrublands biomass. This methodology was implemented using Landsat TM images (1994 to 2011) for an area between the Judean Mountains and the deserts bordering them to the east and south. More than 50% of the study area revealed low biomass change (±0.2 kg/m²), compared with 30% of the woodlands of the Jerusalem Mountains, where biomass increased between 0.2 and 1.4 kg/m² and with 50% of the semi-arid shrublands, where it decreased between 0.2 and 1.4 kg/m². These results suggest that aridity lines in southern Israel are migrating northwards.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.