The aims of this research were to investigate the impacts of climate variations on land use policies, food security and vegetation cover in Gadarif State (eastern Sudan) during 1961 to 2013. Analysis of precipitation and temperature time series revealed that the annual precipitation was decreasing while the temperature was increased in the study area. Precipitation was decreasing at a rate of −50.3 mm/10a, while the temperature was increasing at a rate of 0.02 °C/10a. The result of both SPEI and SPI showed that the Gadarif State has been changed to a high frequency of drought during 1961-2013. Sorghum yield showed a significant positive relationship with precipitation during July and October (CC = 0.364 and 0.321, respectively), moreover, a significant positive relationship between Sesame yield and precipitation was observed during July (CC = 0.335). A significant negative relationship between Sorghum yield and mean temperature was observed during the rainy season (July to October) with CC = −0.278. The yield productivity of Sorghum and Sesame had decreased significantly (from more than 800 kg/ha in the 1960s to less than 200 kg/ha in 2000s for Sorghum, while 500 kg/ha in 1960s to 100 kg/ha in 2000s for Sesame). The Mechanized Rain-fed Agriculture (MRA) area of Sorghum and Sesame in the Gadarif State had been increased from 1,058,241 ha to 2,799,655 ha during 1961 to 2013. Thus, we ultimately suggest that in the Gadarif State, policy makers must strive for an increase in yield per unit area by using sufficient fertilizers along with the gradual increment in tendencies of grain production through expansion of the cultivated area.
Climate change is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is as well as natural climate variability observed over comparable times [
Gadarif State underwent a highly significant increase of maximum temperature during summer, winter and autumn [
Previously, [
The objectives of this research were to investigate influences of climate change on food security and vegetation cover, a number of specific objectives were formulated to assess climate change in Gadarif State considering the period of 1961 to 2013 in the light of the status.
Gadarif State is located in latitudes 12˚48' and 15˚50' N and longitudes 33˚40' and 36˚47'E, covers an area of about 6225794.91 ha (
Monthly and annual precipitation and temperature data of Gadarif State were collected from the Sudan Meteorological Authority. Figures 2(a)-(e) showed the annual precipitation and temperature, in addition, monthly precipitation and temperature of the rainy season (July to October) during 1961-2013. This study consisted of two types of data. The primary data involves climatic data for the years 1961-2013. Vegetation and crop yield in eastern Sudan rain-fed agriculture would highly depend on the state of the climate, particularly precipitation
variables [
Food security data of Gadarif State during 1961 to 2013 was the crop yield of Sorghum (Sorghum bicolor) and Sesame (Sesamum indicum). Moreover, research documents, national and international relevant projects documents, related official records and annual reports were used as supporting data.
Figures 2(a)-(e) showed the variations of annual and monthly precipitation and temperature anomaly in Gadarif State for the 53 years. Annual precipitation and temperature anomalies showed great fluctuations all over the Gadarif State. By alternating the fluctuations of positive and negative anomalies, the most negative precipitation anomalies periods have been recorded, for example, in 1965, 1973, 1983, 1984, 1990, 1991, 1999, 2000 and 2002 (
addition, both SPEI and SPI showed that the Gadarif State from 1999 to 2011 was been changed to a high frequency of drought. As reported by [
Projected climate change impacts and growing socioeconomic pressures on agriculture highlighted the intensification of desertification of arable areas. Moreover, the humid agroclimatic zones are likely to shift southward, rendering areas of the north increasingly unsuitable for agriculture [
Month | Precipitation | Temperature | |
---|---|---|---|
Sorghum | Jul | 0.364** | −0.248 |
Aug | 0.058 | −0.25 | |
Sep | 0.251 | −0.133 | |
Oct | 0.321* | 0.131 | |
Jul to Oct | 0.329* | −0.278* | |
Sesame | Jul | 0.335* | −0.233 |
Aug | 0.069 | −0.233 | |
Sep | 0.254 | −0.132 | |
Oct | 0.053 | −0.192 | |
Jul to Oct | 0.318* | −0.260 |
**Correlation is significant at the 0.01 level (2-tailed), *Correlation is significant at the 0.05 level (2-tailed).
of July and October; respective correlation coefficients were 0.364 and 0.321. A significant negative correlation of Sorghum yield with the mean temperature was found during July to October (CC = −0.278). There was a significant positive relationship between Sesame yield and precipitation of July (CC = 0.335). In Africa, in addition to the greatest problem of high annual variability of precipitation, the seasonal precipitation also varies drastically as well [
Land use patterns had changed significantly in Gadarif State from 1986 to 2013. The natural vegetation was changed drastically (from 1,538,597 ha in 1986 to 2,459,264 ha in 2013) to MRA. That leads to extensive loss and degradation of rangeland areas in Gadarif State. Rangeland areas in the state were decreased from 4,342,154 ha in 1986 to 3,473,940 ha in 2013. Forest area and rangeland were reduced due to the expansion of modern mechanized farming to satisfy an increased demand for food due to increased human population [
[
In this study, we have combined the results of impacts of variations in climate and land use policies on food security from 1961 to 2013 to provide a base line for policy makers in Gadrif State, eastern Sudan. We conclude that the policy makers must consider an increase in yield per unit area and utilization of different varieties of fertilizer in addition to the enhancement of grain production through expansion of the cultivated area. We recommend the establishment of strong coordination among the concerned sectors such as Forest National Corporation, Mechanized Rain-fed Agriculture, Rangeland management, Wildlife management and Research Institutes to arrive for land use management.
Based on the findings of this study, it is recommended that additional investigations on crops suitable for Gadarif State during drought season should also be carried out for more accurate information, which can be used for crop modeling of appropriate agricultural and water management during a drought cycle. Further studies on drought prediction using future climate scenarios in Gadarif State by utilizing methods presented in this study may be considered for in-depth analysis. Nowadays, climate change has become the major determinant to environment worldwide and most of the environmental changes are associated with the climatic anomalies. To best of our knowledge, a few of studies have so far been conducted to address this global problem.
Agricultural activities in Gadarif State are directly affecting the proportion of forest resources because of change in agricultural ends up, in the unfair exploitation of the forests. Throughout the last four decades, progressive changes within the environment occurred due to the conversion of forest and grassland into cultivated land.
The present research was supported by the National Natural Science Foundation of China, Grant number: [
Yagoub, Y.E., Li, Z.Q., Musa, O.S., Anjum, M.N., Wang, F.T. and Bo, Z. (2017) Investigation of Climate and Land Use Policy Change Impacts on Food Security in Eastern Sudan, Gadarif State. Journal of Geographic Information System, 9, 546-557. https://doi.org/10.4236/jgis.2017.95034