1. Introduction
In recent decades, the Southern African Development Community (SADC) has witnessed a surge in natural disasters, resulting in significant livestock losses and the onset of severe food and water shortages. These events have had far-reaching consequences on livelihoods and businesses. According to EM-DAT [
1], SADC countries have witnessed approximately 63 million people being affected by droughts between 1900 and 2016. Based on the EM-DAT [
1] data, the proportion of affected countries relative to their populations was determined, and
Figure 1 reveals that Eswatini, Lesotho, and Zimbabwe are, respectively, the most affected nations in the SADC when it comes to drought disasters. In contrast, DRC, Mauritius, and Seychelles have experienced fewer threats from drought disasters compared to the other twelve countries [
2]. The proportion-per-population calculation in
Figure 1 illustrates the severity of the impact of drought disasters on the SADC population.
Despite being the smallest country in the region, the Kingdom of Eswatini, possibly due to its agroecology and larger proportion of population (about 70%) that is still agrarian, has borne the brunt of climate variability, particularly drought. Critical challenges faced by Eswatini include insufficient and/or unreliable rainfall, leading to a decline in food production levels [
3,
4]. The 2004/2005 crop and food supply assessment by the Food and Agriculture Organization of the United Nations (FAO) and the World Food Programme (WFP) over five years revealed a 70% drop in the production of the country’s staple food, maize [
5].
The most recent 2015/2016 El Niño drought had profound effects, leading to crop failures, livestock losses, and a heightened level of food insecurity. As a consequence, the country experienced a comprehensive domestic shortfall in cereal stocks, amounting to 59%, equivalent to 121,170 tonnes. A considerable demographic segment experienced adverse effects, with an estimated 638,251 individuals affected, constituting approximately 50% of Eswatini’s total population (ESERPAC, 2017) [
6]. Over the past 30 years, the mean annual rainfall has significantly decreased, with increased temporal variability. Some regions in Eswatini have experienced up to 60% of the yearly precipitation within two consecutive months. This variability poses a serious threat to food production, particularly cereals like maize.
The frequent exposure of farmers to extreme climatic shocks is a major threat to the sustainable development of agriculture and agriculture-based livelihoods, hindering improvements in food and nutrition security and the eradication of rural poverty in developing countries [
7,
8,
9,
10,
11].
To address the mitigation of drought risks in Eswatini, there is a need for comprehensive plans and their coordination and implementation in the affected agricultural areas. This involves the identification of these areas for farm-level adaptation to climate change, an impact assessment on the local population, and the development of rapid deployment methods for humanitarian relief to affected people [
12,
13,
14,
15,
16].
In recent years, remote sensing has emerged as a reliable method for identifying and monitoring drought, especially for further evaluation of drought impact. According to Huang et al. [
17], applying remote sensing and a Geographic Information System (GIS) potentially provides an extra contribution to drought assessment and monitoring, for instance, in terms of the accuracy of results, amount of information obtained, temporal availability, and so on.
This study, therefore, addresses the growing threat of drought in the Kingdom of Eswatini by utilizing remote sensing technologies and a GIS to monitor drought and assess its repercussions, evaluating the impact on agricultural production. To fulfill the above aim, we strongly invite contributions on various drought monitoring indexes from satellites and other data sources. According to Wang et al. [
18], commonly used methods include the vegetation index, canopy temperature, thermal inertia, and microwave remote sensing. The vegetation index method, particularly the Vegetation Health Index (VHI), has become a primary approach for monitoring agricultural drought [
19]. Other indices, such as the Palmer Drought Severity Index (PDSI) and Crop Moisture Index (CMI), are utilized to determine the timeline for emergency drought assistance and reflect short-term moisture supply across major crop-producing regions, respectively [
20,
21,
22]. The VHI, which combines the vegetation leaf surface and temperature effects on vegetation, is applied to identify drought areas and assess the impacts on agricultural production in Eswatini.
Furthermore, in order to develop a comprehensive approach that involves coordination and the development of swift humanitarian relief strategies, additional geospatial tools were employed, including Open Route Service (ORS) and Near Neighbor Analysis algorithms on QGIS, for humanitarian supply chain and logistics analysis.
4. Discussion
4.1. Vulnerability and Resilience of Agricultural Systems
Understanding these geographical and agroecological distinctions is essential for effective land use planning, resource management, and sustainable agricultural development in Eswatini. It enables policymakers, researchers, and local communities to tailor interventions that address the specific needs and challenges of each region and agroecological zone. In this study, the vulnerability assessment conducted underscores the heightened susceptibility of smallholder farmers engaged in rainfed agriculture, specifically in the lower Middleveld and western Lowveld, to the adverse impacts of drought. Remote sensing has revealed that the lower Middleveld and western Lowveld zones have struggled with recurring drought events affecting their abilities to sufficiently produce for livelihoods. This observation resonates with the findings from the Vulnerability Assessment Committee (VAC) in 2006 [
42], revealing that during the droughts of 2004 and 2005, over a quarter of Eswatini’s population needed emergency food assistance. Parry et al. [
46], IPCC [
47], Ojwang et al. [
48], and Belloumi [
49] stated that countries with a high dependency on rainfed agriculture are significantly threatened by changes in rainfall patterns. Ninety-three percent of cultivated land in sub-Saharan Africa, including in Eswatini, is rainfed, thirteen percent above the global average of 80% [
50,
51,
52]. In recent years, a poor rainfall distribution coupled with drought periods, particularly inter-seasonal dry spells, has increased the burden on food security and income among many farming families [
53,
54,
55]. Notably, between 1990 and 2009, there was a substantial reduction in the maize cultivation area, plummeting from 84,000 to 52,000 hectares, as documented by Oseni and Masarirambi [
4]. This decline vividly underscores the agriculture sector’s vulnerability to the dynamic challenges posed by climate change and drought. The most recent drought in the 2015/16 farming season further accentuated the precarious state of the agriculture sector, witnessing a staggering 64 percent decrease in maize production, a staple food in the region. This drastic drop, from 93,653 MT in 2013/14 to 33,460 MT in 2015/16, coincided with the distressing loss of 67,120 cattle, as reported by the VAC in 2016 [
42]. The impact of this decline reverberates through the livelihoods of farmers, exacerbating their vulnerability. The situation is compounded by the limited access to irrigation infrastructure, emphasizing the urgent need for targeted interventions in these regions. Among the interventions is the exploration of adaptive strategies employed by smallholder farmers to cope with recurrent drought conditions. It is essential to assess the effectiveness of community-based adaptation/resilience approaches and identify potential areas for improvement or innovation.
Fuchs et al. [
56] emphasize the significance of enhancing communities’ adaptive capacity to ensure the sustainability of livelihoods and landscapes in smallholder systems. The benefits of bolstering the adaptive capacity include targeted improvements that positively impact communities’ ability to overcome climate-related constraints and other developmental barriers [
57]. Within the context of smallholder farming as the primary livelihood source for most of the population, the literature on drought adaptation suggests that enhancing well-being is particularly effective in elevating the adaptive capacity [
58,
59,
60].
Munyaka and Yadavalli [
61] further assert that community preparedness for drought, including heat-related challenges, constitutes a sound adaptive capacity strategy. The European Commission Disaster Risk Management Knowledge Centre (accessed on 23 December 2023) highlights that community awareness of climate change risks presents a dynamic adaptive approach crucial for saving lives [
62].
Disasters are not a new phenomenon; they have impacted communities globally for centuries. There is a wealth of literature discussing community-based resilience approaches employed to mitigate the impacts of disasters, particularly in the southern hemisphere. Community-based resilient approaches have historically provided local populations with a unique means of survival against rising challenges.
Moreover, it is imperative to assess the role of technological advancements and innovative practices in enhancing resilience within the agriculture sector. For example, Ewbank et al. [
63] employed early warning systems, forecasts, and drought management advice in rural communities in Nicaragua and Ethiopia, both before and during the agricultural season. Their research demonstrated the value of community-based actions, revealing that participants who could better mitigate impacts were more organized in accessing relief and recovering more effectively. In Zimbabwe, a participatory workshop providing farmers with seasonal forecasts resulted in a 9.4% harvest increase over two years [
64]. Similarly, in Mali, early warning systems for millet and sorghum farms, using agro-meteorological information, led to yield increases of 37% and 36%, respectively [
65]. These studies underscore that early warning systems improve farmers’ decision making and reduce losses of scarce resources.
While new technologies may incur costs, it is worthwhile to initiate a discussion on the cost-effectiveness of introducing these technologies in relation to the benefits they bring to sustainable farming practices. Indigenous early warning systems have shown great value in strengthening preparedness as they indicate drought conditions and opportunities to devise response actions to absorb threats and even reduce vulnerabilities [
66,
67].
Additionally, sub-Saharan communities commonly employ practical resilience approaches, such as liquidating productive assets, defaulting on loans, withdrawing children from school, and engaging in exploitative environmental management practices to survive [
68].
Finally, collaboration among government agencies, non-governmental organizations (NGOs), and local communities is crucial for developing a comprehensive and coordinated strategy to tackle agricultural vulnerabilities. Such collaboration can pave the way for much-needed discussions on the effectiveness of existing agricultural policies in addressing challenges posed by climate change and drought. It is essential to propose policy recommendations that can bolster the resilience of smallholder farmers and foster sustainable agriculture.
4.2. Remote Sensing as a Drought Monitoring Tool
Integrating spatial approaches into the assessment of community-based strategies, particularly in resource-scarce environments, is an avenue worth exploring. The use of remote sensing, specifically the Vegetation Health Index, proves instrumental in timely and accurate drought monitoring. In the Kingdom of Eswatini, the generated VHI for the years 1990–2020 accurately depicted the periods the kingdom was faced with agricultural droughts. The 1990, 1995, and 2015 VHI products show the scale and extent of drought conditions that were generally experienced around those periods. The VHI product for years like 2020 accurately shows the good cropping periods recorded for those years. The integration of satellite data with climate and socioeconomic information enhances the understanding of the multifaceted impact of drought on agricultural systems. The results play a crucial role in selecting central warehouses and determining the fastest/shortest routes for humanitarian relief deliveries from primary hubs, achieved through the implementation of the Open Route Service (ORS) algorithm in QGIS. However, it is crucial to note that relying solely on remote sensing approaches may pose challenges due to satellite revisit times and the need for cloud-free images. Validation on the ground remains essential for accurate remote sensing drought indices.
4.3. Geospatial Analysis for Humanitarian Relief
Geospatial tools, including ORS and Near Neighbor Analysis, play a pivotal role in optimizing supply chain routes and identifying priority areas for efficient humanitarian relief efforts. The integration of technology into relief planning enhances the effectiveness and timeliness of response measures. The research findings provide decision makers with an effective strategy for responding to humanitarian needs in the event of a disaster in the Kingdom of Eswatini. This study indicates that humanitarian relief can be supplied from any primary hub to any secondary hub in a minimum time of 0.49 h and maximum time of 12.37 h. The swift delivery of relief within a day of the demand being logged is particularly significant in the context of a drought disaster, potentially saving more lives in other critically affected areas of Eswatini. In a country where the impacts of drought can rapidly escalate, especially in vulnerable regions such as the lower Middleveld and western Lowveld, ensuring the timely and efficient transportation of humanitarian aid becomes paramount. The immediate response to demands for relief plays a crucial role in preventing further escalation of the humanitarian crisis and mitigating the socioeconomic impacts on communities. This model not only addresses urgent needs for food, water, and other essentials but also contributes to building resilience by providing timely support that can prevent the deterioration of health, livelihoods, and overall well-being. Apart from the effectiveness of the humanitarian logistics system applied in Eswatini, other factors, such as the country’s capability to mobilize resources, coordinate efforts, and respond promptly to the pressing needs of affected populations, will determine the success of the life-saving operation. This agile and responsive logistics approach becomes a lifeline for communities facing the harsh consequences of drought, ensuring that assistance reaches those in need when they need it the most.
5. Conclusions
The examination of Vegetation Health Index (VHI) values over the last three decades has revealed significant variations, closely aligning with recorded drought events in Eswatini. The extreme drought of the VHI, spanning 1990 to 2020, impacted approximately 0.41% of vegetated areas, with the Hhohho and Lubombo regions being the most affected. These findings corroborate the observations of previous studies, such as the Eswatini Vulnerability Assessment Committee (VAC), which noted heightened levels of food insecurity during droughts in 2004 and 2005.
Spatial relief chain analysis, utilizing geospatial tools like ORS and Near Neighbor Analysis, identified areas with extreme, severe, and moderate drought levels that require immediate attention for focused relief efforts. The strategic placement of central warehouses in populated centers facilitates efficient distribution to vulnerable areas. The analysis of routes connecting primary hubs to secondary hubs, performed using the ORS algorithm, ensures timely and effective relief delivery, especially in areas severely affected by drought.
The socioeconomic impact assessment underscores the profound consequences of agricultural drought on the local population and economy. Agricultural losses, reduced yields, and livestock deaths have led to food shortages, income loss, and increased food prices. The vulnerability of smallholder farmers practicing rainfed agriculture is evident, emphasizing the need for targeted interventions, especially in regions like the lower Middleveld and western Lowveld. The socioeconomic fallout has forced rural populations to migrate, straining urban infrastructure and services.
This study demonstrates the effectiveness of remote sensing, specifically the VHI, as a tool for timely and accurate drought monitoring. Integrating satellite data with climate and socioeconomic information enhances our understanding of drought impacts and aids in relief planning. Geospatial tools contribute significantly to optimizing supply chain routes, ensuring swift and efficient humanitarian relief in the face of drought disasters.
In conclusion, the comprehensive analysis presented in this study provides valuable insights for decision makers, offering a strategic framework for responding to humanitarian needs during drought events in the Kingdom of Eswatini. The findings underscore the importance of coordinated efforts, targeted interventions, and the integration of technology in building resilience and mitigating the socioeconomic impact of drought.