2. Related past research on climate variability and adaptation to climate change by smallholder maize farmers

This above expressed scenarios have motivated several past research works on climate variability on maize production over the past decade [12, 13, 33, 34]. Specifically, [33] identified climate variability as a global environmental challenge that is likely to have a serious effect on natural and human systems, economies and infrastructures. However, the nature of these biophysical effects and the human responses to these changes are complex and uncertain as the changes keep manifesting in different forms on a yearly basis. Climate change has already exhibited strong negative impacts on food security in many African countries such as: Eritrea [35]; Ethiopia [36]; Kenya [12, 37]; South Africa [38]; Nigeria [39]; etcetera.

Consequently, past studies have indicated substantial diversity in the awareness level of Nigerian maize farmers in regard to climate change adaption techniques [3, 10]. Adaptation to climate variability is defined as an adjustment in natural or human systems to actual or expected climatic stimuli or their effects, which moderates harm and exploit beneficial opportunities [40, 41]. Climate change adaptation depends on: demand for improved seeds for maize, category of techniques adopted to curtail climate variability, time of planting, among others [4]. Planting time is an essential component of maize crop management, especially in the South-eastern part of Nigeria [8]. Yields decline with lateness of planting after an optimum time, usually the start of the rains [17]. Response of maize varieties to climate variability is dependent upon planting time. Optimum planting in each of the major agro-ecological zones of Nigeria falls within the following ranges [42]: Forest zone—Mid April—second week in May; forest—Savannah transition third week in April—third week in May; South Guinea Savannah comes up during the last week in April to the third week in May. These planting dates coincide with the period that flooding occurs with the riverine communities of the study area. Re-occurring flood is an impact of climate that strongly manifests in South-eastern Nigeria; thereby decreasing maize production in flood prone zones [43].

Furthermore, some other previous long-term climate change studies have established a nexus between the effects of carbon dioxide concentrations in the atmosphere, and the mean global temperature [13, 44]. In addition, the studies by [43, 45] opined that, global warming has influenced agricultural productivity negatively in parts of Sub-Saharan Africa, mostly in Nigeria, and had thus resulted in decline of food production. Numerous climate variability effects are outcomes of human activities bothering on industrialization, agricultural expansion, deforestation, bush burning, use of inorganic fertilizers, intensive livestock farming system and storage of wastes in landfills [46]. Landfill for example, releases lots of greenhouse gases to the environment thereby increasing the scourge of global- warming on humans and their crops [16]. Literature asserts that non-adaptation of climate smart strategies vis-à-vis lack of awareness creation about climate variability in communities, could aggravate a poor Nigerian economy at a percentage loss of between 2% and 11% GDP, by year 2020 [47]. The foregoing assertion could further worsen, to a record low of 12–50% by year 2050 [1, 48]. Such a negative trend can compromise the attainment of the purported Sustainable Development related Goals [27, 49] in Nigeria.

Therefore, the overall objective of this present study is to fill the knowledge gap between the perception of smallholders' maize farmers on climate variability and their use of climate change adaptation approaches in relation to GIS, toward contributing to sustainable food

GIS-Based Assessment of Smallholder Farmers' Perception of Climate Change Impacts and Their…

http://dx.doi.org/10.5772/intechopen.79009

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Located in South-eastern Nigeria, Anambra state lies between Latitude 6� 45<sup>0</sup> and 5� 44<sup>0</sup> N and Longitudes 6� 36<sup>0</sup> and 7� 20�E [38]. The climate is humid with mean average rainfall of 2010 mm and average temperature of 87�C (Figure 1). It has a weak soil that is easily eroded [38]. The climate here is tropical. The average annual temperature is 27.0�C. The rainfall here averages 1828 mm. The driest month is December, with 7 mm of rain. Most precipitation falls

The state is divided into four agro-ecological zones (AEZ): Aguata, Awka, Anambra and Onitsha. The sites for this present study are shown in Figure 3. There is a difference of 299 mm of precipitation between the driest and wettest months. The average temperatures vary during the year by 3.8�C. The state occupies a land area of approximately 4887 km<sup>2</sup> and a population of 4,182,032 people based on the 2006 census figures. According to the Nigeria's National Population Commission figures of 2006, the population distribution is 2,174,641 million males and 2,007,391 million females. Anambra state is bounded to the north by Kogi state, to the south by Imo and Abia state, to the east by Enugu state and to

In 2006, maize production index for Anambra state was put at 69,1000 metric tonnes [48]. However, the state has in recent years, been substantially experiencing fluctuations in maize production at a decline rate of 23.28%. The decrease in maize yield in this Southern Nigeria, can be attributed to: (a) climate change related flooding [9, 25]; that re-occurs almost every year; and (b) non-adaptation of climate-smart measures by smallholder maize farmers [52, 53]. However, climate change adaption measures for maize, which is one of the most important grain crops, is less studied in Anambra State [6]. Another knowledge gap scenario is that, there is a limited

Figure 1. Average temperature per month (left) and average days with precipitation per month (right). Source: adopted

from https://www.yr.no/place/Nigeria/Anambra/Anambra\_State/statistics.html.

security in Anambra State, South-eastern Nigeria.

in September, with an average of 306 mm (Figure 2).

4. Research location

the west by Delta state.

Nevertheless, the magnitude to which maize yield drastically reduced in last two consecutive years in Nigeria, creates the need for researchers to examine existing knowledge gaps on smallholder maize farmers' perception climate change variability in South-eastern Nigeria; as a remedy to forestalling future low maize productivity in the country.
