3. Natural resources degradation process: An overview

Transcript

Hi! Friends, in the last lecture, we were discussing about the overview of the drylands and about the constraints involved in rainfed drylands. Today let us study about the natural resource degradation process. An overview of the natural resource degradation process. And which are all the natural resources degrading. And what are the causes for the occurrence of drylands due to this. Natural degradation process: an overview.

Now the degradation is a process which occurs when the resources are overused or misused either through naturally or through human action. So it is a process, wherein the resources are overused. That means to say that the resources are being used above their potential or misused. The resources which are being used, not for the purpose which are being meant, either naturally or through the human action. That is the degradation which is taking place. So what is the reason for this natural degradation to occur.  Population pressure is the major cause for the overuse of the land resulting its degradation. Now over the years population is increasing like anything. It is increasing at an alarming rate. And population pressure or population explosion is considered to be the main reason for the natural resources degradation. So the availability of useful lands globally, has decreased over the years and will reduce further in the years to come. So the resultant of the population explosion is that we are losing the useful lands over the years. And we will be losing the further these lands in the years to come.

So if you see the world population and arable land between 1960 to 2020. The present world population is 7.7 billion and India’s population is 1.36 billion. Roughly Indian population constitutes about 18% of the ²world’s population. If you take the population from 1960 to 2020, which is being projected; the population is expanding exponentially, and at the same time the arable land is decreasing. And around 2020 the arable land availability will be around 0.2 hectare per person. Natural resource degradation process. If you plot the population in billions, and again we are here somewhere; and is around 7.6 billions. Then we may not to go here. That means we have to arrest the population considerably to reduce the degradation of natural resources.

So coming to the farmed area per capita compared to world population. In the year 1970, the total area available per person was 3208 meter². But in the latest years what has been happened. Around 2039 meter² is available. That means to say that the population is increasing at the same rate, at the same time the availability of farmland per person is decreasing gradually. Now when you analyze the things, what may be the causes for the natural degradation of the resources. The resources may be soil. The resources may be water, the resources may be nutrient. So what may be the causes of the natural degradation of resources. If you analyze the things, 28% is due to agricultural practices. It maybe faulty practices. It maybe overuse of the natural resources, or it maybe the misuse of the natural resources, either naturally or by the human action.

Next comes overgrazing. We are not separately earmarking the grazing lands for the cattles. What’s happening is when the farm crops are harvested. Now that land is only used for grazing cattle. So there will be no covering on the soil surface, which is leading to degradation of the resources, particularly soil. Then coming to the 30%, is for deforestation, which doesn’t need any explanation. All of you know at what an alarming rate we are destroying the forests or clearing the forest for our own use.

Then coming to the natural resource degradation process. In that the soil erosion plays an important role. What are the effects of this soil erosion? Reduced infiltration and moisture holding capacity of the soil. Because of the soil erosion, the top soil layer will be eroded. And there is no chance for the rainwater to infiltrate. And also whatever the little amount of moisture entered, it will not be retained in the soil. Then comes the impaired soil surface characteristics and seed bed quality. That means the soil surface characteristics particularly soil structure is destroyed. When the soil structure is destroyed there will be no amenable establishment of the soil beds or the soil seed beds, wherein the plant grows easily. Then coming to the next one; loss of organic matter. So this is the organic matter is the life of the soil. When the top fertile soil is eroded. Due to the soil erosion along with that, organic matter will also be flown away. So loss of organic matter along with the soil the life will also be lost through the organic matter. Next is reduced depth of the soil. Because of the fact that the top soil is being eroded, the depth of the soil is very less. When the depth of the soil is very less, whatever the crops growing in that area, the roots cannot penetrate deep into the soil, and they are not able to extract the moisture from the deeper layers of the soil.

Then coming to the siltation of the reservoir, leading to reduction in life of the reservoir and irrigated area. Along with the top soil the important seed particles also removed from the top soil. These seeds collectively accumulate in the reservoir, reducing the reservoir capacity, or the storage capacity of the reservoir, on account of which, the water, the space available for storing will also be reduced; consequently the irrigated area will also be come down.

So friends, in this lecture we have learnt about the resources degradation, the resources are not being used judiciously, they are being used indiscriminately. So second one is population pressure is considered as main factor for the degradation process to occur. Then third one is increasing population, the farm area available per hectare, per person is decreasing. So among the reasons for the degradation, it is the agricultural practices, then the grazing; over grazing and deforestation are the major reasons for the natural degradation to occur So in the next class we will be studying in detail about the effects of soil erosion and how to control the soil erosion, and how to combat the soil erosion for the reversal of the degradation process.

Thank You.