Mapping global cropland and field size.

A new 1 km global IIASA-IFPRI cropland percentage map for the baseline year 2005 has been developed which integrates a number of individual cropland maps at global to regional to national scales. The individual map products include existing global land cover maps such as GlobCover 2005 and MODIS v.5, regional maps such as AFRICOVER and national maps from mapping agencies and other organizations. The different products are ranked at the national level using crowdsourced data from Geo-Wiki to create a map that reflects the likelihood of cropland. Calibration with national and subnational crop statistics was then undertaken to distribute the cropland within each country and subnational unit. The new IIASA-IFPRI cropland product has been validated using very high-resolution satellite imagery via Geo-Wiki and has an overall accuracy of 82.4%. It has also been compared with the EarthStat cropland product and shows a lower root mean square error on an independent data set collected from Geo-Wiki. The first ever global field size map was produced at the same resolution as the IIASA-IFPRI cropland map based on interpolation of field size data collected via a Geo-Wiki crowdsourcing campaign. A validation exercise of the global field size map revealed satisfactory agreement with control data, particularly given the relatively modest size of the field size data set used to create the map. Both are critical inputs to global agricultural monitoring in the frame of GEOGLAM and will serve the global land modelling and integrated assessment community, in particular for improving land use models that require baseline cropland information. These products are freely available for downloading from the http://cropland.geo-wiki.org website.

Malnutrition and morbidity trends in Somalia between 2007 and 2016: results from 291 cross-sectional surveys.

BACKGROUND: More than two decades of conflict and natural disasters in Somalia have resulted in one of the longest running humanitarian crises in the world. Nutrition data have been collected over the years despite challenges to inform programmatic action. This paper explores malnutrition and morbidity trends in Somalia during the last decade, disaggregated by geographical zone and livelihood system. METHODS: We used data from 291 cross-sectional surveys conducted in children aged 6-59 months between 2007 and 2016 in Somalia. Wasting, morbidity and stunting prevalences over time were analysed by geographic area, livelihood system and season. Logistic regressions were used to test trends. RESULTS: The wasting trends show a striking peak in 2011, more marked in southern and central Somalia and coinciding with the famine declaration. The trend declines slightly thereafter although not consistently across all zones and livelihoods, and it raises again in 2016 especially among internally displaced persons (IDPs). Stunting declined for all groups and in all zones but with more consistent patterns in northern Somalia.Morbidity also showed a declining trend, although with multiple peaks depicting disease outbreaks.Pastoralist showed the lowest stunting estimates overall, while agrarian populations showed the lowest prevalence of wasting and morbidity. IDPs were the most affected by all outcomes. Seasonality affected the three outcomes differently by livelihood system. Stunting rates increased after the 2011 famine for all age groups within children under 5 years. CONCLUSIONS: Despite the continuous complex situation in Somalia, there has been a sustained decline in stunting and morbidity in the last decade. Wasting trends have remained at very high levels especially in north-east and the south zones of Somalia. The findings support the importance of performing trend analyses disaggregated by zone and livelihood groups within countries to better identify priorities for programme intervention.

Children's dietary diversity and related factors in Rwanda and Burundi: A multilevel analysis using 2010 Demographic and Health Surveys.

BACKGROUND: One of the reported causes of high malnutrition rates in Burundi and Rwanda is children's inadequate dietary habits. The diet of children may be affected by individual characteristics and by the characteristics of the households and the communities in which they live. We used the minimum dietary diversity of children (MDD-C) indicator as a proxy of diet quality aiming at: 1) assess how much of the observed variation in MDD-C was attributed to community clustering, and 2) to identify the MDD-C associated factors. METHODS: Data was obtained from the 2010 Demographic and Health Surveys of Burundi and Rwanda, from which only children 6 to 23 months from rural areas were analysed. The MDD-C was calculated according to the 2007 WHO/UNICEF guidelines. We computed the intra-class coefficient to assess the percentage of variation attributed to the clustering effect of living in the same community. And then we applied two-level logit regressions to investigate the association between MDD-C and potential risk factors following the hierarchical survey structure of DHS. RESULTS: The MDD-C was 23% in rural Rwanda and 16% in rural Burundi, and a 29% of its variation in Rwanda and 17% in Burundi was attributable to community clustering. Increasing age and living standards were associated with higher MDD-C in both countries, and only in Burundi also increasing level of education of the mother's partner. In Rwanda alone, the increasing ages of the head of the household and of the mother at first birth were also positively associated with it. Despite the identification of an important proportion of the MDD-C variation due to clustering, we couldn't identify any community variable significantly associated with it. CONCLUSIONS: We recommend further research using hierarchical models, and to integrate dietary diversity in holistic interventions which take into account both the household's and the community's characteristics the children live in.

MUAC-for-age more useful than absolute MUAC for nutritional surveillance in Somalia: results from nineteen cross-sectional surveys (2007-2016).

BACKGROUND: Somalia is affected by a civil war and a protracted humanitarian crisis for more than two decades. The international community has put in place nutrition surveillance systems to monitor the situation and inform decisions. However, the indicators commonly used to identify acute malnutrition, weight-for-height Z-score (WHZ) and mid upper arm circumference (MUAC), do not always converge in their estimations of acute malnutrition, creating challenges for decision making. Furthermore, the divergences are not consistent across livelihood populations within the country. We explored the MUAC-for-age Z-score (MUACAZ) as an alternative indicator in Somalia to minimize the discrepancy. METHODS: We analyzed data from nineteen cross-sectional surveys conducted in Somalia between 2007 and 2016. We compared the acute malnutrition prevalence estimates by each of the indicators and the degree of overlap in the individual diagnosis of acute malnutrition between the WHZ and the MUAC-based indicators. We performed multivariate regression analysis with sex, age and stunting as independent variables and acute malnutrition as the dependent outcome, defined by WHZ, MUAC or MUACAZ. We performed all the analysis in the population overall and in each of the livelihood populations separately. RESULTS: A total 255,623 measurements of children 6-59 months of age were analyzed. The overall prevalence of global acute malnutrition by MUACAZ (15.8%) was similar to the one obtained using WHZ (16%), whereas prevalence based on MUAC was much lower (7.8%). These patterns of divergence were sustained throughout the nineteen surveys and the livelihoods studied, with only few exceptions. However, the proportion of overlap in the individual diagnosis of children as acutely malnourished was low between WHZ and absolute MUAC diagnosis (18.1%) and also between WHZ and MUACAZ (28.3%). Results show that age, sex and stunting status of the child affected the likelihood of being diagnosed as acutely malnourished to varying degrees, depending on the indicator used. CONCLUSIONS: The MUAC-for-age (MUACZ) indicator yielded acute malnutrition prevalence estimates convergent with those obtained by WHZ indicator. However, the degree of overlap between these two indicators for individual diagnosis of acute malnutrition is low. Further studies of MUACAZ as an alternative indicator for nutrition surveillance are needed.