Department of Medical Statistics and Epidemiology, School of Public Health, Sun Yat-sen University, Guangzhou, 510080, China.
Sun Yat-sen Global Health Institute, Sun Yat-sen University, Guangzhou, 510275, China.
Int J Equity Health. 2018 Apr 2;17(1):40. doi: 10.1186/s12939-018-0754-8.
Per United Nations' Sustainable Development Goals, Nepal is aspiring to achieve universal and equitable access to safe and affordable drinking water and provide access to adequate and equitable sanitation for all by 2030. For these goals to be accomplished, it is important to understand the country's geographical heterogeneity and inequality of access to its drinking-water supply and sanitation (WSS) so that resource allocation and disease control can be optimized. We aimed 1) to estimate spatial heterogeneity of access to improved WSS among the overall Nepalese population at a high resolution; 2) to explore inequality within and between relevant Nepalese administrative levels; and 3) to identify the specific administrative areas in greatest need of policy attention.
We extracted cluster-sample data on the use of the water supply and sanitation that included 10,826 surveyed households from the 2011 Nepal Demographic and Health Survey, then used a Gaussian kernel density estimation with adaptive bandwidths to estimate the distribution of access to improved WSS conditions over a grid at 1 × 1 km. The Gini coefficient was calculated for the measurement of inequality in the distribution of improved WSS; the Theil L measure and Theil T index were applied to account for the decomposition of inequality.
57% of Nepalese had access to improved sanitation (range: 18.1% in Mahottari to 100% in Kathmandu) and 92% to drinking-water (range: 41.7% in Doti to 100% in Bara). The most unequal districts in Gini coefficient among improved sanitation were Saptari, Sindhuli, Banke, Bajura and Achham (range: 0.276 to 0.316); and Sankhuwasabha, Arghakhanchi, Gulmi, Bhojpur, Kathmandu (range: 0.110 to 0.137) among improved drinking-water. Both the Theil L and Theil T showed that within-province inequality was substantially greater than between-province inequality; while within-district inequality was less than between-district inequality. The inequality of several districts was higher than what is calculated by regression of the Gini coefficient and our estimates.
This study showed considerable geographical heterogeneity and inequality not evidenced in previous national statistics. Our findings may be useful in prioritizing resources to reduce inequality and expand the coverage of improved water supply and sanitation in Nepal.
根据联合国可持续发展目标，尼泊尔力争到 2030 年实现普及和公平获得安全和负担得起的饮用水，并为所有人提供充足和公平的环境卫生设施。为了实现这些目标，重要的是要了解该国在获得饮用水供应和环境卫生设施方面的地理异质性和不平等，以便优化资源分配和疾病控制。我们的目的是：1）以高分辨率估算尼泊尔全国人口获得改良饮用水供应服务的空间异质性；2）探讨尼泊尔各级行政单位内部和之间的不平等情况；3）确定最需要政策关注的具体行政区域。
我们从 2011 年尼泊尔人口与健康调查中提取了包含 10826 户调查家庭的供水和环境卫生设施使用情况的聚类抽样数据，然后使用具有自适应带宽的高斯核密度估计来估算改良饮用水供应服务条件在 1x1km 网格上的分布情况。基尼系数用于衡量改良饮用水供应服务分布的不平等程度；泰尔 L 测度和泰尔 T 指数用于解释不平等的分解。
57%的尼泊尔人可以获得改良的环境卫生设施（范围：马哈特哈里的 18.1%至加德满都的 100%），92%的人可以获得饮用水（范围：多蒂的 41.7%至巴拉的 100%）。在改良环境卫生设施方面，基尼系数最不平等的地区是萨普塔里、辛杜利、班克、巴朱拉和阿恰姆（范围：0.276 至 0.316）；在改良饮用水方面，基尼系数最不平等的地区是桑库瓦萨巴哈、阿尔乔哈奇、古尔米、博杰布尔、加德满都（范围：0.110 至 0.137）。泰尔 L 和泰尔 T 都表明，省内不平等程度大大高于省际不平等程度；而县级内部不平等程度低于县级之间的不平等程度。一些地区的不平等程度高于基尼系数回归和我们的估计所计算的水平。
本研究表明，存在相当大的地理异质性和不平等，这在以前的国家统计数据中没有体现。我们的研究结果可能有助于优先分配资源，以减少不平等现象，并扩大尼泊尔改良供水和环境卫生设施的覆盖范围。
