Step 1: Understanding the Concept:
Environmental degradation is the deterioration of the environment through the depletion of resources such as quality of air, water, and soil. Human activities like intensive agriculture, urbanization, and industrialization are the primary drivers of this degradation, which negatively impacts the ecosystem's ability to support life and provide resources.
Step 2: Detailed Explanation:
Let's analyze the ecological impact of each statement:
Statement i: Trees act as a protective cover for the earth. Their roots hold the soil together. Removing trees (deforestation) exposes the soil to rain and wind, causing erosion. It also destroys the natural habitats of thousands of species, leading to a massive loss in biodiversity. This is correct.
Statement ii: In states like Gujarat and Rajasthan, where animal husbandry is a major occupation, livestock often graze on common lands beyond their carrying capacity. This removes vegetation cover, leading to soil hardening and increased vulnerability to desertification. This is correct.
Statement iii: Excessive use of synthetic fertilizers to boost crop yields alters the chemical balance of the soil. These chemicals also leach into the groundwater or run off into nearby lakes and rivers (eutrophication), causing severe water pollution. This is correct.
Statement iv: Land degradation refers to the decline in the quality of the land's health. Whether through salinity (from over-irrigation), erosion, or nutrient depletion, the "productive capacity" (how much crop can grow) of the land diminishes over time, making farming less viable. This is correct.
Since all the provided statements describe well-documented causes and effects of environmental issues, option (D) is correct.
Step 3: Final Answer:
All four statements are scientifically accurate descriptions of environmental and land degradation processes. Therefore, option (D) is the correct answer.