Approaches of Surface Water Management: Watershed-Based Approaches

Surface water management refers to the strategies used to regulate and optimize the availability, distribution, and quality of surface water resources such as rivers, lakes, and reservoirs. One of the most effective strategies is the watershed-based approach, which considers the entire watershed or drainage basin as a unit for water resource management, ensuring sustainability and minimizing conflicts between upstream and downstream users.

1. Watershed-Based Approaches

Watershed

A watershed (or drainage basin) is a geographical area where all precipitation and surface runoff flow into a common outlet such as a river, lake, or ocean.

Example: The Ganga River Basin is a watershed that drains into the Bay of Bengal.

Hydrological Cycle and Watershed Management

Watershed-based approaches work by managing the hydrological cycle, which involves precipitation, infiltration, runoff, evapotranspiration, and groundwater recharge.

Precipitation: Rainfall or snowfall within a watershed.
Runoff: Water that flows over land into streams, lakes, or reservoirs.
Infiltration: Water absorbed by the soil, which recharges groundwater.
Evapotranspiration: Water loss from surfaces and vegetation.

2. Key Approaches in Watershed-Based Surface Water Management

A. Integrated Watershed Management (IWM)

This approach integrates land, water, and biodiversity management to ensure sustainable water availability.

Key Strategies:

Afforestation & Reforestation: Increases infiltration and reduces soil erosion.
Soil Conservation Techniques: Check dams, contour bunding, and terracing help in retaining water and preventing runoff.
Community Participation: Engaging local communities for sustainable water management.
Example: The Sukhomajri Watershed Project in India implemented soil and water conservation measures, leading to improved water availability and agricultural productivity.

B. River Basin Management

Focuses on managing water resources at the river basin level to ensure equitable distribution and conflict resolution between users.

Key Strategies:

Upstream and Downstream Coordination: Prevents water conflicts between different regions.
Flow Regulation: Dams and reservoirs help regulate water availability.
Water Quality Monitoring: Prevents industrial pollution and ensures safe drinking water.
Example: The Ganga Action Plan (GAP) aims to improve the water quality of the Ganga River by controlling pollution and promoting sustainable watershed management.

C. Participatory Watershed Development

Encourages stakeholder involvement, including farmers, industries, and local governments, in decision-making.

Key Strategies:

Rainwater Harvesting: Collection and storage of rainwater for agricultural and domestic use.
Livelihood-Based Interventions: Ensuring that watershed management also benefits local communities.
Micro-Watershed Approach: Dividing large watersheds into smaller units for efficient management.
Example: The Jal Shakti Abhiyan in India promotes community-led water conservation efforts, including rainwater harvesting and watershed rejuvenation.

D. Eco-Hydrological Approach

Focuses on maintaining the natural ecological balance of watersheds while managing water resources.

Key Strategies:

Wetland Conservation: Protects wetlands that act as natural water filters.
Sustainable Land Use Planning: Prevents deforestation and urban encroachment on water bodies.
Groundwater-Surface Water Interaction Management: Ensures sustainable groundwater recharge.
Example: The Ramsar Convention aims to protect wetland ecosystems worldwide, ensuring their role in water purification and flood control.

Comments

Platforms in Remote Sensing

In remote sensing, a platform is the physical structure or vehicle that carries a sensor (camera, scanner, radar, etc.) to observe and collect information about the Earth's surface. Platforms are classified mainly by their altitude and mobility : Ground-Based Platforms Definition : Sensors mounted on the Earth's surface or very close to it. Examples : Tripods, towers, ground vehicles, handheld instruments. Applications : Calibration and validation of satellite data Detailed local studies (e.g., soil properties, vegetation health, air quality) Strength : High spatial detail but limited coverage. Airborne Platforms Definition : Sensors carried by aircraft, balloons, or drones (UAVs). Altitude : A few hundred meters to ~20 km. Examples : Airplanes with multispectral scanners UAVs with high-resolution cameras or LiDAR High-altitude balloons (stratospheric platforms) Applications : Local-to-regional mapping ...

Optical Sensors in Remote Sensing

1. What Are Optical Sensors? Optical sensors are remote sensing instruments that detect solar radiation reflected or emitted from the Earth's surface in specific portions of the electromagnetic spectrum (EMS) . They mainly work in: Visible region (0.4–0.7 µm) Near-Infrared – NIR (0.7–1.3 µm) Shortwave Infrared – SWIR (1.3–3.0 µm) Thermal Infrared – TIR (8–14 µm) — emitted energy, not reflected Optical sensors capture spectral signatures of surface features. Each object reflects/absorbs energy differently, creating a unique spectral response pattern . a) Electromagnetic Spectrum (EMS) The continuous range of wavelengths. Optical sensing uses solar reflective bands and sometimes thermal bands . b) Spectral Signature The unique pattern of reflectance or absorbance of an object across wavelengths. Example: Vegetation reflects strongly in NIR Water absorbs strongly in NIR and SWIR (appears dark) c) Radiance and Reflectance Radi...

Types of Remote Sensing

Remote Sensing means collecting information about the Earth's surface without touching it , usually using satellites, aircraft, or drones . There are different types of remote sensing based on the energy source and the wavelength region used. 🛰️ 1. Active Remote Sensing 📘 Concept: In active remote sensing , the sensor sends out its own energy (like a signal or pulse) to the Earth's surface. The sensor then records the reflected or backscattered energy that comes back from the surface. ⚙️ Key Terminology: Transmitter: sends energy (like a radar pulse or laser beam). Receiver: detects the energy that bounces back. Backscatter: energy that is reflected back to the sensor. 📊 Examples of Active Sensors: RADAR (Radio Detection and Ranging): Uses microwave signals to detect surface roughness, soil moisture, or ocean waves. LiDAR (Light Detection and Ranging): Uses laser light (near-infrared) to measure elevation, vegetation...

Resolution of Sensors in Remote Sensing

Spatial Resolution 🗺️ Definition : The smallest size of an object on the ground that a sensor can detect. Measured as : The size of a pixel on the ground (in meters). Example : Landsat → 30 m (each pixel = 30 × 30 m on Earth). WorldView-3 → 0.31 m (very detailed, you can see cars). Fact : Higher spatial resolution = finer details, but smaller coverage. Spectral Resolution 🌈 Definition : The ability of a sensor to capture information in different parts (bands) of the electromagnetic spectrum . Measured as : The number and width of spectral bands. Types : Panchromatic (1 broad band, e.g., black & white image). Multispectral (several broad bands, e.g., Landsat with 7–13 bands). Hyperspectral (hundreds of very narrow bands, e.g., AVIRIS). Fact : Higher spectral resolution = better identification of materials (e.g., minerals, vegetation types). Radiometric Resolution 📊 Definition : The ability of a sensor to ...

Radar Sensors in Remote Sensing

Radar sensors are active remote sensing instruments that use microwave radiation to detect and measure Earth's surface features. They transmit their own energy (radio waves) toward the Earth and record the backscattered signal that returns to the sensor. Since they do not depend on sunlight, radar systems can collect data: day or night through clouds, fog, smoke, and rain in all weather conditions This makes radar extremely useful for Earth observation. 1. Active Sensor A radar sensor produces and transmits its own microwaves. This is different from optical and thermal sensors, which depend on sunlight or emitted heat. 2. Microwave Region Radar operates in the microwave region of the electromagnetic spectrum , typically from 1 mm to 1 m wavelength. Common radar frequency bands: P-band (70 cm) L-band (23 cm) S-band (9 cm) C-band (5.6 cm) X-band (3 cm) Each band penetrates and interacts with surfaces differently: Lo...

Vineesh V, Geography

Search This Blog