Table 2.
Impacts of hydropower dam constructions illustrated by average changed values of five indices of the buffer zones for different sized dams
| Dam size | All | Small | Medium | Large | ||||
| △GDP (Million dollars) | ||||||||
| Zone 1 (<5 km) | −6,021,947 | −19% | 9,139,494 | 29% | −13,273,861 | −49% | −20,071,921 | −34% |
| Zone 2 (5 to 20 km) | −8,731,524 | −27% | 327,899 | 1% | −10,439,957 | −38% | −29,266,543 | −50% |
| Zone 3 (20 to 50 km) | −7,381,805 | −23% | −3,825,735 | −12% | −6,749,536 | −25% | −21,468,156 | −37% |
| NAHD (0 to 50 km) | −7,570,664 | −23% | −3,073,038 | −10% | −7,368,342 | −27% | −22,623,952 | −39% |
| Reference Zone (50 to 60 km) | 32,326,438 | 31,593,303 | 27,226,239 | 58,216,089 | ||||
| △Urban (km2) | ||||||||
| Zone 1 (<5 km) | −2.52 × 10−08 | −49% | −2 × 10−08 | −47% | −2 × 10−08 | −51% | −7 × 10−08 | −49% |
| Zone 2 (5 to 20 km) | −2.05 × 10−08 | −40% | −2 × 10−08 | −44% | −2 × 10−08 | −49% | −4 × 10−08 | −26% |
| Zone 3 (20 to 50 km) | −1.68 × 10−08 | −33% | −2 × 10−08 | −39% | −2 × 10−08 | −49% | −1 × 10−08 | −9% |
| NAHD (0 to 50 km) | −1.74 × 10−08 | −34% | −2 × 10−08 | −40% | −2 × 10−08 | −49% | −2 × 10−08 | −12% |
| Reference Zone (50 to 60 km) | 5.14 × 10−08 | 5 × 10−08 | 3 × 10−08 | 1 × 10−07 | ||||
| △NTL (DN) | ||||||||
| Zone 1 (<5 km) | 1.0 | 54% | 0.8 | 38% | 1.2 | 68% | 0.9 | 44% |
| Zone 2 (5 to 20 km) | 0.2 | 9% | 0.3 | 16% | 0.1 | 3% | 0.2 | 10% |
| Zone 3 (20 to 50 km) | 0.1 | 7% | 0.4 | 20% | 0.0 | −1% | 0.1 | 3% |
| NAHD (0 to 50 km) | 0.2 | 8% | 0.4 | 19% | 0.0 | 0% | 0.1 | 4% |
| Reference Zone (50 to 60 km) | 1.9 | 2.0 | 1.8 | 2.1 | ||||
| △Pop (Person/km2) | ||||||||
| Zone 1 (<5 km) | −2.4 | −16% | −6.1 | −45% | −0.2 | −1% | −1.3 | −9% |
| Zone 2 (5 to 20 km) | −5.2 | −35% | −5.2 | −38% | −6.3 | −40% | −0.7 | −5% |
| Zone 3 (20 to 50 km) | −6.9 | −46% | −6.8 | −50% | −7.4 | −47% | −4.7 | −32% |
| NAHD (0 to 50 km) | −6.6 | −45% | −6.6 | −49% | −7.1 | −45% | −4.0 | −28% |
| Reference Zone (50 to 60 km) | 14.8 | 13.6 | 15.7 | 14.4 | ||||
| △NDVI (index number) | ||||||||
| Zone 1 (<5 km) | −0.004 | −34% | −0.002 | −15% | −0.005 | −44% | −0.008 | −40% |
| Zone 2 (5 to 20 km) | −0.002 | −15% | 0.000 | 0% | −0.003 | −23% | −0.004 | −20% |
| Zone 3 (20 to 50 km) | −0.001 | −4% | 0.000 | 0% | −0.001 | −5% | −0.002 | −9% |
| NAHD (0 to 50 km) | −0.001 | −6% | 0.000 | 0% | −0.001 | −8% | −0.002 | −11% |
| Reference Zone (50 to 60 km) | 0.013 | 0.012 | 0.012 | 0.019 | ||||
Note that this table indicates the average changed values of five indices in different sizes of buffer zones (Zones 1 through 3) in NAHDs and reference zones for different sizes of dams (small, medium, and large). It also shows their relative proportions to the changes in the respective reference zones. While large dams were associated with significantly reduced GDP and greenness, small and medium dams were linked with more decrease in population and urban land, whereas large and medium dams had noticeably less NTL in nearby areas.