TY - JOUR
T1 - Acacia trees pattern distribution as an indicator for changes in flow spatial distributions in a hyper-arid environment
AU - Isaacson, Sivan
AU - Ephrath, Jhonathan E.
AU - Rachmilevitch, Shimon
AU - Maman, Shimrit
AU - Blumberg, Dan G.
PY - 2017/4/1
Y1 - 2017/4/1
N2 - Arid regions are characterized by high spatial and temporal variability
of precipitation, resulting in high spatial and temporal variation of
vegetation cover. Because of low rainfall, the acacia trees in southern
Israel are usually restricted to ephemeral stream (Wadi) beds, which
possess higher soil moisture content than the surrounding landscape.
Spatial analyses of tree distribution at the drainage basin scale
contributes to a better understanding of the geo-hydrologic regime
because water is the main limiting factor in such areas. That is, the
spatial distribution of trees and their characteristics within the Wadi
may reflect the spatial variance of water availability within different
segments of the Wadi. The main objective of this study was to use the
spatial distribution of different parameters of acacia trees as an
indicator of past and present hydrological regimes within different
segments of the Wadi. Tree size distribution was used as an indicator of
long-term (decades) geo-hydrologic spatial processes affecting the
acacia population. The tree health (NDVI) distribution was used as an
indicator of short-term (months to a few years) geo-hydrologic spatial
processes, such as the paths of recent flashfloods events. The
distribution of the trees in the Wadi (ephemeral river) was divided into
three distinct categories: (1) large trees with high NDVI values, (2)
large trees with low NDVI values and (3) small trees with medium NDVI
values. Using the resulting classification, we divided the Wadi into
three sections, each representing a unique combination of long- and
short-term geo-hydrologic processes affecting the acacia trees. We
suggest that the lack of spatial correlation between tree size and
health status is a result of spatio-temporal changes in the water
supply. Our main conclusion is that past and current alterations of the
runoff path can be detected by the spatial analysis of trees in
hyper-arid regions
AB - Arid regions are characterized by high spatial and temporal variability
of precipitation, resulting in high spatial and temporal variation of
vegetation cover. Because of low rainfall, the acacia trees in southern
Israel are usually restricted to ephemeral stream (Wadi) beds, which
possess higher soil moisture content than the surrounding landscape.
Spatial analyses of tree distribution at the drainage basin scale
contributes to a better understanding of the geo-hydrologic regime
because water is the main limiting factor in such areas. That is, the
spatial distribution of trees and their characteristics within the Wadi
may reflect the spatial variance of water availability within different
segments of the Wadi. The main objective of this study was to use the
spatial distribution of different parameters of acacia trees as an
indicator of past and present hydrological regimes within different
segments of the Wadi. Tree size distribution was used as an indicator of
long-term (decades) geo-hydrologic spatial processes affecting the
acacia population. The tree health (NDVI) distribution was used as an
indicator of short-term (months to a few years) geo-hydrologic spatial
processes, such as the paths of recent flashfloods events. The
distribution of the trees in the Wadi (ephemeral river) was divided into
three distinct categories: (1) large trees with high NDVI values, (2)
large trees with low NDVI values and (3) small trees with medium NDVI
values. Using the resulting classification, we divided the Wadi into
three sections, each representing a unique combination of long- and
short-term geo-hydrologic processes affecting the acacia trees. We
suggest that the lack of spatial correlation between tree size and
health status is a result of spatio-temporal changes in the water
supply. Our main conclusion is that past and current alterations of the
runoff path can be detected by the spatial analysis of trees in
hyper-arid regions
M3 - תקציר הצגה בכנס
SN - 1029-7006
VL - 19
SP - 3156
JO - Geophysical Research Abstracts
JF - Geophysical Research Abstracts
ER -