@article{DubovykMenzConradetal.2012,
  author    = {Dubovyk, Olena and Menz, Gunter and Conrad, Christopher and Kann, Elena and Machwitz, Miriam and Khamzina, Asia},
  title     = {Spatio-temporal analyses of cropland degradation in the irrigated lowlands of Uzbekistan using remote-sensing and logistic regression modeling},
  series = {Environmental Monitoring and Assessment},
  volume    = {185},
  journal   = {Environmental Monitoring and Assessment},
  number    = {6},
  doi       = {10.1007/s10661-012-2904-6},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-129912},
  pages     = {4775-4790},
  year      = {2012},
  abstract  = {Advancing land degradation in the irrigated areas of Central Asia hinders sustainable development of this predominantly agricultural region. To support decisions on mitigating cropland degradation, this study combines linear trend analysis and spatial logistic regression modeling to expose a land degradation trend in the Khorezm region, Uzbekistan, and to analyze the causes. Time series of the 250-m MODIS NDVI, summed over the growing seasons of 2000-2010, were used to derive areas with an apparent negative vegetation trend; this was interpreted as an indicator of land degradation. About one third (161,000 ha) of the region's area experienced negative trends of different magnitude. The vegetation decline was particularly evident on the low-fertility lands bordering on the natural sandy desert, suggesting that these areas should be prioritized in mitigation planning. The results of logistic modeling indicate that the spatial pattern of the observed trend is mainly associated with the level of the groundwater table (odds = 330 \%), land-use intensity (odds = 103 \%), low soil quality (odds = 49 \%), slope (odds = 29 \%), and salinity of the groundwater (odds = 26 \%). Areas, threatened by land degradation, were mapped by fitting the estimated model parameters to available data. The elaborated approach, combining remote-sensing and GIS, can form the basis for developing a common tool for monitoring land degradation trends in irrigated croplands of Central Asia.},
  language  = {en}
}
@article{KumarKhamzinaKnoefeletal.2021,
  author    = {Kumar, Navneet and Khamzina, Asia and Kn{\"o}fel, Patrick and Lamers, John P. A. and Tischbein, Bernhard},
  title     = {Afforestation of degraded croplands as a water-saving option in irrigated region of the Aral Sea Basin},
  series = {Water},
  volume    = {13},
  journal   = {Water},
  number    = {10},
  issn      = {2073-4441},
  doi       = {10.3390/w13101433},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-239626},
  year      = {2021},
  abstract  = {Climate change is likely to decrease surface water availability in Central Asia, thereby necessitating land use adaptations in irrigated regions. The introduction of trees to marginally productive croplands with shallow groundwater was suggested for irrigation water-saving and improving the land's productivity. Considering the possible trade-offs with water availability in large-scale afforestation, our study predicted the impacts on water balance components in the lower reaches of the Amudarya River to facilitate afforestation planning using the Soil and Water Assessment Tool (SWAT). The land-use scenarios used for modeling analysis considered the afforestation of 62\% and 100\% of marginally productive croplands under average and low irrigation water supply identified from historical land-use maps. The results indicate a dramatic decrease in the examined water balance components in all afforestation scenarios based largely on the reduced irrigation demand of trees compared to the main crops. Specifically, replacing current crops (mostly cotton) with trees on all marginal land (approximately 663 km\(^2\)) in the study region with an average water availability would save 1037 mln m\(^3\) of gross irrigation input within the study region and lower the annual drainage discharge by 504 mln m\(^3\). These effects have a considerable potential to support irrigation water management and enhance drainage functions in adapting to future water supply limitations.},
  language  = {en}
}