Next Article in Journal
Next Article in Special Issue
Previous Article in Journal
Previous Article in Special Issue
Remote Sens. 2014, 6(9), 8134-8164; doi:10.3390/rs6098134
Article

Structural Changes of Desertified and Managed Shrubland Landscapes in Response to Drought: Spectral, Spatial and Temporal Analyses

1, 1
, 1
, 2
 and 1,*
Received: 18 June 2014; in revised form: 28 July 2014 / Accepted: 6 August 2014 / Published: 28 August 2014
(This article belongs to the Special Issue Remote Sensing of Land Degradation in Drylands)
Download PDF [9698 KB, uploaded 28 August 2014]
Abstract: Drought events cause changes in ecosystem function and structure by reducing the shrub abundance and expanding the biological soil crusts (biocrusts). This change increases the leakage of nutrient resources and water into the river streams in semi-arid areas. A common management solution for decreasing this loss of resources is to create a runoff-harvesting system (RHS). The objective of the current research is to apply geo-information techniques, including remote sensing and geographic information systems (GIS), on the watershed scale, to monitor and analyze the spatial and temporal changes in response to drought of two source-sink systems, the natural shrubland and the human-made RHSs in the semi-arid area of the northern Negev Desert, Israel. This was done by evaluating the changes in soil, vegetation and landscape cover. The spatial changes were evaluated by three spectral indices: Normalized Difference Vegetation Index (NDVI), Crust Index (CI) and landscape classification change between 2003 and 2010. In addition, we examined the effects of environmental factors on NDVI, CI and their clustering after successive drought years. The results show that vegetation cover indicates a negative ∆NDVI change due to a reduction in the abundance of woody vegetation. On the other hand, the soil cover change data indicate a positive ∆CI change due to the expansion of the biocrusts. These two trends are evidence for degradation processes in terms of resource conservation and bio-production. A considerable part of the changed area (39%) represents transitions between redistribution processes of resources, such as water, sediments, nutrients and seeds, on the watershed scale. In the pre-drought period, resource redistribution mainly occurred on the slope scale, while in the post-drought period, resource redistribution occurred on the whole watershed scale. However, the RHS management is effective in reducing leakage, since these systems are located on the slopes where the magnitude of runoff pulses is low.
Keywords: remote sensing; normalized difference vegetation index; crust index; landscape cover; runoff-harvesting system; source-sink systems remote sensing; normalized difference vegetation index; crust index; landscape cover; runoff-harvesting system; source-sink systems
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Export to BibTeX |
EndNote


MDPI and ACS Style

Paz-Kagan, T.; Panov, N.; Shachak, M.; Zaady, E.; Karnieli, A. Structural Changes of Desertified and Managed Shrubland Landscapes in Response to Drought: Spectral, Spatial and Temporal Analyses. Remote Sens. 2014, 6, 8134-8164.

AMA Style

Paz-Kagan T, Panov N, Shachak M, Zaady E, Karnieli A. Structural Changes of Desertified and Managed Shrubland Landscapes in Response to Drought: Spectral, Spatial and Temporal Analyses. Remote Sensing. 2014; 6(9):8134-8164.

Chicago/Turabian Style

Paz-Kagan, Tarin; Panov, Natalya; Shachak, Moshe; Zaady, Eli; Karnieli, Arnon. 2014. "Structural Changes of Desertified and Managed Shrubland Landscapes in Response to Drought: Spectral, Spatial and Temporal Analyses." Remote Sens. 6, no. 9: 8134-8164.


Remote Sens. EISSN 2072-4292 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert