Spatial targeting of land rehabilitation: a relational analysis of cropland productivitiy decline in arid Uzbekistan

Abstract

Irrigated croplands of Central Asia are highly prone to land degradation due to their fragile physical settings and extensive agricultural land use. Current remote-sensing data and spatio-temporal analyses allow for detecting regional trends in a land decline and for relating them to underlying factors which is important for developing mitigation strategies. This study aimed to (1) assess the cropland’s state in the large irrigated agricultural areas in the northern Uzbekistan based on the time series of MODIS NDVI images, (2) relate the degradation trend to its factors including soil quality, terrain, population density and land use, and (3) synthesize the results to provide recommendation on spatial targeting of land rehabilitation measures. An NDVI-based land degradation assessment revealed a significant decline of land productivity across 23.13% (94834.90 ha) of the arable area in the study region. The degraded cropland, located in the areas of high population pressure and characterized by better-quality soils, should be prioritized for rehabilitation measures. For the degraded cropland, found on the poor-quality soils and in the areas of low population density, depending on the severity of degradation, a decision has to be made whether to vacant the land from agriculture or to continue cultivation if the latter is an economically viable option.